X-ray binary
View article: GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral Open
On August 17, 2017 at 12∶41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio o…
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GW190425: Observation of a Compact Binary Coalescence with Total Mass ∼ 3.4 M<sub>⊙</sub> Open
On 2019 April 25, the LIGO Livingston detector observed a compact binary coalescence with signal-to-noise ratio 12.9. The Virgo detector was also taking data that did not contribute to detection due to a low signal-to-noise ratio, but were…
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GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo during the Second Part of the Third Observing Run Open
Plenary Talk presented at the XX International Workshop on Neutrino Telescopes - Venice 23-27 October 2023
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Discovery of pulsations from NGC 300 ULX1 and its fast period evolution Open
The supernova impostor SN 2010da located in the nearby galaxy NGC 300, later identified as a likely supergiant B[e] high-mass X-ray binary, was simultaneously observed by NuSTAR and XMM–Newton between 2016 December 16 and 20, over a total …
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A noninteracting low-mass black hole–giant star binary system Open
A black hole hiding in a binary star As material falls toward a black hole, it heats up and emits x-rays. Almost all black holes are discovered by this x-ray emission. Thompson et al. observed light from a giant star that is Doppler shifte…
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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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Multimessenger Bayesian parameter inference of a binary neutron star merger Open
The combined detection of a binary neutron star merger in both gravitational waves (GWs) and electromagnetic (EM) radiation spanning the entire spectrum – GW170817/AT2017gfo/GRB170817A – marks a breakthrough in the field of multimessenger …
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Eccentric Black Hole Mergers in Dense Star Clusters: The Role of Binary–Binary Encounters Open
We present the first systematic study of strong binary–single and binary–binary black hole (BH) interactions with the inclusion of general relativity. By including general relativistic effects in the equations of motion during strong encou…
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Improving the NRTidal model for binary neutron star systems Open
Accurate and fast gravitational waveform (GW) models are essential to extract\ninformation about the properties of compact binary systems that generate GWs.\nBuilding on previous work, we present an extension of the NRTidal model for\nbina…
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Global simulations of strongly magnetized remnant massive neutron stars formed in binary neutron star mergers Open
We perform a general-relativistic magnetohydrodynamics simulation for\n$\\approx 30$ ms after merger of a binary neutron star to a remnant massive\nneutron star (RMNS) with a high spatial resolution of the finest grid\nresolution $12.5$ m.…
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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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Neutron Stars and the Nuclear Matter Equation of State Open
Neutron stars provide a window into the properties of dense nuclear matter. Several recent observational and theoretical developments provide powerful constraints on their structure and internal composition. Among these are the first obser…
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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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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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Greatly Enhanced Merger Rates of Compact-object Binaries in Non-spherical Nuclear Star Clusters Open
The Milky Way and a significant fraction of galaxies are observed to host a central massive black hole (MBH) embedded in a non-spherical nuclear star cluster. We study the secular orbital evolution of compact-object binaries in these envir…
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A Deep Chandra X-Ray Study of Neutron Star Coalescence GW170817 Open
We report Chandra observations of GW170817, the first neutron star–neutron star merger discovered by the joint LIGO-Virgo Collaboration, and the first direct detection of gravitational radiation associated with an electromagnetic counterpa…
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Rotational properties of hypermassive neutron stars from binary mergers Open
Determining the differential-rotation law of compact stellar objects produced\nin binary neutron stars mergers or core-collapse supernovae is an old problem\nin relativistic astrophysics. Addressing this problem is important because it\nim…
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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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How to tell an accreting boson star from a black hole Open
The capability of the Event Horizon Telescope (EHT) to image the nearest supermassive black hole candidates at horizon-scale resolutions offers a novel means to study gravity in its strongest regimes and to test different models for these …
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Polarized x-rays constrain the disk-jet geometry in the black hole x-ray binary Cygnus X-1 Open
A black hole x-ray binary (XRB) system forms when gas is stripped from a normal star and accretes onto a black hole, which heats the gas sufficiently to emit x-rays. We report a polarimetric observation of the XRB Cygnus X-1 using the Imag…
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General relativistic simulations of compact binary mergers as engines for short gamma-ray bursts Open
Black hole - neutron star (BHNS) and neutron star - neutron star (NSNS)\nbinaries are among the favored candidates for the progenitors of the black hole\n- disk systems that may be the engines powering short-hard gamma ray bursts.\nAfter a…
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Constraints on binary neutron star merger product from short GRB observations Open
Binary neutron star mergers are strong gravitational wave (GW) sources and the leading candidates to interpret short duration gamma-ray bursts (SGRBs). Under the assumptions that SGRBs are produced by double neutron star mergers and that t…
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Neutron-Star Radius from a Population of Binary Neutron Star Mergers Open
We show how gravitational-wave observations with advanced detectors of tens to several tens of neutron-star binaries can measure the neutron-star radius with an accuracy of several to a few percent, for mass and spatial distributions that …
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Model comparison from LIGO–Virgo data on GW170817’s binary components and consequences for the merger remnant Open
GW170817 is the very first observation of gravitational waves originating from the coalescence of two compact objects in the mass range of neutron stars, accompanied by electromagnetic counterparts, and offers an opportunity to directly pr…
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Relativistic simulations of eccentric binary neutron star mergers: One-arm spiral instability and effects of neutron star spin Open
We perform general-relativistic hydrodynamical simulations of dynamical capture binary neutron star mergers, emphasizing the role played by the neutron star spin. Dynamical capture mergers may take place in globular clusters, as well as ot…
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Observation of Gravitational Waves from the Coalescence of a 2.5–4.5 M <sub>⊙</sub> Compact Object and a Neutron Star Open
We report the observation of a coalescing compact binary with component masses 2.5–4.5 M ⊙ and 1.2–2.0 M ⊙ (all measurements quoted at the 90% credible level). The gravitational-wave signal GW230529_181500 was observed during the fourth ob…
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On the Origin of Black Hole Spin in High-mass X-Ray Binaries Open
Black hole (BH) spins in low-mass X-ray binaries cover a range of values that can be explained by accretion after BH birth. In contrast, the three BH spin measurements in high-mass X-ray binaries (HMXBs) show only values near the maximum a…
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Equation of State Constraints from the Threshold Binary Mass for Prompt Collapse of Neutron Star Mergers Open
Using hydrodynamical simulations for a large set of high-density matter equations of state (EOSs), we systematically determine the threshold mass M_{thres} for prompt black-hole formation in equal-mass and asymmetric neutron star (NS) merg…