Speaker
Description
Dual AGN at kpc-scale separations (<7 kpc) within the same galaxy trace a key phase of galaxy mergers, when gas fuels both star formation and supermassive black hole (SMBH) growth. At z > 0.5, near the peak of star formation and AGN activity, these systems provide a direct view of this critical stage of galaxy evolution.
Despite their importance, only a limited number of sub-arcsecond (0.7”~7 kpc at z = 0.5–2) dual AGN at z>0.5 were previously known. Using the Gaia Multi-Peak (GMP) method, we have now identified a sample of ~35 candidate systems at sub-arcsecond scales, representing a significant increase in the known population.
However, their cold molecular gas content remains largely unexplored: the few targets observed so far are mostly confined to the local Universe, with only one system at z>1 (Ishikawa+25). I will present ongoing ALMA observations of a sub-sample of confirmed dual AGN, probing their cold molecular gas reservoirs. All confirmed systems have measured SMBH masses, and we report evidence for an ionized gas outflow in one system. These observations provide first constraints on the gas content of these systems and on the role of AGN feedback in the phase preceding SMBH coalescence.