The (black hole mass)-(host spheroid luminosity) relation at high and low masses, the quadratic growth of black holes, and intermediate-mass black hole candidates

Understand

From a sample of 72 galaxies with reliable supermassive black hole masses M_(bh), we derive the M_(bh)-(host spheroid luminosity, L) relation for (i) the subsample of 24 core-Sersic galaxies with partially depleted cores, and (ii) the remaining subsample of 48 Sersic galaxies.

• Using (K_s)-band 2MASS data, we find the near-linear relation M_(bh) ~ L_(K_s)^(1.10+/-0.20) for the core-Sersic spheroids thought to be built in additive dry merger events, while M_(bh) ~ L_(K_s)^(2.73+/-0.55) for the Sersic spheroids built from gas-rich processes.
• After converting literature B-band disk galaxy magnitudes into inclination- and dust-corrected bulge magnitudes, via a useful new equation presented herein, we obtain a similar result.
• Unlike with the M_(bh)-sigma diagram, which is also updated here using the same galaxy sample, it remains unknown whether barred and non-barred Sersic galaxies are offset from each other in the M_(bh)-L diagram.