The most massive galaxies with large depleted cores: structural parameter relations and black hole masses

Abstract

[Abridged] Luminous spheroids (M_V < - 21.50 +- 0.75 mag) contain partially depleted cores with sizes (R_ b) typically 0.02 - 0.5 kpc. However, galaxies with R_b > 0.5 kpc are rare and poorly understood. Here we perform detailed decompositions of the composite surface brightness profiles, extracted from archival Hubble Space Telescope and ground-based images, of 12 extremely luminous "large-core" galaxies that have R_b > 0.5 kpc and M_V < -23.50 +- 0.10 mag, fitting a core-Sérsic model to the galaxy spheroids. Using 28 "normal-core" (i.e., R_b < 0.5 kpc) galaxies and 1 "large-core" (i.e., R_b > 0.5 kpc) galaxy from the literature, we constructed a final sample of 41 core-Sérsic galaxies. We find that large-core spheroids (with stellar masses M_* > 10^12 M_sun) are not simple high-mass extensions of the less luminous normal-core spheroids having M_* ~ 8 x 10^10 - 10^12 M_sun. While the two types follow the same strong relations between the spheroid luminosity L_V and R_b (R_b prop L_V^(1.38 +- 0.13), and the spheroid half-light radius R_e (R_e prop L_V^(1.08 +- 0.09), for ellipticals plus BCGs), we discover a break in the core-Sérsic sigma-L_V relation occurring at M_V ~ -23.50 +- 0.10 mag. Furthermore, we find a strong log-linear R_b-M_BH relation for the 11 galaxies in the sample with directly determined SMBH masses M_BH---3/11 galaxies are large-core galaxies ---such that R_b prop M_BH^(0.83 +- 0.10). However, for the large-core galaxies the SMBH masses estimated from the M_BH-sigma and core-Sérsic M_BH-L relations are undermassive, by up to a factor of 40, relative to expectations from their large R_b values, confirming earlier results. Our findings suggest that large-core galaxies harbour overmassive SMBHs (M_BH > 10^10 M_sun), considerably (~ 3.7-15.6 sigma and ~ 0.6-1.7 sigma) larger than expectations from the spheroid sigma and L, respectively.

24 pages, 14 figures (some with low quality due to arXiv file size limitations), accepted (2019, October 14) for publication in ApJ, v2: surname/forename tagged correctly

References in corpus (33)

• The hierarchical formation of the brightest cluster galaxies
• An ultra-luminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30
• A Compact Supermassive Binary Black Hole System
• The Dual Origin of Stellar Halos
• Ejection of Supermassive Black Holes from Galaxy Cores
• The luminosities, sizes and velocity dispersions of Brightest Cluster Galaxies: Implications for formation history
• Observational constraints on the merger history of galaxies since $z\approx 6$: Probabilistic galaxy pair counts in the CANDELS fields
• Chandra unveils a binary Active Galactic Nucleus in Mrk463
• Intracluster light and the extended stellar envelopes of cD galaxies: An analytical description
• Dissipation and Extra Light in Galactic Nuclei: III. 'Core' Ellipticals and 'Missing' Light
• Intracluster Light at the Frontier II: The Frontier Fields Clusters
• A consistent measure of the merger histories of massive galaxies using close-pair statistics I: Major mergers at $z<3.5$
• The MASSIVE Survey - V. Spatially-Resolved Stellar Angular Momentum, Velocity Dispersion, and Higher Moments of the 41 Most Massive Local Early-Type Galaxies
• The importance of dry and wet merging on the formation and evolution of elliptical galaxies
• The Cluster Velocity Dispersion of the Abell 2199 cD Halo of NGC 6166
• Hiding in plain sight: An abundance of compact massive spheroids in the local Universe
• Production of Hypervelocity Stars through Encounters with Stellar-Mass Black Holes in the Galactic Centre
• The central elliptical galaxy in fossil groups and formation of BCGs
• Discovery of a close-separation binary quasar at the heart of a z~0.2 merging galaxy and its implications for low-frequency gravitational waves
• Overmassive black holes in the $M_{\mathrm{BH}}-\sigma$ diagram do not belong to over (dry) merged galaxies
• The Brightest Cluster Galaxy in Abell 85: The Largest Core Known so far
• The most massive black holes on the Fundamental Plane of Black Hole Accretion
• A remarkably large depleted core in the Abell 2029 BCG IC 1101
• Diffuse stellar emission in X-ray luminous galaxy clusters at z~0.3 I. Is the diffuse optical light boosted and rejuvenated in merging clusters?
• Specific Frequencies and Luminosity Profiles of Cluster Galaxies and Intracluster Light in Abell 1689
• The quest for the largest depleted galaxy core: supermassive black hole binaries and stalled in-falling satellites
• Complex central structures suggest complex evolutionary paths for barred S0 galaxies
• Expanding the Sample: The Relationship Between the Black Hole Mass of BCGs and the Total Mass of Galaxy Clusters
• A Search for the Most Massive Galaxies. III. Global and Central Structure
• The nuclear activity and central structure of the elliptical galaxy NGC 5322
• Core shapes and orientations of core-Sersic galaxies
• Too big to be real? No depleted core in Holm 15A
• Supermassive Black Hole Demographics: Evading $M-\sigma$