X-Ray Timing of the 34 Millisecond Binary Pulsar SAX J0635+0533
Abstract
Modulations detected in the observed spin period of the 34 ms X-ray pulsar SAX J0635+0533 show that the pulsar is in a binary system with a period of 11.2+/-0.5 days, a projected orbital semimajor axis asini=83+/-11 lt-s, a mass function in the range of 3.4-7.8 Msolar, and an orbital eccentricity of 0.29+/-0.09. A combination of observations spanning 2 yr places a lower bound on the intrinsic period derivative of the pulsar of 3.8×10-13. The period derivative implies a high torque on the neutron star that would require a very high mass accretion rate, in excess of 6×10-7 Msolar yr-1, if produced via accretion. The torque and X-ray luminosity are both within the range typical of young, rotation-powered pulsars.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2000
- DOI:
- 10.1086/312918
- Bibcode:
- 2000ApJ...542L..41K
- Keywords:
-
- Gamma Rays: Observations;
- Stars: Pulsars: General;
- Stars: Individual: Alphanumeric: 2EG J0635+0521;
- Stars: Individual: Alphanumeric: SAX J0635+0533;
- Stars: Neutron