论文标题
超光线X射线瞬态源的模型
Models of Ultra-Luminous X-ray transient sources
论文作者
论文摘要
现在，广泛认为，大多数超X射线源（ULX）是二进制系统的大型系统（高于$ 10^{39} $ erg s $^{ - 1} $）明显的亮度由超级埃德丁顿（Super-Eddington）吸收出现在一个恒星的压实物体上。许多ULX，尤其是那些含有磁性中子星的ulx，都有很大的变化。一些表现出瞬态行为。较大的亮度可能意味着大型积聚盘，因此可能容易出现热粘膜不稳定，已知可以驱动矮novae和低质量X射线二进制二进制瞬态来源的爆发。本文的目的是将X射线瞬态圆盘稳定模型扩展和推广到大型（大于$ 10^{12} $ cm）的大型振动盘的情况，并将其应用于爆发时具有超级 - 埃德丁顿积聚率的系统的描述，在某些情况下，超级 - 埃德丁顿质量转移率。我们已经使用了圆盘稳定模型代码来计算积聚盘和爆发属性的时间演变。我们表明，前提是，即使吸积率超过了爱丁顿的值，也有效的增值盘是有效的，这可能是由于盘式在圆盘外部的盘中散射出的X射线通量的散射，加热界面可以达到光盘的外边缘发电率的高增强率。我们还为爆发的可观察特性提供了分析近似。我们已经成功地复制了带有大盘的银河瞬变的特性，例如V404 CYG，以及一些ULX，例如M51 XT-1。如果增生器是中子星，我们的模型可以重现ESO 243-39 HLX-1爆发的峰值光度和衰减时间。欢迎对我们预测的爆发时间和衰减时间之间的预测关系的观察性测试，这是最受欢迎的。
It is now widely accepted that most ultraluminous X-ray sources (ULXs) are binary systems whose large (above $10^{39}$ erg s$^{-1}$) apparent luminosities are explained by super-Eddington accretion onto a stellar-mass compact object. Many of the ULXs, especially those containing magnetized neutron stars, are highly variable; some exhibit transient behaviour. Large luminosities might imply large accretion discs that could be therefore prone to the thermal-viscous instability known to drive outbursts of dwarf novae and low-mass X-ray binary transient sources. The aim of this paper is to extend and generalize the X-ray transient disc-instability model to the case of large (outer radius larger than $10^{12}$ cm) accretion discs and apply it to the description of systems with super-Eddington accretion rates at outburst and, in some cases, super-Eddington mass transfer rates. We have used our disc-instability-model code to calculate the time evolution of the accretion disc and the outburst properties. We show that, provided that self-irradiation of the accretion disc is efficient even when the accretion rate exceeds the Eddington value, possibly due to scattering back of the X-ray flux emitted by the central parts of the disc on the outer portions of the disc, heating fronts can reach the disc's outer edge generating high accretion rates. We also provide analytical approximations for the observable properties of the outbursts. We have reproduced successfully the observed properties of galactic transients with large discs, such as V404 Cyg, as well as some ULXs such as M51 XT-1. Our model can reproduce the peak luminosity and decay time of ESO 243-39 HLX-1 outbursts if the accretor is a neutron star. Observational tests of our predicted relations between the outburst duration and decay time with peak luminosity would be most welcome.
