X射线脉冲星4U 1538—52 的时间和能谱特性

本文处理分析了EXOSAT卫星对4U1538-524次中能观测资料,并结合其他观测结果对4U1538-52的时间和能谱特性作了分析和解释:中子星自转仍在减慢;能谱为幂律谱,Tenma卫星以后的观测未见Fe发射线;X射线dip现象可解释为一前景星对中子星的遮掩而形成;X射线爆发在不同的轨道位相出现,持续近1小时;在1keV附近似有一发射线。 

SOME CHARACTERISTICS OF TIMING AND ENERGY SPECTRUM OF X-RAY PULSAR 4U 1538-52

The source 4U 1538--52 is one of the well-studied X-ray pulsars. 4 mediumenergy (ME) observations with EXOSATare processed and analyzed, in which 2observations are during the X-ray eclipsing. Combined with the results of the otherobservations, some analyses and explainations are given in this paper. The spin-downof the neutron star is continuing duering the observations. The energy spectrum isthe power law spectrum, the iron line is not seen after Tenma observations. It isassumed that the X-ray dips will occur when the neutron star is eclipsed by a foreground star, a late-type dwarf. The X-ray bursts which sustained about 1 hour areformed by the increasing mass exchange and could occur at the different orbit phase.And there seem to be an emission line at the energy near 1 keV, if it is a cyclotronline, the magnetic field of the surface of the neutron star would be 8.6(1 + z) × 106T.