arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1402.4863astro-ph.HE
收藏

HLX-1的风积模型

A Wind Accretion Model for HLX-1

M. Coleman Miller, Sean A. Farrell, Thomas J. Maccarone

摘要:

目前已知的最亮的超亮X射线源HLX-1已经被观测到经历了五次爆发周期。这些爆发的周期性,以及推测的$\sim{\rm few}\times 10^{-4} M_\odot {\rm yr}^{-1}$的最大吸积率,自然表明在偏心轨道的近心处有罗氏瓣溢出。然而,洛希瓣溢出模型很难解释在不同的爆发衰减时间减少的明显趋势,而积分亮度也下降。因此,如果这一趋势是真实的,而不仅仅是吸积盘复杂物理学的反映,那么就有必要采取不同的设想。我们提出了一个推测模型,在该模型中,在过去十年内,一颗高质量巨星的大部分包层被HLX-1中的$\sim 10^{4-5} M_\odot$黑洞潮汐剥离,剩余的核心加上低质量氢包层现在为黑洞提供强风。该模型可以解释圆盘衰减时间短的现象,也可以解释当风速随时间增加时衰减时间快速减小的现象。这个模型的一个关键预测是,将有多余的线吸收,由于风,我们的分析,事实上发现在$\sim 0.9-1.1$千电子伏范围内的通量赤字是一致的预测,虽然在低的意义。如果这个想法是正确的,我们还预计,在几十年内,来自原始分裂的束缚物质将返回,并使HLX-1成为一个持续明亮的光源。

英文摘要:

The brightest ultraluminous X-ray source currently known, HLX-1, has been observed to undergo five outburst cycles. The periodicity of these outbursts, and their high inferred maximum accretion rates of $\sim{\rm few}\times 10^{-4} M_\odot {\rm yr}^{-1}$, naturally suggest Roche lobe overflow at the pericenter of an eccentric orbit. It is, however, difficult for the Roche lobe overflow model to explain the apparent trend of decreasing decay times over the different outbursts while the integrated luminosity also drops. Thus if the trend is real rather than simply being a reflection of the complex physics of accretion disks, a different scenario may be necessary. We present a speculative model in which, within the last decade, a high-mass giant star had most of its envelope tidally stripped by the $\sim 10^{4-5} M_\odot$ black hole in HLX-1, and the remaining core plus low-mass hydrogen envelope now feeds the hole with a strong wind. This model can explain the short decay time of the disk, and could explain the fast decrease in decay time if the wind speed increases with time. A key prediction of this model is that there will be excess line absorption due to the wind; our analysis does in fact find a flux deficit in the $\sim 0.9-1.1$ keV range that is consistent with predictions, albeit at low significance. If this idea is correct, we also expect that within tens of years the bound material from the original disruption will return and will make HLX-1 a persistently bright source.

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。

↑