Stellar black hole ≈ Stellar black hole
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First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole Open
When surrounded by a transparent emission region, black holes are expected to reveal a dark shadow caused by gravitational light bending and photon capture at the event horizon. To image and study this phenomenon, we have assembled the Eve…
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First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring Open
The Event Horizon Telescope (EHT) has mapped the central compact radio source of the elliptical galaxy M87 at 1.3 mm with unprecedented angular resolution. Here we consider the physical implications of the asymmetric ring seen in the 2017 …
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ASTROPHYSICAL IMPLICATIONS OF THE BINARY BLACK HOLE MERGER GW150914 Open
The discovery of the gravitational-wave (GW) source GW150914 with the Advanced LIGO detectors provides the first observational evidence for the existence of binary black hole (BH) systems that inspiral and merge within the age of the unive…
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Binary Black Hole Population Properties Inferred from the First and Second Observing Runs of Advanced LIGO and Advanced Virgo Open
We present results on the mass, spin, and redshift distributions with phenomenological population models using the 10 binary black hole (BBH) mergers detected in the first and second observing runs completed by Advanced LIGO and Advanced V…
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Binary black hole mergers from globular clusters: Masses, merger rates, and the impact of stellar evolution Open
The recent discovery of GW150914, the binary black hole merger detected by Advanced LIGO, has the potential to revolutionize observational astrophysics. But to fully utilize this new window into the universe, we must compare these new obse…
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Rapid and Bright Stellar-mass Binary Black Hole Mergers in Active Galactic Nuclei Open
The Laser Interferometer Gravitational-wave Observatory (LIGO) found direct evidence for double black hole binaries emitting gravitational waves. Galactic nuclei are expected to harbor the densest population of stellar-mass black holes. A …
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Gravitational-wave signatures of exotic compact objects and of quantum corrections at the horizon scale Open
Gravitational waves from binary coalescences provide one of the cleanest signatures of the nature of compact objects. It has been recently argued that the post-merger ringdown waveform of exotic ultracompact objects is initially identical …
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Post-Newtonian Dynamics in Dense Star Clusters: Highly Eccentric, Highly Spinning, and Repeated Binary Black Hole Mergers Open
We present models of realistic globular clusters with post-Newtonian dynamics for black holes. By modeling the relativistic accelerations and gravitational-wave emission in isolated binaries and during three- and four-body encounters, we f…
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Black holes: The next generation—repeated mergers in dense star clusters and their gravitational-wave properties Open
When two black holes merge in a dense star cluster, they form a new black\nhole with a well-defined mass and spin. If that "second-generation" black hole\nremains in the cluster, it will continue to participate in dynamical\nencounters, fo…
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Are merging black holes born from stellar collapse or previous mergers? Open
Advanced LIGO detectors at Hanford and Livingston made two confirmed and one\nmarginal detection of binary black holes during their first observing run. The\nfirst event, GW150914, was from the merger of two black holes much heavier that\n…
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The effect of pair-instability mass loss on black-hole mergers Open
Context. Mergers of two stellar-origin black holes are a prime source of gravitational waves and are under intensive investigation. One crucial ingredient in their modeling has been neglected: pair-instability pulsation supernovae with ass…
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Primordial Black Holes as a Dark Matter Candidate Are Severely Constrained by the Galactic Center 511 keV-Ray Line Open
We derive the strongest constraint on the fraction of dark matter that can be composed of low mass primordial black holes by using the observation of the Galactic Center 511 keV γ-ray line. Primordial black holes of masses ≲10^{15} kg will…
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Cygnus X-1 contains a 21–solar mass black hole—Implications for massive star winds Open
A heavy black hole in an x-ray binary If a black hole interacts with a binary companion star, the system emits x-rays and can form a radio jet. The masses of black holes in these x-ray binaries are all lower than those detected using gravi…
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Testing General Relativity with Stellar Orbits around the Supermassive Black Hole in Our Galactic Center Open
We demonstrate that short-period stars orbiting around the supermassive black hole in our Galactic center can successfully be used to probe the gravitational theory in a strong regime. We use 19 years of observations of the two best measur…
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Spectroscopy of Kerr Black Holes with Earth- and Space-Based Interferometers Open
We estimate the potential of present and future interferometric gravitational-wave detectors to test the Kerr nature of black holes through "gravitational spectroscopy," i.e., the measurement of multiple quasinormal mode frequencies from t…
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Black holes on FIRE: stellar feedback limits early feeding of galactic nuclei Open
We introduce massive black holes (BHs) in the Feedback In Realistic Environments (FIRE) project and perform high-resolution cosmological hydrodynamic simulations of quasar-mass haloes [Mhalo(z = 2) ≈ 1012.5 M⊙] down to z = 1. These simulat…
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DYNAMICAL FORMATION OF THE GW150914 BINARY BLACK HOLE Open
We explore the possibility that GW150914, the binary black hole (BBH) merger recently detected by Advanced LIGO, was formed by gravitational interactions in the core of a dense star cluster. Using models of globular clusters (GCs) with det…
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Black hole growth through hierarchical black hole mergers in dense star clusters: implications for gravitational wave detections Open
In a star cluster with a sufficiently large escape velocity, black holes\n(BHs) that are produced by BH mergers can be retained, dynamically form new BH\nbinaries, and merge again. This process can repeat several times and lead to\nsignifi…
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The spin of the second-born black hole in coalescing binary black holes Open
Context . Various binary black hole formation channels have been proposed since the first gravitational event GW150914 was discovered by the Advanced Laser Interferometer Gravitational-Wave Observatory (AdLIGO). The immediate progenitor of…
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Forming short-period Wolf–Rayet X-ray binaries and double black holes through stable mass transfer Open
We show that black-hole High-Mass X-ray Binaries (HMXBs) with O- or B-type\ndonor stars and relatively short orbital periods, of order one week to several\nmonths may survive spiral in, to then form Wolf-Rayet (WR) X-ray binaries with\norb…
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Black hole and neutron star mergers in galactic nuclei Open
Nuclear star clusters surrounding supermassive black holes (SMBHs) in galactic nuclei contain large numbers of stars, black holes (BHs), and neutron stars (NSs), a fraction of which are likely to form binaries. These binaries were suggeste…
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UPPER LIMITS ON THE RATES OF BINARY NEUTRON STAR AND NEUTRON STAR–BLACK HOLE MERGERS FROM ADVANCED LIGO’S FIRST OBSERVING RUN Open
We report here the non-detection of gravitational waves from the merger of binary–neutron star systems and neutron star–black hole systems during the first observing run of the Advanced Laser Interferometer Gravitational-wave Observatory (…
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Orbital Migration of Interacting Stellar Mass Black Holes in Disks around Supermassive Black Holes Open
The merger rate of stellar-mass black hole binaries (sBHBs) inferred by the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) suggests the need for an efficient source of sBHB formation. Active galactic nucleus (AGN) disk…
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Black holes in galaxies: Environmental impact on gravitational-wave generation and propagation Open
We introduce a family of solutions of Einstein's gravity minimally coupled to an anisotropic fluid, describing asymptotically flat black holes with "hair"and a regular horizon. These spacetimes can describe the geometry of galaxies harbori…
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A quasi-periodic modulation of the iron line centroid energy in the black hole binary H1743−322 Open
Accreting stellar-mass black holes often show a ‘Type-C’ quasi-periodic oscillation (QPO) in their X-ray flux and an iron emission line in their X-ray spectrum. The iron line is generated through continuum photons reflecting off the accret…
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Distinguishing boson stars from black holes and neutron stars from tidal interactions in inspiraling binary systems Open
Binary systems containing boson stars---self-gravitating configurations of a complex scalar field--- can potentially mimic black holes or neutron stars as gravitational-wave sources. We investigate the extent to which tidal effects in the …
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Constraining Primordial Black Hole Abundance with the Galactic 511 keV Line Open
Models in which dark matter consists entirely of primordial black holes (PBHs) with masses around 10^{17} g are currently unconstrained. However, if PBHs are a component of the Galactic dark matter density, they will inject a large flux of…
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A lower bound on the maximum mass if the secondary in GW190814 was once a rapidly spinning neutron star Open
The recent detection of GW190814 featured the merger of a binary with a primary having a mass of $\sim 23\, \mathrm{ M}_{\odot }$ and a secondary with a mass of $\sim 2.6\, \mathrm{ M}_{\odot }$. While the primary was most likely a black h…
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A Multimass Velocity Dispersion Model of 47 Tucanae Indicates No Evidence for an Intermediate-mass Black Hole Open
In this paper, we analyze stellar proper motions in the core of the globular cluster 47 Tucanae to explore the possibility of an intermediate-mass black hole (IMBH) influence on the stellar dynamics. Our use of short-wavelength photometry …
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Properties and astrophysical implications of the 150 M binary black hole merger GW190521 Open
The gravitational-wave signal GW190521 is consistent with a binary black hole merger source at redshift 0.8 with unusually high component masses, $85^{+21}_{-14}\\,M_{\\odot}$ and $66^{+17}_{-18}\\,M_{\\odot}$, compared to previously repor…