The spectral and temporal variability of the X-ray transient 4U1630-47

✍ Scribed by A. N. Parmar; L. Stella; N. E. White

• Publisher: Springer Netherlands
• Year: 1985
• Tongue: English
• Weight: 377 KB
• Volume: 40
• Category: Article
• ISSN: 0038-6308
• DOI: 10.1007/bf00179847

✦ Synopsis

We present the results of four observations made by the European Space Agency's EXOSAT Observatory of the X-ray transient 4U1630-47 during its 1984 outburst. We observed marked spectral changes as the source decayed from a maximum observed intensity of 8x10 -9 erg/cm2/sec (1.5-10 keV). The spectrum could be modelled by a soft 'thermal-like' component with a high energy power-law tail. The relative contribution of the soft to hard component decreased as the total luminosity decreased. We compare these changes with those observed from the black hole candidate Cyg X-1 when it transitions from a high to a low state. In addition we report the discovery of short timescale intensity variations (down to ~ 50 msec) with a characteristic timescale of ~ 20 sec. We present a precise position for this unidentified source.