NGC 1624-2：缓慢旋转的发光X射线，具有超强磁场cp星
NGC 1624-2: A slowly rotating, X-ray luminous Of?cp star with an extraordinarily strong magnetic field
摘要：
本文介绍了第一次观测调查的微弱？cp星NGC 1624-2，产生重要的新的限制，其光谱和物理特性，旋转，磁场强度，X射线发射和磁层特性。通过对光谱和光谱能量分布的模拟，我们得出结论：NGC 1624-2是一颗质量为M {\simeq } 30 M{ \odot }的主序星，有效温度为35 { \pm } 2 kK，log g = 4.0 { \pm } 0.2。基于广泛的时间序列的光谱观测，我们报告了大量的谱线的显着变化，并推断出一个独特的周期为157.99 { \pm } 0.94 d，我们解释为旋转周期的恒星。我们报告检测到一个非常强的- 5.35 { \pm } 0.5 kG -纵向磁场<Bz>，加上可能的塞曼分裂斯托克斯我配置文件的金属线确认表面场模量<B>为14 { \pm } 1 kG，符合表面偶极子的极性强度>~ 20 kG。这是有史以来在O型恒星中探测到的最大磁场，也是第一次报道在这样的天体中塞曼分裂斯托克斯I剖面。我们还报告了检测到与弱，高激发发射线的O三，我们建议可能形成在密切的磁层的恒星的反斯托克斯V配置文件。我们分析档案钱德拉ACIS-I X射线数据，推断一个非常硬的频谱与X射线效率日志LX/Lbol =-6.4，一个因素4大于典型值的O型恒星和可比的年轻的磁性O型星θ1 Ori C和其他的？p星。最后，我们研究了这颗恒星可能的磁层性质，特别报告了非常强的星风磁约束，η* { \simeq } 1.5 { \times } 10 ^4，以及非常大的阿尔文半径，RAlf = 11.4 R*。
英文摘要：
This paper presents a first observational investigation of the faint Of?cp star NGC 1624-2, yielding important new constraints on its spectral and physical characteristics, rotation, magnetic field strength, X-ray emission and magnetospheric properties. Modeling the spectrum and spectral energy distribution, we conclude that NGC 1624-2 is a main sequence star of mass M {\simeq} 30 M{\odot}, and infer an effective temperature of 35 {\pm} 2 kK and log g = 4.0 {\pm} 0.2. Based on an extensive time series of optical spectral observations we report significant variability of a large number of spectral lines, and infer a unique period of 157.99 {\pm} 0.94 d which we interpret as the rotational period of the star. We report the detection of a very strong - 5.35 {\pm} 0.5 kG - longitudinal magnetic field <Bz>, coupled with probable Zeeman splitting of Stokes I profiles of metal lines confirming a surface field modulus <B> of 14 {\pm} 1 kG, consistent with a surface dipole of polar strength >~ 20 kG. This is the largest magnetic field ever detected in an O-type star, and the first report of Zeeman splitting of Stokes I profiles in such an object. We also report the detection of reversed Stokes V profiles associated with weak, high-excitation emission lines of O iii, which we propose may form in the close magnetosphere of the star. We analyze archival Chandra ACIS-I X-ray data, inferring a very hard spectrum with an X-ray efficiency log Lx/Lbol = -6.4, a factor of 4 larger than the canonical value for O-type stars and comparable to that of the young magnetic O-type star θ1 Ori C and other Of?p stars. Finally, we examine the probable magnetospheric properties of the star, reporting in particular very strong magnetic confinement of the stellar wind, with η* {\simeq} 1.5 {\times} 10^4, and a very large Alfven radius, RAlf = 11.4 R*.
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。
