Colóquios do NAT

18/11 - AGN in low-mass galaxies: linking the local and the high-redshift Universe 

Dr. Mar Mezcua - Institute of Space Sciences, Spain)

Hundreds of black holes of 1e5-1e6 Msun have now been found actively accreting as AGN in local dwarf galaxies. These black holes could be the ungrown seeds of the first supermassive black holes formed in the early Universe, however this is difficult to prove. In this talk I will present a large sample of AGN in local dwarf galaxies found via integral-field spectroscopy that sheds further light into the origin of seed black holes. I will also present a new sample of overmassive black holes found in low-mass galaxies at cosmic noon (z~1-3), a key epoch in the history of the Universe in which both AGN and star formation had their highest peak of activity. These sources have much higher black hole-to-stellar mass ratios than local values, similarly to those AGN newly discovered by the James Webb Space Telescope at z =  4 − 10, suggesting they are all remnants of the first black hole seeds but at different cosmic epochs.