Noise variability in CYG X-1 and HER X-1
Abstract
The aperiodic variability in the x ray emission of Cyg X-1 and Her X-1 is examined from EXOSAT archive data by means of the production of broad band power spectra. The power spectra of Cyg X-1 is analyzed and show a complex shape and variations of the break frequency over one order of magnitude. Good agreement with the data is obtained using a shot noise model with a distribution in shot lifetimes. The noise in Her X-1 shows variations correlated with the 35d cycle of the source. The observations are consistent with occultation by the inner accretion disk.
- Publication:
-
Contributions of the X Ray Astronomy Group of the Max-Planck-Institut fuer Extraterrestrische Physik
- Pub Date:
- November 1989
- Bibcode:
- 1989xras.rept...17B
- Keywords:
-
- Neutron Stars;
- Noise Spectra;
- Shot Noise;
- Variability;
- X Ray Stars;
- Binary Stars;
- Cygnus Constellation;
- European Space Programs;
- Exosat Satellite;
- X Ray Astronomy;
- Astronomy