arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1902.04058astro-ph.HE
收藏

关于M51 ULX-8中的磁场

On the magnetic field in M51 ULX-8

Matthew Middleton, Murray Brightman, Fabio Pintore, Matteo Bachetti, Andrew Fabian, Felix Fuerst, Dominic Walton

摘要:

在M51 ULX-8的光谱中发现的回旋共振散射特征(CRSF)可能为研究中子星所在的超亮X射线源中的磁场的性质提供了重要线索。在本文中,我们给出了M51 ULX-8在长时间(> 2000 s)尺度上的协方差(线性相关变异性)谱。这使我们能够明确地分解光谱,这需要多个组件,以解释宽带发射。有一个更清晰的图片的光谱分解导致各种测试的偶极磁场强度的中子星,可以扩展到其他ULX时,满足某些标准。在M51 ULX-8的情况下,我们排除了具有亚临界或超临界圆盘的非常强(~10^15 G)的偶极解。相反,我们的测试表明偶极场的上限约为10^12 G,并且存在经典的超临界流入,类似于在其他发现有中子星的ULX中推断的情况,尽管我们不排除存在额外的强多极场(约为10^15 G),该多极场随着与中子星的距离急剧下降。

英文摘要:

The reported discovery of a cyclotron resonance scattering feature (CRSF) in the spectrum of M51 ULX-8 may provide an important clue as to the nature of the magnetic field in those ultraluminous X-ray sources hosting neutron stars. In this paper we present the covariance (linearly correlated variability) spectrum of M51 ULX-8 on long (> 2000s) timescales. This allows us to unambiguously decompose the spectrum which requires multiple components in order to explain the broad-band emission. Having a clearer picture of the spectral decomposition leads to various tests for the dipole field strength of the neutron star which can be extended to other ULXs when certain criteria are met. In the case of M51 ULX-8, we rule out a very strong (~10^15 G) dipole solution with either a sub- or super-critical disc. Instead, our tests indicate an upper limit on the dipole field of ~10^12 G, and a classical super-critical inflow, similar to that inferred in other ULXs found to harbour neutron stars, although we do not rule out the presence of an additional, strong (~10^15 G) multipole field falling off steeply with distance from the neutron star.

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。

↑