Speaker
Hiroto Yanagisawa
Description
We investigate the spectroscopic demography of “little red dots” (LRDs) using 37 objects at z~3–7 compiled from various JWST programs. We identifiy a tight scaling relation between Ha luminosity (L_Ha) and bolometric luminosity (L_bol), which is enhanced by a factor of ~40 in L _Ha relative to that of low-z type 1 AGN. We explore the physical origin of this enhancement based on the classic locally optimally-emitting cloud (LOC) framework, and find that it can be explained by an increase in the broad line region (BLR) covering factor from ~20% (Type 1 AGN) to ~100% (LRDs), together with an increase in the hydrogen column density from N_H~10^23 cm−2 to >10^24 cm−2.
