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 ◽  
...  

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.

2019 ◽  
Vol 15 (S356) ◽  
pp. 143-143
Author(s):  
Jaya Maithil ◽  
Michael S. Brotherton ◽  
Bin Luo ◽  
Ohad Shemmer ◽  
Sarah C. Gallagher ◽  
...  

AbstractActive Galactic Nuclei (AGN) exhibit multi-wavelength properties that are representative of the underlying physical processes taking place in the vicinity of the accreting supermassive black hole. The black hole mass and the accretion rate are fundamental for understanding the growth of black holes, their evolution, and the impact on the host galaxies. Recent results on reverberation-mapped AGNs show that the highest accretion rate objects have systematic shorter time-lags. These super-Eddington accreting massive black holes (SEAMBHs) show BLR size 3-8 times smaller than predicted by the Radius-Luminosity (R-L) relationship. Hence, the single-epoch virial black hole mass estimates of highly accreting AGNs have an overestimation of a factor of 3-8 times. SEAMBHs likely have a slim accretion disk rather than a thin disk that is diagnostic in X-ray. I will present the extreme X-ray properties of a sample of dozen of SEAMBHs. They indeed have a steep hard X-ray photon index, Γ, and demonstrate a steeper power-law slope, ασx.


Universe ◽  
2019 ◽  
Vol 5 (6) ◽  
pp. 145 ◽  
Author(s):  
David Garofalo ◽  
Damian J. Christian ◽  
Andrew M. Jones

By exploring more than sixty thousand quasars from the Sloan Digital Sky Survey Data Release 5, Steinhardt & Elvis discovered a sub-Eddington boundary and a redshift-dependent drop-off at higher black hole mass, possible clues to the growth history of massive black holes. Our contribution to this special issue of Universe amounts to an application of a model for black hole accretion and jet formation to these observations. For illustrative purposes, we include ~100,000 data points from the Sloan Digital Sky Survey Data Release 7 where the sub-Eddington boundary is also visible and propose a theoretical picture that explains these features. By appealing to thin disk theory and both the lower accretion efficiency and the time evolution of jetted quasars compared to non-jetted quasars in our “gap paradigm”, we explain two features of the sub-Eddington boundary. First, we show that a drop-off on the quasar mass-luminosity plane for larger black hole mass occurs at all redshifts. But the fraction of jetted quasars is directly related to the merger function in this paradigm, which means the jetted quasar fraction drops with decrease in redshift, which allows us to explain a second feature of the sub-Eddington boundary, namely a redshift dependence of the slope of the quasar mass–luminosity boundary at high black hole mass stemming from a change in radiative efficiency with time. We are able to reproduce the mass dependence of, as well as the oscillating behavior in, the slope of the sub-Eddington boundary as a function of time. The basic physical idea involves retrograde accretion occurring only for a subset of the more massive black holes, which implies that most spinning black holes in our model are prograde accretors. In short, this paper amounts to a qualitative overview of how a sub-Eddington boundary naturally emerges in the gap paradigm.


2015 ◽  
Vol 799 (2) ◽  
pp. 164 ◽  
Author(s):  
Daeseong Park ◽  
Jong-Hak Woo ◽  
Vardha N. Bennert ◽  
Tommaso Treu ◽  
Matthew W. Auger ◽  
...  

2009 ◽  
Vol 5 (S267) ◽  
pp. 262-262
Author(s):  
Javiera Guedes ◽  
Piero Madau ◽  
Lucio Mayer ◽  
Michael Kuhlen ◽  
Jürg Diemand ◽  
...  

AbstractThe coalescence of black hole binaries is a significant source of gravitational wave radiation. The typically asymmetric nature of this emission, which carries linear momentum, can result in the recoil of the black hole remnant with velocities in the range 100 < Vrecoil < 3750 km s−1. The detectability of recoiling massive black holes (MBH) as off-nuclear QSOs is tightly connected with the properties of the host galaxy, which determine the MBH's orbit and fuel reservoir. We present the results of N-body simulations of recoiling MBHs in high-resolution, non-axisymmetric potentials. We find that if the recoil velocities are high enough to reach regions of the galaxy dominated by the generally triaxial dark matter distribution, the return time is significantly extended when compared to a spherical distribution. We also perform simulations of recoiling MBHs traveling in gas merger remnants, where large amounts of gas have been funneled to the central regions, In this case, the MBHs remain within R<1 kpc from the center of the host even for high recoil velocities (Vrecoil = 1200 km s−1) due to the compactness of the remnant galaxy's nuclear disk. We discuss the implications of both scenarios for detectability.


2016 ◽  
Vol 12 (S324) ◽  
pp. 219-222
Author(s):  
Shai Kaspi

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?


2019 ◽  
Vol 630 ◽  
pp. A94 ◽  
Author(s):  
Margherita Giustini ◽  
Daniel Proga

Context. Understanding the physics and geometry of accretion and ejection around super massive black holes (SMBHs) is important to understand the evolution of active galactic nuclei (AGN) and therefore of the large scale structures of the Universe. Aims. We aim at providing a simple, coherent, and global view of the sub-parsec accretion and ejection flow in AGN with varying Eddington ratio, ṁ, and black hole mass, MBH. Methods. We made use of theoretical insights, results of numerical simulations, as well as UV and X-ray observations to review the inner regions of AGN by including different accretion and ejection modes, with special emphasis on the role of radiation in driving powerful accretion disk winds from the inner regions around the central SMBH. Results. We propose five ṁ regimes where the physics of the inner accretion and ejection flow around SMBHs is expected to change, and that correspond observationally to quiescent and inactive galaxies; low luminosity AGN (LLAGN); Seyferts and mini-broad absorption line quasars (mini-BAL QSOs); narrow line Seyfert 1 galaxies (NLS1s) and broad absorption line quasars (BAL QSOs); and super-Eddington sources. We include in this scenario radiation-driven disk winds, which are strong in the high ṁ, large MBH regime, and possibly present but likely weak in the moderate ṁ, small MBH regime. Conclusions. A great diversity of the accretion/ejection flows in AGN can be explained to a good degree by varying just two fundamental properties: the Eddington ratio ṁ and the black hole mass MBH, and by the inclusion of accretion disk winds that can naturally be launched by the radiation emitted from luminous accretion disks.


2019 ◽  
Vol 487 (4) ◽  
pp. 5764-5780 ◽  
Author(s):  
Nicole Thomas ◽  
Romeel Davé ◽  
Daniel Anglés-Alcázar ◽  
Matt Jarvis

ABSTRACT We examine the co-evolution of galaxies and supermassive black holes in the simba cosmological hydrodynamic simulation. simba grows black holes via gravitational torque-limited accretion from cold gas and Bondi accretion from hot gas, while feedback from black holes is modelled in radiative and jet modes depending on the Eddington ratio (fEdd). simba shows generally good agreement with local studies of black hole properties, such as the black hole mass–stellar velocity dispersion (MBH–σ) relation, the black hole accretion rate versus star formation rate (BHAR–SFR), and the black hole mass function. MBH–σ evolves such that galaxies at a given MBH have higher σ at higher redshift, consistent with no evolution in MBH–M⋆. For $M_{\rm BH}\lesssim 10^8\, {\rm M}_{\odot }$, fEdd is anticorrelated with MBH since the BHAR is approximately independent of MBH, while at higher masses fEdd–MBH flattens and has a larger scatter. BHAR versus SFR is invariant with redshift, but fEdd drops steadily with time at a given MBH, such that all but the most massive black holes are accreting in a radiatively efficient mode at $z\gtrsim 2$. The black hole mass function amplitude decreases with redshift and is locally dominated by quiescent galaxies for MBH > 108 M⊙, but for $z\gtrsim 1$ star-forming galaxies dominate at all MBH. The z = 0 fEdd distribution is roughly lognormal with a peak at $f_{\rm Edd}\lesssim 0.01$ as observed, shifting to higher fEdd at higher redshifts. Finally, we study the dependence of black hole properties with H i content and find that the correlation between gas content and SFR is modulated by black hole properties, such that higher SFR galaxies at a given gas content have smaller black holes with higher fEdd.


1998 ◽  
Vol 184 ◽  
pp. 377-384 ◽  
Author(s):  
H.C. Ford ◽  
Z.I. Tsvetanov ◽  
L. Ferrarese ◽  
W. Jaffe

After correcting spherical aberration in the Hubble Space Telescope in 1993, the central masses of galaxies can be measured with a resolution 5 to 10 times better than can be achieved at the best terrestrial sites. This improvement in resolution is decisive for detecting the gravitational signature of massive black holes in galaxy nuclei. The discovery of small (r ~ 100–200 pc) rotating gaseous and stellar disks in the centers of many early-type galaxies provides a new and efficient means for measuring the central potentials of galaxies. Concomitantly, VLBI observations of H2O masers in the nuclei of NGC 4258 and NGC 1068 revealed exquisite Keplerian rotation curves around massive black holes at radii as small as 0.1 pc. Recent terrestrial K-band measurements of the proper motions of stars in the cluster at the center of the galaxy provide irrefutable evidence for a black hole with a mass of 2.7 × 106M⊙. At the time of this symposium, the presence of central massive black holes has been established in 12 galaxies. The evidence suggests that there are massive black holes in the centers of all AGNs and in most, if not all, nucleated galaxies. The present data show at best a weak correlation between black hole mass and bulge luminosity.


2014 ◽  
Vol 10 (S312) ◽  
pp. 269-273 ◽  
Author(s):  
Alister W. Graham

AbstractThere is a growing array of supermassive black hole and nuclear star cluster scaling relations with their host spheroid, including a bent (black hole mass)–(host spheroid mass) Mbh–Msph relation and a different (massive compact object mass)–(host spheroid velocity dispersion) Mmco–σ relations for black holes and nuclear star clusters. By combining the observed Mbh ∝ σ5.5 relation with the observed Mnc ∝ σ1.6–2.7 relation, we derive the expression Mbh ∝ Mnc2–3.4, which should hold until the nuclear star clusters are eventually destroyed in the larger core-Sérsic spheroids. This new mass scaling relation helps better quantify the rapid evolutionary growth of massive black holes in dense star clusters, and the relation is consistently recovered when coupling the observed Mnc ∝ Msph0.6–1.0 relation with the recently observed quadratic relation Mbh ∝ Msph2 for Sérsic spheroids.


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