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arXiv 1609.09511astro-ph.HE
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黑洞与中子星X射线~双星硬态光谱性质的二分法

A dichotomy between the hard state spectral properties of black hole and neutron star X-ray~binaries

M. J. Burke, M. Gilfanov, R. Sunyaev

摘要:

利用RXTE观测资料,分析了黑洞(BH)和中子星(NS)X射线双星(XB)在硬态的光谱。我们发现,在NS和BH源之间的康普顿化强度中存在明显的二分法,如通过康普顿y参数和放大因子A测量的,具有在y~0.9和A~3处分离的不同组的BH和NS XB。电子温度kTe在BH系统中可以占据很宽的范围,从kTe~30-200 keV,而对于NS,kTe在~15-25 keV处达到峰值,但可以延伸到更高的值。BH和NS之间在y上的差异意味着对于BH XB,在给定的光学深度处kTe更高。我们的结果还意味着,对于NS系统的吸积材料失去了约1/2-2/3的能量,通过康普顿在日冕。剩余的能量被释放到中子星的表面,使其成为一个强大的软辐射源,这改变了康普顿化日冕的性质。最后,我们发现在2.4西格玛置信水平的证据,康普顿参数可能与中子星自旋,而没有相关性的BH spin是found. Our结果突出了进一步的观察BH和NS XB之间的区别,这是一个后果,NS拥有一个物理表面。

英文摘要:

We analyse the spectra of black hole (BH) and neutron star (NS) X-ray binaries (XBs) in the hard state using archival RXTE observations. We find that there is a clear dichotomy in the strength of Comptonisation between NS and BH sources, as measured by both the Compton y-parameter and amplification factor A, with distinct groups of BH and NS XBs separated at y~0.9 and A~3. The electron temperature kTe can occupy a broad range in BH systems, from kTe~30-200 keV, whereas for NSs kTe is peaked at ~15-25 keV, but can extend to higher values. The difference between BHs and NSs in y implies that kTe is higher at a given optical depth for BH XBs. Our results also imply that for NS systems the accreting material loses ~1/2-2/3 of its energy through Comptonisation in the corona. The remaining energy is released on the surface of the neutron star, making it a powerful source of soft radiation, which alters the properties of the Comptonising corona. Finally, we find evidence at the 2.4 sigma confidence level that Comptonisation parameters may be correlated with the neutron star spin, whereas no correlation with the BH spin is found. Our results highlight a further observational distinction between BH and NS XBs that is a consequence of NSs possessing a physical surface.

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。

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