High frequencies in the power spectrum of Cyg X-1 in the hard and soft spectral states

Details High frequencies in the power spectrum of Cyg X-1 in the hard and soft spectral states High frequencies in the power spectrum of Cyg X-1 in the hard and soft spectral states

2000-07-07

arxiv.org/abs/astro-ph/0007092v2

Astronomy and Astrophysics

Astrophysics

7 pages, 8 figures. Accepted for publication in A&A

Scientific paper

We analyzed a large number of RXTE/PCA observations of Cyg X-1 in the hard and soft spectral states with total exposure time of ~190 and ~10 ksec respectively and time resolution better than ~250us in order to investigate its variability down to a few milliseconds time scales. The model of modifications of the power density spectra due to the dead time effect was tested using RXTE observations of an extremely bright source - Sco X-1. The results of these tests demonstrated, that although some problems still remain, for sources like Cyg X-1 (which is an order of magnitude less bright than Sco X-1) present knowledge of the instrument is sufficient to reliably analyze the power spectra in the kHz frequency range. In both spectral states of Cyg X-1 we detected statistically significant variability up to ~150-300 Hz with a fractional rms amplitude above 100 Hz at the level of ~2-3%. The power spectrum in the hard state shows a steepening at frequency of ~40-80 Hz with the power law slope changing from ~1.7 to ~2.3-2.4. In the soft state the slope of power spectrum changes from ~1 to ~2 at the frequency of ~15-20 Hz without any evidence of further steepening up to \~100-150 Hz. These break frequencies represent the highest characteristic frequencies detected in the power density spectrum of Cyg X-1 so far.

Affiliated with

Also associated with

No associations

Rating

High frequencies in the power spectrum of Cyg X-1 in the hard and soft spectral states 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 High frequencies in the power spectrum of Cyg X-1 in the hard and soft spectral states, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High frequencies in the power spectrum of Cyg X-1 in the hard and soft spectral states will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-574692