Observing the Universe at millimetre wavelengths

LPSC Grenoble

LPSC Grenoble

Frederic Mayet (LPSC)


The observations of the sky at millimetre wavelengths in the past years contributed to tremendous improvements in our understanding of a great variety of scientific topics ranging from the star formation in the Milky Way to the measurement of cosmological parameters.

The mm Universe conference series has started in 2019. The two first editions were mainly focused on NIKA2 although opened to the entire scientific community. Since then, the series evolved, and the name has been changed, in order to include all observations of the Universe at mm wavelength, at all scales from stellar to cosmological ones.  As multi-wavelength analysis is a key approach to understand astrophysical processes and cosmological issues, the conferences series is of course opened to results and observations at other wavelengths.  

The first edition of the mm Universe conference was held at LPSC in Grenoble in June 2019 and the second edition was organized by the Department of Physics at Sapienza University in Rome and held online via Zoom due to the pandemic situation at that time.

The third edition will be held at LPSC in Grenoble in 2023 from June 26th to June 30th.

This international conference will bring together the scientific community working on science related to millimetre observations. It includes both theoretical and observational topics related to the mm Universe, from stellar to cosmological scales.


  • mm Cosmology (CMB & clusters)
  • Thermal & kinetic SZ
  • Galaxy cluster physics (SZ, X, visible)
  • Galaxy formation in the early Universe
  • Nearby galaxies
  • Galactic star formation
  • From dust to planets
  • mm instruments
  • Simulations


Registration is closed.

Registration Fees

  • Registrations price, with conference dinner : 250 euros
  • Registrations price, without conference dinner : 210 euros
  • Conference dinner for accompanying person : 40 euros
  • LPSC members : internal payment only. Please contact mmuniverse2023-l@lpsc.in2p3.fr


Basic Registration (210 euros)  includes : coffee breaks, 5 lunches and one proceeding book.


Financial Support


The mm Universe conference gratefully acknowledges financial support from: 


    • 9:30 AM
    • 1
      Introducing mm Universe Amphitheatre


      LPSC Grenoble

      Speaker: Frederic Mayet (LPSC)
    • Monday A Amphitheatre


      LPSC Grenoble

      Convener: Frederic Mayet (LPSC)
      • 2
        The South Pole Telescope Cluster Samples

        The South Pole Telescope (SPT) is a 10-meter millimeter-wavelength telescope located at the geographic South Pole, one of the world’s premier sites for millimeter-wave observations. The SPT has been used to conduct several generations of wide-field high resolution cosmic microwave background (CMB) surveys including the 2500-square-degree SPT-SZ survey, the SPTpol 500d and ECS surveys, and the SPT-3G survey.
        One of the primary objectives of these surveys has been the construction of mass-limited samples of galaxy clusters identified via the thermal Sunyaev- Zel’dovich (SZ) effect, through which massive clusters imprint subtle temperature distortions on the CMB. The abundance of such clusters is a powerful cosmological probe as it depends sensitively upon both the expansion history of the universe and the growth of density fluctuations. In this talk I will discuss progress analyzing these datasets, including a discussion of the SPTpol 500d and SPT-3G cluster samples. I will also provide projections for cosmological results from the full SPT-3G cluster survey.

        Speaker: Lindsey Bleem (Argonne National Laboratory)
      • 3
        Cluster Abundance Cosmology with the South Pole Telescope and the Dark Energy Survey

        The abundance of massive halos (and of the galaxy clusters they host) has long been recognized as an extremely promising probe of the large-scale structure of the universe. Over the past decade, tremendous progress was made, notably thanks to the availability of high-resolution surveys of the Cosmic Microwave Background (CMB), of high-quality measurements of gravitational lensing, and of advanced numerical simulations.
        The sample of galaxy clusters selected by the South Pole Telescope (SPT, combining the SPT-SZ and SPTpol surveys) in the CMB now exceeds a thousand objects. The systematics in weak-lensing based mass calibration using Dark Energy Survey Year 3 (DES Y3) are less than 5%. The joint analysis of the cluster abundance and weak-lensing mass calibration can therefore provide tight cosmological constraints.
        In my talk, I will review the SPT cluster cosmology and mass calibration program. I will focus on the SPT + DES Y3 analysis and present new constraints on the ΛCDM and wCDM models.

        Speaker: Sebastian Bocquet (LMU Munich)
      • 4
        The Simons Observatory

        The Simons Observatory is a ground-based cosmic microwave background (CMB) experiment being built on Cerro Toco in the Atacama Desert in Chile that promises to provide breakthrough discoveries in fundamental physics, cosmology, and astrophysics. I will review the design of the project, its science goals and schedule, and I will give a brief description of some of the analysis pipelines that are currently developed and designed to characterize primordial B-modes.

        Speaker: Josquin Errard (APC / CNRS)
      • 5
        The search for the clusters of galaxies in X-Rays during 4.4 scans of the whole sky by SRG/eRosita (preliminary results)
        Speaker: Rashid Sunyaev (MPA)
    • 12:30 PM
    • Monday P Amphitheatre


      LPSC Grenoble

      Convener: Jens Chluba
      • 6
        Planck and SPT cluster catalogs: a combined analysis

        Galaxy clusters are a powerful cosmological probe, being able to describe the latest evolution of large scale structure.
        In recent years, cluster catalogs of thousands of objects have been detected in the mm wavelengths, through the thermal Sunyaev-Zeldovich effect.
        In this talk I will show the results for the first combined analysis of clusters detected by the Planck satellite and the South Pole Telescope (SPT). The combination of these two experiments, with different resolution, mass and redshift range, allows to track the full cosmological evolution of galaxy clusters and the interplay between astrophysics and cosmology.
        While we are building the pipeline for a coherent combined analysis between the two experiments, in this first analysis we exploit the cosmological constraining power of SPT-SZ clusters to provide an independent calibration of Planck scaling relations, and therefore a new estimation of Planck cluster masses. Combining the two cluster catalogs we are thus able to test the hypotheses of self-similarity and hydrostatic equilibrium.
        We show therefore the huge potentiality of combining catalogs from different experiments, in improving the cosmological analysis and the treatment of different astrophysical and systematic uncertainties.

        Speaker: Laura Salvati (IAS, Paris-Saclay)
      • 7
        Detection of Thermal SZ -- CMB Lensing Cross-Correlation in Planck Legacy Data

        We report a high-precision detection of the cross-correlation of the thermal Sunyaev-Zel'dovich (tSZ) effect and gravitational lensing of the cosmic microwave background (CMB) using data from the Planck 2018 legacy release. This is only the second reported detection of this cross-correlation to date, following early work using the Planck nominal mission data (Hill & Spergel 2014). In our analysis, we first construct component-separated tSZ maps from Planck data using a custom needlet internal linear combination (NILC) pipeline. We then cross-correlate our tSZ maps with publicly available Planck CMB lensing maps. We implement a novel moment-based approach to mitigate cosmic infrared background (CIB) contamination in our NILC tSZ maps. We validate our full analysis pipeline using detailed mm-wave sky simulations from the WebSky suite. We interpret our measurement of the tSZ -- CMB lensing cross-correlation using halo model calculations. We derive constraints on cosmological parameters ($S_8$, $\Omega_m$) and on parameters describing gas physics in the intracluster medium (ICM), for which our measurement probes the poorly explored regime of low-mass, high-redshift groups and clusters.

        Speaker: Colin Hill (Columbia University)
      • 8
        Small scale CMB cosmological information

        The Cosmic Microwave data at very small scales are known to probe not only primordial CMB fluctuations but also many extragalactic components such as tSZ, kSZ, CIB, points sources.
        I will show how to use the cosmological dependent SZ signatures (tSZ and kSZ) at small scales coherently with the large scales and the cosmology framework in Planck and SPT experiments to retrieve both cosmological parameters and reionisation history. Using machine learning to compute efficiently the SZ angular power spectra, I will show new constraints obtained using SPT CMB observations combined with the latest Planck observed tSZ spectrum.  I will discuss how such a coherent analysis could bring additional cosmological information and shed light on the sigma8 tension observed between CMB and clusters.

        Speaker: Marian Douspis (IAS (Orsay))
      • 9
        class_sz: a fast and accurate code for SZ and cross-correlations

        Class_sz is at the core of several pipelines for parameter inference in the Atacama Cosmology Telescope and the Simons Observatory. It enables a fast and accurate evaluation of SZ observables, such as the SZ power spectrum, cluster number counts and kinetic SZ cross-correlations, as well as cross and auto-correlations between a wide range of large-scale structure tracers, including CMB and galaxy weak lensing, galaxy clustering and the cosmic infrared background. In this talk, I will present the code, how to use it, and show recent published results that were obtained with it. I will also discuss how to interface the code with neural network emulators in order to accelerate calculations.

        Speaker: Boris Bolliet (University of Cambridge)
    • 4:00 PM
      Coffee break
    • Monday P Amphitheatre


      LPSC Grenoble

      Convener: Tony Mroczkowski (European Southern Observatory (ESO))
      • 10
        Status of the NIKA2 Sunyaev-Zeldovich Large Program

        The NIKA2 camera operating at the IRAM 30-m telescope has unique performance for the resolved observation of the Sunyaev-Zel’dovich effect towards galaxy clusters. As part of the NIKA2 guaranteed-time, the SZ Large Program (LPSZ) is devoted to the high-angular resolution SZ mapping of a representative sample of about 40 galaxy clusters drawn from the SZ-selected catalogues of the Planck satellite and of the Atacama Cosmology Telescope, and also observed in X-ray with XMM-Newton or Chandra. The main goal of this program is to provide the community with unprecedented measurements of the mean pressure profile of galaxy clusters and of the scaling law between the SZ observable and the hydrostatic mass, extending previous measurements to higher redshifts and lower masses, in order to improve the accuracy of cosmological constraints with galaxy clusters. I will review the status of the LPSZ observation, present the standard analysis to go from NIKA2 raw data to the thermodynamical properties of galaxy clusters and offer a panorama of the studies of some interesting clusters drawn from the LPSZ sample.

        Speaker: Laurence Perotto (LPSC)
      • 11
        panco2: ICM pressure profiles from tSZ observations in python

        Measuring the distribution of gas pressure in galaxy clusters is a key ingredient of cluster science, both from a cosmological and an astrophysical standpoint. Millimeter-wave observations offer highly valuable datasets for these measurements thanks to the thermal Sunyaev-Zeldovich (tSZ) effect, a spectral distorsion of the CMB with an amplitude directly proportional to the line of sight-integrated pressure of the intracluster medium (ICM). To perform these measurements, we have developed panco2, a Python library using MCMC forward modeling to extract ICM pressure profile estimates from millimeter-wave datasets. The software uses very flexible inputs, allowing its user to take into account various systematics affecting millimeter-wave observations, such as point source contamination, spatial filtering, and colored noise.

        In this talk, I will present panco2, its usage and validation. I will describe the algorithm used to perform the pressure profile estimation, the different observational features that can be taken into account, and the data required to perform the analysis. I will describe the validation framework that has been created for panco2, using mock clusters of different masses and redshifts, with simulated observations by different millimeter-wave instruments. Finally, I will discuss the code availability, from the public Github including the code and the validation products, to the online documentation.

        Speaker: Florian Kéruzoré (Argonne National Laboratory)
      • 12
        NIKA2 observations of 3 low mass clusters at z ~ 1: P(r) and Y-M relation

        Three galaxy clusters selected from the XXL X-ray survey at high redshift and low mass (z ~ 1 and M500 ~ 1-2 x 10^14 Msun) were observed with NIKA2 to image their Sunyaev-Zel'dovich effect (SZE) signal. They all present an SZE morphology, together with the comparison with X-ray and optical data, that indicates dynamical activity related to merging events. Despite their disturbed intracluster medium, their high redshifts and their low masses, the three clusters follow remarkably well the pressure profile and the SZE flux-mass relation expected from standard evolution. This suggests that the physics that drives cluster formation is already in place at z ~ 1 down to M500 ~ 10^14 Msun.

        Speaker: Rémi Adam (Laboratoire Lagrange, Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Blvd de l'Observatoire, CS 34229, 06304 Nice cedex 4, France)
    • Tuesday A Amphitheatre


      LPSC Grenoble

      Convener: Dr François-Xavier Désert (Univ Grenoble Alpes, CNRS, IPAG)
      • 13
        The zGAL survey: first results

        zGAL observed a sample of ~140 bright Herschel-selected sources with NOEMA at 1, 2 and 3 mm, detecting more than 170 individual sources. Each object is detected in at least two emission lines, guaranteeing a 100% redshift success rate. I am going to present the first results of the survey. The spectral energy distributions - finely sampled by NOEMA - are used to derive the dust properties of the sources, namely their dust mass, temperature and emissivity index, as well as to estimate their IR luminosities and SFR. Molecular gas masses are computed from the CO, [CI] and mm continuum tracers. Finally, combining dust and gas results, the sources were positioned in the frame of the Kennicutt-Schmidt and "main sequence" relations, thus drawing some first conclusions about their nature.

        Speaker: Stefano Berta
      • 14
        IRAM 30-meter millimetre follow-up of deep OSIRIS / 10.4-meter GTC optical surveys

        It is broadly accepted that CO is a reliable tracer of molecular H in massive IR ($L_{\rm IR}\ \ge\ 10^9\ L_{\odot}$) galaxies, and that there are clear correlations between $L_{\rm IR}$ and $L'_{\rm CO}$ that are qualitatively independent of environment and even redshift. We present two tales on the search for $^{12}$CO emission from dusty star-forming galaxies in both field (Lockman Hole, z $<$ 0.1) and cluster (Zw Cl0024.1+1652, z $\sim$ 0.4) environments, according to the capabilities of the EMIR receiver at the IRAM-30m telescope. The observed galaxies are part of two follow-up programs in the millimetre regime of the spectroscopic Lockman-SpReSO and GLACE surveys in the optical (OSIRIS / 10.4m GTC). From these data we derived $L_{\rm IR}$ and $L'_{\rm CO}$ estimations and put them in the framework of the historic records according to the literature for each environmental case. Among others, the results suggest that the reservoir of cold gas is smaller in cluster galaxies than in the field at a given star formation rate (SFR). Furthermore, there is also evidence that the amount of cold gas increases with the cluster-centric distance, hence pointing to an environmental dependency. Finally, we provide insights about some practical limits of the current facilities (IRAM observatories, ALMA, LMT) to get reliable $L'_{\rm CO}$ estimations for IR at low and intermediate redshifts.

        Speaker: Dr Miguel Sánchez-Portal (IRAM, ASPID)
      • 15
        TolTEC surveys: mapping the dusty galaxy contribution to the star formation history of the Universe

        TolTEC a large-format (~7000 detector) imaging polarimeter will conduct two legacy extragalactic surveys at 1.1, 1.4 and 2.0mm at the 50m Large Millimeter Telescope. The Ultra-Deep Survey of Star-forming Galaxies (~0.8 sq.deg., r.m.s. ~0.025mJy at 1.1mm) is a confusion-limited survey which ties the entire Luminous Infrared Galaxy population from redshifts 2 to 10 directly to their optical counterparts and addresses the question of how do massive galaxies build up metals and stellar mass over cosmic time. The Large Scale Structure Survey (~40-60 sq. deg., r.m.s.~0.25 mJy at 1.1mm) probes the relationships between the spatial distribution of star forming galaxies and large scale structure and provides a detailed view of clusters and their substructure via the Sunyaev-Zeldovich (SZ) effect. We show the predictions derived from cosmologically motivated simulations for these surveys and the accessibility of the community to them, as well as the commissioning data acquired to prove their feasibility. We will also briefly show the design of the Galactic surveys we will perform with the camera.

        Speaker: Itziar Aretxaga (INAOE)
    • 10:25 AM
      Coffee Break
    • Tuesday A Amphitheatre


      LPSC Grenoble

      Convener: Alessandro Monfarini (CNRS)
      • 16
        The case for an all-sky millimetre survey at subarcminute resolution

        There are several new projects to survey the sky with millimetre eyes, the biggest being Simons Observatory and CMB-S4, in the Southern Hemisphere. The NIKA2 collaboration has acquired a knowledge sufficient to build a large focal plane KID camera for a 15-m antenna. This would allow covering the whole Northern Hemisphere in a couple of years at subarcminute resolution and with milliJansky sensitivity. We describe the main scientific drivers for such a project: the SZ sky, the high-redshift millimetre Universe and the interstellar medium in our Galaxy and the nearby galaxies. Then we show the main difficulties (organisational, technical and financial).

        Speaker: François-Xavier Désert (Univ Grenoble Alpes, CNRS, IPAG)
      • 17
        CONCERTO: instrument and first results

        CONCERTO (CarbON CII line in post-rEionization and ReionizaTiOn) is a low-resolution spectrometer with an instantaneous field-of-view of 18.6 arcmin, operating in the 130–310 GHz transparent atmospheric window. It is installed on the 12-meter Atacama Pathfinder Experiment (APEX) telescope at 5 100 m above sea level.
        The Fourier transform spectrometer (FTS) contains two focal planes hosting a total of 4 304 kinetic inductance detectors.
        The FTS interferometric pattern is recorded on the fly while continuously scanning the sky.
        One of the goals of CONCERTO is to characterize the large-scale structure of the Universe by observing the integrated emission from unresolved galaxies via the line intensity mapping technique.
        In this presentation, I will introduce the CONCERTO instrument and show some first results.

        Speaker: Alessandro Fasano (Laboratoire d'astrophysique de Marseille (LAM))
      • 18
        The European Low Frequency Survey: observing the radio sky to understand the beginning of the Universe

        The leading theory to understand the initial conditions of the Big Bang is inflation, which predicts the existence of a primordial background of gravitational waves that must have left its imprint in the CMB polarization: the so-called B-modes. The main difficulty in measuring the B-mode polarization comes not just from its sheer faintness, but from the fact that many other objects in the Universe also emit polarized microwaves, which mask the faint CMB signal.

        The European Low Frequency Survey (ELFS) is a project that will enable the detection of primordial B-mode polarization by measuring the Galactic and extra-Galactic foregrounds in the 5 - 120 GHz frequency window.

        The first stage of this project will be carried out in synergy with the Simons Array (SA) collaboration, installing a 5.5-11 GHz coherent receiver at the focus of one of the three 3.5 m SA telescopes in Atacama, Chile (“ELFS on SA”).

        The receiver will be equipped with a fully digital back-end based on the latest Xilinx RF System-on-Chip devices that will provide frequency resolution of 1MHz across the whole observing band, allowing us to clean the scientific signal from unwanted radio frequency interference, particularly from low-earth orbit satellite mega-constellations.

        In this talk we will review the scientific motivation for ELFS and its instrumental characteristics, and we will provide an update on the development of ELFS on SA.

        Speaker: Aniello Mennella (Università degli Studi di Milano - Istituto Nazionale di Fisica Nucleare)
    • 12:00 PM
      Conference picture (on the LPSC stoop)
    • 12:15 PM
    • Tuesday P1 Room 9

      Room 9

      LPSC Grenoble

      Convener: Stefano Berta
      • 19
        Multi-band ALMA survey for dusty star-forming galaxies

        Wide, deep, blind continuum surveys at submillimetre/millimetre (submm/mm) wavelengths are required to provide a full inventory of the dusty, distant Universe. However, conducting such surveys to the necessary depth, with sub-arcsec angular resolution, is prohibitively time-consuming, even for the most advanced submm/mm telescopes. In this talk, I will report the most recent results from the ALMACAL project, which exploits the 'free' calibration data from the Atacama Large Millimetre/submillimetre Array (ALMA) to map the lines of sight towards and beyond the ALMA calibrators. ALMACAL has now covered 1,001 calibrators, with a total sky coverage around 0.3 deg2, distributed across the sky accessible from the Atacama desert, and has accumulated more than 1,000 h of integration. The depth reached by combining multiple visits to each field makes ALMACAL capable of searching for faint, dusty, star-forming galaxies (DSFGs), with detections at multiple frequencies to constrain the emission mechanism. Based on the most up-to-date ALMACAL database, I will report the detection of 186 DSFGs with flux densities down to S870μm ~ 0.2 mJy, comparable with existing ALMA large surveys but less susceptible to cosmic variance. I will also report the number counts at five wavelengths between 870 μm and 3 mm, in ALMA bands 3, 4, 5, 6 and 7, providing a benchmark for models of galaxy formation and evolution. By integrating the observed number counts and the best-fitting functions, I also present the resolved fraction of the cosmic infrared background (CIB) and the CIB spectral shape. Combining existing surveys, ALMA has currently resolved about half of the CIB in the submm/mm regime.

        Speaker: Jianhang Chen (European Southern Observatory)
      • 20
        A sensitive CO and Carbon line survey of local ULIRGs using APEX and ALMA

        We use high sensitivity, beam-matched APEX, ALMA, and ACA (sub)-mm observations to study the state of the cold molecular gas in a sample of ~40 local ultra luminous infrared galaxies (ULIRGs), hence probing mostly galaxy mergers characterized by strong starburst and AGN activity. We aim to understand how such energetic feedback processes affect the kinematics and excitation of the molecular ISM of ULIRGs. To do so, we use proxy tracers such as low-J CO (up to J=3) and neutral atomic carbon ([CI](1-0)) emission lines, which allow us to study their different line ratios and in turn get insight on the physical properties of the ISM, such as its excitation temperature and density, which in turn allow us to constrain the H2 mass using two independent gas tracers. Additionally, by performing a multi-Gaussian component fit to the high S/N CO spectral line observations, we can study separately the spectral line components that are characterised by different line-of-sight velocities and velocity dispersions, comparing the CO line excitation of the quiescent and the fast-moving molecular gas. We find extremely high average line ratios, however no correlation with SFR, AGN luminosity or SFE, indicating that these low-J CO lines are poor tracers of ISM heating mechanisms in such IR luminous mergers. We, however, suggest that large gas velocity gradients caused by turbulence and/or massive molecular outflows are at the origin of the most extremely high CO line ratios measured the our sample. Lastly, we find that these sources are very bright in [CI](1-0) compared to other galaxies and this enhancement seems to correlate with the line widths (turbulence/outflows), which are on average narrower for [CI] than CO lines in our sample of local ULIRGs, which may suggest different behaviours for different gas tracers.

        Speaker: Isabel Montoya Arroyave (University of Oslo - Institute of Theoretical Astrophysics)
      • 21
        Lessons learnt from observing a z~13 candidate with ALMA

        Over the last year, we have witnessed a mad dash as the community tries to confirm candidate z>10 galaxies identified through HST and JWST photometry. Multiple ALMA DDT observations have been conducted, targeting the [OIII] 88 micron (and [CII] 158 micron) emission of these candidates, with the aim of securing their redshifts. But, at the time of this abstract submission, none of these candidates have been "robustly" detected in the [OIII] or [CII] transition. In this talk, I will discuss the statistical tests of the ALMA data that we performed for the observations of the z~13 candidate, HD1, for which we found no credible evidence of any [OIII] or [CII] emission. I will also present the broader lessons learnt from performing these tests and put these in context of the other candidates targeted, but not confirmed, with ALMA.

        Speaker: Melanie Kaasinen (European Southern Observatory)
      • 22
        Millimeter Interferometry: Radio Quiet Quasars and Galaxy Evolution

        Despite recent discoveries of quasar feedback in action through outflows and jets, the amount of energy that the active nucleus is capable of injecting into the extended interstellar medium of the host galaxy remains unknown. The most mysterious component of quasar feedback is the lowest density, hot volume-filling gas. Though there are tentative detections of this component via its thermal Sunyaev-Zel'dovich (SZ) effect through stacking and targeted measurements, the results remain controversial. There is no consensus on how quasar winds are launched or how they become coupled to the host's interstellar medium or what is their physical extent into the circumgalactic medium of the host galaxy over the quasar lifetime. With targeted multi-wavelength interferometric observations, we are working to reveal the mysteries of the SZ effect and the mm-wave regime in z>2 quasars, separating individual quasars’ emission from their surrounding circumgalactic medium. I will discuss the status of these efforts using targeted VLA, ALMA, and SMA observations, and a vision for the future of mm-wave interferometry efforts as probes of galaxy evolution in active environments.

        Speaker: Kirsten Hall (Center for Astrophysics | Harvard & Smithsonian)
      • 23
        Radio-selected NIR-Dark galaxies: likely progenitors of high-z massive galaxies?

        Since the first (sub)mm observations, it has been clear that the cosmic census of high-z galaxies based on deep optical/NIR surveys is quite far from complete. The "darkest galaxies", in which significant amounts of dust absorb the stellar emission, are missed by these surveys, even though their contribution to the cosmic Star Formation Rate Density and to the evolution of massive galaxies is thought to be significantly high. Due to their elusive nature - however - most of the studies regarding these extremely obscured sources still rely on low statistics and are potentially biased by cosmic variance. In this talk, I will illustrate the potentialities of a radio selection, paired to the lack of a NIR counterpart, to assemble the largest homogeneous sample of "dark" star-forming galaxies currently known. I will present the Radio-Selected NIR-Dark galaxies collected in the COSMOS field, their properties estimated through SED-fitting and their likely evolutionary path (Gentile 2023a, in prep.). Finally, I will discuss our first results on these sources obtained through a new series of ALMA observations and the future perspectives of this project (Gentile 2023b, in prep.).

        Speaker: Fabrizio Gentile (Università di Bologna)
      • 24
        Metal enrichment in the CGM around high-z merging galaxies

        We study the emission of the [CII]158 𝜇m from the gas sourrounding merging systems at 4 ≤ z ≤ 6 (post Reionization Epoch), when galaxies rapidly assembled their masses and reached their chemical maturity. It has now become clear that galaxies are complex ecosystems, continuously exchanging material with the surrounding environment, and understanding the physical mechanisms that drive galaxy evolution at these remote cosmic epochs, requires an appropriate combination of observational and theoretical tools. The observational part of this work makes use of major merger systems present in the ALMA Large Program to Investigate [CII] at Early times (ALPINE) survey, which is designed to measure [CII] and the FIR-continuum emission for a sample normal galaxies at z = [4.4-5.8]. In particular, we consider and analyse merging systems whose components can be spatially and/or spectrally resolved, so that we can distinguish between the [CII] emission coming from the single components of the system and that coming from the system as a whole, this distinction between emissions help us understanding the metal enrichment of the circumgalactic medium (CGM) around the selected candidates. How much of the [CII] emission is coming from the components of the merging system? And from the gas surrounding the system? We then, make use of the hydrodinamical cosmological simulation dustyGadget (Graziani+2020) to select synthetic analogues of observed galaxies, which help us interpret observational results. Indeed, simulated counterparts give us hints on the feedback processes regulating baryon cycling at the CGM scale and on the role of outflows and gas stripping in merging systems. In the end, the comparison between simulated and observed galaxies gives us information on how these early galaxies acquire their gas content and get enriched with metals and dust grains.

        Speaker: Claudia Di Cesare
      • 25
        CO-CAVITY: molecular gas in void galaxies

        Galaxies in voids have experienced a different environment than non-void galaxies during their entire existence. Their properties are possibly different from non-void galaxies, however, systematic studies have been missing for a long time. The Legacy Survey CAVITY (Calar Alto Void Treasury Integral-field Survey) aims to fill this gap. It will observe about 300 carefully selected void galaxies with the PMAS integral field spectrograph at the Calar Alto 3.5m telescope which will allow to derive the star formation histories, ionised gas properties and dynamical mass, including the amount of dark matter.

        In order to fully characterise and understand void galaxies, in particular how star formation proceeds, we need to know its molecular gas content. To fill this gap, we are observing a sample of $\sim$ 130 CAVITY galaxies with the EMIR receiver at the IRAM 30m telescope in Pico Veleta targeting the CO(1-0) and CO(2-1) lines. The data will allow us to derive the SFE (=SFR/molecular gas mass), molecular-to-atomic gas mass ratio and molecular-to-stellar mass ratio. Comparing the combined results from the CO(1-0) and CO(2-1) and, once available, IFU data with non-void galaxies will allow us to better understand the influence that the low-density environment has on the molecular gas content and the process of star formation.
        The analysis of the CO data is in full progress and we will present first results.

        Speaker: Miguel Sánchez-Portal (IRAM, ASPID)
    • Tuesday P2 Amphitheatre


      LPSC Grenoble

      Convener: Laura Salvati (IAS, Paris-Saclay)
      • 26
        Towards precision cluster SZ cosmology: from Planck to the Simons Observatory

        As demonstrated by Planck, ACT, and SPT, the abundance of tSZ-detected galaxy clusters across mass and redshift is a powerful cosmological probe. The upcoming Simons Observatory (SO) will lead to the detection of about 20 000 clusters, an order of magnitude more objects than what previous experiments found, thereby providing an unprecedented constraining potential. However, in order for this potential to be realised, cluster detection and analysis (likelihood) pipelines will have to be developed and understood to a much higher level of accuracy than previously demonstrated.

        In this talk I will discuss ongoing efforts towards the accurate modelling of cluster SZ counts, focusing on the improvements regarding noise biases, covariance estimation, and deprojection of contaminating signals such as the CIB of Zubeldia et al. 2021, 2022a & 2022b. I will then discuss the application of these improved cluster detection and characterisation methods to Planck data, presenting a new Planck catalogue and cosmological constraints derived from it. Finally, I will briefly address how these improved techniques can be applied to SO data and will show some results from an end-to-end cluster cosmology validation project currently under way.

        Speaker: Inigo Zubeldia (University of Cambridge)
      • 27
        An updated and improved thermal SZ y-map from Planck PR4 data

        An all-sky map of the thermal Sunyaev-Zeldovich (SZ) effect has been publicly released by the Planck Collaboration in 2015, using a Needlet Internal Linear Combination (NILC) component separation method on Planck PR2 data. The quality of the Planck data has improved since then. The Planck PR4 data release provides full-sky maps in LFI and HFI frequency bands with improved systematics and sensitivity. I will present a new all-sky map of the thermal SZ Compton y-parameter obtained by implementing NILC on the latest Planck PR4 data and discuss improvements in terms of noise and residual foreground contamination.

        Speaker: Jyothis Chandran (IFCA, Universida de Cantabria)
      • 28
        Cosmology with galaxy clusters: an improved multi-wavelength analysis

        Galaxy clusters are a powerful cosmological probe: they track the latest evolution of large scale structure and are therefore fundamental for testing the cosmological model in the recent Universe. To compare the observations of galaxy clusters with the theoretical prediction and thus constrain the cosmological parameters of the underlying model, a precise knowledge of clusters’ masses and redshift is required. Scaling relations relating the mass with a given cluster observable (like the richness in optical wavelength, Ysz in the mm-band or Yx in X-rays) are usually used to compute the mass of clusters. My work aims at estimating a new scaling relation using a sample of clusters from the Planck ESZ catalogue that was observed in X-rays by Chandra, and ultimately combining all available SZ and X-ray data in a single likelihood to compute cosmological parameters.
        XMM-Newton data being available for a large part of the Chandra-Planck sample, I also compare profiles and integrated values for both telescopes.

        Speaker: Gaspard Aymerich (Institut d'Astrophysique Spatiale, Université Paris-Saclay)
      • 29
        Probing the Hubble constant from X-ray and millimetre observations of CHEX-MATE galaxy clusters

        Assuming spherical symmetry, joint X-ray and millimetre observations of galaxy cluster atmospheres allow us to measure intra-cluster distances. Using XMM-Newton and Planck observations of CHEX-MATE galaxy clusters, we investigate the relationship between X-ray and X-ray+mm inferences of cluster temperature profiles. The average ratio between X-ray and X-ray+mm temperatures, $\eta_T=kT_{XMM}\;\,/(P_{Planck}\;\:/ne_{XMM}\;\,$), is distributed around 1, in agreement with previous estimates of pressure ratios obtained using the same instruments. We find that the overall distribution of $\eta_T$ is affected by the morphological state of galaxy clusters. On the other hand, the $\eta_T$ distribution does not exhibit any significant dependence on cluster masses or redshifts. Combining $\eta_T$ values with Bayesian priors on the cluster morphological states obtained from hydrodynamical simulations of The Three Hundred project, we used CHEX-MATE clusters as cosmological rulers and derived a value of the Hubble constant of $H_0 = 67.3^{+2.2}_{-2.1} \;\,\rm km \,s^{-1}\, Mpc^{-1}$.

        Speaker: Federico De Luca (Università degli Studi di Roma Tor Vergata)
      • 30
        Multicomponent Analysis of Strong Lensing Galaxy Clusters as an Observational Test of Cosmological Structure Predictions

        Strong lensing galaxy clusters provide a powerful observational test of Cold Dark Matter (CDM) structure predictions derived from simulation. Specifically, the shape and relative alignments of the dark matter halo, stars, and hot intracluster gas tells us the extent to which theoretical structure predictions hold for clusters in various dynamical states. We measure the position angles, ellipticities, and locations/centroids of the brightest cluster galaxy (BCG), intracluster light (ICL), the hot intracluster medium (ICM), and the core lensing mass for a sample of strong lensing galaxy clusters from the SDSS Giant Arcs Survey (SGAS). We use iterative elliptical isophote fitting methods and GALFIT modeling on HST WFC3/IR imaging data to extract ICL and BCG information and use similar iterative ellipse fitting methods on Chandra ACIS-I X-ray data to make measurements of the ICM. Comparing these measurements to the core lensing mass derived from the clusters' lens profiles, we attempt to constrain the physical state of these strong lensing clusters and evaluate the different observable components in terms of their ability to trace out the gravitational potential of the cluster.

        Speaker: Raven Gassis (University of Cincinnati)
      • 31
        Characterizing the dynamics of galaxy cluster mergers with multi-wavelength observations and hydrodynamical simulations

        Galaxy clusters represent the current stage of cosmological structure formation, and major mergers are central to the growth of these objects. Studies of merger dynamics can therefore test the paradigm of hierarchical structure formation in the universe over cosmic time. We have assembled a set of deep, multi-wavelength data (X-ray, SZ, and optical) for a sample of 8 galaxy clusters, 7 of which have previously been identified as likely mergers. For the first time in such an analysis, the data form a complete set of observables that probe the POS morphology and LOS velocity structure of both the ICM and DM components of mergers. I will discuss progress towards performing a systematic comparison of these novel multi-probe observations to corresponding mock observables generated from idealized hydrodynamical binary galaxy cluster merger simulations in order to constrain the merger geometry and dynamics for each member of our sample. I will describe in detail an ongoing investigation into the first member of the galaxy cluster sample, MACS J0018.5+1626 (aka CL 0016+16), and future plans to use population statistics of major mergers in our sample to test the ΛCDM cosmological model.

        Speaker: Emily Silich (Caltech)
    • 4:10 PM
      Coffee Break
    • Tuesday P1 Room 9

      Room 9

      LPSC Grenoble

      Convener: Andrea Catalano (LPSC)
      • 32
        Challenges for new discoveries from cosmic microwave background experiments

        One of the main challenges of the next generation of cosmic microwave background (CMB) experiments is probing the primordial gravitational waves signal that have left an imprint in the curly pattern (a.k.a B -modes) of the CMB polarization. This very weak signal, if detected, will probe the existence of the inflation era and open the path to a physics beyond the standard model.
        This goal has motivated a huge technological effort to reach an unprecedented level of instrument sensitivity. However, the most limiting factors nowadays are: i) high control of instrumental systematics; ii) absolute calibration of polarization angle and iii) removal of foreground emissions. In this context, recent findings (Ritacco et al. 2023 ) have shown that important information is still lacking for the correct reconstruction of the spectral energy distribution of foreground dust in polarization signals E and B, which could therefore, if not correctly interpreted, significantly bias the CMB signal. The presentation aims at presenting these latest results that drive the motivations of a project idea, called COSMOCal, to deliver a model and instrument independent method to ensure the absolute calibration of CMB experiments with the accuracy required to probe CMB B-modes and the cosmic birefringence. This project consists on building an artificial calibration source to be mounted on a nanosatellite placed in geostationary orbit and to be used for the self calibration of ground-based telescopes. We are currently building the first prototype to be tested at IRAM 30m telescope with the NIKA2 camera. I will present the scientific motivations for this project together with the technical challenges and the status of the prototype construction.

        Speaker: Alessia Ritacco (INAF, Osservatorio astronomico di Cagliari)
      • 33
        Observing galaxy clusters and the cosmic web using the Sunyaev Zel'dovich effect with MISTRAL

        The MIllimeter Sardinia radio Telescope Receiver based on Array of Lumped elements kids (MISTRAL) is a millimetric total power camera operating at 90 GHz installed at the Sardinia Radio Telescope (SRT). MISTRAL provides a wide 4’ field of view, sampled at a resolution of 12’’ with ~400 Kinetic Inductance Detectors. After technical and scientific commissioning (planned for 2023), MISTRAL will be open to proposals from scientists as a facility instrument. The operational band of MISTRAL allows to probe a number of astrophysical processes in galactic and extragalactic environments. In this contribution we will concentrate on the capability of MISTRAL to provide sentitive, accurate and high-angular-resolution Sunyaev Zel'dovich measurements from galaxy clusters as well as from the elusive cosmic web.

        Speaker: Prof. Elia Stefano Battistelli (Sapienza, University of Rome)
      • 34
        ALMA Band 9 upgrade: a feasibility study

        We present the results of a study on the feasibility of upgrading the existing ALMA Band 9 receivers (602-720 GHz). In the current configuration, each receiver is a dual channel heterodyne system capable of detecting orthogonally polarized signals through the use of a wire grid and a compact arrangement of mirrors. The main goals of the study are the upgrade of the mixer architecture from Double-Sideband (DSB) to Sideband-separating (2SB), the extension of the IF and RF bandwidth, and the analysis of the possibilities of improving the polarimetric performance.
        We demonstrate the performance of 2SB mixers both in the lab and on-sky with the SEPIA660 receiver at APEX, which shows image rejection ratios exceeding 20 dB and can perform successful observations of several spectral lines close to the band edges. The same architecture in ALMA Band 9 would lead to an increase in the effective spectral sensitivity and a gain of a factor two in observation time.
        We set up also an electromagnetic model of the optics to simulate the polarization performance of the receivers, which is currently limited by the cross-polar level and the beam squint, i.e. pointing mismatch between the two polarizations. We present the results of the simulations compared to the measurements and we conclude that the use of a polarizing grid is the main responsible of the limitations.

        Speaker: Sabrina Realini (Kapteyn Institute, University of Groningen)
    • Tuesday P2 Amphitheatre


      LPSC Grenoble

      Convener: Florian Ruppin (IP2I)
      • 35
        Deep Learning Generative Models to Infer Mass Maps from SZ, X-ray and galaxy members Observations in Galaxy Clusters.

        In our previews works, deep learning techniques have succeeded in estimating galaxy cluster masses in observations of Sunyaev Zel'dovich maps, e.g. in the Planck PSZ2 catalog and mass radial profiles from SZ mock maps. In the next step, we explore inferring 2D mass density from mock observations of SZ, X-ray and stars using THE THREE HUNDRED (The300) cosmological simulation. In order to do that, we investigate state-of-the-art deep learning models that have been proven to be successful for image generation in multiple areas of research including astrophysics and medical imaging. These models are conditioned to observations, e.g. SZ maps, to generate the most likely matter 2D distribution given our dataset, composed of around 70 thousand mock maps from The300. We show that these models can successfully infer the 2D matter distribution with a scatter of around $10\%$ in their mass radial profiles and reproduce the matter power spectrum when comparing the generated maps with the ground-truth from the simulations.

        The next natural step of this project is to apply DL models on high resolution SZ observation, such as NIKA2, SPT and ACT. However, mock images needed for training deep learning models must fully take into consideration the observational impact of the telescopes in order to mimic real observations.

        Speaker: Daniel de Andres Hernandez (Universidad Autonoma de Madrid)
      • 36
        Systematics effects on the upcoming NIKA2 LPSZ scaling relation

        In Sunyaev Zeldovich (SZ) cluster cosmology, one of the main parameter of interest is cluster mass. It is needed to constrain cosmological parameters through the cluster number count. As the mass is not an observable, a scaling relation is needed to link cluster masses to the integrated Compton parameters Y, i.e the SZ observable.

        Current cosmological results use the Planck scaling relation obtained with clusters at low redshift (z<0.5) observed in SZ and X-ray.
        In the SZ Large Program (LPSZ) of the NIKA2 collaboration, the scaling relation can be obtained with a sample of 45 clusters at high redshift (from z=0.5 to z=0.9) and observed at high resolution both in SZ and X-ray. From these data, it will be possible to study various systematic effects that can affect the scaling relation.

        For this purpose, several galaxy cluster samples have been simulated with gNFW pressure profiles and Compton maps similar to the NIKA2 ones. In addition, to quantify the impact of the cluster dynamical state, different features have been applied to the simulated sample (overpressure, non-sphericity, substructures, …). Their impact on the scaling parameter estimation has been studied.

        In this talk, I will present the various systematic effects that can affect the Y-M scaling relation used in SZ cluster cosmology.

        Speaker: Alice Moyer (LPSC IN2P3)
      • 37
        Towards the first mean pressure profile estimate with the NIKA2 Sunyaev-Zeldovich Large Program

        As the largest gravitationally bound objects in the Universe, galaxy clusters are key tools to study large-scale structure formation processes and to constrain cosmological models. These studies, however, require a precise characterization of cosmological tools such as a mass-observable scaling relation and a mean electronic pressure profile. Systematic effects, in particular at high redshift, have an impact on these tools and are currently the main limitation of cluster-based cosmology.

        NIKA2, a millimeter camera installed at the IRAM 30-m telescope is a major experiment to extend our understanding of galaxy clusters. Combining sub-arcminute (17.6’’ at 150 GHz) angular resolution and a 6.5 arcmin diameter field of view, NIKA2 can resolve and map the Sunyaev-Zel'dovich (SZ) effect towards clusters up to high redshifts. Combined with X-ray data from XMM-Newton satellite, we can infer with high precision the thermodynamical properties and the hydrostatic masses of such objects within the NIKA2 SZ Large Program (LPSZ), which covers a representative sample of about 40 galaxy clusters at 0.5<z<0.9.

        In this talk I will present the first characterization of a sub-sample of the LPSZ and discuss the methodology to measure the mean pressure profile.

        Speaker: Corentin Hanser
    • Wednesday A Amphitheatre


      LPSC Grenoble

      Convener: Gustavo yepes (Universidad Autonoma de Madrid)
      • 38
        Baryon Pasting Project

        In this talk, I will present the Baryon Pasting project, which aims to develop a physically-motivated, computationally efficient model for large multi-wavelength cosmological surveys (including microwave, X-ray and optical skies). I will discuss the current status, challenges, and future prospects of forward-modeling multi-wavelength cosmological surveys and enabling cross-survey, cross-correlation cosmology.

        Speaker: Daisuke Nagai (Yale University)
      • 39
        Towards accurate millimeter-wave sky maps from gravity-only simulations

        Galaxy cluster-based cosmology is at a crossroads, with the current and next-generation surveys delivering deep sky surveys and large cluster catalogs. In this framework, the use of simulations to calibrate systematics in cosmological analyses is crucial. As a large proportion of cosmological simulations are gravity-only (effectively only evolving dark matter particles), the exploitation of these simulations for cosmology require the inference of baryon properties from the dark matter distribution.

        In this talk, I will present ongoing efforts to develop a baryon pasting algorithm and calibrate it on hydrodynamical simulations. We use the BorgCube universe, a large cosmological volume with initial conditions evolved both as a gravity-only simulation and as a hydrodynamic one, using the new CRK-HACC solver. This approach allows us to compare individual cluster-sized dark matter halos in gravity-only simulations to their direct counterparts in hydrodynamic simulations. We use this comparison to tailor baryon pasting to produce cluster gas properties recreating those found in the hydrodynamic simulation. We focus in particular on recreating the pressure and density of the intracluster medium gas, enabling the creation of maps of the thermal and kinetic Sunyaev-Zeldovich (SZ) effects. This work will allow us to create realistic millimeter-wave sky maps from gravity-only simulations which, coupled with efforts to create realistic sky maps at other frequencies, will help us understand systematics in multi-wavelength cluster cosmology.

        Speaker: Florian Kéruzoré (Argonne National Laboratory)
      • 40
        The high-resolution 300 clusters

        Building upon the success of the300 galaxy cluster project, I will present our current efforts on simulating the same clusters but with an order of magnitude higher resolution, which is crucial to (1) understand the galaxy cluster evolution in detail; (2) match the capability of the upcoming telescopes.
        With the updated SIMBA-C model which has improvements in several aspects, especially a new chemical evolution model, I will discuss its success and deficit, as well as possible future development.

        Speaker: Weiguang Cui (UAM)
    • 10:30 AM
      Coffee Break
    • Wednesday A Amphitheatre


      LPSC Grenoble

      Convener: Michael McDonald (MIT)
      • 41
        The Cluster XMM-Heritage project CHEX-MATE: current results and future prospects

        The Cluster HEritage project with XMM-Newton – Mass Assembly and Thermodynamics at the Endpoint of structure formation (CHEX-MATE)
        is a three-mega-second Multi-Year Heritage Programme to obtain X-ray observations of a minimally-biased, signal-to-noise-limited sample of 118 galaxy clusters detected by Planck through the Sunyaev–Zeldovich effect. The program aims to study the ultimate products of structure formation in time and mass. We will present the most recent results obtained from our large international collaboration, highlighting the role of X-ray and SZ data in resolving the astrophysics of the most massive collapsed halos in the universe and in studying the interplay between hot plasma and dark matter. These studies will pave the way for using the next generation of X-ray observatories, like XRISM and Athena, to construct a consistent picture of the formation and composition in mass and energy of galaxy clusters.

        Speaker: Stefano Ettori (INAF-Osservatorio di Astrofisica e Scienza dello Spazio in Bologna)
      • 42
        X-ray absorption and molecular content of the interstellar medium toward CHEX-MATE galaxy clusters

        The X-ray spectrum of extragalactic sources, such as galaxy clusters, is affected by the photo-absorption of various components of the Galactic InterStellar Medium (ISM). The resulting spectral distortion contributes to the systematics of cluster temperature measurements. It essentially depends on the total (atomic+molecular) Galactic hydrogen density column, N_H, which remains challenging to map across the sky in the lack of a straightforward tracer of the molecular gas phase in the ISM. Combining data from the Planck HFI and HI4PI sky surveys, we investigate the mass fraction of molecular gas across the line of sight of CHEX-MATE galaxy clusters by looking for thermal dust emission excesses with respects to the neutral atomic hydrogen density column, N_HI. Consistent with earlier studies of the ISM based on IRAS and Planck data, we detect dust emission excesses along the line of sight of some members of the CHEX-MATE cluster catalogue mostly localised in dense ISM regions. We find that the CHEX-MATE cluster catalogue can be divided in 40 % of members located behind low N_HI regions where the molecular mass fraction is negligible, 40% of members located in intermediate N_HI regions where the molecular gas fraction would reach 10% on average, and the remaining 20% of members located in high N_HI regions that locally exhibits even higher molecular gas fractions. The cluster temperature shifts associated with molecular content of the ISM is about 1% or less for most CHEX-MATE clusters, but can exceed 5% in the highest N_HI regions.

        Speaker: Herve Bourdin (University of Rome "Tor vergata")
    • 12:00 PM
    • Wednesday P1 Amphitheatre


      LPSC Grenoble

      Convener: Colin Hill (Columbia University)
      • 43
        Towards Cosmology with the Kinematic SZ Projected-Fields Estimator

        Over the past decade, the kinetic SZ effect has emerged as a probe of the distribution of baryons and the large-scale velocity field in the late Universe. Of the several ways to detect it, the so-called Projected-Fields kSZ estimator has the promising characteristic of not being limited to spectroscopic samples of galaxies. The original theoretical formulation of this estimator included approximations that are expected to be valid only at small scales, thus limiting its reach to only probing the baryon distribution and not the cosmological parameters. We rigorously derive the Projected-Fields kSZ estimator without these approximations, and show that this improvement leads to significant scale-dependent differences in the predicted signal for future observations from Simons Observatory and CMB-S4. We show that our improved formulation is a necessary step in order to use this estimator for constraining cosmological parameters, and also for accurately estimating the high signal-to-noise ratio measurements from these future CMB surveys. We explore the cosmological dependence of the improved Projected-Fields estimator and illustrate its potential as a cosmological probe with forecasted constraints on cosmological parameters.

        Speaker: Raagini Patki (Cornell University)
      • 44
        Enhancing Kinematic Sunyaev-Zel'dovich Power Spectrum Measurements by Removing CIB Contamination Using unWISE Galaxies

        Extracting the kinematic Sunyaev-Zel'dovich (kSZ) effect—the Compton scattering of CMB photons off moving electrons—requires cleaning of other sky components. In this work, we use large-scale structure (LSS) tracers that are correlated with both the cosmic infrared background (CIB) and thermal Sunyaev-Zel'dovich (tSZ) signal, but whose two-point correlations with the kSZ signal vanish on small scales due to the equal likelihood of positive and negative velocities. We consider various methods involving these LSS tracers to remove the CIB and tSZ contaminants without biasing the kSZ signal. In particular, we use the unWISE galaxy samples as tracer maps. We present our primary methods of interest, de-CIBing and de-(CIB+tSZ)ing, methods analogous to delensing, as ways to use these tracers to clean the CIB and tSZ signals without requiring exact assumptions about the CIB spectral energy distribution. We then explore comparisons of these methods to internal linear combination (ILC) methods, as well as combinations of both types of approaches. We provide specific calculations for a combined Simons Observatory and Planck-like experiment, with our simulated sky model consisting of component auto- and cross- spectra generated with $\verb|class_sz|$ at six frequencies ranging from 93 to 353 GHz. Our code is publicly available in $\verb|ILC_deCIB|$. For current data, improvements with these methods over current approaches are already non-negligible, and will become more significant with larger LSS surveys in the future.

        Speaker: Kristen Surrao (Columbia University)
      • 45
        Cosmological parameters with CMB primary anisotropies observed by the SPT-3G instrument

        The South Pole Telescope (SPT) is observing the cosmic microwave background (CMB) anisotropies with arcminute resolution using its state-of-the-art camera (SPT-3G). Upcoming constraints on cosmological constraints from power spectrum analyses with the 2019/2020 data will be at least as tight as Planck’s ones, while remaining independent from the satellite experiment, thus allowing to test the consistency of the two data sets and potentially discover evidence of new physics. In this talk, I will describe the SPT-3G experiment, review current results and highlight future prospects for cosmological constraints. Then, I will present improvements to the likelihood pipeline for the next data release.

        Speaker: Etienne Camphuis (Institut d'Astrophysique de Paris)
      • 46
        Constraints on primordial non-Gaussianity from halo bias measured through CMB lensing cross-correlations

        Local primordial non-Gaussianity, parametrized by $f_{NL}^{\mathrm{loc}}$, induces a characteristic scale dependence in the large-scale bias of halos. This scale dependence is a promising path to constrain multi-field inflation theories, which predict non-zero $f_{NL}^{\mathrm{loc}}$. We use the cosmic infrared background (CIB), measured by $\textit{Planck}$, which is sourced by thermal emission from dust grains in star-forming galaxies, to constrain the scale dependent bias and thus $f_{NL}^{\mathrm{loc}}$. As the CIB is difficult to separate from the dust emission in our own galaxy, we use the cross-correlation with the CMB lensing map of $\textit{Planck}$ to isolate the cosmological signal and thus use only information from the cross power spectra $C_\ell^{\nu\kappa}$ on large scales. We find no evidence for primordial non-Gaussianity and find $−87

        Speaker: Fiona McCarthy (Flatiron Institute)
    • Wednesday P2 Room 9

      Room 9

      LPSC Grenoble

      Convener: Juan Francisco Macias-Perez (LPSC)
      • 47
        Constraining the mass and redshift evolution of the hydrostatic mass bias using the gas mass fraction in galaxy clusters

        The gas mass fraction in galaxy clusters is a convenient probe to use in cosmological studies, as it can help derive constraints on a collection of cosmological parameters.
        It is however subject to various effects from the baryonic physics inside galaxy clusters, which may bias the obtained cosmological constraints.
        Among different aspects of the baryonic physics, in this presentation I focus on the impact of the hydrostatic equilibrium assumption.
        I analyse the hydrostatic mass bias $B$, constraining a possible mass and redshift evolution of this quantity and its impact on the cosmological constraints.
        To that end I consider cluster observations of the $Planck$-ESZ sample and evaluate the gas mass fraction using X-ray counterpart observations.
        I show a degeneracy between the redshift dependence of the bias and cosmological parameters.
        In particular I find a $3.8 \sigma$ evidence for a redshift dependence of the bias when assuming a $Planck$ prior on $\Omega_m$.
        On the other hand, assuming a constant mass bias would lead to the extreme large value of $\Omega_m > 0.860$.
        I however show that these results are entirely dependent on the cluster sample I consider.
        In particular, the mass and redshift trends that I find for the lowest mass-redshift and highest mass-redshift clusters of our sample are not compatible.
        Nevertheless, in all the analyses I find a value for the amplitude of the bias that is consistent with $B \sim 0.8$, as expected from hydrodynamical simulations and local measurements, but still in tension with the low value of $B \sim 0.6$ derived from the combination of cosmic microwave background primary anisotropies with cluster number counts.
        I will also discuss cosmological constraints obtained from gas fraction data, combined with other probes like cluster number counts.

        Speaker: Raphaël Wicker (Institut d'Astropysique Spatiale)
      • 48
        Probing the Ionized Gas Thermodynamics in unWISE Galaxies with the Sunyaev-Zel’dovich Effect

        The Sunyaev-Zel’dovich Effect—the Doppler boost of low-energy Cosmic Microwave Background photons scattering off free electrons—is an excellent probe of ionized gas residing in distant galaxies. Its two constituents are the kinematic SZ effect (kSZ), where electrons have a non-zero line-of-sight (LOS) velocity and which probes the electron line-of-sight momentum, and the thermal SZ effect (tSZ), where electrons have high energies due to their temperature, and which probes the electron integrated pressure. These two effects provide complementary information to constrain the thermodynamic profile of the gas residing in distant galaxies, which can be further used to understand feedback processes, a necessary ingredient to describe the evolution of the large scale structure in our Universe. Both tSZ and kSZ can be measured in cross-correlation with large-scale structure.

        In this talk, I will show my ongoing measurements of the tSZ-galaxy cross-correlation using unWISE galaxies with the newest ACT DR6 data, along with the measured kSZ signal of unWISE galaxies with Planck using the projected-field estimator (which does not require spectroscopic redshift information of the galaxy sample). unWISE is a galaxy catalog, which consists of three subsamples of mean redshifts z=0.5, 1.1, 1.5 and contains over 500 million galaxies on the full sky, and whose halo occupation distribution I have already constrained. The tSZ-galaxy cross-correlation measurement will be the highest SNR to date. I will also discuss the prospects of combining both measurements and applying the method to other galaxy samples.

        Speaker: Aleksandra Kusiak (Columbia University)
      • 49
        An ALMA+ACA+ACT view on the z=2 galaxy cluster, XLSSC 122

        In recent years there have been an increasing amount of studies on the overdensities of galaxies in the distant Universe, even beyond a redshift of z>4. However, how these so-called protoclusters evolve from a structure stretching several hundreds of Mpc to a bonafide galaxy cluster and how these distant clusters of galaxies differ from local ones are still open questions in modern astronomy. This is because there are only a handful of observational constraints of clusters at intermediate, z~2, redshifts.

        Despite being named for their visible galaxy constituents, a galaxy cluster's main baryonic matter component is the thermalized, low-density plasma found between the galaxies, which is known as the intracluster medium (ICM). Therefore, observations of the ICM in distant clusters of galaxies are key to answering the above-mentioned questions. However, many sub-mm observations focus only on the cluster members.

        In this talk, I will show you how to jointly model ALMA+ACA+ACT observations of the ICM observed through the Sunyaev-Zeldovich (SZ) effect via a bayesian forward-modeling technique implemented in the Fourier domain. With this routine, we detect and characterize the ICM of the most distant galaxy cluster found in current SZ-cluster catalogs, namely XLSSC 122. This case study will be the start of a high-resolution era for observations of the ICM in high-z systems as single-dish telescopes start finding more and more high-z galaxy clusters, which can be followed up and combined with ALMA Band 3 and future Band 1 and 2 observations.

        Speaker: Joshiwa van Marrewijk (European Southern Observatory (ESO))
      • 50
        Characterizing new low-z clusters with the CEREAL sample

        In the coming years, we will use the latest generation of Sunyaev-Zel'dovich (SZ) detectors to discover galaxy clusters at lower masses---and therefore higher redshifts---than ever before. These high-z, low-mass clusters are the progenitors of low-z, high-mass clusters, and follow-up X-ray observations will reveal insight into the origin and evolution of clusters. However, our understanding of the properties of z$\sim$0 clusters is currently limited by selection biases, so we are in need of a statistically complete low-z sample to anchor our studies of high-z clusters.

        To this end, we designed the Cluster Evolutionary Reference Ensemble At Low-z (CEREAL) to be a representative population of massive, nearby galaxy clusters. These 108 clusters were cleanly selected in mass and redshift from the Planck 2nd SZ Survey and followed up uniformly with Chandra. They have masses spanning the range between the evolutionary tracks of the Perseus cluster and the Coma cluster as well as a narrow redshift spread around z=0.2. They correspond to the descendants of the lowest mass clusters that we expect to observe at z$\sim$2 with the third-generation detector on the South Pole Telescope (SPT-3G).

        We are using the CEREAL sample to completely characterize the population of low-z clusters. We study the cool core fraction, the merger rate, and other morphological properties, as well as the thermodynamic and chemical enrichment profiles. We also carefully examine each cluster in search of interesting phenomena like bubbles produced by AGN feedback or multiple mergers. Together with new high-z observations, the CEREAL sample will facilitate evolutionary studies of galaxy clusters.

        Speaker: Laurel White (MIT)
      • 51
        Detection of forming intracluster gas in a galaxy protocluster at z~2.16

        Until now, direct observations of the intracluster medium (ICM) have been limited only to mature clusters in the latter three-quarters of the history of the Universe, and we have been lacking a direct view of the hot, thermalised cluster atmosphere beyond z~2, the epoch when the first massive clusters formed. Probing the thermal evolution of cosmic structures through z~2 — the epoch when intracluster gas starts to assemble and virialise, and cosmic star formation and the activity of active galactic nuclei (AGN) manifest a concurrent peak — is however crucial for exploring the link between galaxy clusters and their over-dense progenitors, as well as finding the observational fingerprint of feedback effects that regulate the later coevolution of the galaxy and intracluster/circumgalactic medium ecosystems.
        In my talk, I will present our recent detection of the thermal Sunyaev-Zeldovich (SZ) effect in the direction of the protocluster complex surrounding the famous Spiderweb Galaxy (z~2.16), made possible only thanks to the superior capabilities of the Atacama Large Millimeter/Submillimeter Array (ALMA). Such identification of a nascent intracluster halo represents the unambiguous proof that we are witnessing the transition through which a sparse overdensity of galaxies turns into a massive galaxy cluster. In my presentation, I will particularly focus on the observational challenges of extracting SZ information from ALMA measurements as well as on the astrophysical implications of such SZ detection.

        Speaker: Luca Di Mascolo (Università degli Studi di Trieste)
      • 52
        A HST dark galaxy merger at z~1 revealed by ALMA

        Galaxy mergers are known to be one of the major paths through which galaxies evolve across cosmic time, therefore it is absolutely necessary to study such systems at different redshifts to further our understanding of galaxy evolution. Significant progress has been made in the last decades thanks to HST, although a remaining challenge is the presence of obscuring dust, which can make one or more individual components invisible and therefore, completely impossible to identify as a merger. This is where radio telescopes such as ALMA enter. Not only has ALMA recently opened a new window to observe rest-frame far-infrared emission, thus revealing dust obscured sources, but ALMA also provides high-resolution observations essential to distinguishing multiple components.
        While studying CO(5-4) and CO(2-1) emission of a massive star-forming galaxy part of the COSMOS field, we revealed an adjacent companion which was totally invisible to HST, uncovering an ongoing major merger of galaxies at z=1.17. This redshift makes this merger particularly interesting as it is happening at the end of the peak of star formation activity in our Universe, also known as cosmic noon, where this class of mergers still remains unexplored.
        In my talk, I will show our findings for this example of a so far poorly understood class of mergers, i.e., morphological and kinematics properties of the two galaxies, their stellar and gas budget as well as their ISM conditions. I will also discuss the importance of multi-wavelength studies to fully access all baryonic properties of galaxies, and include future plans to further explore similar systems.

        Speaker: Ivanna Langan (ESO (Garching))
    • Wednesday P1 Amphitheatre


      LPSC Grenoble

      Convener: Daisuke Nagai (Yale University)
      • 53
        Galaxy catalog from SAGE calibration using the hydrodynamic simulation The300

        The Three Hundreds project consists of a 324 regions sample simulated with full-physics hydrodynamical re-simulations. They have been produced starting from the dark-matter-only MultiDark Simulations [MDPL2 8], which consists in a 1 h$^{-1}$ Gpc cube containing 3840$^3$ dark matter (DM) particles with a mass of $1.5 \times 10^9$ h$^{-1}$ M$_\odot$ each (LR DMONLY). This produces 324 Full-physics hydrodynamics zoom simulations at low resolution (LR HYDRO). With this resolution it is not possible to access a good enough comparison of magnitudes/luminosities between the simulated galaxies with the observation from Euclid for example. For this reason 324 Dark-matter-only simulations at high resolution (HR DMONLY) were generated. With respect to LR DMONLY, it has twice particles per dimension, thus, 7680$^3$, with eight times less mass per particle i.e., $1.8 \times 10^8$ h$^{-1}$ M$_\odot$ each. Thanks to this we generated catalogs of galaxies from the SAGE Semi-Analytical Model of galaxy formation using the new HR DMONLY merger trees. To obtain catalogs consistent with a hydrodynamic simulation, the internal physical parameters of SAGE were calibrated with the Particle swarm optimization (PSO) calibrator using clusters with M$_{star}=10^{14}$ h$^{-1}$ M$_\odot$ from 5 regions of full-physics hydrodynamics zoom simulations at high resolution (HR HYDRO) as HR DMONLY. This calibration was carried out by comparing the cumulative stellar mass function and cumulative luminosity functions from different bands of SAGE with HR HYDRO at $z=0$. With this calibration, we generate catalogs of galactic properties for the 324 regions in high resolution at 3 different redshifts: $z= 0$, $z=0.5$ and $z=1$ which we can compare the new luminosities with observations.

        Speaker: Jonathan Gómez (Universidad Autónoma de Madrid)
      • 54
        The Clusters Galaxy Density from high resolution dark matter only simulations with realistic SAMs and its application to the Euclid Survey

        The Euclid Satellite Mission expects to unveil the nature of dark energy and dark matter through the measurement of several cosmological probes, among which are the cluster number count. One main limitation for constraining cosmological parameters will be the determination of the Selection Function (SF) which characterizes the probability of detecting a cluster of a given mass and redshift. One way of determining it is from realistic simulated clusters, which are injected into the survey and then the detection procedure is re-applied. To do so, we intend to use the THE THREE HUNDRED project, a 324 cluster region sample extracted from the MDPL2 simulation, that were run using several semi-analytic and hydrodynamical codes. However, the high computational cost of hydrodynamical simulations does not allow to have a large volume of highly resolved galaxy clusters. In this paper, we use a calibrated version of the SAGE semi-analytical galaxy formation code with the new GIZMO-SIMBA high resolution hydrodynamical simulations in order to populate the high resolution dark matter only version of the THREE HUNDRED with galaxies reducing massively the computational cost. Then, we study the differences with the Euclid Survey in the clusters properties and the possible resolution limits of the different simulations.

        Speaker: Alejandro Jimenez
    • 4:00 PM
      Coffee Break
    • Wednesday P1 Amphitheatre


      LPSC Grenoble

      Convener: Daisuke Nagai (Yale University)
      • 55
        Impact of filaments on galaxy clusters properties in The Three Hundred simulation

        Filaments connecting galaxy clusters in the Cosmic Web are thought to quantify, or to simply have an impact on several intrinsic and observational properties of the halos. From the gas filamentary structure of the 324 simulated regions of The Three Hundred project extracted with the DisPerSE filament finder at z=0, we estimate the connectivity, the number of filaments to which clusters are connected, at different radial apertures from the cluster centre. The connectivity is extracted from the 3D structure and compared with the connectivity inferred from gas maps to take into account projection effects. We confirm that the number of filaments connected to a cluster is closely related to its mass, with more massive galaxy clusters being also more connected. The connectivity is then studied in the context of the dynamical state of the clusters and their mass accretion rate, both parameters linked to cluster evolution. Lastly, the impact of filaments on the integrated Compton parameter signal of the clusters and on their deviation from the Y-M scaling law is investigated.

        Speaker: Sara Santoni (Sapienza University of Rome)
      • 56
        The Three Hundred project: A Machine Learning method to infer clusters of galaxies mass radial profiles from mock THE THREE HUNDRED Sunyaev-Zel'dovich maps

        We develop a machine learning algorithm that infers the radial profiles of total and gas mass of galaxy clusters given thermal Sunyaev-Zeldovich (SZ) effect maps. The architecture is composed of a combination of an autoencoder and a random forest. The first is used to extract the information from the maps, while the second performs the final estimation of the radial mass profiles. This ML algorithm is trained and tested on a sample of 73,138 mock SZ maps. Each map is generated from one of 29 projections of 2522 galaxy clusters from The Three Hundred simulation. We show that the model can reconstruct the gas mass profile, responsible for the SZ effect, but also the total mass one, without any a priori assumption on the physics of the cluster. We demonstrate that both total and gas mass radial profiles are unbiased with a scatter of about 10% slightly increasing towards the core and the outskirt of the cluster.
        We selected the clusters in a wide mass range, 10^13.5 - 10^15.5 h^-1 Msun and in a different dynamical state from very relaxed to very disturbed. We see that both the accuracy and precision of this method have a slight dependence on the dynamical state, but not on the cluster mass.
        In summary, we find ML techniques to offer a powerful method to predict model-independent mass profiles for large samples of clusters.

        Speaker: Antonio Ferragamo (Sapienza Università di Roma)
      • 57
        3D scaling laws and projection effects in The300-NIKA2 Sunyaev-Zeldovich Large Program Twin Samples

        The abundance of galaxy clusters with mass and redshift is a well-known cosmological probe. The cluster mass is a key parameter for studies that aim to constrain cosmological parameters using galaxy clusters, making it critical to understand and properly account for the errors in galaxy cluster mass estimates. Subsequently, it becomes important to correctly calibrate scaling relations between observables like the integrated Compton parameter and the mass of the cluster. 

        The NIKA2 Sunyaev-Zeldovich Large program (LPSZ) with its high (11 to 17 arcsecond) resolution allows one to map the intracluster medium profiles in the mm-wavelength band with great detail and hence, to estimate the cluster hydrostatic mass more precisely than previous SZ observations. However, there are certain systematic effects which can only be accounted for with the use of simulations. For this purpose, we employ the300 simulations which have been modelled with a range of physics modules to simulate galaxy clusters. The so-called twin samples are constructed by picking synthetic clusters of galaxies with properties close to the observational targets of the LPSZ. In particular, we use the Compton parameter maps and projected total mass maps of these twin samples along 29 different lines of sight. We investigate the scatter that projection induces on the total and the hydrostatic masses (inferred using the Compton maps and density profiles under the assumption of hydrostatic equilibrium) at different overdensities. Eventually, we consider the average and median values along different lines of sight to construct a kind of 3D scaling law between the integrated Compton parameter, total mass, and overdensity of the galaxy clusters to determine the overdensity that is least impacted by the projection effect.

        Speaker: Aishwarya Paliwal
    • Wednesday P2 Room 9

      Room 9

      LPSC Grenoble

      Convener: Carsten Kramer (IRAM)
      • 58
        Stellar and dust emission profiles of IMEGIN galaxies

        I will present a morphological analysis of a set of spiral galaxies from the NIKA2 Guaranteed Time Large Program, IMEGIN, by fitting simultaneously a single Sérsic model on broadband images, from UV to millimeter (mm) wavelengths, using the multiband modelling code GALFITM. With the recently acquired NIKA2 1.2- and 2-mm observations, it is possible to extend such a morphological analysis to the mm regime and investigate the two-dimensional (2D) distribution (exponential, Gaussian) of the very cold dust (<15K). I will show preliminary results of the 2D large-scale distribution of stars and dust in spiral galaxies, how they relate to each other, and highlight how they differ from galaxy to galaxy.

        Speaker: Angelos Nersesian (Gent University)
      • 59
        Binary nature of supernovae type Ic revealed by molecular gas observations of nearby galaxies

        Supernova (SN) explosions are important for galaxy evolution because they enrich the interstellar medium with heavy elements and provide feedback which can halt further star formation. These effects depend on what stellar progenitors explode as a given SN type. Type Ic SNe (without hydrogen or helium lines in their spectra) can either be a binary system of ~10 solar mass stars or a very massive (>30 Msun) star. These models involve very different lifetimes of the SN progenitors, so predict very different states of molecular gas around the explosion. Exploiting this, I will show that millimetre carbon monoxide observations of nearby galaxies hosting SNe provide evidence for the binary model of type Ic SNe. This is an important distinction from the point of view of stellar evolution as well as galaxy's future star formation.

        Speaker: Michał Michałowski (Adam Mickiewicz University)
      • 60
        ICED: IAS/CEA Evolution of Dust in Nearby Galaxies

        Interstellar dust (ISD) grains are solid particles made of heavy elements (e.g., O, C, Si, Mg, Fe) available in the Interstellar Medium (ISM), with sizes ranging typically from 0.3 nm to 0.3 $\mu$m, and rather uniformly mixed with the gas. Although accounting just for 1% of the ISM mass, they have a radical impact on galaxy emission, since they scatter and absorb starlight, and re-radiate at longer wavelengths a large amount of the total stellar power (about the 30% in normal disk galaxies; up to the 99% in ultraluminous infrared galaxies) [1]. Dust grain seeds are formed and injected in the ISM during specific phases of stellar evolution, by asymptotic giant branch (AGB) stars and core-collapse supernovae (CC-SNe). At the same time, ISD constitutes one of the main fuels of star formation in galaxies. Moreover, dust grains are catalysts of numerous chemical reactions, including the formation of molecular hydrogen [2], and are responsible for the heating of the gas in Photodissociation Regions (PDR), by photoelectric effect [3]. As such, a detailed knowledge of grain properties is crucial to study both the evolution of galaxies and the ISM lifecycle. For example, it is needed to: unredden UV-visible observations; study deeply embedded regions; build reliable diagnostics of ISM physical conditions and of the evolutionary stage of galaxies; provide accurate prescriptions in photoionization and photodissociation models, and simulations of the star formation process.

        Most of our knowledge of dust grain properties comes from studies of the Milky Way (MW). However, the latter is limited by a narrow range of environmental conditions (e.g. no extremely luminous star-forming region; narrow radial metallicity gradient; passive central black hole) and by confusion along the sightline (we have access just to the projected material of the entire disk). As a consequence, nearby galaxies (i.e., within 100 Mpc from the MW) are becoming more and more important to constrain dust properties in different ambients [4]. High latitude observations of face-on nearby galaxies can provide cleaner sightlines. Harbouring a wider diversity of metallicities, star-forming regions, etc., nearby galaxies allow us to study dust grains in extreme conditions and constitute a necessary intermediate step towards understanding distant galaxies, as they are spatially resolved and have a better wavelength coverage. This provides the scientific rationale for our study. The main objective is to put constraints on dust grain evolution and properties under the many environmental conditions that can be observed in local galaxies.

        In this talk, I will present the major and latest results of our project, applied to a selection of nearby galaxies in the multi-wavelength DustPedia Archive [5], that is being observed at 1 and 2 mm by NIKA2 (IRAM 30-m telescope), at unprecedented resolution (i.e., 12'' and 18'' respectively), as a part of the European consortium of NIKA2 Guaranteed Time program, IMEGIN (PI Madden). Interstellar dust grain properties, such as composition, size, geometry, temperature, mass, etc., are derived by the pixel-by-pixel modelling of galaxy optical-to-cm Spectral Energy Distribution (SED) using the THEMIS dust evolution model [6], implemented within the hierarchical Bayesian SED fitting code HerBIE [7]. In this respect, the millimetre maps by NIKA2 play a crucial role, since they allow us to distinguish the dust emission from free-free and synchrotron radiation, to put constraints on the properties of cold dust in galaxies (e.g., dust millimetre opacity), and to investigate the origin of the observed sub-millimetre excess.

        [1] Clements DL et al. 1996. MNRAS 279:477-497 [2] Gould RJ, Salpeter EE. 1963. ApJ 138:393 [3] Draine BT. 1978. ApJS 36:595–619 [4] Galliano et al. 2018. ARA\&A 56:673-713 [5] http://dustpedia.astro.noa.gr/ [6] Jones et al. 2017. A\&A 602, A46 [7] Galliano 2018. MNRAS 476, 1445–1469

        Speaker: Lara Pantoni (CEA Paris-Saclay)
    • 5:30 PM
      Conference reception @ LPSC
    • 8:00 PM
      Conference Dinner @ Le Bouillon A


    • Thursday A Amphitheatre


      LPSC Grenoble

      Convener: Elia Stefano Battistelli (Sapienza, University of Rome)
      • 61
        OLIMPO: a Balloon-Borne SZE Imager to Probe ICM Dynamics and the WHIM

        I will present our concept and science projections for OLIMPO, a proposed Antarctic balloon-borne SZE imager to study gas dynamics associated with structure formation along with the properties of the WHIM thought to reside in large scale structure filaments and to comprise a significant fraction of the universal baryon budget. During a planned 25 day circum-polar flight in 2026 OLIMPO will image a total of 10 z~0.05 galaxy clusters and 4 known emission bridges at 145, 250, 365, and 460 GHz with a diffraction-limited angular resolution between 3' and 1'. The resulting maps will be deeper than those planned for upcoming surveys from CMB-S4 and CCAT-P, and will have excellent fidelity at the large angular scales associated with our low-z targets, which are difficult to probe from the ground. In combination with X-ray data from eROSITA and XRISM we will transform our current static view of galaxy clusters into a full dynamic picture by measuring the internal ICM velocity structure with the kinematic SZE, high resolution X-ray spectroscopy, and the power spectrum of ICM fluctuations observed in the thermal SZE and X-ray surface brightness. We will also include radio observations from ASKAP and MeerKAT to better understand the connection between ICM turbulence and shocks with the relativistic plasma. Beyond the cluster boundary, we will combine thermal SZE maps from OLIMPO with X-ray imaging from eROSITA to fully constrain the thermodynamics of the WHIM residing in filaments, providing a better understanding of its properties and its contribution to the total baryon budget of the universe. To minimize potential systematics and to facilitate the most robust interpretation of our observational data, we will perform mock analyses of matched systems from numerical simulations.

        Speaker: Jack Sayers (Caltech)
      • 62
        The BLAST Observatory

        The Balloon-borne Large Aperture Submillimeter Telescope Observatory (BLAST Observatory) is a proposed NASA super-pressure balloon mission. BLAST Observatory will include a 1.8 m off-axis primary mirror and observe at 175, 250, and 350 microns simultaneously, with a total of 8274 polarization-sensitive microwave kinetic inductance detectors (MKIDs) cooled to 100 mK. The telescope will be launched from Wanaka, NZ, and we expect a 31-day flight, limited by the hold-time of the Helium-4 cooled cryostat.
        The BLAST Observatory will map polarized thermal emission from dust in giant molecular clouds and the diffuse interstellar medium (ISM) of the Milky Way, allowing us to answer fundamental questions about star formation and the physical properties of dust.
        The three main science goals are to (a) investigate the origins of low star formation efficiency, (b) measure the properties of magneto-hydrodynamic turbulence in the diffuse ISM, and (c) constrain the size distribution, composition, and alignment properties of dust.
        With the previous BLAST-TNG experiment, the collaboration pioneered several technologies and shared-risk observing for balloon-borne experiments. We plan to continue this with BLAST Observatory by opening 30% of our observing time to the community."

        Speaker: Federico Nati (University of Milano-Bicocca)
      • 63
        Progress with the Atacama Large Aperture Submm Telescope

        Here I will describe progress with AtLAST, a wide field of view (1-2 degree), 50-meter aperture single dish telescope that will be located at over 5000 meters above sea level, high in the Atacama Desert. AtLAST will accommodate a vast range of large (2 to 4.5 meter diameter) instruments operating from 30 GHz to 1 THz in a cabin that enables expedient switching between receivers. AtLAST will also feature a throughput unprecedented in the mm and submm regime, thus delivering a sustainable, upgradeable platform into the foreseeable future.

        Speaker: Tony Mroczkowski (European Southern Observatory (ESO))
    • 10:20 AM
      Coffee Break
    • Thursday A Amphitheatre


      LPSC Grenoble

      Convener: Helene Roussel (IAP)
      • 64
        Large Millimeter Telescope Survey of the Galactic Central Molecular Zone

        The central molecular zone (CMZ) of our Galaxy hosts an extreme interstellar environment analogous to that found in typical starburst galaxies in the distant Universe. In order to understand dust properties in such environments, we have conducted a survey of the CMZ with the AzTEC/Large Millimeter Telescope (LMT) in the 1.1 mm continuum. This survey has been analyzed together with complementary low resolution millimeter and far-IR data data, using a novel Bayesian modeling that enables the full utilization of our high-resolution (10.5 arcsec) map at 1.1 mm and reveals unprecedentedly detailed information on the spatial distributions of dust column density, temperature, and spectral index across the CMZ. In particular, we find a remarkable trend of increasing index, from 2.0 to 2.4, towards dense peaks in the CMZ, indicating a deficiency of large grains or a fundamental change in dust optical properties. This environmental dependence of the index has a significant impact on the determination of dust temperature. A proposed 50-m LMT/TolTEC survey in the 2023 spring will hopefully lead to a simultaneous mapping of the CMZ in the 1.1, 1.4, and 2 mm bands, enabling a decomposition of dust, free-free, and synchrotron emissions and advancing our understanding of dust properties, star formation, and energetic feedback in the extreme interstellar environment.

        Speaker: Q. Daniel Wang (University of Massachusetts)
      • 65
        Dust and gas of pre-stellar cores

        Dust grain surface chemistry plays an important role in the formation and freeze-out of molecules that are key to the chemical network and govern the formation of cores from the diffuse interstellar medium. The evolution of dust properties such as grain sizes from the diffuse interstellar medium to dense cores is not well understood. We present IRAM-30m observations towards eight starless cores obtained with the NIKA-2 camera and with EMIR, combining 2mm and 1mm continuum observations with spectral line observations of key species of the gas phase. The aim is to study the evolution of grain properties and their dependence on the environment. Eventually, we plan to delineate a comprehensive evolutionary trend by combining the dust properties derived from NIKA-2 with the gas chemical composition as determined with GEMS data and performing a detailed comparison with state-of-the-art hydrodynamical models. Complementary Herschel data are available. In addition, we have obtained MUSTANG-2 3mm maps of all cores.

        Speaker: Carsten Kramer (IRAM)
      • 66
        Dust grain evolution from star-forming filaments to T-Tauri stars: Results from NIKA2 observations of the Taurus B211/B213 filament in the GASTON large program

        Understanding the evolution of dust properties in molecular clouds is important for tracing the star formation process through submm observations. We aim at constraining the evolution of dust grains from star-forming filaments to prestellar and protostellar cores to T Tauri stars. Using the NIKA2 continuum camera on the IRAM 30~m telescope, we observed the Taurus B211/B213 filament in the 1.2mm and 2mm wavebands with unprecedented sensitivity and used the resulting continuum maps to derive the dust emissivity index beta. Based on a sample of ~ 50 cores protostellar and prestellar cores in the B211/B213 filament, our results indicate that the dust emissivity index decreases from filaments and prestellar cores (beta~2) to protostellar cores (beta~1.7) to T Tauri stars (beta~1). This tentatively suggests that dust grains start to grow significantly in size only after the onset of the gravitational contraction/collapse of prestellar cores to protostars, reaching big sizes in T Tauri protoplanetary disks.

        Speaker: Quang Nguyen Luong (American University of Paris / CEA Paris-Saclay)
    • 12:00 PM
    • Thursday P1 Amphitheatre


      LPSC Grenoble

      Convener: Marco De Petris (Sapienza, University of Rome)
      • 67
        Biases in the estimation of the hydrostatic mass of the Virgo simulated clone

        An accurate mass calibration of galaxy clusters is a crucial step towards precise constraints on the cosmological parameters $\sigma_8$ and $\Omega_m$ from clusters. In the millimeter, via the Sunyaev-Zel'dovich (SZ) effect, and X-rays domains, cluster masses can be estimated assuming hydrostatic equilibrium, but several physical and observational effects can alter this calculation. One of those are projection effects which are the focus of our present analysis.
        As a matter of fact, any hot and ionised gas along the line of sight of clusters can contribute to the observed pressure and thus impact our analysis of the clusters' SZ or X-ray signals. Moreover, the usually assumed spherical symmetry of clusters is not always verified, so the observed properties may strongly depend on the direction of observation. Cosmological simulations permit us to study the clusters from any point of view, they are therefore well suited to study projection effects.
        In this presentation, I will show the results of a case study of the simulated Virgo cluster, extracted from the CLONE constrained simulation. In this study, we analyse Virgo properties when they are projected along different directions, including along the Milky Way-Virgo axis which mimics our observation direction. By comparing the deduced hydrostatic mass and the hydrostatic mass bias from the different observation directions to the one derived from the 3D profiles, we will show and quantify the impact of projection effects on the determination of Virgo mass as a first analysis that will later be generalised to a large sample of simulated clone clusters.

        Speaker: Théo Lebeau (Institut d'Astrophysique Spatiale, Université Paris-Saclay)
      • 68
        Reconstruction of Galaxy Cluster Physical Properties: a Non-parametric Bayesian Nodal Approach

        I will present a nodal approach to recovering the fundamental properties of galaxy clusters like pressure, density, and temperature. The method involves constructing piecewise functions that describe the quantities of galaxy clusters through a set of control points, which are inferred using a non-parametric Bayesian analysis. I will show an application of this method to the analysis of Planck Sunyaev-Zel’dovich (SZ) observations. Unlike the traditional parametric approach, it gets rid of the assumptions about the specific model of the cluster. This work has the potential to facilitate unbiased translations from observations to fundamental properties such as the gas pressure profile and improve our understanding of the cluster.

        Speaker: Kang Wang (Victoria University of Wellington)
      • 69
        Effects of observed projections on turbulence statistics in the intracluster medium

        The total mass of a cluster is one of its most fundamental properties. Measurements of the galaxy cluster mass often relies upon assuming hydrostatic equilibrium. However, this is often invalidated as the intracluster medium (ICM) is continuously disturbed by mergers, feedback processes, and motions of galaxies. These processes generate gas motions that contribute nonthermal pressure; typically turbulence, that leads to an underestimation of the mass by as much as 30%. We can measure turbulence through indirect probes that come in the form of fluctuations in the X-ray surface brightness and Sunyaev-Zeldovich effect maps. These are projected characteristics, encoding the 3D structure of the turbulence in the ICM. I will present an analysis of the 3D to 2D projections of the intracluster medium and its effect on the retrieved statistical measures commonly used in turbulence analysis like the power spectrum by using numerical simulations appropriate to galaxy clusters.

        Speaker: Mark Bishop (Victoria University of Wellington)
      • 70
        Probing the evolution of galaxy clusters using Sunyaev-Zel’dovich effect

        Mass is the most fundamental property of galaxy clusters however measuring it is still a challenge. Calibrating mass from intracluster medium observables such as the Sunyaev-Zel’dovich (SZ) effect is subject to uncertainty and biases because of the hydrostatic equilibrium assumption. On the other hand, merging cluster systems have been shown to exhibit radio emission which implies a link with disturbances from hydrostatic equilibrium. I will present work on studying deviations of galaxy cluster gas pressure profile from the average (universal) pressure profile using a sample of clusters with SZ effect data from the Arcminute Microkelvin Imager and Planck. These clusters have also been observed at low radio frequency with the Murchison Widefield Array allowing the investigation of links between gas pressure profile deviations and the presence of radio emission.

        Speaker: Mohini Pachchigar
      • 71
        Studying the impact of galaxy cluster morphologies on their detection through SZ effect

        In any cosmological analysis based on the galaxy cluster number count, a very important ingredient is the selection function of the detection method used to produce the galaxy cluster catalog. Indeed, an incorrect determination of this function can lead to biases in the cosmological parameters estimated from the data. In this work we aim to study the possible impact of complex cluster morphology on the selection function of the matched multi-filter (MMF) algorithm, used to detect galaxy clusters through the Sunyaev-Zel’dovich (SZ) effect. For the determination of the selection function, we apply the same method as in Planck Collaboration XXVII (2015), using mock cluster images from hydrodynamical simulations injected in the Planck high frequency maps. We compare these results with the analytical form of the completeness derived from assuming gaussian noise, and with the same method of injection/detection using spherical clusters generated from a generalised NFW profile.

        Speaker: Stefano Gallo
      • 72
        Morphology with Zernike polynomials: the first application on Planck-SZ galaxy clusters

        The Zernike polynomials has been recently used to model 2D projection maps of galaxy clusters to recover their morphological features. The study of the morphology of clusters maps is, in fact, a well suited approach used to infer, from real data, the dynamical state of those systems. After the validation of the Zernike polynomials as suitable tools to constrain galaxy clusters morphologies, done on a set of mock maps of clusters in THE THREE HUNDRED project, we present here the first application of this method on real data. We analyzed Compton parameter maps of local ($z < 0.1$) galaxy clusters observed by the Planck satellite and we use a single parameter, defined from the Zernike modeling, to quantify morphological differences between them. A set of Planck-like Compton parameter maps, realized for THE THREE HUNDRED clusters, is also used to correlate our analysis with a proper dynamical state classification achievable, in that case, from 3D information. This approach allow to test the efficiency of the Zernike morphological analysis in discriminating different dynamical populations in the real Planck sample.

        Speaker: Valentina Capalbo (Sapienza, University of Rome)
    • Thursday P2 Room 9

      Room 9

      LPSC Grenoble

      Convener: Federico Nati (University of Milano-Bicocca)
      • 73
        New techniques to control instrumental Systematics for CMB experiments

        Cosmic Microwave Background experiments need to measure instrumental systematics very accurately to achieve their scientific goals. As a result of that, it is necessary to properly characterize these telescopes. However, natural sources cannot be used to calibrate all the properties of the instrument but we need to complement these with artificial sources. For this reason, we developed the PROTOtype CALibrator for Cosmology, PROTOCALC, which is a calibrator source designed for the 90 GHz band of these telescopes. This source is purely polarized and the direction of the polarization vector is known with an accuracy better than 0.1°. This source can be used to study optical properties such as beam size and polarization angle.

        Speaker: Dr Gabriele Coppi (Università degli studi Milano-Bicocca)
      • 74
        Millimeter-Wave and Far-IR Kinetic Inductance Detectors at NIST-Boulder

        Kinetic inductance detectors carry the promise of a truly scalable detector solution, providing a practical path to filling the large and densely populated focal planes envisioned for future far-infrared and millimeter-wave instruments. At the same time, this detector technology shows promise in meeting the ambitious sensitivity and dynamic range specifications required to achieve the next generation of imaging and spectroscopic science goals. At NIST, we have developed and fabricated a wide range of detector, optical coupling, and readout technologies to further advance the goals of a variety of current and future experiments. This has included recently deployed millimeter-wave arrays for the TolTEC polarimeter (1.1, 1.4, 2.0 mm bands; Wilson et al 2020), sub-millimeter arrays for BLAST-TNG (250, 350, 500 μm bands; Coppi et al 2020), and several experiments actively under development for the CCAT-Prime project ranging from 350–1100 μm (Vavagiakis et al 2018) and the BLAST Observatory (Lowe et al 2020). Beyond these projects, the detector and related technologies have continued to evolve, with improved capabilities and an expanded scope. Recently, significant advances have been made in detector materials, noise performance, channel yield, operational wavelength range, and RFSoC (radio frequency system-on-chip) based readout. Here I review the microwave kinetic inductance detector (MKID) development program at NIST, provide status updates for the TolTEC and CCAT-Prime projects, describe some of the latest technological advancements, and explore technological prospects of the future.

        Speaker: Jason Austermann (NIST-Boulder)
      • 75
        Measuring the CMB primordial B-modes with Bolometric Interferometry: status and future prospects of the QUBIC experiment

        The Q\&U Bolometric Interferometer for Cosmology (QUBIC) is the first bolometric interferometer to measure the primordial B-mode polarization of the Cosmic Microwave Background (CMB).

        Bolometric interferometry is a novel technique that combines the sensitivity of bolometric detectors with the control of systematic effects that is typical of interferometry, which are both key features in the quest for the faint signal of the primordial B-modes.

        A unique feature of bolometric interferometry is the so-called ``spectral imaging'', i.e., the ability to recover the sky signal in several sub-bands within the physical band during data analysis. This feature provides an in-band spectral resolution of $\Delta\nu/\nu\sim 0.04$. This is a key tool for controlling the Galactic foregrounds contamination.

        The first qubic prototype is the so-called Technological Demonstrator. It has successfully completed laboratory testing and it will observe about 1% of the sky at 150 GHz from the high altitude site Alto Chorillo, Argentina, starting from the beginning of 2023. Subsequently, during 2024, the full instrument is expected to be operational and will observe in two frequency bands, centered at 150 GHz and 220 GHz.

        In this talk, we describe the principles of Bolometric Interferometry, the current status of the QUBIC experiment and its future prospects.

        Speaker: Aniello Mennella (Università degli Studi di Milano - Istituto Nazionale di Fisica Nucleare)
      • 76
        Overview of the LiteBIRD project

        LiteBIRD, the Lite (Light) satellite for the study of B-mode polarization and Inflation from cosmic background Radiation Detection, is a space mission aimed to probe primordial cosmology and fundamental physics. The Japan Aerospace Exploration Agency (JAXA) selected LiteBIRD in May 2019 as a strategic large-class (L-class) mission, with an expected launch at the end of the decade. LiteBIRD will orbit the Sun-Earth Lagrangian point L2, where it will measure the cosmic microwave background (CMB) polarization over the entire sky for three years. The primary scientific objective of LiteBIRD is to search for the footprint left by cosmic inflation in the CMB polarization, achieving a precision on the tensor-to-scalar ratio measurement of 0.001. LiteBIRD will observe in 15 frequency bands between 34 and 448 GHz spread over three telescopes. The goal is to achieve an unprecedented total sensitivity of 2.2 μK-arcmin, with a typical angular resolution of 0.5° at 100 GHz. In this presentation, we will provide an overview of the LiteBIRD project, including status of the mission, scientific objectives, current instrument design and system requirements.

        Speaker: Louise Mousset (IRAP)
      • 77
        Early High-resolution Millimeter-wave Maps and Instrument Properties of TolTEC

        TolTEC is a polarization-sensitive camera at millimeter wavelengths with unprecedented sensitivity at 5-11 arcsecond resolution in three photometric bands. TolTEC achieved first-light on the 50 meter Large Millimeter Telescope in July 2022 just prior to a planned summer telescope maintenance shutdown, and began commissioning observations when the telescope resumed observations in December 2022. The commissioning program consisted of observations of targeted nebulae, molecular clouds, polarized quasars, galaxies, and clusters of galaxies. The goals of these observations include demonstrating the science capabilities of the camera, and characterizing the performance and instrumental properties including noise, beams, and polarization sensitivity in its three bands centered at 1.1, 1.4, and 2.0 mm and with angular resolutions of 5, 7, and 11 arcseconds, respectively.

        We present selected results from the commissioning observations and discuss the instrument properties which enable planning for future observations. Upcoming observations will include selected proposals from the broader astronomy community in Mexico and the United States and legacy surveys focused on mapping galactic molecular clouds, cold dust emission in local galaxies, polarized dust emission in filaments around star forming regions, and massive galaxy clusters.

        Speaker: Joseph Golec (University of Chicago)
    • 3:50 PM
      Coffee Break
    • Thursday P1 Amphitheatre


      LPSC Grenoble

      Convener: Sebastian Bocquet (LMU Munich)
      • 78
        Blending impact on galaxy clusters with Rubin/LSST

        Galaxy clusters trace the highest peaks in the density of the Universe. Therefore, their abundance is a powerful probe to constrain cosmological parameters, expansion of the Universe and give information on the growth of structures. However, since the density of galaxies is significantly higher, these latter may appear to overlap on the line of sight and have their respective fluxes blended. This effect, called blending, significantly distorts individual galaxy measurements such as shapes or photometric redshifts, hence the need to study it.
        This talk will present matching algorithms used to identify blended systems from LSST-DC2 catalogs, as well as distribution and proportion of blends in galaxy clusters. The impact of blending on shear profiles and inferred cluster masses will also be discussed.

        Speaker: Manon Ramel (LPSC / IN2P3)
      • 79
        Galaxy cluster mass inference using weak lensing shear multipoles

        Weak gravitational lensing is a powerful tool to probe the matter distribution around massive galaxy clusters. In general, such effect can be measured by estimating the averaged tangential shear of background galaxies in circular annuli around the lens center. In addition to the average tangential shear, valuable information on the underlying dark matter distribution can be extracted by using shear multipoles, sensitive to higher order moments of the projected matter distribution. By releasing the spherical hypothesis of halo dark matter density, joint analysis of shear multipoles can be used to improve weak lensing mass reconstruction of massive clusters. In this work, we use the data from the project {\sc The Three Hundred} (Cui et al. 2018), which allows to perform our weak lensing analysis for the different line of sight projections available in the simulation. We show that using shear multipoles enables not only to have constraints on halo triaxiality, but can also affects the mass reconstruction of individual massive clusters.

        Speaker: Constantin Payerne (LPSC-IN2P3)
      • 80
        The hydrostatic-to-lensing mass bias and its evolution with redshift

        Accurate reconstruction of galaxy cluster masses is key to use this population of objects as cosmological probe. In this work we present a study on the hydrostatic to lensing mass scaling relation for a sample of 53 clusters, with redshifts from z = 0.05 to 1.07, for which masses have been reconstructed homogeneously. Masses for each individual cluster have been measured from reconstructed mass profiles from X-ray and lensing data, without using any observable-mass scaling relation. We calibrate the systematic scatter between the masses reconstructed with our reference analyses with respect to published results. Accounting for the systematic scatter does not change our main results, but allows propagating the uncertainties related to the mass reconstruction method or used data set. Our analysis gives an hydrostatic-to-lensing mass bias in the range of (1 − b) = 0.5 to 0.9 and a weak evidence of evolution with redshift.

        Speaker: Miren Muñoz Echeverría (LPSC)
      • 81
        CHEX-MATE: constraining the origin of the scatter in galaxy cluster radial X-ray surface brightness profiles

        We present a detailed study of the surface brightness profiles derived from a representative sample of 118 clusters selected via the Sunyaev-Zel'Dovich effect. These profiles represent an ideal tool to investigate the properties of the hot plasma filling the cluster volume. Studies of these profiles have been hampered by selection biases and faintness of the emission in the outskirts. We overcome these problems leveraging the recently accepted XMM-Heritage program CHEXMATE which observed an unbiased sample of 118 clusters drawn from the Planck catalogue in the redshift z=[0.1,0.7] and mass M=[2e14,2e15]Msun range with an unprecedented homogeneous data quality.
        We investigate the shape of the surface brightness profiles and the origin of the scatter between them leveraging this exceptional dataset and by comparing them with a similar sample drawn from cosmological simulations.

        Speaker: Iacopo Bartalucci (INAF-IASF)
    • Thursday P2 Room 9

      Room 9

      LPSC Grenoble

      Convener: Nabila Aghanim (Institut d'Astropysique Spatiale)
      • 82
        Compton-y distortion: CMB constraints and new prospects with CIB

        The thermal Sunyaev-Zel’dovich effect refers to a spectral distortion in the cosmic microwave background (CMB) due to the inverse-Compton scattering of CMB photons off free, energetic electrons present in the Universe. It is primarily sourced by the electrons in the intracluster medium with smaller contributions from the intergalactic medium and the epoch of reionization. The amplitude of its monopole signal is a unique probe of the total thermal energy contained in the electrons in the Universe and of the period of structure formation with an upper limit |< y >| < 15 x 10^-6 set by the measurements from COBE-FIRAS. I will present new constraints on the all-sky y-distortion from re-analyzing FIRAS CMB monopole data. Additionally, I will present the first calculation of a tSZ-like distortion in the cosmic infrared background (CIB). CIB photons originating from the thermal dust emission in star-forming galaxies are expected to similarly inverse-Compton scatter. Using a halo model approach, we find that the resulting distortion in the CIB monopole spectrum has a positive (negative) peak amplitude of 4 Jy/sr (-5 Jy/sr) at 2260 GHz (940 GHz) and two null frequencies, at approximately 196 GHz and 1490 GHz. In addition to being a similar probe of the intervening free electrons, this signal would provide new insight into the star formation history of the Universe.

        Speaker: Alina Sabyr (Columbia University)
      • 83
        Towards Instruments Measuring Spectral Distortions of the Cosmic Microwave Background

        The measurement of the Cosmic Microwave Background spectrum made by COBE/FIRAS in the 1990s showed that the CMB spectral energy distribution is close to a perfect blackbody. However, the CMB spectrum contains tiny departures from a perfect blackbody to $\Delta I/I \simeq 10^{-5}$, referred to as spectral distortions. CMB spectral distortions encode information about the full thermal history of the Universe.
        The two main types of CMB spectral distortions are the Compton $y$-distortion from energy release in the optically thin regime at redshifts $z < 5 \times 10^{4}$, and chemical potential or $\mu$-distortion from the optically thick regime imprinted at $z > 5 \times 10^{4}$. CMB spectral distortions allow us to access information, from the present to the very early Universe, that cannot be extracted in any other way.

        High-precision spectroscopy of the CMB is one of the three themes that have been selected by the ESA Voyage 2050 programme. Several dedicated space missions such as PIXIE, PRISTINE, and FOSSIL have been proposed since 2011. Additionally, balloon-borne missions, such as BISOU, have also been considered as a pathfinder of a future space mission dedicated to CMB spectral distortions.\

        I will present an effort undertaken to define future missions and instruments dedicated to the measurement of the CMB spectral distortions. It combines two models allowing for sensitivity estimates that could be reached by such projects. The first is an versatile photometric model based on key instrument subsystem choices together with their parameters. The second is a sky emission model taking into account spatially varying foregrounds at frequencies relevant to CMB spectral distortions.

        Combining outputs of those models, optimizing both instrument concept and mission parameters (mission duration, scanning strategy, ...) can be achieved. This would be apply here in the case of FOSSIL, a space mission propose to answer the recent ESA M7 proposal and BISOU, a CNES Phase 0 study for a balloon-borne mission.

        Speaker: Mr Xavier COULON (IAS-CNRS)
      • 84
        The advantage of Bolometric Interferometry for controlling Galactic foreground contamination in CMB primordial B-modes measurements

        In the quest for the faint primordial B-modes of the Cosmic Microwave
        Background, three are the key features for any present or future experiment: an utmost sensitivity, excellent control over instrumental systematic effects and over Galactic foreground contamination.
        Bolometric Interferometry (BI) is a novel technique that matches them all by combining the sensitivity from bolometric detectors, the control of instrumental systematics from interferometry and a software-based spectral resolution of ∆ν/ν ∼ 0.04, due to the ability to recover the sky signal in several sub-bands within the physical band during data analysis (spectral imaging).
        Moreover, the software-based nature of spectral imaging allows to reanalyze the data with different spectral configurations, which can help detecting biases in our results.
        In this talk, we present a study to investigate how the increased spectral resolution provided by BI can help controlling foregrounds contamination in the case of unaccounted Galactic dust frequency decorrelations, by focusing on the next generation of ground-based CMB experiments, CMB-S4, and comparing its anticipated sensitivities, frequency and sky coverage with an hypothetical bolometric interferometry version of the same experiment (CMB-S4-BI).
        We will show results from a Monte-Carlo analysis based on parametric component separation methods (FGBuster and Commander), highlighting how BI increased spectral resolution provides an unmatched capability to diagnose the presence of foreground contamination in estimates of the tensor-to-scalar ratio $r$.

        Speaker: Elenia Manzan (University of Milan, INFN)
      • 85
        A “temperature inversion” estimator to detect the screening of the CMB by the large-scale structure

        Electrons with certain optical depth within galaxy groups and clusters Thomson scatter CMB photons out of and into the line of sight, an effect known as patchy screening. In this talk, I will propose a new "temperature inversion" (TI) estimator to detect this screening effect of the electrons. Our estimator is analogous to the 'shear only' and 'gradient inversion' estimators of CMB lensing. I will show that the screening signal is correlated with the local un-screened primary CMB temperature, whose sign alternates and averages to zero. As a result, all other foregrounds (CIB, tSZ, kSZ) cancel and do not bias our screening estimator. This is a big advantage over the traditional quadratic estimator (QE) proposed for the patchy screening which is biased by foregrounds and CMB lensing. I will identify the regimes where TI estimator outperforms QE in terms of SNR. If possible, I will also show results after applying our method to the CMB and galaxy data.

        Speaker: Abhishek Maniyar
    • Friday A Amphitheatre


      LPSC Grenoble

      Convener: Jack Sayers (Caltech)
      • 86
        Temperature measurements with the relativistic Sunyaev-Zel'dovich effect

        At temperatures above ~5 keV, the non-relativistic approximation used to derive the classical thermal Sunyaev-Zel'dovich effect spectrum begins to fail. When relativistic effects are included, the spectrum becomes temperature-dependent. This leads to both a problem and an opportunity: a problem, because when the temperature dependence is not accounted for the Compton-y estimate is biased; and an opportunity, because it represents a new way to measure the temperature of the intracluster medium independently of X-ray observations. I will present current results from recalibrating the Planck mass-observable scaling relation to include relativistic effects, and projections for future measurements of cluster temperatures using AtLAST.

        Speaker: Yvette Perrott (Victoria University of Wellington)
      • 87
        Non-thermal pressure support in galaxy clusters: current constraints and perspective

        I will discuss how current (with XMM-Newton) and future X-ray observations (with XRISM and Athena) will be able to characterize the non-thermal pressure support in galaxy clusters, and how we can convert it in an estimate of the hydrostatic mass bias, also for a cosmological purpose.

        Speaker: Stefano Ettori (INAF-Osservatorio di Astrofisica e Scienza dello Spazio in Bologna)
      • 88
        Evolution of the Cooling Flow Problem in SPT-Selected Galaxy Clusters

        For years we have grappled with the “cooling flow problem” in galaxy clusters, where the massive reserves of hot ($10^7$ K) gas in the intracluster medium (ICM) have been universally observed to form stars with an efficiency of only 1-10%. Feedback from accreting active galactic nuclei (AGN) has been identified as the likely heating source capable of suppressing runaway cooling by up to two orders of magnitude. However, many details about how this balance between cooling and feedback is established, and for how long it’s been operating in clusters, are still unresolved. Recent Sunyaev Zeldovich (SZ) effect-based surveys at mm wavelengths have been discovering galaxy clusters out to high redshifts at a prodigious rate, opening a new window allowing us to answer questions about how clusters and the multiphase gas, stars, and galaxies within them evolve over cosmic time. In this talk, we will present new results based on our large (~100) sample of SZ-selected galaxy clusters discovered by the South Pole Telescope, spanning a redshift range ($0.3

        Speaker: Michael Calzadilla (MIT)
      • 89
        Illuminating the Physical Processes of Galaxy Evolution with the Cosmic Microwave Background

        A new window into the growth and evolution of large-scale structure
        has opened up with the recent observations of the thermal and kinetic
        Sunyaev-Zel’dovich (SZ) effects. I will review recent observations of
        the SZ signals and highlight their expected rapid growth over the next
        decade with upcoming cosmic microwave background experiments, like
        Simons Observatory and CMB-S4. I will present ongoing work to extract
        SZ signals in data from the Atacama Cosmology Telescope and how they
        can be used to constrain the important baryonic processes that govern
        galaxy formation. I will conclude by showing the tension between these
        new SZ observations and state-of-the-art cosmological simulations and
        discuss the prospects for future constraints.

        Speaker: Nicholas Battaglia (Cornell University)
    • 10:40 AM
      Coffee Break
    • Friday A Amphitheatre


      LPSC Grenoble

      Convener: Suzanne Madden (CEA Paris-Saclay)
      • 90
        Calibrating Star formation Rate and Constraining Dust SED with NIKA2 Observations

        Observing galaxies in millimeter continuum emission is vital to study the physical properties of the dusty interstellar medium as it provides constraints on the low-frequency end of the dust spectral energy distribution (SED). We present observations of NGC2146 (starburst spiral) and NGC2976 (peculiar dwarf) with the NIKA2 camera on the IRAM-30m telescope, as part of the IMEGIN guaranteed time large program. Combined with available FIR and radio continuum observations, we model the radio-to-infrared SEDs of these two galaxies, both globally and locally, using a Bayesian method. The total dust mass estimated is $4.88\times10^7 M_{\odot}$ and $1.02\times 10^6 M_{\odot}$ in NGC2146 and NGC2976, respectively. We find a Galactic value for the dust emissivity index in the center of NGC2146 decreasing towards its outer disk. It is however flatter and smoothly distributed in NGC2976. We present calibration relations between mm emission and star formation rate (SFR). We also present a dust-to-gas ratio (DGR) map for NGC2976 and find a reverse relation between DGR and dust temperature. Lastly, we deduce an important role of the radiation field and star formation feedback in the shattering and dissociation of dust grains and the molecular-to-atomic gas ratio in the dwarf galaxy.

        Speaker: Golshan Ejlali (PhD student)
      • 91
        Exploring the interstellar medium of nearby galaxies at millimeter wavelengths using the NIKA2 camera: the case of NGC 891

        High resolution observations of nearby galaxies at mm wavelengths allow us to study emission from interstellar medium in great detail. In the framework of the IMEGIN Large program, the NIKA2 camera on the IRAM 30-m telescope is used to map 22 nearby galaxies at 1.15 and 2 mm and at resolutions of 11.1" and 17.6", respectively. At these wavelengths we are able to trace the emission from very cold dust (< 15 K) as well as additional emission from Bremsstrahlung and synchrotron radiation. In our pilot study, NIKA2 observations of the edge-on galaxy NGC 891 are combined with observations at other wavelengths to examine the physical properties of this galaxy using the HerBIE SED fitting code. Our analyses indicate an excess of cold dust emission towards the outer parts of the galactic disk. Furthermore, emission originating from warm dust in compact HII regions is only detected at mid-IR wavelengths with, practically, no emission at submm/mm wavelengths. However, emission from the dust in the spiral arms is measured at all wavelengths from mid-IR to mm wavelengths. The SED fitting modelling provides the fraction of the mass of the small (< 15 Å) dust grains to the total dust mass which, for NGC 891, is found to be 9.5%, on average, but it increases, up to $\sim20$% at large distances (|z| > 3 kpc) beyond the galactic plane and in dense environments in the disk. Finally decomposing the mm/cm wavelength range into dust, free-free, and synchrotron emission we detect enhanced free-free emission at the regions where dust concentrations exist along the plane of the disk.

        Speaker: Stavroula Katsioli (National and Kapodistrian University of Athens, Department of Physics & National Observatory of Athens, IAASARS)
    • 12:00 PM
    • Friday P Amphitheatre


      LPSC Grenoble

      Convener: Lindsey Bleem (Argonne National Laboratory)
      • 92
        Probing the Evolution of the Intracluster Medium with Joint X-ray+SZ Surveys

        I will discuss the progress that has been made by coming SZ data from the South Pole Telescope (SPT) with X-ray data from Chandra and XMM-Newton. To date, we have followed up hundreds of SPT-selected clusters with these two X-ray telescopes, providing the strongest constraints on the enrichment history of the intracluster medium (ICM), the dynamical evolution of clusters, the cooling and feedback history of cluster cores, and the deviations from self-similar evolution in cluster cores. These observations have become extremely challenging as we discover clusters at z~2, and so I will also include a discussion of how a next generation of X-ray surveys with STAR-X and AXIS, coupled with resolved SZ experiments, could enable us to trace cluster evolution to the epoch of their formation.

        Speaker: Michael McDonald (MIT)
      • 93
        First massive galaxy clusters emerging from the cosmic web at z~2

        In this talk we report upon results the intracluster medium (ICM) of two galaxy clusters at the time the first objects start to emerge from the cosmic web, z~2. Results are derived from new high resolution, deep SZ and X-ray data providing us with the measurement of the two most distant resolved pressure profiles. IDCSJ1426 cluster at z=1.75 has a core whose properties has likely reached the final stage, while the remaining part of the cluster is experiencing a sizeable gas, heat and entropy transfer. JKCS041 at z=1.80 is caught just after a major merger event as evidenced by its SZ-X-ray peak offset, its low central pressure, and its low Compton-Y parameter compared to its WL mass. Comparison with plausible descendant shows that its ICM will experience major changes at all radii.

        Speaker: Stefano Andreon (INAF-OA Brera)
    • 2:30 PM
      Coffee Break
    • Friday P
      Convener: Laurence Perotto (LPSC)
      • 94
        The South Pole Telescope Strong Lensing Cluster Sample

        The strong gravitational lensing regime provides a unique probe of structure formation in the Universe. There has been significant effort to identify and characterize strong lensing clusters selected in the X-ray and optical wavelengths; here we extend such studies to a large sample of strong lensing clusters identified by the Sunyaev Zel'dovich (SZ) effect in >5,000 square degrees of South Pole Telescope (SPT) data. In this talk I will describe (i) the identification of the strong lensing subset of the SPT cluster sample using observations from the PISCO imager on the Magellan/Clay telescope and the Hubble Space Telescope, (ii) first constraints on the mass-concentration relation of massive clusters using this dataset, and (iii) simulation efforts using large cosmological simulations to both generate predictions for the abundances of strong lenses in the SPT sample as well as to extract constraints from the observational data.

        Speaker: Lindsey Bleem (Argonne National Laboratory)
      • 95
        Prospects for Kinematic Sunyaev-Zeldovich Measurements from South Pole Telescope data.

        The Doppler boosting of cosmic microwave background (CMB) photons due to scattering off free electrons produces the Kinematic Sunyaev-Zeldovich (kSZ) effect. It offers a unique way to probe the epoch of reionisation. However, the kSZ signal is sub-dominant to other astrophysical signals, in particular the emission from dusty star forming galaxies that form the diffuse component of the cosmic infrared background (CIB) at millimetre wavelengths. In this talk, I will present results from an ongoing work that combines data from the South Pole Telescope (SPT) and the Herschel-SPIRE experiments to detect the kSZ power spectrum in a manner which is robust against the contamination from CIB. I will also discuss the future prospects for kSZ measurements and the constraints on the physics of reionisation expected from SPT-3G, the current camera on the South Pole Telescope, and its proposed successor SPT4. The forecasts indicate that the future kSZ measurements from SPT can constrain the optical depth to reionisation with \sigma(\tau) = 0.005, which is highly complementary to primary CMB-based constraints from Planck, and the duration of reionisation with \sigma(\Delta z_{\rm re}) = 0.42, which is currently unconstrained by Planck.

        Speaker: Srinivasan Raghunathan (National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign)
      • 96
        Fluctuations in Galaxy Clusters at millimeter wavelengths

        Cosmological constraints from galaxy clusters are currently limited by the precision of mass estimation. Non-thermal pressure support is suspected to be the primary culprit in biasing mass estimations from the intracluster medium (ICM). Moreover, (quasi-)turbulent gas motions are thought to be the dominant source of non-thermal pressure, in which case high resolution X-ray spectrographs on Hitomi and upcoming missions should greatly expand our knowledge. There is also an indirect approach which observes fluctuations in the surface brightness of clusters, accessed either in X-ray or Sunyaev-Zel’dovich (SZ) images. Exploring fluctuations in SZ images is relatively novel and should still be advantageous for probing turbulence in high-redshift clusters and cluster outskirts. I will present results of SZ (observed by SPT or MUSTANG-2) and X-ray (observations with XMM-Newton) fluctuations and the inferred pressure and density fluctuations.

        Speaker: Charles Romero (Center for Astrophysics | Harvard & Smithsonian)