arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1102.1033astro-ph.HEastro-ph.GAnucl-exnucl-th
收藏

Terzan 5瞬态IGR J17480-2446:爆发和光谱特性随光谱状态的变化

Terzan 5 transient IGR J17480-2446: variation of burst and spectral properties with spectral states

Manoneeta Chakraborty, Sudip Bhattacharyya, Arunava Mukherjee

摘要:

利用Rossi X射线定时探测器数据,研究了Terzan 5瞬态中子星低质量X射线双星IGR J17480-2446的光谱态演化,以及最佳拟合光谱参数和爆发性质随这些状态的演化.正如其他作者所报告的那样,这是显示环礁状态和“Z”状态之间转变的第二个来源。我们发现大规模的滞后在几乎'C'样的硬度强度轨道的源在环礁状态。这一发现可能会提供拼图中缺失的一块,涉及各种类型的硬度-强度轨迹,从Aquila X-1,4U 1608-52的“q”形和许多黑洞到许多环礁源的“C”形。此外,从IGR J17480-2446中观察到的规则脉动、软硬态之间的对角过渡以及大尺度滞后现象与先前关于环礁和毫秒级彗星的磁场的一些建议相矛盾。我们的研究结果还表明,整个爆发的光谱演化的性质不,至少完全取决于爆发的峰值亮度。此外,该来源至少花了一个月的时间来追踪较软的香蕉状态,而不是几个小时到一天,这是典型的环礁来源。此外,虽然在环礁源较软的部分,柔和的颜色通常随着强度的增加而增加,但IGR J17480-2446显示了相反的行为。从详细的光谱拟合,我们得出结论,一个黑体+幂律模型是最简单的,它描述了整个爆发源连续谱。我们发现,这两个光谱分量是相互联系的,它们共同作用导致了源态的演化。(截短)。

英文摘要:

We study the spectral state evolution of the Terzan 5 transient neutron star low-mass X-ray binary IGR J17480-2446, and how the best-fit spectral parameters and burst properties evolved with these states, using the Rossi X-ray Timing Explorer data. As reported by other authors, this is the second source which showed transitions between atoll state and `Z' state. We find large scale hysteresis in the almost `C'-like hardness-intensity track of the source in the atoll state. This discovery is likely to provide a missing piece of the jigsaw puzzle involving various types of hardness-intensity tracks from `q'-shaped for Aquila X-1, 4U 1608-52, and many black holes to `C'-shaped for many atoll sources. Furthermore, the regular pulsations, a diagonal transition between soft and hard states, and the large scale hysteresis observed from IGR J17480-2446 argue against some of the previous suggestions involving magnetic field about atolls and millisecond pulsars. Our results also suggest that the nature of spectral evolution throughout an outburst does not, at least entirely, depend on the peak luminosity of the outburst. Besides, the source took at least a month to trace the softer banana state, as opposed to a few hours to a day, which is typical for an atoll source. In addition, while the soft colour usually increases with intensity in the softer portion of an atoll source, IGR J17480-2446 showed an opposite behaviour. From the detailed spectral fitting we conclude that a blackbody+powerlaw model is the simplest one, which describes the source continuum spectra well throughout the outburst. We find that these two spectral components were plausibly connected with each other, and they worked together to cause the source state evolution. (Truncated).

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。

↑