Orateur
Description
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.
