期刊
ASTROPHYSICAL JOURNAL
卷 732, 期 1, 页码 -出版社
IOP PUBLISHING LTD
DOI: 10.1088/0004-637X/732/1/32
关键词
circumstellar matter; dust, extinction; stars: evolution; stars: individual (SN 2009ip, UGC 2773 OT2009-1); stars: massive; stars: mass-loss; stars: variables: general; stars: variables: S Doradus; stars: winds, outflows
资金
- NASA GSRP
- NASA, ARCS
- NASA, VSGC
- Ford Foundation
- NASA [NAS 5-26555]
Despite both being outbursts of luminous blue variables (LBVs), SN 2009ip and UGC 2773 OT2009-1 have very different progenitors, spectra, circumstellar environments, and possibly physical mechanisms that generated the outbursts. From pre-eruption Hubble Space Telescope images, we determine that SN 2009ip and UGC 2773 OT2009-1 have initialmasses of greater than or similar to 60 and greater than or similar to 25 M-circle dot, respectively. Optical spectroscopy shows that at peak, SN 2009ip had a 10,000 K photosphere and its spectrum was dominated by narrow H Balmer emission, similar to classical LBV giant outbursts, also known as supernova impostors. The spectra of UGC 2773 OT2009-1, which also have narrow Ha emission, are dominated by a forest of absorption lines, similar to an F-type supergiant. Blueshifted absorption lines corresponding to ejecta at a velocity of 2000-7000 km s(-1) are present in later spectra of SN 2009ip-an unprecedented observation for LBV outbursts, indicating that the event was the result of a supersonic explosion rather than a subsonic outburst. The velocity of the absorption lines increases between two epochs, suggesting that there were two explosions in rapid succession. A rapid fading and rebrightening event concurrent with the onset of the high-velocity absorption lines is consistent with the double-explosion model. A near-infrared excess is present in the spectra and photometry of UGC 2773 OT2009-1 that is consistent with similar to 2100 K dust emission. We compare the properties of these two events and place them in the context of other known massive star outbursts such as eta Car, NGC 300 OT2008-1, and SN 2008S. This qualitative analysis suggests that massive star outbursts have many physical differences that can manifest as the different observables seen in these two interesting objects.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据