SMC X-1
Abstract
S. N. Zhang, C. R. Robinson, R. B. Wilson, B. A. Harmon, and D. M. Scott, on behalf of the BATSE/CGRO team; and R. Remillard, on behalf of the ASM/RXTE team, report: "Quasiperiodic flux variations have been observed from the 0.7-s pulsar SMC X-1 with a period around 60 days, in the energy bands 1.3-12 keV (ASM/RXTE) and 20-100 keV (BATSE/CGRO), confirming the HEAO-1 results in 1977-1978 (Gruber and Rothschild 1984, Ap.J. 283, 546). A sequence of five outbursts between early Oct. 1995 and mid-Aug. 1996 is apparent in the BATSE/CGRO lightcurve, of which the last three coincide with those observed from ASM/RXTE (the first two of the three ASM outbursts have been reported by Levine et al. 1996, Ap.J. 469, L33). The peak flux is about 30 mCrab in both bands. No significant outbursts were observed in the BATSE data between Apr. 1991 and Oct. 1995, though a weak level of emission at about 10-20 mCrab was sometimes detected. Eclipses with a duration of about 20 percent of the orbital period of 3.9 days are observed in both data sets. The current outburst was detected about Aug. 27."
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- September 1996
- Bibcode:
- 1996IAUC.6468....1Z