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 Tidal disruption events from massive black hole binaries: predictions for ongoing and future surveys

2019 ◽  
Vol 488 (3) ◽  
pp. 4042-4060 ◽  
Author(s):  
Stephen Thorp ◽  
Eli Chadwick ◽  
Alberto Sesana
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Low Frequency ◽  
Mass Range ◽  
Tidal Disruption ◽  
Massive Black Hole ◽  
Massive Black Holes ◽  
X Ray ◽  
Black Hole Binaries ◽  
Survey Instruments

ABSTRACT We compute the expected cosmic rates of tidal disruption events (TDEs) induced by individual massive black holes (MBHs) and by MBH binaries (MBHBs) – with a specific focus on the latter class – to explore the potential of TDEs to probe the cosmic population of sub-pc MBHBs. Rates are computed by combining MBH and MBHB population models derived from large cosmological simulations with estimates of the induced TDE rates for each class of objects. We construct empirical TDE spectra that fit a large number of observations in the optical, UV, and X-ray and consider their observability by current and future survey instruments. Consistent with results in the literature, and depending on the detailed assumption of the model, we find that LSST and Gaia in optical and eROSITA in X-ray will observe a total of 3000–6000, 80–180, and 600–900 TDEs per year, respectively. Depending on the survey, 1 to several per cent of these are prompted by MBHBs. In particular, both LSST and eROSITA are expected to see 150–450 MBHB-induced TDEs in their respective mission lifetimes, including 5–100 repeated flares. The latter provide an observational sample of binary candidates with relatively low contamination and have the potential of unveiling the sub-pc population of MBHBs in the mass range $10^5\lt M\lt 10^7\, \mathrm{M}_\odot$, thus informing future low-frequency gravitational wave observatories.

scholarly journals Tidal disruption events from different kinds of astrophysical objects: a preliminary analysis

2016 ◽  
Vol 12 (S324) ◽  
pp. 132-133
Author(s):  
Aurora Clerici ◽  
Andreja Gomboc
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Preliminary Analysis ◽  
Tidal Disruption ◽  
Massive Black Hole ◽  
Massive Black Holes ◽  
Astrophysical Objects

AbstractTidal disruption events are a powerful tool to study quiescent massive black holes residing in the centre of galaxies. Occasionally, astrophysical objects such as stars, planets and smaller bodies are captured and tidally disrupted by the massive black hole, giving rise to a luminous flare. A detailed study of disruption parameters and the emitted radiation can give important insights on the black hole and its surroundings.

scholarly journals Rapid late-time X-ray brightening of the tidal disruption event OGLE16aaa

2020 ◽  
Vol 639 ◽  
pp. A100 ◽  
Author(s):  
Jari J. E. Kajava ◽  
Margherita Giustini ◽  
Richard D. Saxton ◽  
Giovanni Miniutti
Keyword(s):  
Black Hole ◽  
Host Galaxy ◽  
Late Time ◽  
Tidal Disruption ◽  
Massive Black Hole ◽  
X Ray ◽  
Tidal Forces ◽  
Upper Limits ◽  
Optical Light Curve ◽  
Disruption Event

Stars that pass too close to a super-massive black hole may be disrupted by strong tidal forces. OGLE16aaa is one such tidal disruption event (TDE) which rapidly brightened and peaked in the optical/UV bands in early 2016 and subsequently decayed over the rest of the year. OGLE16aaa was detected in an XMM-Newton X-ray observation on June 9, 2016 with a flux slightly below the Swift/XRT upper limits obtained during the optical light curve peak. Between June 16–21, 2016, Swift/XRT also detected OGLE16aaa and based on the stacked spectrum, we could infer that the X-ray luminosity had jumped up by more than a factor of ten in just one week. No brightening signal was seen in the simultaneous optical/UV data to cause the X-ray luminosity to exceed the optical/UV one. A further XMM-Newton observation on November 30, 2016 showed that almost a year after the optical/UV peak, the X-ray emission was still at an elevated level, while the optical/UV flux decay had already leveled off to values comparable to those of the host galaxy. In all X-ray observations, the spectra were nicely modeled with a 50–70 eV thermal component with no intrinsic absorption, with a weak X-ray tail seen only in the November 30 XMM-Newton observation. The late-time X-ray behavior of OGLE16aaa strongly resembles the tidal disruption events ASASSN-15oi and AT2019azh. We were able to pinpoint the time delay between the initial optical TDE onset and the X-ray brightening to 182 ± 5 days, which may possibly represent the timescale between the initial circularization of the disrupted star around the super-massive black hole and the subsequent delayed accretion. Alternatively, the delayed X-ray brightening could be related to a rapid clearing of a thick envelope that covers the central X-ray engine during the first six months.

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 Optical Flares from the Tidal Disruption of Stars by Massive Black Holes

2009 ◽  
Vol 5 (S267) ◽  
pp. 337-337 ◽  
Author(s):  
Linda E. Strubbe ◽  
Eliot Quataert
Keyword(s):  
Galactic Nuclei ◽  
Stellar Dynamics ◽  
Theoretical Models ◽  
X Rays ◽  
Tidal Disruption ◽  
Massive Black Hole ◽  
Detection Rates ◽  
Massive Black Holes ◽  
Near Ir ◽  
Nuclear Regions

A star that wanders too close to a massive black hole (BH) is shredded by the BH's tidal gravity. Stellar gas falls back to the BH, releasing a flare of energy. In anticipation of upcoming transient surveys, we predict the light curves and spectra of tidal flares as a function of time, highlighting the unique signatures of tidal flares in the optical and near-IR. Some of the gas initially bound to the BH is likely blown away when the fallback rate is super-Eddington at early times. This outflow produces an optical luminosity comparable to that of a supernova (Figure 1, left panel); such events have durations of ~ 10 days and may have been missed in supernova searches that exclude the nuclear regions of galaxies. When the fallback rate subsides below Eddington, the gas accretes onto the BH via a thin disk whose emission peaks in the UV to soft X-rays. Some of this emission is reprocessed by the unbound stellar debris, producing a spectrum of very broad emission lines, with no corresponding narrow forbidden lines (center panel). These lines are strongest for BHs with MBH ~ 105–106M⊙ and thus optical surveys are particularly sensitive to the lowest mass BHs in galactic nuclei. Calibrating our models to ROSAT and GALEX observations, we predict detection rates for Pan-STARRS, Palomar Transit Factory, and LSST (right panel) and highlight observational challenges in the optical. Pan-STARRS should detect at least several events per year — many more if current theoretical models of super-Eddington outflows are correct. These surveys will significantly improve our knowledge of stellar dynamics in galactic nuclei, the physics of super-Eddington accretion, the demography of intermediate mass BHs, and the role of tidal disruption in the growth of massive BHs.

scholarly journals Constraining the stellar mass function from the deficiency of tidal disruption flares in the nuclei of massive galaxies

2019 ◽  
Vol 485 (3) ◽  
pp. 4413-4422 ◽  
Author(s):  
Daniel J D’Orazio ◽  
Abraham Loeb ◽  
James Guillochon
Keyword(s):  
Black Hole ◽  
Mass Function ◽  
Stellar Mass ◽  
High Mass ◽  
Black Hole Mass ◽  
Tidal Disruption ◽  
Massive Black Hole ◽  
Massive Black Holes ◽  
Massive Galaxies ◽  
O 10

ABSTRACT The rate of tidal disruption flares (TDFs) per mass of the disrupting black hole encodes information on the present-day mass function (PDMF) of stars in the clusters surrounding super massive black holes. We explore how the shape of the TDF rate with black hole mass can constrain the PDMF, with only weak dependence on black hole spin. We show that existing data can marginally constrain the minimum and maximum masses of stars in the cluster, and the high-mass end of the PDMF slope, as well as the overall TDF rate. With $\mathcal {O}(100)$ TDFs expected to be identified with the Zwicky Transient Facility, the overall rate can be highly constrained, but still with only marginal constraints on the PDMF. However, if ${\lesssim } 10 {{\ \rm per\ cent}}$ of the TDFs expected to be found by LSST over a decade ($\mathcal {O}(10^3)$ TDFs) are identified, then precise and accurate estimates can be made for the minimum stellar mass (within a factor of 2) and the average slope of the high-mass PDMF (to within $\mathcal {O}(10{{\ \rm per\ cent}})$) in nuclear star clusters. This technique could be adapted in the future to probe, in addition to the PDMF, the local black hole mass function and possibly the massive black hole binary population.

scholarly journals Very high redshift quasars and the rapid emergence of super-massive black holes

2020 ◽  
Author(s):  
Pavel Kroupa ◽  
Ladislav Subr ◽  
Tereza Jerabkova ◽  
Long Wang
Keyword(s):  
Black Hole ◽  
Massive Star ◽  
High Redshift ◽  
Host Galaxy ◽  
Massive Black Hole ◽  
First Stars ◽  
Massive Black Holes ◽  
Nuclear Cluster ◽  
Gas Accretion ◽  
Very High

Abstract The observation of quasars at very high redshift such as Pōniuā’ena is a challenge for models of super-massive black hole (SMBH) formation. This work presents a study of SMBH formation via known physical processes in star-burst clusters formed at the onset of the formation of their hosting galaxy. While at the early stages hyper-massive star-burst clusters reach the luminosities of quasars, once their massive stars die, the ensuing gas accretion from the still forming host galaxy compresses its stellar black hole (BH) component to a compact state overcoming heating from the BH–BH binaries such that the cluster collapses, forming a massive SMBH-seed within about a hundred Myr. Within this scenario the SMBH–spheroid correlation emerges near-to-exactly. The highest-redshift quasars may thus be hyper-massive star-burst clusters or young ultra-compact dwarf galaxies (UCDs), being the precursors of the SMBHs that form therein within about 200 Myr of the first stars. For spheroid masses ≲ 109.6 M⊙ a SMBH cannot form and instead only the accumulated nuclear cluster remains. The number evolution of the quasar phases with redshift is calculated and the possible problem of missing quasars at very high redshift is raised. SMBH-bearing UCDs and the formation of spheroids are discussed critically in view of the high redshift observations. A possible tension is found between the high star-formation rates (SFRs) implied by downsizing and the observed SFRs, which may be alleviated within the IGIMF theory and if the downsizing times are somewhat longer.

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.

scholarly journals Observational Progress in Identifying and Characterizing Tidal Disruption Flares

2016 ◽  
Vol 12 (S324) ◽  
pp. 93-98
Author(s):  
S. Bradley Cenko
Keyword(s):  
Black Hole ◽  
Optical Spectra ◽  
Starburst Galaxies ◽  
Electromagnetic Spectrum ◽  
Speed Of Light ◽  
Tidal Disruption ◽  
Massive Black Hole ◽  
X Ray ◽  
Tidal Forces

AbstractI present an overview of observational efforts across the electromagnetic spectrum to identify and study tidal disruption flares (TDFs), when a star wanders too close to a super-massive black hole and is torn apart by tidal forces. In particular I will focus on four unexpected surprises that challenge the most basic analytic picture of these events: 1) large inferred radii for the optical/UV-emitting material; 2) the ubiquity of outflows, detected at radio, X-ray, and UV wavelengths, ranging from speeds of 100 km/s to near the speed of light; 3) the peculiar atomic abundances observed in the UV and optical spectra of these objects; and, 4) the preference for these events to occur in post-starburst galaxies.

scholarly journals Tidal disruption events on to stellar black holes in triples

2019 ◽  
Vol 489 (1) ◽  
pp. 727-737 ◽  
Author(s):  
Giacomo Fragione ◽  
Nathan W C Leigh ◽  
Rosalba Perna ◽  
Bence Kocsis
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Force ◽  
Main Sequence ◽  
Initial Conditions ◽  
Main Sequence Stars ◽  
Tidal Disruption ◽  
Mean Velocity ◽  
Massive Black Holes ◽  
The Mean

ABSTRACT Stars passing too close to a black hole can produce tidal disruption events (TDEs), when the tidal force across the star exceeds the gravitational force that binds it. TDEs have usually been discussed in relation to massive black holes that reside in the centres of galaxies or lurk in star clusters. We investigate the possibility that triple stars hosting a stellar black hole (SBH) may be sources of TDEs. We start from a triple system made up of three main-sequence stars and model the supernova (SN) kick event that led to the production of an inner binary comprised of an SBH. We evolve these triples with a high-precision N-body code and study their TDEs as a result of Kozai–Lidov oscillations. We explore a variety of distributions of natal kicks imparted during the SN event, various maximum initial separations for the triples, and different distributions of eccentricities. We show that the main parameter that governs the properties of the SBH–MS binaries that produce a TDE in triples is the mean velocity of the natal kick distribution. Smaller σ’s lead to larger inner and outer semimajor axes of the systems that undergo a TDE, smaller SBH masses, and longer time-scales. We find that the fraction of systems that produce a TDE is roughly independent of the initial conditions, while estimate a TDE rate of $2.1\times 10^{-4}{\!-\!}4.7 \, \mathrm{yr}^{-1}$, depending on the prescriptions for the SBH natal kicks. This rate is almost comparable to the expected TDE rate for massive black holes.

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