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Dynamical Evidence for a Black Hole in the Microquasar XTE J1550-564
Optical spectroscopic observations of the companion star (type G8 IV to K4 III) in the microquasar system XTE J1550-564 reveal a radial velocity curve with a best-fitting spectroscopic period of Psp
Multiwavelength spectrum of the black hole xte j1118+480 in quiescence
We present an X-ray/UV/optical spectrum of the black hole primary in the X-ray nova XTE J1118+480 in quiescence at LX ? 4 ? 10-9LEdd. The Chandra, Hubble Space Telescope, and Multiple Mirror
Previously we claimed that black hole X-ray novae (BHXNs) in quiescence are much less luminous than equivalent neutron star X-ray novae (NSXNs). This claim was based on the quiescent detection of a
We consider the X-ray luminosity difference between neutron star and black hole soft X-ray transients (NS and BH SXTs) in quiescence. The current observational data suggest that BH SXTs are
Advection-dominated Accretion and Black Hole Event Horizons
The defining characteristic of a black hole is that it possesses an event horizon through which matter and energy can fall in but from which nothing escapes. Soft X-ray transients (SXTs), a class of
A Black Hole Greater Than 6 M☉ in the X-Ray Nova XTE J1118+480*
Observations of the quiescent X-ray nova XTE J1118+480 with the new 6.5 m Multiple Mirror Telescope have revealed that the velocity amplitude of the dwarf secondary is 698 ± 14 km s-1 and the orbital
A catalog of transient X-ray sources in M31
From 1999 October to 2002 August, 45 transient X-ray sources were detected in M31 by Chandra and XMM-Newton. We have performed spectral analysis of all XMM-Newton and Chandra ACIS detections of these
A synoptic X-ray study of M31 with the Chandra high resolution camera
The frequency of bright X-ray transients in the M31 bulge suggests that the ratio of neutron star to black hole primaries in low-massX-ray binaries (NS/BH) is ~1.5 and the cumulative luminosity function (CLF) of the disk sources is well-fit by a power-law with a slope comparable to those observed in typical elliptical galaxies.
The Smithsonian Astrophysical Observatory
Between September 2006 and February 2007, the galactic bina ry LS I +61 303 was monitored in the TeV band with the VERITAS array of imaging Cherenkov te lescopes. These observations confirm LS I +61
Two Neutron Star Soft X-Ray Transients in Quiescence: 4U 2129+47 and EXO 0748−676
We report on X-ray observations of two soft X-ray transients containing neutron stars, 4U 2129+47 and EXO 0748-676. Our emphasis is on the quiescent properties of these sources. The X-ray spectrum