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arXiv 1602.07372astro-ph.SR
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RW Aur A上质量吸积的稳定和不稳定状态

Stable and Unstable Regimes of Mass Accretion onto RW Aur A

Michihiro Takami, Yu-Jie Wei, Mei-Yin Chou, Jennifer L. Karr, Tracy L. Beck, Nadine Manset, Wen-Ping Chen, Ryuichi Kurosawa, Misato Fukagawa, Marc White, Robert… 展开作者

Michihiro Takami, Yu-Jie Wei, Mei-Yin Chou, Jennifer L. Karr, Tracy L. Beck, Nadine Manset, Wen-Ping Chen, Ryuichi Kurosawa, Misato Fukagawa, Marc White, Roberto Galvan-Madrid, Hauyu Baobab Liu, Tae-Soo Pyo, Jean-Francois Donati

摘要:

我们目前的监测观测活动的金牛座T星RW Aur,从2010年10月至2015年1月,使用光学高分辨率(R>10000)光谱与CFHT-ESPaDOnS。文献中的光学光度测量显示,在这一时期的大部分时间里,通量都很明亮,稳定,通量较低(2-3等)。在2010年和2014年。在亮期,我们的光谱显示出清晰的光球吸收,Ca II 8542 A发射轮廓形状的复杂变化,以及O I 7772和8446 A以及He I 5876 A线的红移吸收的大变化,表明在此期间不稳定的质量吸积。相比之下,这些线的轮廓是相对均匀的,在微弱的时期,这表明稳定的质量吸积。在微弱的时期,光球吸收线是不存在的或边缘,平均Li I的配置文件显示红移吸收由于流入。我们讨论了(1)星周物质或伴星的掩星和(2)质量吸积活动的变化,以解释上述结果,以及2011-2015年的近红外和X射线观测。这两种情况都不能简单地解释所有观察到的趋势,需要更多的理论工作来进一步研究它们的特征。

英文摘要:

We present monitoring observations of the active T Tauri star RW Aur, from 2010 October to 2015 January, using optical high-resolution (R>10000) spectroscopy with CFHT-ESPaDOnS. Optical photometry in the literature shows bright, stable fluxes over most of this period, with lower fluxes (by 2-3 mag.) in 2010 and 2014. In the bright period our spectra show clear photospheric absorption, complicated variation in the Ca II 8542 A emission}profile shapes, and a large variation in redshifted absorption in the O I 7772 and 8446 A and He I 5876 A lines, suggesting unstable mass accretion during this period. In contrast, these line profiles are relatively uniform during the faint periods, suggesting stable mass accretion. During the faint periods the photospheric absorption lines are absent or marginal, and the averaged Li I profile shows redshifted absorption due to an inflow. We discuss (1) occultation by circumstellar material or a companion and (2) changes in the activity of mass accretion to explain the above results, together with near-infrared and X-ray observations from 2011-2015. Neither scenario can simply explain all the observed trends, and more theoretical work is needed to further investigate their feasibilities.

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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