| タイトル | High Velocity Absorption during Eta Car B's Periastron Passage |
| 著者（英） | Hartman, H.; Gull, Theodore R.; Hillier, J.; Damineli, A.; Groh, J. H.; Weigelt, G.; Okazaki, A. T.; Owocki, S. P.; Teodoro, M.; Nielsen, Krister E. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2010-01-05 |
| 言語 | eng |
| 内容記述 | Eta Car is one of the most luminous massive stars in the Galaxy, with repeated eruptions with a 5.5 year periodicity. These events are caused by the periastron passage of a massive companion in an eccentric orbit. We report the VLT/CRIRES detection of a strong high-velocity, (<1900 km/s) , broad absorption wing in He I at 10833 A during the 2009.0 periastron passage. Previous observations during the 2003.5 event have shown evidence of such high-velocity absorption in the He I 10833 transition, allowing us to conclude that the high-velocity gas is crossing the line-of-sight toward Eta Car over a time period of approximately 2 months. Our analysis of HST/STlS archival data with observations of high velocity absorption in the ultraviolet Si IV and C IV resonance lines, confirm the presence of a high-velocity material during the spectroscopic low state. The observations provide direct detection of high-velocity material flowing from the wind-wind collision zone around the binary system, and we discuss the implications of the presence of high-velocity gas in Eta Car during periastron |
| NASA分類 | Astronomy |
| 権利 | Copyright |
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