HEXE observations of Cygnus X-1.

Details HEXE observations of Cygnus X-1. HEXE observations of Cygnus X-1.

Oct 1995

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995a%26a...302..115d&link_type=abstract

Astronomy and Astrophysics, v.302, p.115

Astronomy and Astrophysics

Astrophysics

5

X-Rays: Stars, Stars: Cyg X-1, Black Holes

Scientific paper

The High Energy X-ray Experiment (HEXE) observed the black hole candidate Cyg X-1 on several occasions during the years 1987 to 1991. Together, these observations comprise the most sensitive measurements in the hard X-ray range of 20-200keV of this source to date. We present results of the spectroscopy and the timing analysis. During all observation periods in 1987 to 1991 Cyg X-1 was in the low, hard state. The variability of the hard X-ray intensity on long time scales was less than 20%. The flux was comparable to the γ_2_ level as observed by HEAO 3. There were no significant spectral changes during all this time. Comptonisation models do not give a good description for the time-averaged spectrum. A much better fit can be obtained using a Compton reflection model, assuming a primary hard power law spectrum with photon index α=1.64+/-0.01, which is partially reflected by cool matter with a covering factor of 0.59+/-0.04. The timing analysis shows the pattern of a low-frequency plateau followed by a 1/f decrease in the power spectrum, which is well known from observations at lower energies. No QPO peaks were detected.

Affiliated with

Also associated with

No associations

Rating

HEXE observations of Cygnus X-1. does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with HEXE observations of Cygnus X-1., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and HEXE observations of Cygnus X-1. will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1351175