Ultra-massive Black Holes Research Articles

On the need of an ultramassive black hole in OJ 287

ABSTRACT The highly variable blazar OJ 287 is commonly discussed as an example of a binary black hole system. The 130 yr long optical light curve is well explained by a model where the central body is a massive black hole of 18.35 $\times$ 109 solar mass that supports a thin accretion disc. The secondary black hole of 0.15 $\times$ 109 solar mass impacts the disc twice during its 12 yr orbit, and causes observable flares. Recently, it has been argued that an accretion disc with a typical Active Galactic Nuclei (AGN) accretion rate and above mentioned central body mass should be at least six magnitudes brighter than OJ 287’s host galaxy and would therefore be observationally excluded. Based on the observations of OJ 287’s radio jet, detailed in Marscher and Jorstad (2011), and up-to-date accretion disc models of Azadi et al. (2022), we show that the V-band magnitude of the accretion disc is unlikely to exceed the host galaxy brightness by more than one magnitude, and could well be fainter than the host. This is because accretion power is necessary to launch the jet as well as to create electromagnetic radiation, distributed across many wavelengths, and not concentrated especially on the optical V-band. Further, we note that the claimed V-band concentration of accretion power leads to serious problems while interpreting observations of other AGN. Therefore, we infer that the mass of the primary black hole and its accretion rate do not need to be smaller than what is determined in the standard model for OJ 287.

Triple and quadruple black holes in the ASTRID simulation at z ∼ 2

ABSTRACT We use the ASTRID cosmological hydrodynamic simulation to investigate the properties and evolution of triple and quadruple massive black hole (MBH) systems at z = 2–3. Only a handful of MBH tuple systems have been detected to date. In ASTRID, we find 4 per cent of the $M_{\rm BH}\gt 10^7\, M_\odot$ are in tuples with $\Delta r_{\rm max} \lt 200\, {\rm kpc}$. The tuple systems span a range of separations with the majority of the observable AGN systems at Δr ∼ 50–100 kpc. They include some of the most massive BHs (up to $10^{10} \, M_\odot$) but with at least one of the components of $M_{\rm BH} \sim 10^7 \, {\rm M}_{\odot }$. Tuples’ host galaxies are typically massive with $M_* \sim 10^{10-11} \, M_\odot$. We find that $\gt 10~{{\ \rm per\ cent}}$ massive haloes with Mhalo > 1013 M⊙ host MBH tuples. Following the subsequent interactions between MBHs in tuples, we found that in $\sim 5~{{\ \rm per\ cent}}$ of the triplets all three MBHs merge within a Gyr, and 15 per cent go through one merger. As a by-product of the complex multigalaxy interaction of these systems, we also find that up to $\sim 5~{{\ \rm per\ cent}}$ of tuples lead to runaway MBHs. In ASTRID, virtually all of the ultramassive black holes ($\gt 10^{10} \, M_\odot$) have undergone a triple quasar phase, while for BHs with $M_{\rm BH} \sim 10^9 \, M_\odot$, this fraction drops to 50 per cent.

Abell 1201: detection of an ultramassive black hole in a strong gravitational lens

ABSTRACTSupermassive black holes (SMBHs) are a key catalyst of galaxy formation and evolution, leading to an observed correlation between SMBH mass MBH and host galaxy velocity dispersion σe. Outside the local Universe, measurements of MBH are usually only possible for SMBHs in an active state: limiting sample size and introducing selection biases. Gravitational lensing makes it possible to measure the mass of non-active SMBHs. We present models of the $z$ = 0.169 galaxy-scale strong lens Abell 1201. A cD galaxy in a galaxy cluster, it has sufficient ‘external shear’ that a magnified image of a $z$ = 0.451 background galaxy is projected just ∼1 kpc from the galaxy centre. Using multiband Hubble Space Telescope imaging and the lens modelling software PYAUTOLENS, we reconstruct the distribution of mass along this line of sight. Bayesian model comparison favours a point mass with MBH = 3.27 ± 2.12 × 1010 M⊙ (3σ confidence limit); an ultramassive black hole. One model gives a comparable Bayesian evidence without an SMBH; however, we argue this model is nonphysical given its base assumptions. This model still provides an upper limit of MBH ≤ 5.3 × 1010 M⊙, because an SMBH above this mass deforms the lensed image ∼1 kpc from Abell 1201’s centre. This builds on previous work using central images to place upper limits on MBH, but is the first to also place a lower limit and without a central image being observed. The success of this method suggests that surveys during the next decade could measure thousands more SMBH masses, and any redshift evolution of the MBH−σe relation. Results are available at https://github.com/Jammy2211/autolens_abell_1201.

Ultra-low-frequency Gravitational Waves from Massive Clusters at z ∼ 1

Recent progress with pulsar timing array experiments, especially from the NANOGrav collaboration, indicates that we are on the cusp of detecting significant signals from the inspiral of supermassive black hole (BH) binaries. While recent analysis has focused on nearby galaxies as possible sources of the loudest signals, we show that mergers in identified clusters at z ∼ 1 can have larger strain amplitudes. We make an estimate comparing the nearby Two Micron All Sky Survey redshift survey (2MASS) galaxy sample with the more distant Massive and Distant Clusters of WISE Survey (MaDCoWs) cluster sample, showing that the latter might be expected to contribute more, and louder, gravitational-wave events. Thus, the first individual source detections may well be from ultramassive BHs in clusters at z ∼ 1, rather than nearby galaxies.

Ultramassive Black Holes Formed by Triple Quasar Mergers at z ∼ 2

The origin of rare and elusive ultramassive black holes (UMBH; with M BH > 1010 M ⊙) is an open question. Using the large volume cosmological hydrodynamic simulation ASTRID, we report on the formation of an extremely massive UMBH with M BH ∼ 1011 M ⊙ at z ∼ 2. The UMBH is assembled as a result of two successive mergers of massive galaxies each with stellar mass M * > 3 × 1011 M ⊙ that also produces a bright, rare triple quasar system powered by three ∼109 M ⊙ black holes. The second merger of supermassive black holes (SMBHs) follows the first after 150 Myr. The merger events lead to sustained Eddington accretion onto the central SMBH, forming a UMBH in the center of a massive compact stellar core with M * > 2 × 1012 M ⊙. The strong feedback of the UMBH quenches the surrounding star formation to <10 M ⊙ yr−1 in the inner 50 h −1 kpc region. There are two more UMBHs with M BH > 5 × 1010 M ⊙ at z > 2 in ASTRID that are also produced by major mergers of galaxies, and their progenitors can be observed as quasar triplets of lower luminosity. The rarely observed quasar multiples can be the cradle of UMBHs at high redshift, and likely end up in the center of the most massive clusters.

A Study on the detection and formation mechanisms of ultra-massive black holes

With the discovery of Ultra-massive black holes and Super-massive black holes, humans have yet to find out the cause of their formation with modern technology. Based on the analysis, we will look at the detection methods and calculation methods for black holes and their mass. Besides, we will also dive deeper into the actual formation of these Ultra-massive black holes. Taking a closer look at black holes’ sizes, there are many black holes between 0.1Ms and up to its maximum 150Ms, but something interesting is that after 150 Ms, we can barely find any black holes bigger than that until we reach black holes with millions of times the mass of our sun. This is quite fascinating, as if the knowledge we have now suggests that bigger black holes are formed through devouring and merging of other black holes. It is simply impossible for some of these black holes to even exist, as looking at the amount of time the universe existed, that is impossible for black holes of this mass to even form. In this paper, the detection method for black holes and black holes’ mass and the formation model of ultra-massive black holes will be discussed, which involves concepts like Quasi Stars and Quasi Black holes. These results shed light for us to discover the formation of ultra-massive black holes.

Probing within the Bondi radius of the ultramassive black hole in NGC 1600

ABSTRACT We present deep (250 ks) Chandra observations of the nearby galaxy group NGC 1600, which has at its centre an ultramassive black hole (17 ± 1.5 billion M⊙). The exceptionally large mass of the black hole coupled with its low redshift makes it one of only a handful of black holes for which spatially resolved temperature and density profiles can be obtained within the Bondi radius with the high spatial resolution of Chandra. We analysed the hot gas properties within the Bondi accretion radius R$_{\mbox{B}}=1.2\!-\!1.7\:\mathrm{ arcsec}= 0.38\!-\!0.54 \,{\mbox{kpc}}$. Within a ∼3 kpc radius, we find two temperature components with statistical significance. Both the single-temperature and two-temperature models show only a very slight rise in temperature towards the centre, and are consistent with being flat. This is in contrast with the expectation from Bondi accretion for a temperature profile which increases towards the centre, and appears to indicate that the dynamics of the gas are not being determined by the central black hole. The density profile follows a relatively shallow ρ ∝ r−[0.61 ± 0.13] relationship within the Bondi radius, which suggests that the true accretion rate on to the black hole may be lower than the classical Bondi accretion rate.

Is Hawking effect short-lived in polymer quantization?

It is widely believed that the Hawking effect might hold clues to the possible, yet unknown, trans-Planckian physics. On the other hand, one could ask whether the effect itself might be altered by such trans-Planckian physics. We seek an answer to this question within a framework where matter field is quantized using polymer quantization, a canonical quantization technique employed in loop quantum gravity. We provide an exact derivation of the Hawking effect using canonical formulation by introducing a set of near-null coordinates which allows one to overcome the challenges posed by a Hamiltonian-based derivation of the Hawking effect. Subsequently, we show that in polymer quantization, the Hawking effect is short-lived and it eventually disappears for an asymptotic future observer. Such an observer finds the duration of the Hawking effect to be few milliseconds for a solar mass black hole, whereas it is few years for an ultramassive black hole. Consequently, it provides a new way to resolve the so-called information loss paradox.

Cosmological tests of Everpresent Λ

Everpresent Λ is a cosmological scenario in which the observed cosmological ‘constant’ Λ fluctuates between positive and negative values with a vanishing mean, and with a magnitude comparable to the critical density at any epoch. In accord with a longstanding heuristic prediction of causal set theory, it postulates that Λ is a stochastic function of cosmic time that will vary from one realization of the scenario to another. Herein, we consider two models of ‘dark energy’ that exhibit these features. Via Monte Carlo Markov chains, we explore the space of cosmological parameters and the set of stochastic realizations of these models, finding that Everpresent Λ can fit current cosmological observations as well as the ΛCDM model does. Furthermore, it removes the observational tensions that ΛCDM experiences in relation to low redshift measurements of the Hubble constant, and to the baryonic acoustic oscillations (BAO) in Lyman-α forest at –3. It does not, however, help significantly with the early growth of ultramassive black holes, or with the Lithium problem in Big Bang nucleosynthesis. Future measurements of ‘dark energy’ at high redshifts will further test the viability of Everpresent Λ as an alternative to the ΛCDM cosmology.

Ultramassive black hole feedback in compact galaxies

Recent observations confirm the existence of ultra-massive black holes (UMBH) in the nuclei of compact galaxies, with physical properties similar to NGC 1277. The nature of these objects poses a new puzzle to the `black hole-host galaxy co-evolution' scenario. We discuss the potential link between UMBH and galaxy compactness, possibly connected via extreme active galactic nucleus (AGN) feedback at early times ($z > 2$). In our picture, AGN feedback is driven by radiation pressure on dust. We suggest that early UMBH feedback blows away all the gas beyond a $\sim$kpc or so, while triggering star formation at inner radii, eventually leaving a compact galaxy remnant. Such extreme UMBH feedback can also affect the surrounding environment on larger scales, e.g. the outflowing stars may form a diffuse stellar halo around the compact galaxy, or even escape into the intergalactic or intracluster medium. On the other hand, less massive black holes will drive less powerful feedback, such that the stars formed within the AGN feedback-driven outflow remain bound to the host galaxy, and contribute to its size growth over cosmic time.

Black-hole mass estimates for a homogeneous sample of bright flat-spectrum radio quasars

We have selected a complete sample of flat-spectrum radio quasars (FSRQs) from the WMAP 7-yr catalog within the SDSS area, all with measured redshift, and have compared the black hole mass estimates based on fitting a standard accretion disk model to the `blue bump' with those obtained from the commonly used single epoch virial method. The sample comprises 79 objects with a flux density limit of 1 Jy at 23 GHz, 54 of which (68%) have a clearly detected `blue bump'. Thirty-four of the latter have, in the literature, black hole mass estimates obtained with the virial method. The mass estimates obtained from the two methods are well correlated. If the calibration factor of the virial relation is set to $f=4.5$, well within the range of recent estimates, the mean logarithmic ratio of the two mass estimates is equal to zero with a dispersion close to the estimated uncertainty of the virial method. The fact that the two independent methods agree so closely in spite of the potentially large uncertainties associated with each lends strong support to both of them. The distribution of black-hole masses for the 54 FSRQs in our sample with a well detected blue bump has a median value of $7.4\times 10^{8}\,M_\odot$. It declines at the low mass end, consistent with other indications that radio loud AGNs are generally associated with the most massive black holes, although the decline may be, at least partly, due to the source selection. The distribution drops above $\log(M_\bullet/M_\odot) = 9.4$, implying that ultra-massive black holes associated with FSRQs must be rare.

A Captured Black Hole?

Astronomy NGC 1277, a compact lenticular galaxy located in the Perseus Cluster, hosts a black hole 17 billion times as massive as the Sun. Most galaxies are thought to have a massive black hole at their centers, but it usually represents only 0.1% of the mass of the stellar bulge of the galaxy. The black hole in NGC 1277 accounts for 59% of the stellar bulge mass. Shields and Bonning propose that such an overweight black hole did not form in NGC 1277 but was instead captured from another, much larger galaxy, where ultra-massive black holes are more likely to form. They suggest that the black hole formed through the merger of two giant elliptical galaxies, each containing a massive black hole. The inspiral of the two black holes resulted in the ejection of the larger black hole produced by merger. The ejected black hole then wandered in the core of the cluster until it got captured by NGC 1277 during a chance encounter. Astrophys. J. 772 , L5 (2013).

X-ray emission from the ultramassive black hole candidate NGC 1277: implications and speculations on its origin

Abstract We study the X-ray emission from NGC 1277, a galaxy in the core of the Perseus cluster, for which van den Bosch et al. have recently claimed the presence of an ultramassive black hole (UMBH) of mass $1.7\times 10^{10}{\,\mathrm{M}_{{\odot }}}$, unless the initial mass function of the stars in the stellar bulge is extremely bottom heavy. The X-rays originate in a power-law component of luminosity $1.3\times 10^{40}{\,{\rm erg}\,{\rm s}^{-1}\,}$ embedded in a 1 keV thermal minicorona which has a half-light radius of about 1.3 kpc, typical of many early-type galaxies in rich clusters of galaxies. If Bondi accretion operated on to the UMBH from the minicorona with a radiative efficiency of 10 per cent, then the object would appear as a quasar with luminosity $10^{46}{\,{\rm erg}\,{\rm s}^{-1}\,}$, a factor of almost 106 times higher than observed. The accretion flow must be highly radiatively inefficient, similar to past results on M87 and NGC 3115. The UMBH in NGC 1277 is definitely not undergoing any significant growth at the present epoch. We note that there are three UMBH candidates in the Perseus cluster and that the inferred present mean mass density in UMBHs could be $10^5{\,\mathrm{M}_{{\odot }}}\,{\rm Mpc^{-3}}$, which is 20–30 per cent of the estimated mean mass density of all BHs. We speculate on the implied growth of UMBHs and their hosts, and discuss the possibility that extreme active galactic nucleus feedback could make all UMBH host galaxies have low stellar masses at redshifts around 3. Only those which end up at the centres of groups and clusters later accrete large stellar envelopes and become brightest cluster galaxies. NGC 1277 and the other Perseus core UMBH, NGC 1270, have not, however, been able to gather more stars or gas owing to their rapid orbital motion in the cluster core.

On the hunt for ultramassive black holes in brightest cluster galaxies

We investigate where brightest cluster galaxies (BCGs) sit on the fundamental plane of black hole (BH) activity, an established relation between the X-ray luminosity, the radio luminosity and the mass of a BH. Our sample mostly consists of BCGs that lie at the centres of massive, strong cooling flow clusters, therefore requiring extreme mechanical feedback from their central active galactic nucleus (AGN) to offset cooling of the intracluster plasma (L_mech>10^44-45 erg/s). Based on the BH masses derived from the M_BH-sigma and M_BH-M_K correlations, we find that all of our objects are offset from the plane such that they appear to be less massive than predicted from their X-ray and radio luminosities (to more than a 99 per cent confidence level). For these objects to be consistent with the fundamental plane, the M_BH-sigma and M_BH-M_K correlations therefore seem to underestimate the BH masses of BCGs, on average by a factor of 10. Our results suggest that the standard relationships between BH mass and host galaxy properties no longer hold for these extreme galaxies. Furthermore, our results imply that if these BHs follow the fundamental plane, then many of those that lie in massive, strong cool core clusters must be ultramassive with M_BH>10^10M_sun. This rivals the largest BH masses known and has important ramifications for our understanding of the formation and evolution of BHs.

AN ENERGETIC AGN OUTBURST POWERED BY A RAPIDLY SPINNING SUPERMASSIVE BLACK HOLE OR AN ACCRETING ULTRAMASSIVE BLACK HOLE

Powering the 10^62 erg nuclear outburst in the MS0735.6+7421 cluster central galaxy by accretion implies that its supermassive black hole (SMBH) grew by ~6x10^8 solar masses over the past 100 Myr. We place upper limits on the amount of cold gas and star formation near the nucleus of <10^9 solar masses and <2 solar masses per year, respectively. These limits imply that an implausibly large fraction of the preexisting cold gas in the bulge must have been consumed by its SMBH at the rate of ~3-5 solar masses per year while leaving no trace of star formation. Such a high accretion rate would be difficult to maintain by stellar accretion or the Bondi mechanism, unless the black hole mass approaches 10^11 solar masses. Its feeble nuclear luminosities in the UV, I, and X-ray bands compared to its enormous mechanical power are inconsistent with rapid accretion onto a ~5x10^9 solar mass black hole. We suggest instead that the AGN outburst is powered by a rapidly-spinning black hole. A maximally-spinning, 10^9 solar mass black hole contains enough rotational energy, ~10^62 erg, to quench a cooling flow over its lifetime and to contribute significantly to the excess entropy found in the hot atmospheres of groups and clusters. Two modes of AGN feedback may be quenching star formation in elliptical galaxies centered in cooling halos at late times. An accretion mode that operates in gas-rich systems, and a spin mode operating at modest accretion rates. The spin conjecture may be avoided in MS0735 by appealing to Bondi accretion onto a central black hole whose mass greatly exceeds 10^10 solar mass. The host galaxy's unusually large, 3.8 kpc stellar core radius (light deficit) may witness the presence of an ultramassive black hole.

Is there an upper limit to black hole masses?

We make a case for the existence for ultra-massive black holes (UMBHs) in the Universe, but argue that there exists a likely upper limit to black hole masses of the order of $M \sim 10^{10} \msun$. We show that there are three strong lines of argument that predicate the existence of UMBHs: (i) expected as a natural extension of the observed black hole mass bulge luminosity relation, when extrapolated to the bulge luminosities of bright central galaxies in clusters; (ii) new predictions for the mass function of seed black holes at high redshifts predict that growth via accretion or merger-induced accretion inevitably leads to the existence of rare UMBHs at late times; (iii) the local mass function of black holes computed from the observed X-ray luminosity functions of active galactic nuclei predict the existence of a high mass tail in the black hole mass function at $z = 0$. Consistency between the optical and X-ray census of the local black hole mass function requires an upper limit to black hole masses. This consistent picture also predicts that the slope of the $M_{\rm bh}$-$\sigma$ relation will evolve with redshift at the high mass end. Models of self-regulation that explain the co-evolution of the stellar component and nuclear black holes naturally provide such an upper limit. The combination of multi-wavelength constraints predicts the existence of UMBHs and simultaneously provides an upper limit to their masses. The typical hosts for these local UMBHs are likely the bright, central cluster galaxies in the nearby Universe.

A Giant Radio Jet Ejected by an Ultramassive Black Hole in a Single-lobed Radio Galaxy

We report the discovery of a very unusual, highly asymmetric radio galaxy whose radio jet, the largest yet detected, emits strongly polarized synchrotron radiation and can be traced all the way from the galactic nucleus to the hot spot located ~440 kpc away. This jet emanates from an extremely massive black hole (>10^9 solar mass) and forms a strikingly compact radio lobe. No radio lobe is detected on the side of the counterjet, even though it is similar to the main jet in brightness up to a scale of tens of kiloparsecs. Thus, contrary to the nearly universal trend, the brightness asymmetry in this radio galaxy increases with distance from the nucleus. With several unusual properties, including a predominantly toroidal magnetic field, this Fanaroff-Riley type II megajet is an exceptionally useful laboratory for testing the role of magnetic field in jet stabilization and radio lobe formation.

Ultraluminous X-Ray Sources in External Galaxies

We investigate models for the class of ultraluminous nonnuclear X-ray sources (i.e., ultraluminous compact X-ray sources [ULXs]) seen in a number of galaxies and probably associated with star-forming regions. Models in which the X-ray emission is assumed to be isotropic run into several difficulties. In particular, the formation of sufficient numbers of the required ultramassive black hole X-ray binaries is problematic, and the likely transient behavior of the resulting systems is not in good accord with observation. The assumption of mild X-ray beaming suggests instead that ULXs may represent a short-lived but extremely common stage in the evolution of a wide class of X-ray binaries. The best candidate for this is the phase of thermal-timescale mass transfer that is inevitable in many intermediate- and high-mass X-ray binaries. This in turn suggests a link with the Galactic microquasars. The short lifetimes of high-mass X-ray binaries would explain the association of ULXs with episodes of star formation. These considerations still allow the possibility that individual ULXs may contain extremely massive black holes.

Where Are the Dead Quasars?

Le modele standard de quasar admet un corollaire: de nombreuses galaxies proches, parmi lesquelles peut-etre meme la Voie Lactee, sont des quasars morts qui abritent encore des trous noirs ultra massifs

Gamma rays and neutrinos as complementary probes in astrophysics

Electrons are more susceptible to energy losses in magnetic fields and photon fields than protons. Hence, photons at various wavelengths, including gamma rays, bring more readily information on high-energy electrons than on protons. Neutrinos provide a unique tracer for protons. Furthermore, at high energies the neutrino flux can considerably exceed the gamma-ray flux, as gamma rays above ~ 1 MeV are degraded by γ-γ interactions in compact high-intensity sources. Active galactic nuclei (AGN) with outputs > 1045 ergs s−1 and dimensions ~ 1014 cm would constitute such sources. If the AGN are powered by ultra-massive black holes, then these numerical conditions are satisfied, and at high energies the flux J ν > J γ. Berezinsky and Ginzburg have pointed out that the photon intensity around spinars is not sufficient to cause gamma-ray degradation. These authors have demonstrated that the measurement of neutrino flux, combined with the measurement (or upper limit) of gamma-ray flux would show whether the active galactic nuclei are powered by massive black holes or spinars. We estimate that gamma rays would be degraded at spinars, too, at energies > 1 GeV.