THE COSMIC EVOLUTION OF MASSIVE BLACK HOLES AND GALAXY SPHEROIDS: GLOBAL CONSTRAINTS AT REDSHIFTz≲ 1.2

Abstract

We study observational constraints on the cosmic evolution of the relationships between massive black hole (MBH) mass (M • ) and stellar mass (M * ,sph ; or velocity dispersion σ ) of a host galaxy/spheroid. Assuming that the M • -M * ,sph (or M • -σ ) relation evolves with redshift as ∝ (1 + z) Γ , the MBH mass density can be obtained from either the observationally determined galaxy stellar mass functions or velocity dispersion distribution functions over redshift z ∼ 0-1.2 for any given Γ. The MBH mass density at different redshifts can also be inferred from the luminosity function of QSOs/active galactic nuclei (AGNs) provided the radiative efficiency is known. By matching the MBH density inferred from galaxies to that obtained from QSOs/AGNs, we find that Γ = 0.64 +0.27 −0.29 for the M • -M * ,sph relation and Γ = −0.21 +0.28 −0.33 for the M • -σ relation, and = 0.11 +0.04 −0.03 . Our results suggest that MBH mass growth precedes bulge mass growth but that the galaxy velocity dispersion does not increase with the mass growth of the bulge after nuclear activity is quenched, which is roughly consistent with the two-phase galaxy formation scenario proposed by Oser et al. in which a galaxy roughly doubles its mass after z = 1 due to accretion and minor mergers while its velocity dispersion drops slightly.

GRAVITATIONAL WAVES AND STALLED SATELLITES FROM MASSIVE GALAXY MERGERS ATz⩽ 1

“…Due to the observed constancy of the M • -M relationship for BCGs, and the small fractional change in density from accretion for massive black holes (Yu & Tremaine 2002), we treat ρ • as constant. This choice is consistent with observational results (Hopkins et al 2007;Zhang et al 2012;Sesana 2013) …”

Stellar and Black Hole Mass Densities as Empirical Tracers of Co-Evolution Show Lock-Step Growth Since Z ∼ 3

“…Whenever we calculate values for the BHMD, we adopt a value of   -= 1 0 . 1 ( ) to be comparable with previous works (Yu & Tremaine 2002;Ueda et al 2003;Marconi et al 2004;Hopkins et al 2007;Zhang et al 2012). …”

“…In this study we focus on the global properties of the whole galaxy and BH population by calculating the evolution of the total stellar mass (stellar mass density, SMD) and BH mass density (BHMD) over redshifts = z 0 5 -. This methodology has been applied to obtain star formation rates and black hole accretion rates at z < 3 (Merloni et al 2004) and more recently by Zhang et al (2012) at  z 1.2 to investigate the connection between SMD and BHMD. Below redshifts of z ≈ 1.5 it is possible to estimate not only the total SMD but the bulge stellar mass density from bulge to total mass ratios and morphology distributions.…”

Was 49b: An Overmassive AGN in a Merging Dwarf Galaxy?

“…If Was 49b was originally a late-type/dwarf galaxy, its SMBH is a factor of 10 2 -10 4 as massive as other black holes found in this galaxy type, which are typically between 10 4 and 10 6   M (e.g., Filippenko & Ho 2003;Barth et al 2004;Izotov & Thuan 2008;Shields et al 2008;Reines et al 2011Reines et al , 2013Dong et al 2012;Secrest et al 2012Secrest et al , 2013Secrest et al , 2015Maksym et al 2014;Moran et al 2014;Baldassare et al 2015Baldassare et al , 2016Mezcua et al 2016;Satyapal et al 2016), potentially giving new insight into how SMBHs form and grow in isolated systems. For example, recent work has suggested that black hole mass growth at higher redshifts precedes bulge growth (e.g., Zhang et al 2012), while other work has found no such effect (e.g., Schulze & Wisotzki 2014). Numerical simulations suggest an evolution in black hole/galaxy scaling relations with redshift (e.g., Sijacki et al 2015;Volonteri et al 2016)-although it is not a dramatic effect-and predict increasing scatter in black hole/bulge scaling relations with decreasing bulge mass (e.g., Jahnke & Macciò 2011).…”