论文标题
用磁性中子星的超X射线源的种群合成
Population synthesis of ultraluminous X-ray sources with magnetised neutron stars
论文作者
论文摘要
在螺旋星系中具有磁化中子星（NULX）的超X射线源的种群模型，其恒星形成史类似于用混合方法计算出类似于银河系中的薄盘。首先，应用分析近似（代码BSE），我们构建了近亲（CBS）的合奏，该集合可能是NULX的潜在前体。接下来，通过进化代码MESA计算出积聚到磁性中子星（NS）上的进化。计算Ns和X射线光度的增生率是针对亚和超临界盘的模型以及对流的盘的。在磁化NS上积聚期间，超级埃德丁顿光度$ l_ \ mathrm {x}> 10^{38} $ erg〜s $^{ - 1} $已经在亚临界阶段达到，当时NS Magnetseterperse sub-eDdington在盘的内部边界处的能量释放。 It is shown that standard evolution of CBS with an account of the peculiarities specific for accretion onto magnetised NS allows us to explain quantitatively observed characteristics of NULX (X-ray luminosities, NS spin periods, orbital periods and masses of visual components) without additional model assumptions on the collimation of X-ray emission from NS with high observed super-Eddington luminosity.在带有星形速率的模型星系中，3--5 $ M_ \ odot {\ rm yr^{ - 1}} $可以存在几个nulx。从$ l _ {\ mathrm x} \ sim 10^{41} $ erg〜s $^{ - 1} $发现nulx的强大风将是超级埃德丁顿积聚在磁性ns上的签名。
A model of population of ultraluminous X-ray sources with magnetised neutron stars (NULX) in a spiral galaxy with the star formation history similar to that in the thin disc of Milky Way is computed using a hybrid approach. First, applying analytical approximations (code BSE) we construct the ensemble of close binaries (CBS) which can be potential precursors of NULX. Next, evolution with accretion onto magnetised neutron stars (NS) is computed by the evolutionary code MESA. Accretion rate onto NS and X-ray luminosity are calculated for the models of sub- and supercritical discs and for the discs with advection. During accretion onto magnetised NS, super-Eddington luminosity $L_\mathrm{X}>10^{38}$ erg~s$^{-1}$ is attained already at the subcritical stage, when the energy release at the inner boundary of the disc defined by the NS magnetosphere is sub-Eddington. It is shown that standard evolution of CBS with an account of the peculiarities specific for accretion onto magnetised NS allows us to explain quantitatively observed characteristics of NULX (X-ray luminosities, NS spin periods, orbital periods and masses of visual components) without additional model assumptions on the collimation of X-ray emission from NS with high observed super-Eddington luminosity. In a model galaxy with star formation rate 3--5 $M_\odot {\rm yr^{-1}}$ there can exist several NULX. Discovery of a powerful wind from NULX with $L_{\mathrm X} \sim 10^{41}$ erg~s$^{-1}$ would be a signature of super-Eddington accretion onto magnetised NS.
