标题： 河外黑洞X射线双星中的吸积盘动力学：对M33 X-7、NGC 300 X-1和IC 10 X-1的综合研究 显示英文标题

标题： Accretion disc dynamics in extragalactic black hole X-ray binaries: A comprehensive study of M33 X-7, NGC 300 X-1 and IC 10 X-1

摘要： 河外黑洞X射线双星（BH-XRBs）是最引人入胜的X射线源，因为其中一些是迄今发现的质量最大的恒星级黑洞的“家园”。在本研究中，我们对三个大质量、食双星河外BH-XRBs进行了全面研究，即M33X-7、NGC300X-1和IC10X-1，并利用了从\textit{XMM-Newton}和\textit{NuSTAR}直到现在的全部X射线观测数据。使用\textit{磁盘bb}和\textit{幂律}模型进行的初步分析显示，这些源具有陡峭的光谱和亚爱丁顿光度（L<0.69 L$_{Edd}$），主要流量贡献来自非热成分，类似于相对未被探索的陡峭幂律状态（SPL）。 为了理解该状态下吸积盘的特性，我们探索了另一种建模情景，揭示了一个“热”($kT_{in}=1-2$keV)的薄盘(\textit{磁盘pbb})，其径向温度分布为$T(r)\propto r^{-p}$($p=0.5-0.66$)，同时还存在一个较冷的($kT_{in}=0.1-0.2$keV )标准热盘(\textit{磁盘bb})。 我们使用相对论性薄盘模型 (\textit{slimbh}) 进行连续谱拟合，并估计M33 X-7、NGC300X-1和IC10X-1的质量范围分别为9$-$15 M$_{\odot}$、9$-$28 M$_{\odot}$和10$-$30 M$_{\odot}$。 此外，通过建模光变曲线确定了掩食周期，利用这些周期我们估算了掩食天体的大小。 掩食光谱的建模揭示了在掩食期间软谱成分被完全遮挡，表明硬谱成分来自一个扩展的吸积区。 基于我们的发现，我们对这些风致吸积系统中的吸积盘几何结构进行了推断，并将其特性与其他两个河外黑洞X射线双星进行了比较。 显示英文摘要

摘要： Extragalactic Black Hole X-ray Binaries (BH-XRBs) are the most intriguing X-ray sources as some of them are `home' to the most massive stellar-mass BHs ever found. In this work, we conduct a comprehensive study of three massive, eclipsing extragalactic BH-XRBs i.e., M33X-7, NGC300X-1, and IC10X-1 and using entire X-ray observations available from \textit{XMM-Newton} and \textit{NuSTAR} till date. Preliminary analysis using \textit{diskbb} and \textit{powerlaw} models shows that the sources have steep spectra and sub-Eddington luminosities (L<0.69 L$_{Edd}$), with major flux contribution from non-thermal component, resembling the relatively uncharted Steep Powerlaw State (SPL). To understand the accretion disc properties in this state, we explore alternate modelling scenario that reveals the presence of a `hot' ($kT_{in}=1-2$ keV) slim-disc (\textit{diskpbb}) with radial temperature profile $T(r)\propto r^{-p}$ ($p=0.5-0.66$), along with a cooler ($kT_{in}=0.1-0.2$ keV) standard thermal disc (\textit{diskbb}). We carry out the continuum-fitting method using relativistic slim-disc model (\textit{slimbh}) and estimate the mass range of M33 X-7, NGC300X-1 and IC10X-1 is to be 9$-$15 M$_{\odot}$, 9$-$28 M$_{\odot}$ and 10$-$30 M$_{\odot}$, respectively. Further, eclipse periods are determined by modelling the lightcurve, using which we estimate the size of the eclipsing bodies. Modelling of the eclipse spectra revealed the complete obscuration of soft spectral component during eclipse, implying the emission of hard component from an extended accretion region. Based on our findings, we provide an inference on geometry of accretion disc in these wind-fed systems and compare their properties with the other two extragalactic BH-XRBs.