Browsing Faculty of Arts and Sciences by Keyword "X-rays: binaries"
Now showing items 1-20 of 21
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The Black Hole Mass Distribution in the Galaxy
(IOP Publishing, 2010)We use dynamical mass measurements of 16 black holes in transient low-mass X-ray binaries to infer the stellar black hole mass distribution in the parent population. We find that the observations are best described by a ... -
Chasing the Identification of ASCA Galactic Objects (ChIcAGO) - An X-ray Survey of Unidentified Sources in the Galactic Plane I: Source Sample and Initial Results
(IOP Publishing, 2014)We present the Chasing the Identification of ASCA Galactic Objects (ChIcAGO) survey, which is designed to identify the unknown X-ray sources discovered during the ASCA Galactic Plane Survey (AGPS). Little is known about ... -
Confirmation via the Continuum-Fitting Method That the Spin of the Black Hole in Cygnus X-1 Is Extreme
(IOP Publishing, 2014)In Gou et al., we reported that the black hole primary in the X-ray binary Cygnus X-1 is a near-extreme Kerr black hole with a spin parameter a∗ > 0.95 (3σ). We confirm this result while setting a new and more stringent ... -
The Cool Accretion Disk in ESO 243-49 HLX-1: Further Evidence of an Intermediate-Mass Black Hole
(IOP Publishing, 2011)With an inferred bolometric luminosity exceeding \(10^{42}\;erg\;s^{–1}\), HLX-1 in ESO 243-49 is the most luminous of ultraluminous X-ray sources and provides one of the strongest cases for the existence of intermediate-mass ... -
A Determination of the Spin of the Black Hole Primary in LMC X-1
(IOP Publishing, 2009)The first extragalactic X-ray binary, LMC X-1, was discovered in 1969. In the 1980s, its compact primary was established as the fourth dynamical black hole candidate. Recently, we published accurate values for the mass of ... -
Erratum: "Precise Measurement of the Spin Parameter of the Stellar-Mass Black hole M33 X-7” (2008, ApJ, 679, L37)
(IOP Publishing, 2010)In prior work, Chandra and Gemini-North observations of the eclipsing X-ray binary M33 X-7 have yielded measurements of the mass of its black hole primary and the system’s orbital inclination angle of unprecedented accuracy. ... -
The Extreme Spin of the Black Hole in Cygnus X-1
(IOP Publishing, 2011)The compact primary in the X-ray binary Cygnus X-1 was the first black hole to be established via dynamical observations. We have recently determined accurate values for its mass and distance, and for the orbital inclination ... -
A High-Frequency Doppler Feature in the Power Spectra of Simulated Grmhd Black Hole Accretion Disks
(IOP Publishing, 2014)Black hole binaries exhibit a wide range of variability phenomena, from large-scale state changes to broadband noise and quasi-periodic oscillations, but the physical nature of much of this variability is poorly understood. ... -
Identification of a Population of X-Ray-Emitting Massive Stars in the Galactic Plane
(IOP Publishing, 2011)We present X-ray, infrared, optical, and radio observations of four previously unidentified Galactic plane X-ray sources: AX J163252-4746, AX J184738-0156, AX J144701-5919, and AX J144547-5931. Detection of each source ... -
Improved Mass and Radius Constraints for Quiescent Neutron Stars in Omega Cen and NGC 6397
(Oxford University Press (OUP), 2014)We use Chandra and XMM–Newton observations of the globular clusters ω Cen and NGC 6397 to measure the spectrum of their quiescent neutron stars (NSs), and thus to constrain the allowed ranges of mass and radius for each. ... -
Inferring the Inclination of a Black Hole Accretion Disk From Observations of Its Polarized Continuum Radiation
(IOP Publishing, 2009)Spin parameters of stellar-mass black holes in X-ray binaries are currently being estimated by fitting the X-ray continuum spectra of their accretion disk emission. For this method, it is necessary to know the inclination ... -
The Intermediate Luminosity Optical Transient Sn 2010da: The Progenitor, Eruption, and Aftermath of a Peculiar Supergiant High-Mass X-Ray Binary
(American Astronomical Society, 2016)We present optical spectroscopy, ultraviolet-to-infrared imaging, and X-ray observations of the intermediate luminosity optical transient (ILOT) SN 2010da in NGC 300 (d = 1.86 Mpc) spanning from −6 to +6 years relative to ... -
Jet Power and Black Hole Spin: Testing an Empirical Relationship and Using It to Predict the Spins of Six Black Holes
(IOP Publishing, 2012)Using 5 GHz radio luminosity at light-curve maximum as a proxy for jet power and black hole spin measurements obtained via the continuum-fitting method, Narayan & McClintock presented the first direct evidence for a ... -
The Mass of the Black Hole in Cygnus X-1
(IOP Publishing, 2011)Cygnus X-1 is a binary star system that is comprised of a black hole and a massive giant companion star in a tight orbit. Building on our accurate distance measurement reported in the preceding paper, we first determine ... -
Measuring Black Hole Spin by the Continuum-Fitting Method: Effect of Deviations from the Novikov-Thorne Disc Model
(Oxford University Press (OUP), 2011)The X-ray spectra of accretion discs of eight stellar mass black holes have been analysed to date using the thermal continuum-fitting method, and the spectral fits have been used to estimate the spin parameters of the black ... -
A New Dynamical Model for the Black Hole Binary Lmc X-1
(IOP Publishing, 2009)We present a dynamical model of the high mass X-ray binary LMC X-1 based on high-resolution optical spectroscopy and extensive optical and nearinfrared photometry. From our new optical data we find an orbital period of P ... -
NuSTAR Hard X-ray Survey of the Galactic Center Region II: X-ray Point Sources
(American Astronomical Society, 2016)We present the first survey results of hard X-ray point sources in the Galactic Center (GC) region by NuSTAR. We have discovered 70 hard (3–79 keV) X-ray point sources in a 0.6 deg${}^{2}$ region around Sgr A* with a total ... -
A Parallax Distance to the Microquasar Grs 1915+105 and a Revised Estimate of Its Black Hole Mass
(IOP Publishing, 2014)Using the Very Long Baseline Array, we have measured a trigonometric parallax for the microquasar GRS 1915+105, which contains a black hole and a K-giant companion. This yields a direct distance estimate of 8.6 +2.0 −1.6 ... -
The Spin of the Black Hole in the Soft X-Ray Transient A0620-00
(IOP Publishing, 2010)During its year-long outburst in 1975–76, the transient source A0620–00 reached an intensity of 50 Crab, an all-time record for any X-ray binary. The source has been quiescent since then. We have recently determined accurate ... -
Testing Slim-Disk Models on the Thermal Spectra of LMC X-3
(EDP Sciences, 2011)Slim-disk models describe advective accretion flows at high luminosities, while reducing to the standard thin disk form in the low luminosity limit. We have developed a new spectral model, slimbb, within the framework of ...