GINGA Observations of the Dipping Low-Mass X-Ray Binaries XB 1916-053 and EXO 0748-676
Abstract
Ginga observations of XB 1916-053 and EXO 0748-676, low-mass X-ray binaries with pronounced dips of variable depth and duration in their X-ray light curves, are reported. Periodicity studies of XB-1916-053 show results consistent with those from previous Ginga observations, specifically, that the derived X-ray period is shorter than the optical period by about 1 percent. This problem is discussed, and a more refined model for the system is described. Three bursts were detected during the observation of XB 1916-053, the second of which occurred during a dip. Spectral analysis suggests that the second burst caused an almost instantaneous ionization of the absorbing medium in the line of sight. This material then returned to its equilibrium state on the same time scale as the burst decay. Loose limits are placed upon the possible clumpiness of the material responsible for the accretion disk structure in XB 1916-053 and EXO 0748-676.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1992
- DOI:
- 10.1086/171999
- Bibcode:
- 1992ApJ...400..330S
- Keywords:
-
- Light Curve;
- Satellite Observation;
- Spaceborne Astronomy;
- Stellar Mass;
- X Ray Binaries;
- Accretion Disks;
- Dipping;
- Ginga Satellite;
- Astrophysics;
- STARS: BINARIES: ECLIPSING;
- STARS: INDIVIDUAL ALPHANUMERIC: EXO 0748-676;
- STARS: INDIVIDUAL ALPHANUMERIC: XB 1916-053;
- X-RAYS: STARS