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arXiv 2409.05067astro-ph.HE
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磁制动定律对持续型和暂现型低质量X射线双星演化的影响

The influence of the magnetic braking laws on the evolution of persistent and transient low-mass X-ray binaries

Hao-Ran Yang, Xiang-Dong Li

AI总结:

本文用七种磁制动方案和不同金属丰度模拟LMXB演化,解释J1858及其他双星观测,发现不同MB定律分别更适合暂现型、持续型LMXB或UCXB,难有统一规律。

摘要:

Swift J1858.6−0814(以下简称J1858)是一个暂现型中子星低质量X射线双星(NS LMXB)。由观测和理论计算得到的其供体星质量存在争议。本文采用文献中提出的七种磁制动(MB)方案以及不同的金属丰度Z,来模拟该LMXB的演化。结果表明,采用Rappaport等人2012年提出的MB模型(“rm12”)、Convection And Rotation Boosted(“carb”,对流与自转增强)模型,以及Van等人2019年提出的Intermediate(“inter”,中等)模型和Convection-boosted(“cboost”,对流增强)模型,能够很好地匹配J1858的(部分)观测参数。随后,我们将该方法应用于其他已观测到的LMXB,发现“rm12”和“inter”MB定律在解释暂现型LMXB方面最具前景。相比之下,采用“cboost”和“carb”MB定律的模拟分别更倾向于再现持续型LMXB和超紧凑X射线双星(UCXB)。尽管受到计算和/或观测偏差的影响,我们的结果表明,要找到一条同时适用于NS LMXB各次族群的统一MB定律颇具挑战,这表明我们对真实MB定律仍缺乏理解。此外,我们还探究了各种MB定律对LMXB中分岔周期大小的影响。

英文摘要:

Swift J1858.6$-$0814 (hereafter J1858) is a transient neutron star low-mass X-ray binary (NS LMXB). There is controversy regarding its donor mass derived from observations and theoretical calculations. In this paper, we adopt seven magnetic braking (MB) prescriptions suggested in the literature and different metallicity $Z$ to simulate the evolution of the LMXB. Our results show that, employing the MB model proposed by \citet{2012ApJ...746...43R} ("rm12"), the Convection And Rotation Boosted ("carb") model \citep{2019ApJ...886L..31V}, as well as the Intermediate ("inter") and Convection-boosted ("cboost") models in \citet{2019MNRAS.483.5595V} can match (part of) the observational parameters of J1858 well. We then apply our method to other observed LMXBs and find that the "rm12" and "inter" MB laws are most promising in explaining transient LMXBs. In comparison, the simulations with the "cboost" and "carb" MB laws are more inclined to reproduce persistent LMXBs and ultra-compact X-ray binaries (UCXBs), respectively. Our results, though subject to computational and/or observational bias, show that it is challenging to find a unified MB law that applies to the NS LMXB sub-populations simultaneously, indicating our lack of understanding of the true MB law. In addition, we explore the influence of various MB laws on the magnitude of the bifurcation periods in LMXBs.

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。

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