Investigating the origin of the spectral line profiles of the Hot Wolf-Rayet Star WR 2
Investigating the origin of the spectral line profiles of the Hot Wolf-Rayet Star WR 2
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研究热沃尔夫-拉叶星 WR 2 谱线剖面的起源
DOI：
10.1093/mnras/stz411
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发表时间：
2019
影响因子：
4.8
通讯作者：
Chené A
中科院分区：
文献类型：
--
作者：
Chené A
热WN星星WR 2（HD 6327）被认为具有许多奇异的特征。为了解释其异常圆润且相对较弱的发射线轮廓，有人提出WR 2是在磁场限制风的作用下旋转接近解体。或者，谱线轮廓可以用WR 2的光谱被伴星的光谱稀释来解释。在本文中，我们提出了一个研究WR 2使用近红外AO成像和光学光谱和偏振。我们的光谱揭示了来自B 2.5-4V伴星的弱光球吸收线的存在，然而这只占总光的5- 10%，这表明伴星是一个背景天体。因此，它的流量不会对WR星星的发射线造成任何明显的稀释。WR 2缺乏内在的线性连续偏振，这不支持所提出的快速旋转。我们的Stokes V光谱的质量不足以测试中等强度有组织磁场的存在，但我们的新模型表明，为了限制风，假定的磁场必须比以前提出的强得多，强到足以使其存在不可信。
The hot WN star WR 2 (HD 6327) has been claimed to have many singular characteristics. To explain its unusually rounded and relatively weak emission line profiles, it has been proposed that WR 2 is rotating close to break-up with a magnetically confined wind. Alternatively, the line profiles could be explained by the dilution of WR 2’s spectrum by that of a companion. In this paper, we present a study of WR 2 using near-infrared AO imaging and optical spectroscopy and polarimetry. Our spectra reveal the presence of weak photospheric absorption lines from a B 2.5–4V companion, which however contributes only 5–10 per cent to the total light, suggesting that the companion is a background object. Therefore, its flux cannot be causing any significant dilution of the WR star’s emission lines. The absence of intrinsic linear continuum polarization from WR 2 does not support the proposed fast rotation. Our Stokes V spectrum was not of sufficient quality to test the presence of a moderately strong organized magnetic field but our new modelling indicates that to confine the wind the putative magnetic field must be significantly stronger than was previously suggested sufficiently strong as to make its presence implausible.