arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1111.3817astro-ph.HEastro-ph.SR
收藏

半乳糖醛酸X射线双星总体的集体性质I.高质量X射线双星的光度和轨道周期分布

Collective Properties of X-ray Binary Populations of Galaxies. I. Luminosity and Orbital Period Distributions of High-Mass X-ray Binaries

Harshal Bhadkamkar, Pranab Ghosh

摘要:

介绍了一种获得正常星系星场中(即球状星团外)高质量X射线双星(HMXB)的X射线光度函数(XLF)和双星周期分布的方法。我们开始从标准分布的原始双星的参数,这是祖先的HMXB,并遵循这些distrributions的转变与援助的雅可比形式主义,因为前者演变成后者通过的过程中的第一次质量转移和超新星(SN)如下。我们讨论了后SN双星和HMXB的分布。我们发现,我们计算的模型XLF有一个微分斜率$\approx -1.6$与平坦的低光度,在很好的协议与观测。计算出的二进制周期分布,基本上有一个稍微倾斜的高原状的字符在中间时期,在较短的周期上升到这个高原,并从它在较长的周期下降,是在观测的不确定性内与观测到的分布。我们讨论了这些分布的物理起源。我们证明,虽然(a)HMXB中大质量伴星的性质分布和(b)原始轨道分布和SN动力学的影响都很重要,但前者似乎在确定XLF中占主导地位,而后者在确定HMXB双星周期分布中占主导地位。我们讨论了恒星质量黑洞和超亮X射线源(ULX)在观测到的HMXB的“通用”XLF中可能扮演的角色。

英文摘要:

We introduce a method for obtaining the X-ray luminosity function (XLF) and the binary-period distribution of populations of high-mass X-ray binaries (HMXBs) in the stellar fields (i.e. outside globular clusters) of normal galaxies. We start from standard distributions of the parameters of those primordial binaries which are the progenitors of HMXBs, and follow the transformation of these ditributions with the aid of a Jacobian formalism as the former evolve into the latter through the processes of the first mass transfer and the supernova (SN) that follows. We discuss the distributions of the post-SN binaries and the HMXBs. We show that our calculated model XLF has a differential slope $\approx -1.6$ with a flattening at low luminosities, in excellent agreement with observations. The calculated binary-period distribution, which basically has a slightly sloping plateau-like character at intermediate periods, with a rise to this plateau at shorter periods and fall-off from it at longer periods, is in agreement with the observed distribution within observational uncertainties. We discuss the physical origin of these distributions. We demonstrate that, while the effects of both (a) the distribution of the properties of the massive companion in the HMXBs, and (b) the primordial orbital distribution and the SN dynamics are important, the former appear to be dominant in determining the XLF, and the latter in determining the HMXB binary-period distribution. We discuss the possible roles of stellar-mass black holes and ultra-luminous X-ray sources (ULX) in the observed "universal" XLF of HMXBs.

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。

↑