Darach Watson: Litte red dots

Tuesday 8 Sept 2026, 13:15 → 14:15 Europe/Stockholm

FB51 (AlbaNova Main Building)

Little red dots (LRDs) are a newly discovered population of extremely compact (r<35 pc), luminous JWST sources whose spectra combine features associated with stellar atmospheres and accreting supermassive black holes (SMBHs). Yet they generally lack the X-ray, radio, and variability signatures of classical active galactic nuclei. Proposed explanations range from massive binary stars and supernovae to supermassive stars, direct-collapse or primordial black holes, tidal disruption events, and AGN with suppressed coronae. I will present our work showing that nearly all observed LRD properties can be reproduced by a roughly million-solar-mass black hole accreting from within a dense gaseous cocoon. This raises the possibility that LRDs reveal the earliest, deeply embedded phase of an SMBH accretion episode, visible at these epochs because the low dust content allows us to see through the cocoon.

About the speaker: Darach Watson is a professor of astrophysics at the University of Copenhagen and head of the ERC Synergy project HEAVYMETAL. His research focuses on the early Universe, the formation of the first galaxies and supermassive black holes, gamma-ray bursts and neutron-star mergers, and the origin and evolution of cosmic dust. He has played a leading role in studies of the enigmatic Little Red Dot population discovered by JWST.