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 0803.1834astro-ph
收藏

恒星质量黑洞M33 X-7自旋参数的精确测量

Precise Measurement of the Spin Parameter of the Stellar-Mass Black Hole M33 X-7

Jifeng Liu, Jeffery E. McClintock, Ramesh Narayan, Shane W. Davis, Jerome A. Orosz

摘要:

在先前的工作中,{ \it Chandra}和Gemini North对食X射线双星M33 X-7的观测已经产生了对其黑洞主要质量和系统轨道倾角的前所未有的精确度的测量。同样,到二进制的距离也只有百分之几。在这些精确结果的基础上,15个{ \it Chandra}和{ \it XMM-Newton} X射线谱,以及我们的完全相对论吸积盘模型的分析中,我们发现黑洞的无量纲自旋参数是$a_* = 0.77 \pm 0.05$。所引用的1- $σ$误差包括所有观测不确定性的来源。四个最高质量的{ \it钱德拉}光谱,这是在几年的时间跨度内获得的,都导致相同的估计自旋的统计误差(2%)内,这一估计是由11个较低质量的光谱证实。还有两个不确定性:(1)用于分析观测结果的相对论模型的有效性,这一点正在进行中的理论工作中得到解决;(2)我们假设黑洞的自旋与双星的角动量矢量近似一致,这可以通过未来的X射线偏振测量任务来解决。

英文摘要:

In prior work, {\it Chandra} and Gemini-North observations of the eclipsing X-ray binary M33 X-7 have yielded measurements of the mass of its black hole primary and the system's orbital inclination angle of unprecedented accuracy. Likewise, the distance to the binary is known to a few percent. In an analysis based on these precise results, fifteen {\it Chandra} and {\it XMM-Newton} X-ray spectra, and our fully relativistic accretion disk model, we find that the dimensionless spin parameter of the black hole primary is $a_* = 0.77 \pm 0.05$. The quoted 1-$σ$ error includes all sources of observational uncertainty. Four {\it Chandra} spectra of the highest quality, which were obtained over a span of several years, all lead to the same estimate of spin to within statistical errors (2%), and this estimate is confirmed by 11 spectra of lower quality. There are two remaining uncertainties: (1) the validity of the relativistic model used to analyze the observations, which is being addressed in ongoing theoretical work; and (2) our assumption that the black hole spin is approximately aligned with the angular momentum vector of the binary, which can be addressed by a future X-ray polarimetry mission.

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。

↑