瞬态X射线脉冲星GRO J1008-57的朱雀观测
Suzaku observation of the transient X-ray pulsar GRO J1008-57
摘要：
利用朱雀观测站对2007年11月-12月Be瞬态高质量X射线脉冲双星GRO J1008-57爆发的衰减阶段进行了观测，研究了该脉冲双星的时间和宽带光谱特性。脉冲星的光变曲线在80-100 keV的能量范围内清晰地检测到周期为93.737 s的脉冲。脉冲轮廓被发现是强烈的能量依赖性，在软X射线能量带（< 8 keV）的双峰轮廓和单峰平滑轮廓在硬X射线。本文首次报道了脉冲星的宽带能谱，用三种不同的连续模型，即（i）高能截止幂律，（ii）指数截止的正负幂律（NPEX）和（iii）高能截止的部分覆盖幂律，很好地描述了脉冲星的宽带能谱。尽管在脉冲星的方向上的吸收柱密度的大值，一个黑体组件的温度~0.17 keV的软过剩所需的前两个连续模型。在脉冲星光谱中检测到一条窄的铁K_α发射线。然而，部分覆盖模型被发现可以很好地解释相位平均和相位分辨光谱。脉冲轮廓中的凹陷状特征可以通过在相同脉冲相位处具有高柱密度和覆盖分数的附加吸收分量的存在来解释。详细的结果在文件中描述。
英文摘要：
We report the timing and broad-band spectral properties of the Be transient high mass X-ray binary pulsar GRO J1008-57 using a Suzaku observation in the declining phase of its 2007 November-December outburst. Pulsations with a period of 93.737 s were clearly detected in the light curves of the pulsar up to the 80-100 keV energy band. The pulse profile was found to be strongly energy dependent, a double peaked profile at soft X-ray energy bands (< 8 keV) and a single peaked smooth profile at hard X-rays. The broad-band energy spectrum of the pulsar, reported for the first instance in this paper, is well described with three different continuum models viz. (i) a high energy cut-off power-law, (ii) a Negative and Positive power-law with EXponential cut-off (NPEX), and (iii) a partial covering power-law with high energy cut-off. Inspite of large value of absorption column density in the direction of the pulsar, a blackbody component of temperature ~0.17 keV for the soft excess was required for the first two continuum models. A narrow iron K_αemission line was detected in the pulsar spectrum. The partial covering model, however, is found to explain the phase averaged and phase resolved spectra well. The dip like feature in the pulse profile can be explained by the presence of an additional absorption component with high column density and covering fraction at the same pulse phase. The details of the results are described in the paper.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
