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WISDOM project – VI. Exploring the relation between supermassive black hole mass and galaxy rotation with molecular gas

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 500:2 (2020) 1933-1952

Authors:

Mark D Smith, Martin Bureau, Timothy A Davis, Michele Cappellari, Lijie Liu, Kyoko Onishi, Satoru Iguchi, Eve V North, Marc Sarzi

Abstract:

ABSTRACT Empirical correlations between the masses of supermassive black holes (SMBHs) and properties of their host galaxies are well established. Among these is the correlation with the flat rotation velocity of each galaxy measured either at a large radius in its rotation curve or via a spatially integrated emission-line width. We propose here the use of the deprojected integrated CO emission-line width as an alternative tracer of this rotation velocity, which has already been shown useful for the Tully–Fisher (luminosity–rotation velocity) relation. We investigate the correlation between CO line widths and SMBH masses for two samples of galaxies with dynamical SMBH mass measurements, with spatially resolved and unresolved CO observations, respectively. The tightest correlation is found using the resolved sample of 25 galaxies as $\log (M_\mathrm{BH}/\mathrm{M_\odot })=(7.5\pm 0.1)+(8.5\pm 0.9)[\log (W_\mathrm{50}/\sin i \, \mathrm{km\, s}^{-1})-2.7]$, where MBH is the central SMBH mass, W50 is the full width at half-maximum of a double-horned emission-line profile, and i is the inclination of the CO disc. This relation has a total scatter of $0.6\,$ dex, comparable to those of other SMBH mass correlations, and dominated by the intrinsic scatter of $0.5\,$ dex. A tight correlation is also found between the deprojected CO line widths and the stellar velocity dispersions averaged within one effective radius. We apply our correlation to the COLD GASS sample to estimate the local SMBH mass function.

Luminous Red Nova AT 2019zhd, a new merger in M 31

(2020)

Authors:

A Pastorello, M Fraser, G Valerin, A Reguitti, K Itagaki, P Ochner, SC Williams, D Jones, J Munday, SJ Smartt, KW Smith, S Srivastav, N Elias-Rosa, E Kankare, E Karamehmetoglu, P Lundqvist, PA Mazzali, U Munari, MD Stritzinger, L Tomasella, JP Anderson, KC Chambers, A Rest

The luminous red nova variety: AT 2020hat and AT 2020kog

(2020)

Authors:

A Pastorello, G Valerin, M Fraser, N Elias-Rosa, S Valenti, A Reguitti, PA Mazzali, RC Amaro, JE Andrews, Y Dong, J Jencson, M Lundquist, DE Reichart, DJ Sand, S Wyatt, SJ Smartt, KW Smith, S Srivastav, Y-Z Cai, E Cappellaro, S Holmbo, A Fiore, D Jones, E Kankare, E Karamehmetoglu, P Lundqvist, A Morales-Garoffolo, TM Reynolds, MD Stritzinger, SC Williams, KC Chambers, TJL de Boer, ME Huber, A Rest, R Wainscoat

The SAMI Galaxy Survey: a statistical approach to an optimal classification of stellar kinematics in galaxy surveys

(2020)

Authors:

Jesse van de Sande, Sam P Vaughan, Luca Cortese, Nicholas Scott, Joss Bland-Hawthorn, Scott M Croom, Claudia DP Lagos, Sarah Brough, Julia J Bryant, Julien Devriendt, Yohan Dubois, Francesco D'Eugenio, Caroline Foster, Amelia Fraser-McKelvie, Katherine E Harborne, Jon S Lawrence, Sree Oh, Matt S Owers, Adriano Poci, Rhea-Silvia Remus, Samuel N Richards, Felix Schulze, Sarah M Sweet, Mathew R Varidel, Charlotte Welker

Spatially offset black holes in the Horizon-AGN simulation and comparison to observations

Monthly Notices of the Royal Astronomical Society Oxford University Press 500:4 (2020) staa3516

Authors:

Deaglan J Bartlett, Harry Desmond, Julien Devriendt, Pedro G Ferreira, Adrianne Slyz

Abstract:

We study the displacements between the centres of galaxies and their supermassive black holes (BHs) in the cosmological hydrodynamical simulation Horizon-AGN, and in a variety of observations from the literature. The BHs in Horizon-AGN feel a subgrid dynamical friction force, sourced by the surrounding gas, which prevents recoiling BHs being ejected from the galaxy. We find that (i) the fraction of spatially offset BHs increases with cosmic time, (ii) BHs live on prograde orbits in the plane of the galaxy with an orbital radius that decays with time but stalls near z = 0, and (iii) the magnitudes of offsets from the galaxy centres are substantially larger in the simulation than in observations. We attribute the stalling of the infall and excessive offset magnitudes to the fact that dynamical friction from stars and dark matter is not modelled in the simulation, and hence provide a way to improve the BH dynamics of future simulations.