Post-Periastron ASCA Observation of the PSR B1259-63 System
Abstract
We report on the results of a post-periastron ASCA observation of the PSR B1259-63 system, containing a 48 ms pulsar orbiting a Be star in an eccentric 3.4 yr orbit. The ASCA observation was carried out on 1994 February 28 when the radio pulsar was again visible after a prolonged 40-day radio eclipse near to periastron. The source was clearly detected with an X-ray luminosity (1--10 keV) L_X of ( 1.03 +/- 0.09 ) times 10(34) \ (d/2 kpc)(2) erg s(-1) , where d is the pulsar's distance. The X-ray spectrum is well-represented by a single power-law model of the photon index, alpha = 1.61 +/- 0.06, and a small photoelectric absorption, N_H = (5.6 +/- 0.6) times 10(21) cm(-2) . No significant X-ray pulsations were detected, and the upper limit for the pulsed component was estimated to be 15% of the total X-ray flux, assuming sinusoidal modulation. The characteristics of the X-ray emission detected on 1994 February 28 are similar to those detected by ASCA near periastron when the pulsed radio emission from PSR B1259-63 was eclipsed. Our results strongly favor a non-thermal model of X-ray emission driven by synchrotron radiation from relativistic shocked particles in the pulsar wind interacting with the outflow from the Be star companion.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- December 1996
- DOI:
- 10.1093/pasj/48.6.833
- Bibcode:
- 1996PASJ...48..833H
- Keywords:
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- PULSARS;
- STARS: BE;
- STARS: INDIVIDUAL (PSR B1259-63);
- STARS: INDIVIDUAL (SS 2883);
- X-RAYS: BINARIES