scholarly journals Black hole spin evolution in warped accretion discs

2020 ◽  
Vol 500 (3) ◽  
pp. 3719-3727 ◽  
Author(s):  
Elia Cenci ◽  
Luca Sala ◽  
Alessandro Lupi ◽  
Pedro R Capelo ◽  
Massimo Dotti
Keyword(s):  
Cosmic Time ◽  
Galactic Nuclei ◽  
Companion Paper ◽  
Accretion Disc ◽  
Analytical Models ◽  
Massive Black Holes ◽  
Spin Evolution ◽  
Hydrodynamical Simulations ◽  
Two Parameters ◽  
Gas Accretion

ABSTRACT Massive black holes (BHs) inhabiting galactic nuclei can be described by two parameters only, i.e. mass and spin, that change through cosmic time in response to accretion and merger events. While most numerical simulations accurately track the BH mass, spin evolution is rarely taken into account. In this work, we implement and validate a self-consistent sub-grid model for the evolution of the BH mass and spin via gas accretion in the hydrodynamics code gizmo. The model assumes that accretion from resolved scales does not occur instantaneously but is mediated by a sub-grid geometrically thin α-disc. After validating our model semi-analytically, we test it in an idealized environment consisting of a circumnuclear disc, where gas accretion on to the accretion disc is consistently determined by gizmo. In the absence of any accretion-related feedback, the spin evolution closely traces that observed in the semi-analytical models, and depends on the free parameters of our implementation, such as the initial BH spin, angular momentum of the accretion disc, and radius at which the gas inflow circularizes. In gizmo, we also couple our model with the biconical-outflow model presented in a companion paper, wherein the feedback axis is always aligned with the BH spin. In this last case, the evolution of the central BH differs significantly from the previous cases, since the feedback process modifies the gas dynamics and its inflow rates from resolved scales. Such an interaction cannot be modelled by simple semi-analytical models and should be treated using full N-body hydrodynamical simulations.

scholarly journals What has quenched the massive spiral galaxies?

2020 ◽  
Vol 496 (1) ◽  
pp. L116-L121
Author(s):  
Yu Luo ◽  
Zongnan Li ◽  
Xi Kang ◽  
Zhiyuan Li ◽  
Peng Wang
Keyword(s):  
Black Holes ◽  
Spiral Galaxies ◽  
Theoretical Models ◽  
Mass Range ◽  
Sloan Digital Sky Survey ◽  
Analytical Models ◽  
Gas Content ◽  
Quenching Mechanism ◽  
Massive Black Holes ◽  
Hydrodynamical Simulations

ABSTRACT Quenched massive spiral galaxies have attracted great attention recently, as more data are available to constrain their environment and cold gas content. However, the quenching mechanism is still uncertain, as it depends on the mass range and baryon budget of the galaxy. In this letter, we report the identification of a rare population of very massive, quenched spiral galaxies with stellar mass ≳1011 M⊙ and halo mass ≳1013 M⊙ from the Sloan Digital Sky Survey at redshift z ∼ 0.1. Our CO observations using the IRAM (Institute for Radio Astronomy in the Millimeter Range) 30-m telescope show that these galaxies contain only a small amount of molecular gas. Similar galaxies are also seen in the state-of-the-art semi-analytical models and hydrodynamical simulations. It is found from these theoretical models that these quenched spiral galaxies harbour massive black holes, suggesting that feedback from the central black holes has quenched these spiral galaxies. This quenching mechanism seems to challenge the popular scenario of the co-evolution between massive black holes and massive bulges.

scholarly journals Star formation in accretion discs and SMBH growth

2020 ◽  
Vol 493 (3) ◽  
pp. 3732-3743 ◽  
Author(s):  
Alexander J Dittmann ◽  
M Coleman Miller
Keyword(s):  
Black Holes ◽  
Star Formation ◽  
Active Galactic Nuclei ◽  
Accretion Rate ◽  
High Redshift ◽  
Galactic Nuclei ◽  
Compact Objects ◽  
Accretion Discs ◽  
Massive Black Holes ◽  
Gas Accretion

ABSTRACT Accretion discs around active galactic nuclei (AGNs) are potentially unstable to star formation at large radii. We note that when the compact objects formed from some of these stars spiral into the central supermassive black hole (SMBH), there is no radiative feedback and therefore the accretion rate is not limited by radiation forces. Using a set of accretion disc models, we calculate the accretion rate on to the central SMBH in both gas and compact objects. We find that the time-scale for an SMBH to double in mass can decrease by factors ranging from ∼0.7 to as low as ∼0.1 in extreme cases, compared to gas accretion alone. Our results suggest that the formation of extremely massive black holes at high redshift may occur without prolonged super-Eddington gas accretion or very massive seed black holes. We comment on potential observational signatures as well as implications for other observations of AGNs.

scholarly journals Feedback from central massive black holes in galaxies using cosmological simulations

2019 ◽  
Vol 15 (S359) ◽  
pp. 35-36
Author(s):  
Paramita Barai
Keyword(s):  
Black Holes ◽  
Star Formation ◽  
Galaxy Evolution ◽  
Supermassive Black Holes ◽  
Active Galaxies ◽  
Host Galaxies ◽  
Massive Black Holes ◽  
Energy Feedback ◽  
Hydrodynamical Simulations ◽  
Gas Accretion

AbstractGas accretion onto central supermassive black holes of active galaxies and resulting energy feedback, is an important component of galaxy evolution, whose details are still unknown especially at early cosmic epochs. We investigate BH growth and feedback in quasar-host galaxies at z ⩾ 6 by performing cosmological hydrodynamical simulations. We simulate the 2R200 region around a 2 × 1012Mʘ halo at z = 6, inside a (500 Mpc)3 comoving volume, using the zoom-in technique. We find that BHs accrete gas at the Eddington rate over z = 9–6. At z = 6, our most-massive BH has grown to MBH = 4 × 109 Mʘ. Star-formation is quenched over z = 8–6.

scholarly journals The impact of stellar and AGN feedback on halo-scale baryonic and dark matter accretion in the eagle simulations

2020 ◽  
Vol 498 (2) ◽  
pp. 1668-1692 ◽  
Author(s):  
Ruby J Wright ◽  
Claudia del P Lagos ◽  
Chris Power ◽  
Peter D Mitchell
Keyword(s):  
Dark Matter ◽  
Active Galactic Nuclei ◽  
Cosmic Time ◽  
Galactic Nuclei ◽  
Gas Content ◽  
Stellar Feedback ◽  
Accretion Rates ◽  
Low Mass ◽  
Hydrodynamical Simulations ◽  
The Impact

ABSTRACT We use the eagle suite of hydrodynamical simulations to analyse accretion rates (and the breakdown of their constituent channels) on to haloes over cosmic time, comparing the behaviour of baryons and dark matter (DM). We also investigate the influence of sub-grid baryon physics on halo-scale inflow, specifically the consequences of modelling radiative cooling, as well as feedback from stars and active galactic nuclei (AGNs). We find that variations in halo baryon fractions at fixed mass (particularly their circumgalactic medium gas content) are very well correlated with variations in the baryon fraction of accreting matter, which we show to be heavily suppressed by stellar feedback in low-mass haloes, Mhalo ≲ 1011.5 M⊙. Breaking down accretion rates into first infall, recycled, transfer, and merger components, we show that baryons are much more likely to be smoothly accreted than to have originated from mergers when compared to DM, finding (averaged across halo mass) a merger contribution of $\approx 6{{\ \rm per\ cent}}$ for baryons, and $\approx 15{{\ \rm per\ cent}}$ for DM at z ≈ 0. We also show that the breakdown of inflow into different channels is strongly dependent on sub-grid physics, particularly the contribution of recycled accretion (accreting matter that has been previously ejected from progenitor haloes). Our findings highlight the dual role that baryonic feedback plays in regulating the evolution of galaxies and haloes: by (i) directly removing gas from haloes, and (ii) suppressing gas inflow to haloes.

scholarly journals Non-isotropic feedback from accreting spinning black holes

2020 ◽  
Vol 500 (4) ◽  
pp. 4788-4800
Author(s):  
Luca Sala ◽  
Elia Cenci ◽  
Pedro R Capelo ◽  
Alessandro Lupi ◽  
Massimo Dotti
Keyword(s):  
Black Holes ◽  
Active Galactic Nuclei ◽  
Surrounding Medium ◽  
Galactic Nuclei ◽  
Accretion Disc ◽  
Test Bed ◽  
Host Galaxies ◽  
Massive Black Holes ◽  
Disc Model ◽  
Comparable Mass

ABSTRACT Active galactic nuclei (AGNs) are massive black holes (BHs) caught in the act of accreting gas at the centre of their host galaxies. Part of the accreting mass is converted to energy and released into the surrounding medium, in a process loosely referred to as AGN feedback. Most numerical simulations include AGN feedback as a sub-grid model, wherein energy or momentum (or both) is coupled to the nearby gas. In this work, we implement a new momentum-driven model in the hydrodynamics code gizmo, in which accretion from large scales is mediated by a sub-grid accretion disc model, and gas particles are stochastically kicked over a bi-conical region, to mimic observed kinetic winds. The feedback cone’s axis can be set parallel either to the angular momentum of the gas surrounding the BH or to the BH spin direction, which is self-consistently evolved within the accretion-disc model. Using a circumnuclear disc (CND) as a test bed, we find that (i) the conical shape of the outflow is always visible and is weakly dependent on the launching orientation and aperture, resulting in comparable mass inflows and outflows; (ii) the cone’s orientation is also similar amongst our tests, and it is not always the same as the initial value, due to the interaction with the CND playing a crucial role in shaping the outflow; and (iii) the velocity of the outflow, instead, differs and strongly depends on the interplay with the CND.

scholarly journals Impact of AGN feedback on galaxies and their multiphase ISM across cosmic time

2019 ◽  
Author(s):  
Milena Valentini ◽  
Giuseppe Murante ◽  
Stefano Borgani ◽  
Gian Luigi Granato ◽  
Pierluigi Monaco ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Cosmic Time ◽  
Host Galaxy ◽  
High Angular Momentum ◽  
Hot Gas ◽  
Resolution Model ◽  
Hydrodynamical Simulations ◽  
Gas Accretion ◽  
The Impact ◽  
Cold Gas

Abstract We present simulations of galaxy formation, based on the GADGET-3 code, in which a sub-resolution model for star formation and stellar feedback is interfaced with a new model for AGN feedback. Our sub-resolution model describes a multiphase ISM, accounting for hot and cold gas within the same resolution element: we exploit this feature to investigate the impact of coupling AGN feedback energy to the different phases of the ISM over cosmic time. Our fiducial model considers that AGN feedback energy coupling is driven by the covering factors of the hot and cold phases. We perform a suite of cosmological hydrodynamical simulations of disc galaxies (Mhalo, DM ≃ 2 · 1012 M⊙, at z = 0), to investigate: (i) the effect of different ways of coupling AGN feedback energy to the multiphase ISM; (ii) the impact of different prescriptions for gas accretion (i.e. only cold gas, both cold and hot gas, with the additional possibility of limiting gas accretion from cold gas with high angular momentum); (iii) how different models of gas accretion and coupling of AGN feedback energy affect the coevolution of supermassive BHs and their host galaxy. We find that at least a share of the AGN feedback energy has to couple with the diffuse gas, in order to avoid an excessive growth of the BH mass. When the BH only accretes cold gas, it experiences a growth that is faster than in the case in which both cold and hot gas are accreted. If the accretion of cold gas with high angular momentum is reduced, the BH mass growth is delayed, the BH mass at z = 0 is reduced by up to an order of magnitude, and the BH is prevented from accreting below z ≲ 2, when the galaxy disc forms.

scholarly journals Probing gas disc physics with LISA: simulations of an intermediate mass ratio inspiral in an accretion disc

2019 ◽  
Vol 486 (2) ◽  
pp. 2754-2765 ◽  
Author(s):  
A M Derdzinski ◽  
D D’Orazio ◽  
P Duffell ◽  
Z Haiman ◽  
A MacFadyen
Keyword(s):  
Small Deviation ◽  
Compact Object ◽  
Accretion Disc ◽  
Mass Ratio ◽  
Intermediate Mass ◽  
Laser Interferometer Space Antenna ◽  
Total Phase ◽  
Accretion Rates ◽  
Hydrodynamical Simulations ◽  
And Migration

Abstract The coalescence of a compact object with a $10^{4}\hbox{--}10^{7}\, {\rm M_\odot }$ supermassive black hole (SMBH) produces mHz gravitational waves (GWs) detectable by the future Laser Interferometer Space Antenna (LISA). If such an inspiral occurs in the accretion disc of an active galactic nucleus (AGN), the gas torques imprint a small deviation in the GW waveform. Here, we present two-dimensional hydrodynamical simulations with the moving-mesh code disco of a BH inspiraling at the GW rate in a binary system with a mass ratio q = M2/M1 = 10−3, embedded in an accretion disc. We assume a locally isothermal equation of state for the gas (with Mach number $\mathcal {M}=20$) and implement a standard α-prescription for its viscosity (with α = 0.03). We find disc torques on the binary that are weaker than in previous semi-analytic toy models, and are in the opposite direction: the gas disc slows down, rather than speeds up the inspiral. We compute the resulting deviations in the GW waveform, which scale linearly with the mass of the disc. The SNR of these deviations accumulates mostly at high frequencies, and becomes detectable in a 5 yr LISA observation if the total phase shift exceeds a few radians. We find that this occurs if the disc surface density exceeds $\Sigma _0 \gtrsim 10^{2-3}\rm g\, cm^{-2}$, as may be the case in thin discs with near-Eddington accretion rates. Since the characteristic imprint on the GW signal is strongly dependent on disc parameters, a LISA detection of an intermediate mass ratio inspiral would probe the physics of AGN discs and migration.

scholarly journals Formation of supermassive black holes in galactic nuclei – I. Delivering seed intermediate-mass black holes in massive stellar clusters

2021 ◽  
Vol 502 (2) ◽  
pp. 2682-2700
Author(s):  
Abbas Askar ◽  
Melvyn B Davies ◽  
Ross P Church
Keyword(s):  
Black Holes ◽  
Galactic Nuclei ◽  
Supermassive Black Holes ◽  
Stellar Clusters ◽  
Orbital Eccentricity ◽  
Intermediate Mass ◽  
Stellar Cluster ◽  
Wave Emission ◽  
Gas Accretion ◽  
Intermediate Mass Black Holes

ABSTRACT Supermassive black holes (SMBHs) are found in most galactic nuclei. A significant fraction of these nuclei also contains a nuclear stellar cluster (NSC) surrounding the SMBH. In this paper, we consider the idea that the NSC forms first, from the merger of several stellar clusters that may contain intermediate-mass black holes (IMBHs). These IMBHs can subsequently grow in the NSC and form an SMBH. We carry out N-body simulations of the simultaneous merger of three stellar clusters to form an NSC, and investigate the outcome of simulated runs containing zero, one, two, and three IMBHs. We find that IMBHs can efficiently sink to the centre of the merged cluster. If multiple merging clusters contain an IMBH, we find that an IMBH binary is likely to form and subsequently merge by gravitational wave emission. We show that these mergers are catalyzed by dynamical interactions with surrounding stars, which systematically harden the binary and increase its orbital eccentricity. The seed SMBH will be ejected from the NSC by the recoil kick produced when two IMBHs merge, if their mass ratio q ≳ 0.15. If the seed is ejected then no SMBH will form in the NSC. This is a natural pathway to explain those galactic nuclei that contain an NSC but apparently lack an SMBH, such as M33. However, if an IMBH is retained then it can seed the growth of an SMBH through gas accretion and tidal disruption of stars.

Spherical accretion of massive black holes: A model for galactic nuclei

1981 ◽  
Vol 1 (13) ◽  
pp. 67-70
Author(s):  
L. Maraschi ◽  
G.C. Perola ◽  
A. Treves
Keyword(s):  
Black Holes ◽  
Galactic Nuclei ◽  
Massive Black Holes
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