scholarly journals Observational Signatures of High-Redshift Quasars and Local Relics of Black Hole Seeds

2016 ◽  
Vol 33 ◽  
Author(s):  
Amy E. Reines ◽  
Andrea Comastri
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dwarf Galaxies ◽  
High Redshift ◽  
Observational Constraints ◽  
Solar Mass ◽  
Massive Black Holes ◽  
Eddington Limit ◽  
The Universe ◽  
Review Current

AbstractObservational constraints on the birth and early evolution of massive black holes come from two extreme regimes. At high redshift, quasars signal the rapid growth of billion-solar-mass black holes and indicate that these objects began remarkably heavy and/or accreted mass at rates above the Eddington limit. At low redshift, the smallest nuclear black holes known are found in dwarf galaxies and provide the most concrete limits on the mass of black hole seeds. Here, we review current observational work in these fields that together are critical for our understanding of the origin of massive black holes in the Universe.

The connection between the formation of galaxies and that of their central supermassive black holes

2005 ◽  
Vol 363 (1828) ◽  
pp. 705-713
Author(s):  
Martin G. Haehnelt
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Globular Clusters ◽  
Dwarf Galaxies ◽  
High Redshift ◽  
Host Galaxies ◽  
Massive Black Holes ◽  
Essential Ingredient ◽  
Open Questions ◽  
Very High

Massive black holes appear to be an essential ingredient of massive galactic bulges but little is known yet to what extent massive black holes reside in dwarf galaxies and globular clusters. Massive black holes most likely grow by a mixture of merging and accretion of gas in their hierarchically merging host galaxies. While the hierarchical merging of dark matter structures extends to sub-galactic scales and very high redshift, it is uncertain if the same is true for the build–up of massive black holes. I discuss here some of the relevant problems and open questions.

scholarly journals Dwarf Galaxies with Optical Signatures of Accreting Massive Black Holes

2013 ◽  
Vol 9 (S304) ◽  
pp. 23-23
Author(s):  
Amy Reines ◽  
J. Greene ◽  
M. Geha
Keyword(s):  
Black Holes ◽  
Dwarf Galaxies ◽  
High Redshift ◽  
Formation Mechanisms ◽  
Seed Formation ◽  
Massive Black Holes ◽  
Massive Galaxies ◽  
Cosmological Context ◽  
Initial Seed ◽  
Stellar Masses

AbstractSupermassive black holes (BHs) live at the heart of essentially all massive galaxies with bulges, power AGN, and are thought to be important agents in the evolution of their hosts. Observations of high-redshift quasars demonstrate that supermassive BHs must start out with masses considerably in excess of normal stellar-mass BHs. However, we do not know how the initial “seed” BHs formed in the early Universe, how massive they were originally, or what types of galaxies they formed in. While direct observations of distant seed BHs and their hosts in the infant Universe are unobtainable with current capabilities, models of BH growth in a cosmological context indicate that present-day dwarf galaxies can place valuable constraints on seed masses and distinguish between various seed formation mechanisms at early times. Using optical spectroscopy from the SDSS, we have systematically assembled the largest sample of dwarf galaxies hosting AGN to date. These dwarf galaxies have stellar masses comparable to the Magellanic Clouds and contain some of the least-massive supermassive BHs known. I will present results from this study and discuss our ongoing efforts to find additional examples of AGN in dwarfs and help constrain theories for the formation of the first seed BHs at high redshift.

scholarly journals How a Star’s Death Can Reveal a Black Hole

2022 ◽  
Vol 9 ◽  
Author(s):  
Iair Arcavi
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Massive Black Holes ◽  
Know How ◽  
The Universe

Studying invisible objects in space that are hundreds of millions of light years away may sound impossible. But, in recent years, astronomers have developed a new way to investigate a type of invisible and distant objects—super-massive black holes. Black holes are the most densely packed objects in the Universe. When stars get close to super-massive black holes they can be torn apart, which produces a relatively brief but informative flash of light. These star-destroying events can help us to discover the locations of the most massive black holes in the Universe, but only if we know how to find and interpret them. In this article, we will discuss different ways we can “see” black holes, and particularly what we do and do not yet understand about stars getting “tidally disrupted” by them. Light YearThe distance light travels in a year, which is 5,878,625,370,000 miles.

scholarly journals Studying the outskirts of reverberation mapped AGNs

2016 ◽  
Vol 12 (S324) ◽  
pp. 219-222
Author(s):  
Shai Kaspi
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
High Redshift ◽  
Mapping Technique ◽  
Black Hole Mass ◽  
High Luminosity ◽  
Massive Black Holes ◽  
Reverberation Mapping ◽  
The Past ◽  
Different Types

AbstractAbout 100 AGNs have their black hole mass measured directly using the reverberation mapping technique over the past few decades. By now we have high enough numbers to explore unique subsamples within these objects and to study phenomena across variety of AGNs. I will review recent reverberation mapping studies which focus on high-redshift high-luminosity AGNs and on AGNs with super-Eddington accreting massive black holes. These studies enable to investigate the BLR size, mass, and luminosity relations in different subsamples of AGNs and to check whether there are differences in these relations in different types of AGNs. In particular I will discuss the following questions: Is the BLR size - luminosity relation the same over the whole AGNs luminosity range? Are there different relations for different types of AGNs? What are these studies teaching us about theory of accretion into black holes in AGNs?

scholarly journals Discovery of a 12 billion solar mass black hole at redshift 6.3 and its challenge to the black hole/galaxy coevolution at cosmic dawn

2015 ◽  
Vol 11 (S319) ◽  
pp. 80-83 ◽  
Author(s):  
Xue-Bing Wu ◽  
Feige Wang ◽  
Xiaohui Fan ◽  
Weimin Yi ◽  
Wenwen Zuo ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Infrared Spectroscopy ◽  
Galaxy Formation ◽  
Near Infrared ◽  
Host Galaxy ◽  
Black Hole Mass ◽  
Solar Mass ◽  
Massive Black Holes ◽  
Mass Assembly

AbstractThe existence of black holes with masses of about one billion solar masses in quasars at redshifts z > 6 presents significant challenges to theories of the formation and growth of black holes and the black hole/galaxy co-evolution in the early Universe. Here we report a recent discovery of an ultra-luminous quasar at redshift z = 6.30, which has an observed optical and near-infrared luminosity a few times greater than those of previously known z > 6 quasars. With near-infrared spectroscopy, we obtain a black hole mass of about 12 billion solar masses, which is well consistent with the mass derived by assuming an Eddington-limited accretion. This ultra-luminous quasar with at z > 6 provides a unique laboratory to the study of the mass assembly and galaxy formation around the most massive black holes at cosmic dawn. It raises further challenges to the black hole/galaxy co-evolution in the epoch of cosmic reionization because the black hole needs to grow much faster than the host galaxy.

Local heating of the universe by the Higgs field

2018 ◽  
Vol 27 (06) ◽  
pp. 1841003
Author(s):  
K. M. Belotsky ◽  
A. V. Grobov ◽  
S. G. Rubin
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Chemical Composition ◽  
Scalar Field ◽  
Local Heating ◽  
Dynamical Behavior ◽  
Higgs Field ◽  
Hole Formation ◽  
Massive Black Holes ◽  
The Universe

It is shown that the creation of primordial massive black holes is accompanied by a local heating of the matter. The developed mechanism is based on the interaction of the Higgs field and a scalar field responsible for black hole formation. We also consider dynamical behavior of parameters such as a scale and chemical composition of such heating regions.

Models for galaxy and massive black hole formation and early evolution

2020 ◽  
Vol 15 (S359) ◽  
pp. 11-16
Author(s):  
Rainer Weinberger
Keyword(s):  
Black Holes ◽  
Galaxy Formation ◽  
Luminosity Function ◽  
Accretion Rate ◽  
High Redshift ◽  
Massive Black Hole ◽  
Massive Black Holes ◽  
Complex Processes ◽  
Accretion Rates ◽  
Eddington Limit

AbstractModels for massive black holes are a key ingredient for modern cosmological simulations of galaxy formation. The necessity of efficient AGN feedback in these simulations makes it essential to model the formation, growth and evolution of massive black holes, and parameterize these complex processes in a simplified fashion. While the exact formation mechanism is secondary for most galaxy formation purposes, accretion modeling turns out to be crucial. It can be informed by the properties of the high redshift quasars, accreting close to their Eddington limit, by the quasar luminosity function at peak activity and by low-redshift scaling relations. The need for halo-wide feedback implies a feedback-induced reduction of the accretion rate towards low redshift, amplifying the cosmological trend towards lower accretion rates at low redshift.

scholarly journals Co-Evolution of Supermassive Black Holes and Their Host Galaxies

2009 ◽  
Vol 5 (S267) ◽  
pp. 34-39
Author(s):  
J. K. Kotilainen ◽  
R. Decarli ◽  
R. Falomo ◽  
A. Treves ◽  
M. Labita ◽  
...  
Keyword(s):  
Black Holes ◽  
Stellar Population ◽  
High Redshift ◽  
Host Galaxy ◽  
Host Galaxies ◽  
Massive Black Holes ◽  
Galaxy Masses ◽  
Age Of The Universe ◽  
Black Hole Masses ◽  
The Universe

AbstractWe study the evolution of the MBH/Mhost relation up to z = 3 for a sample of 96 quasars with known host galaxy luminosities. Black hole masses are estimated assuming virial equilibrium in the broad-line regions, while the host galaxy masses are inferred from their luminosities. With this data, we are able to pin down the evolution of the MBH/Mhost relation over 85% of the age of the universe. While the MBH/Lhost relation remains nearly unchanged, taking into account the aging of the stellar population, we find that the MBH/Mhost ratio (Γ) increases by a factor ~ 7 from z = 0 to z = 3. We show that the evolution of Γ is independent of radio loudness and quasar luminosity. We propose that the most massive black holes, in their quasar phase at high-redshift, become extremely rare objects in host galaxies of similar mass in the local universe.

scholarly journals Massive black holes in high-redshift Lyman Break Galaxies

2021 ◽  
Vol 502 (2) ◽  
pp. 2757-2769
Author(s):  
M C Orofino ◽  
A Ferrara ◽  
S Gallerani
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Upper Bound ◽  
Luminosity Function ◽  
High Redshift ◽  
Emission Lines ◽  
Tree Model ◽  
Massive Black Holes ◽  
X Ray ◽  
Lyman Break Galaxies

ABSTRACT Several evidences indicate that Lyman Break Galaxies (LBGs) in the Epoch of Reionization (redshift z > 6) might host massive black holes (MBHs). We address this question by using a merger-tree model combined with tight constraints from the 7 Ms Chandra survey and the known high-z super-MBH population. We find that a typical LBG with MUV = −22 residing in an Mh ≈ 1012 M⊙ halo at z = 6 host an MBH with mass M• ≈ 2 × 108 M⊙. Depending on the fraction, fseed, of early haloes planted with a direct collapse black hole seed (Mseed = 105M⊙), the model suggests two possible scenarios: (i) if fseed = 1, MBHs in LBGs mostly grow by merging and must accrete at a low (λE ≃ 10−3) Eddington ratio not to exceed the experimental X-ray luminosity upper bound $L_\mathrm{ X}^* = 10^{42.5} {\rm erg\, s}^{-1}$; (ii) if fseed = 0.05, accretion dominates (λE ≃ 0.22) and MBH emission in LBGs must be heavily obscured. In both scenarios the UV luminosity function is largely dominated by stellar emission up to very bright mag, $M_{\rm UV} \lower.5ex\hbox{$\,\, \buildrel\gt \over \sim \,\,$}-23$, with BH emission playing a subdominant role. Scenario (i) poses extremely challenging, and possibly unphysical, requirements on DCBH formation. Scenario (ii) entails testable implications on the physical properties of LBGs involving the FIR luminosity, emission lines, and the presence of outflows.

scholarly journals Subhalo sinking and off-centre massive black holes in dwarf galaxies

2020 ◽  
Vol 495 (1) ◽  
pp. L12-L16 ◽  
Author(s):  
Pierre Boldrini ◽  
Roya Mohayaee ◽  
Joseph Silk
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dwarf Galaxies ◽  
Dynamical Friction ◽  
Host Galaxies ◽  
Transfer Energy ◽  
Massive Black Hole ◽  
Massive Black Holes ◽  
First Time

ABSTRACT Using fully GPU N-body simulations, we demonstrate for the first time that subhaloes sink and transfer energy via dynamical friction into the centres of dwarf galaxies. This dynamical heating kicks any central massive black hole out to tens of parsecs, especially at early epochs (z = 1.5–3). This mechanism helps explain the observed off-centre black holes (BHs) in dwarf galaxies and also predicts that off-centre BHs are more common in higher mass dwarf galaxies since dynamical friction becomes significantly weaker and BHs take more time to sink back towards the centres of their host galaxies. One consequence of off-centre BHs during early epochs of dwarf galaxies is to quench any BH feedback.

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