arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 0812.1149astro-ph
收藏

XMM-牛顿探测到ms X射线脉冲星SAX J1808光谱中的相对论性增宽铁谱线。4 -3658

XMM-Newton detects a relativistically broadened iron line in the spectrum of the ms X-ray pulsar SAX J1808.4-3658

A. Papitto, T. Di Salvo, A. D'Aì, R. Iaria, L. Burderi, A. Riggio, M. T. Menna, N. R. Robba

摘要:

本文报道了在2008年9月21日开始的最近一次X射线爆发期间对吸积毫秒脉冲星SAXJ1808.4 -3658进行的63-ks长的XMM-牛顿观测。pn光谱显示出一个非常重要的发射线的能带中,铁K-α线是预期的,我们确定为中性(或轻度电离)铁的发射。线的轮廓似乎是相当广泛的(超过1千电子伏半高宽)和不对称的,最可能的解释是这种配置文件是多普勒和相对论增宽从内部吸积盘。由盘线轮廓拟合得到盘的内径为8.7^(+3.7)_(-2.7)R_g,相当于1.4 Msun中子星的内径为18.0^(+7.6)_(-5.6)km。因此,圆盘在共转半径(SAX J1808.4-3658为31公里)内被截断,这与XMM-牛顿观测期间源仍然显示脉动的事实一致。

英文摘要:

We report on a 63-ks long XMM-Newton observation of the accreting millisecond pulsar SAX J1808.4-3658 during the latest X-ray outburst which started on September 21st 2008. The pn spectrum shows a highly significant emission line in the energy band where the iron K-alpha line is expected, and which we identify as emission from neutral (or mildly ionized) iron. The line profile appears to be quite broad (more than 1 keV FWHM) and asymmetric; the most probable explanation for this profile is Doppler and relativistic broadening from the inner accretion disc. From a fit with a diskline profile we find an inner radius of the disc of 8.7^(+3.7)_(-2.7) R_g, corresponding to 18.0^(+7.6)_(-5.6) km for a 1.4 Msun neutron star. The disc therefore appears truncated inside the corotation radius (31 km for SAX J1808.4-3658) in agreement with the fact that the source was still showing pulsations during the XMM-Newton observation.

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。

↑