Orateur
Description
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.
