Pulse Profiles and Spin Change of VELA X-1
Abstract
X-ray pulsar Vela X-1 was observed with X-ray astronomy satellite HAKUCHO in March 1979 and in March and December 1980. The energy and binary phase dependences of the X-ray pulse profile are accounted for in terms of the circumstellar absorption possibly associated with the accretion flow pattern. The spin period was found to increase over the time span of 22 months, in contrast to a gradual decrease observed in 1976 - 1978.
- Publication:
-
International Cosmic Ray Conference
- Pub Date:
- 1981
- Bibcode:
- 1981ICRC....1...42H
- Keywords:
-
- Eclipsing Binary Stars;
- Pulsars;
- Stellar Mass Accretion;
- Stellar Rotation;
- X Ray Astronomy;
- X Ray Sources;
- Angular Momentum;
- Neutron Stars;
- Stellar Envelopes;
- Stellar Luminosity;
- Astrophysics;
- ECLIPSING BINARY STARS;
- PULSARS;
- STELLAR MASS ACCRETION;
- STELLAR ROTATION;
- X RAY ASTRONOMY;
- X RAY SOURCES;
- ANGULAR MOMENTUM;
- NEUTRON STARS;
- STELLAR ENVELOPES;
- STELLAR LUMINOSITY