Conditions in the WR 140 wind-collision region revealed by the 1.083-micron He I line profile
Peredur M. Williams, Watson P. Varricatt, André-Nicolas Chené, Michael F. Corcoran, Ted R. Gull, Kenji Hamaguchi, Anthony F. J. Moffat, Andrew M. T. Pollock, No… 展开作者
Peredur M. Williams, Watson P. Varricatt, André-Nicolas Chené, Michael F. Corcoran, Ted R. Gull, Kenji Hamaguchi, Anthony F. J. Moffat, Andrew M. T. Pollock, Noel D. Richardson, Christopher M. P. Russell, Andreas A. C. Sander, Ian R. Stevens, Gerd Weigelt
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19 pages, 14 figures, accepted for publication in the MNRAS
We present spectroscopy of the P~Cygni profile of the 1.083-micron He I line in the WC7 + O5 colliding-wind binary (CWB) WR 140 (HD 193793), observed in 2008, before its periastron passage in 2009, and in 2016-17, spanning the subsequent periastron passage. Both absorption and emission components showed strong variations. The variation of the absorption component as the O5 star was occulted by the wind-collision region (WCR) sets a tight constraint on its geometry. While the sightline to the O5 star traversed the WCR, the strength and breadth of the absorption component varied significantly on time-scales of days. An emission sub-peak was observed on all our profiles. The variation of its radial velocity with orbital phase was shown to be consistent with formation in the WCR as it swung round the stars in their orbit. Modelling the profile gave a measure of the extent of the sub-peak forming region. In the phase range 0.93-0.99, the flux in the sub-peak increased steadily, approximately inversely proportionally to the stellar separation, indicating that the shocked gas in the WCR where the line was formed was adiabatic. After periastron, the sub-peak flux was anomalously strong and varied rapidly, suggesting formation in clumps down-stream in the WCR. For most of the time, its flux exceeded the 2-10-keV X-ray emission, showing it to be a significant coolant of the shocked wind.
The formation and evolution of dust in the colliding-wind binary Apep revealed by JWST
California Institute of Technology（加州理工学院）；Macquarie University（麦考瑞大学）；University of Queensland（昆士兰大学）；ASTRON, Netherlands Institute for Radio Astronomy（荷兰射电天文研究所 ASTRON）；University of Amsterdam（阿姆斯特丹大学）；NSF NOIRLab（美国国家光学红外天文研究实验室 NSF NOIRLab）；Embry-Riddle Aeronautical University（埃姆布里-里德尔航空大学）；The University of Sydney（悉尼大学）
Discrepancies in the Properties of a Coronal Mass Ejection on Scales of 0.03~au as Revealed by Simultaneous Measurements at Solar Orbiter and Wind: The 2021 November 3--5 Event
本研究利用 SolO 和 Wind 同步原位观测，发现 2.2° 角向分离即可导致 CME 磁云性质显著差异，排除了时间演化，证实空间变化是主因，且使预测误差显著增大。
