10 papers · 1 filter
Highly Ionized Absorption in the X-ray Spectrum of Cyg X-1
H. L. Marshall, N. S. Schulz, T. Fang +4
Using the Chandra High Energy Transmission Grating Spectrometer (HETGS), we have found significant absorption features in the X-ray spectrum of Cyg X-1 taken in the continuous cloc…
X-ray intensity-hardness correlation in Cyg X-1
Linqing Wen, Wei Cui, Hale V. Bradt
Using data from the All-Sky Monitor aboard the Rossi X-ray Timing Explorer (RXTE), we found that the 1.5-12 keV X-ray count rate of Cyg X-1 is, on time scales from 90 seconds to at…
Phase Lags of QPOs in Microquasar GRS 1915+105
Wei Cui
I report the discovery of hard X-ray phase lags associated with the famous 67 Hz quasi-periodic oscillation (QPO) in microquasar GRS 1915+105. The QPO is seen on multiple occasions…
X-ray Orbital Modulation of Cygnus X-1
Linqing Wen, Wei Cui, Alan M. Levine +1
We have analyzed over 2 years of RXTE/ASM data for Cygnus X-1. We have detected the 5.6-day orbital period in Lomb-Scargle periodograms of both light curves and hardness ratios whe…
X-Ray Spectral Behavior of the Relativistic Jet Source Cygnus X-3
M. L. McCollough, C. R. Robinson, S. N. Zhang +13
Cyg X-3 is an unusual X-ray binary which shows remarkable correlative behavior between the hard X-ray, soft X-ray, and the radio. We present an analysis of these long term light cu…
On Gravitomagnetic Precession and Qpo in Black Hole Candidates
Wei Cui, Wan Chen, S. N. Zhang
The X-ray observation of black hole candidates provides a valuable tool to probe regions very close to the central black hole, where strong-field relativistic effects become import…