scholarly journals Cosmological simulations of massive black hole seeds: predictions for next-generation electromagnetic and gravitational wave observations

2019 ◽  
Vol 491 (4) ◽  
pp. 4973-4992
Author(s):  
C DeGraf ◽  
D Sijacki
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Cosmic Time ◽  
Host Galaxy ◽  
Electromagnetic Spectrum ◽  
Massive Black Hole ◽  
Cosmological Simulations ◽  
Seed Formation ◽  
Order Of Magnitude ◽  
Low Mass

ABSTRACT We study how statistical properties of supermassive black holes depend on the frequency and conditions for massive seed formation in cosmological simulations of structure formation. We develop a novel method to recalculate detailed growth histories and merger trees of black holes within the framework of the Illustris simulation for several seed formation models, including a physically motivated model where black hole seeds only form in progenitor galaxies that conform to the conditions for direct collapse black hole formation. While all seed models considered here are in a broad agreement with present observational constraints on black hole populations from optical, UV, and X-ray studies, we find that they lead to widely different black hole number densities and halo occupation fractions, which are currently observationally unconstrained. In terms of future electromagnetic spectrum observations, the faint-end quasar luminosity function and the low-mass-end black hole–host galaxy scaling relations are very sensitive to the specific massive seed prescription. Specifically, the direct collapse model exhibits a seeding efficiency that decreases rapidly with cosmic time and produces much fewer black holes in low-mass galaxies, in contrast to the original Illustris simulation. We further find that the total black hole merger rate varies by more than one order of magnitude for different seed models, with the redshift evolution of the chirp mass changing as well. Supermassive black hole merger detections with LISA and International Pulsar Timing Array may hence provide the most direct means of constraining massive black hole seed formation in the early Universe.

An accreting < 105M⊙ black hole at the center of dwarf galaxy IC750

2019 ◽  
Vol 15 (S356) ◽  
pp. 376-376
Author(s):  
Ingyin Zaw
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dwarf Galaxies ◽  
Dwarf Galaxy ◽  
Host Galaxy ◽  
Scaling Relations ◽  
Host Galaxies ◽  
Seed Formation ◽  
Maser Emission ◽  
Water Masers

AbstractNuclear black holes in dwarf galaxies are important for understanding the low end of the supermassive black hole mass distribution and the black hole-host galaxy scaling relations. IC 750 is a rare system which hosts an AGN, found in ˜0.5% of dwarf galaxies, with circumnuclear 22 GHz water maser emission, found in ˜3–5% of Type 2 AGNs. Water masers, the only known tracer of warm, dense gas in the center parsec of AGNs resolvable in position and velocity, provide the most precise and accurate mass measurements of SMBHs outside the local group. We have mapped the maser emission in IC 750 and find that it traces a nearly edge-on warped disk, 0.2 pc in diameter. The central black hole has an upper limit mass of ˜1 × 105 M⊙ and a best fit mass of ˜8 × 104 M⊙, one to two orders of magnitude below what is expected from black hole-galaxy scaling relations. This has implications for models of black hole seed formation in the early universe, the growth of black holes, and their co-evolution with their host galaxies.

scholarly journals Black Hole Models of Quasars

1986 ◽  
Vol 119 ◽  
pp. 359-369 ◽  
Author(s):  
R. D. Blandford
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Active Galactic Nuclei ◽  
Cosmic Time ◽  
Galactic Nuclei ◽  
Seyfert Galaxies ◽  
Massive Black Hole ◽  
Binary Black Holes ◽  
Electron Positron ◽  
Gas Supply

Observations of active galactic nuclei are interpreted in terms of a theoretical model involving accretion onto a massive black hole. Optical quasars and Seyfert galaxies are associated with holes accreting near the Eddington rate and radio galaxies with sub-critical accretion. It is argued that magnetic fields are largely responsible for extracting energy and angular momentum from black holes and disks. Recent studies of electron-positron pair plasmas and their possible role in establishing the emergent X-ray spectrum are reviewed. The main evolutionary properties of active galactic nuclei can be interpreted in terms of a simple model in which black holes accrete gas at a rate dictated by the rate of gas supply which decreases with cosmic time. It may be worth searching for eclipsing binary black holes in lower power Seyferts.

scholarly journals The Early Evolution of Massive Black Holes

2009 ◽  
Vol 5 (S267) ◽  
pp. 26-33 ◽  
Author(s):  
Marta Volonteri
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Velocity Dispersion ◽  
Host Galaxy ◽  
Formation Processes ◽  
Hole Formation ◽  
Physical Processes ◽  
Massive Black Hole ◽  
Potential Wells ◽  
Massive Black Holes

AbstractMassive black holes (MBHs) are nowadays believed to reside in most local galaxies. Studies have also established a number of relations between the MBH mass and properties of the host galaxy such as bulge mass and velocity dispersion. These results suggest that central MBHs, while much less massive than their hosts (~ 0.1%), are linked to the evolution of galactic structure. When did it all start? In hierarchical cosmologies, a single big galaxy today can be traced back to the stage when it was split up in hundreds of smaller components. Did MBH seeds form with the same efficiency in small proto-galaxies, or did their formation have to await the buildup of substantial galaxies with deeper potential wells? I briefly review here some of the physical processes that are conducive to the evolution of the massive black hole population. I will discuss black hole formation processes for “seed” black holes that are likely to take place at early cosmic epochs, and possible observational tests of these scenarios.

scholarly journals A loud quasi-periodic oscillation after a star is disrupted by a massive black hole

Science ◽  
2019 ◽  
Vol 363 (6426) ◽  
pp. 531-534 ◽  
Author(s):  
Dheeraj R. Pasham ◽  
Ronald A. Remillard ◽  
P. Chris Fragile ◽  
Alessia Franchini ◽  
Nicholas C. Stone ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Periodic Oscillation ◽  
Host Galaxy ◽  
X Rays ◽  
Tidal Disruption ◽  
Massive Black Hole ◽  
Quasi Periodic Oscillation ◽  
Massive Black Holes ◽  
Tidal Forces

The tidal forces close to massive black holes can rip apart stars that come too close to them. As the resulting stellar debris spirals toward the black hole, the debris heats up and emits x-rays. We report observations of a stable 131-second x-ray quasi-periodic oscillation from the tidal disruption event ASASSN-14li. Assuming the black hole mass indicated by host galaxy scaling relations, these observations imply that the periodicity originates from close to the event horizon and that the black hole is rapidly spinning. Our findings demonstrate that tidal disruption events can generate quasi-periodic oscillations that encode information about the physical properties of their black holes.

scholarly journals Formation of massive black holes in ultracompact dwarf galaxies: migration of primordial intermediate-mass black holes in N-body simulation

2020 ◽  
Vol 496 (1) ◽  
pp. 921-932
Author(s):  
Henriette Wirth ◽  
Kenji Bekki
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dwarf Galaxies ◽  
Model Parameters ◽  
Intermediate Mass ◽  
Massive Black Hole ◽  
Massive Black Holes ◽  
Wide Range ◽  
Central Regions ◽  
Low Mass

ABSTRACT Recent observational studies of ultracompact dwarf galaxies (UCDs) have discovered the massive black hole (MBH), with masses of more than ${10^6~\rm M_\odot }$, in their central regions. We here consider that these MBHs can be formed through the merging of intermediate-mass black hole (IMBH), with masses of (103–105) M⊙, within the stellar nuclei of dwarf galaxies, which are progenitors of UCDs. We numerically investigate this formation process for a wide range of model parameters using N-body simulations. This means that IMBH growth and feedback is neglected in this study. We find that only massive IMBHs of $10^5~\rm M_\odot$ sink into the central regions of their host dwarf ($\approx 10^{10}~\rm M_\odot$) to be gravitationally trapped by its stellar nucleus within less than 1 Gyr in most dwarf models. We also find that lighter IMBHs with $(1\!-\!30) \times 10^3~\rm M_\odot$ sink into the centre in low-mass dwarfs ($\approx 10^{9}~\rm M_\odot$) due to more efficient dynamical frictionitionally, we show that the IMBHs can form binaries in the centre and, rarely, before they reach the centre, which may lead to the IMBHs merging and thus emitting gravitational waves that could be detected by LISA. Finally, we discuss the required number of IMBHs for the MBH formation in UCDs and the physical roles of stellar nuclei in IMBH binaries and mergers.

scholarly journals Forming an “Impossible” 85 solar mass Black Hole

2020 ◽  
Author(s):  
Jorick Vink ◽  
Erin Higgins ◽  
Andreas Sander ◽  
Gautham Sabhahit
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Galaxy Evolution ◽  
Heavy Element ◽  
Massive Stars ◽  
Fundamental Problem ◽  
Cosmic Time ◽  
Host Galaxy ◽  
Solar Mass ◽  
The Masses

Abstract At the end of its life, a very massive star is expected to collapse into a black hole. The masses of these black holes are pivotal for our understanding of the evolution and fate of these stars, as well as for galaxy evolution and the build-up of black hole masses through Cosmic time. The recent detection of an 85 solar mass black hole from the gravitational wave event GW 190521 appears to present a fundamental problem as to how such heavy black holes exist above the approximately 50 solar mass pair-instability limit where stars are expected to be blown to pieces with no remnant left. Here we show that for stellar models at reduced heavy element content, 90-100 solar mass stars can produce core masses sufficiently small to remain below the fundamental pair-instability limit, yet at the same time lose an amount of mass small enough to end up in an 85 solar mass black hole. A key point is that the amount of mass-loss scales with the host galaxy heavy element fraction, and not with the total amount of element enrichment that occurs naturally during the life of massive stars. Our study shows how our Universe is capable of producing heavy black holes, which are important seeds for the production of supermassive black holes that regulate the evolution of galaxies. Our evolutionary channel to the formation of an 85 solar mass black hole is of fundamental relevance for the manner in which metals are released in the outflows and explosions of the most massive stars, which is shown to be a strong function of Cosmic time.

scholarly journals The Process of Stellar Tidal Disruption by Supermassive Black Holes

2021 ◽  
Vol 217 (3) ◽  
Author(s):  
E. M. Rossi ◽  
N. C. Stone ◽  
J. A. P. Law-Smith ◽  
M. Macleod ◽  
G. Lodato ◽  
...  
Keyword(s):  
Black Holes ◽  
Initial Conditions ◽  
Numerical Models ◽  
Binary Star ◽  
Tidal Disruption ◽  
Massive Black Hole ◽  
Accretion Flows ◽  
Simple Order ◽  
Order Of Magnitude ◽  
A Chain

AbstractTidal disruption events (TDEs) are among the brightest transients in the optical, ultraviolet, and X-ray sky. These flares are set into motion when a star is torn apart by the tidal field of a massive black hole, triggering a chain of events which is – so far – incompletely understood. However, the disruption process has been studied extensively for almost half a century, and unlike the later stages of a TDE, our understanding of the disruption itself is reasonably well converged. In this Chapter, we review both analytical and numerical models for stellar tidal disruption. Starting with relatively simple, order-of-magnitude physics, we review models of increasing sophistication, the semi-analytic “affine formalism,” hydrodynamic simulations of the disruption of polytropic stars, and the most recent hydrodynamic results concerning the disruption of realistic stellar models. Our review surveys the immediate aftermath of disruption in both typical and more unusual TDEs, exploring how the fate of the tidal debris changes if one considers non-main sequence stars, deeply penetrating tidal encounters, binary star systems, and sub-parabolic orbits. The stellar tidal disruption process provides the initial conditions needed to model the formation of accretion flows around quiescent massive black holes, and in some cases may also lead to directly observable emission, for example via shock breakout, gravitational waves or runaway nuclear fusion in deeply plunging TDEs.

scholarly journals Feeding and feedback from little monsters: AGN in dwarf galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 238-242
Author(s):  
Mar Mezcua
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Early Universe ◽  
Dwarf Galaxies ◽  
Scaling Relations ◽  
Strong Impact ◽  
Hole Formation ◽  
Intermediate Mass ◽  
Black Hole Formation ◽  
Low Mass

AbstractDetecting the seed black holes from which quasars formed is extremely challenging; however, those seeds that did not grow into supermassive should be found as intermediate-mass black holes (IMBHs) of 100 – 105 M⊙ in local dwarf galaxies. The use of deep multiwavelength surveys has revealed that a population of actively accreting IMBHs (low-mass AGN) exists in dwarf galaxies at least out to z ˜3. The black hole occupation fraction of these galaxies suggests that the early Universe seed black holes formed from direct collapse of gas, which is reinforced by the possible flattening of the black hole-galaxy scaling relations at the low-mass end. This scenario is however challenged by the finding that AGN feedback can have a strong impact on dwarf galaxies, which implies that low-mass AGN in dwarf galaxies might not be the untouched relics of the early seed black holes. This has important implications for seed black hole formation models.

scholarly journals Toward Precision Measurement of Central Black Hole Masses

2009 ◽  
Vol 5 (S267) ◽  
pp. 151-160 ◽  
Author(s):  
Bradley M. Peterson
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Host Galaxy ◽  
Reverberation Mapping ◽  
Line Region ◽  
The Masses ◽  
The Relationship ◽  
Black Hole Masses ◽  
Intrinsic Scatter ◽  
Direct And Indirect Methods

AbstractWe review briefly direct and indirect methods of measuring the masses of black holes in galactic nuclei, and then focus attention on supermassive black holes in active nuclei, with special attention to results from reverberation mapping and their limitations. We find that the intrinsic scatter in the relationship between the AGN luminosity and the broad-line region size is very small, ~0.11 dex, comparable to the uncertainties in the better reverberation measurements. We also find that the relationship between reverberation-based black hole masses and host-galaxy bulge luminosities also seems to have surprisingly little intrinsic scatter, ~0.17 dex. We note, however, that there are still potential systematics that could affect the overall mass calibration at the level of a factor of a few.

scholarly journals Effects of the Hubble parameter on the cosmic growth of the first quasars

2020 ◽  
Vol 496 (1) ◽  
pp. 888-893 ◽  
Author(s):  
Rafael C Nunes ◽  
Fabio Pacucci
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Hubble Parameter ◽  
Crucial Role ◽  
Seed Mass ◽  
Early Growth ◽  
Supermassive Black Holes ◽  
Initial Mass ◽  
Seed Formation ◽  
Mcmc Approach

ABSTRACT Supermassive black holes (SMBHs) play a crucial role in the evolution of galaxies and are currently detected up to $z$ ∼ 7.5. Theories describing black hole (BH) growth are challenged by how rapidly seeds with initial mass $M_\bullet \lesssim 10^5 \, {\rm M_\odot }$, formed at $z$ ∼ 20–30, grew to $M_\bullet \sim 10^9 \, {\rm M_\odot }$ by $z$ ∼ 7. Here we study the effects of the value of the Hubble parameter, H0, on models describing the early growth of BHs. First, we note that the predicted mass of a quasar at $z$ = 6 changes by $\gt 300{{\ \rm per\ cent}}$ if the underlying Hubble parameter used in the model varies from H0 = 65 to H0 = 74 km s−1Mpc−1, a range encompassing current estimates. Employing an MCMC approach based on priors from $z$ ≳ 6.5 quasars and on H0, we study the interconnection between H0 and the parameters describing BH growth: seed mass Mi and Eddington ratio fEdd. Assuming an Eddington ratio of fEdd = 0.7, in agreement with previous estimates, we find $H_0 = 73.6^{+1.2}_{-3.3}$ km s−1Mpc−1. In a second analysis, allowing all the parameters to vary freely, we find log (Mi/M⊙) &gt; 4.5 (at 95 per cent CL), $H_0 = 74^{+1.5}_{-1.4}$ km s−1Mpc−1 and $f_{\rm Edd}=0.77^{+0.035}_{-0.026}$ at 68 per cent CL. Our results on the typical Eddington ratio are in agreement with previous estimates. Current values of the Hubble parameter strongly favour heavy seed formation scenarios, with $M_i \gtrsim 10^4 \, {\rm M_\odot }$. In our model, with the priors on BH masses of quasars used, light seed formation scenarios are rejected at ∼3σ.

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