Constraining the Type Ia Supernova Progenitor: The Search for Hydrogen in Nebular Spectra
Constraining the Type Ia Supernova Progenitor: The Search for Hydrogen in Nebular Spectra
复制标题
DOI：
10.1086/522367
复制
发表时间：
2006-02
期刊：
影响因子：
--
通讯作者：
D. Leonard
中科院分区：
文献类型：
--
作者：
D. Leonard
尽管进行了严格的审查，但产生Ia型超新星的祖先系统仍然是未知的。赞成的理论认为，一颗碳氧白色矮星从一颗近伴星吸积富含氢的物质，直到一个热核失控的包围体将白色矮星烧成灰烬。然而，这种单简并双星通道的模拟结果要求在星云后期拍摄的光谱中存在低速Hα发射，因为伴星的一部分包络被夹带在喷出物中。这种氢从未被探测到，但很少被寻找。在这里，我们提出的结果，从运动获得深，附近的Ia型超新星的星云相光谱，并包括两个事件的多历元观测：SN 2005上午（轻微的亚发光）和SN 2005 cf（正常明亮）。在这两个天体的光谱中都没有检测到Hα发射。根据Mattila等人的模型，当与Marietta等人和Meng等人的质量剥离模拟相结合时，有效地排除了这些超新星的祖先系统，这些超新星的第二个足够接近白色矮星，在爆炸时经历洛希叶溢出。其他解释的Hα排放的情况下，沿着的建议，为未来的调查，有信心地排除它们的可能性，严格评估。
Despite intense scrutiny, the progenitor system(s) that gives rise to Type Ia supernovae remains unknown. The favored theory invokes a carbon-oxygen white dwarf accreting hydrogen-rich material from a close companion until a thermonuclear runaway ensues that incinerates the white dwarf. However, simulations resulting from this single-degenerate, binary channel demand the presence of low-velocity Hα emission in spectra taken during the late nebular phase, since a portion of the companion's envelope becomes entrained in the ejecta. This hydrogen has never been detected, but has only rarely been sought. Here we present results from a campaign to obtain deep, nebular-phase spectroscopy of nearby Type Ia supernovae, and include multiepoch observations of two events: SN 2005am (slightly subluminous) and SN 2005cf (normally bright). No Hα emission is detected in the spectra of either object. An upper limit of 0.01 M☉ of solar abundance material in the ejecta is established from the models of Mattila et al., which, when coupled with the mass-stripping simulations of Marietta et al. and Meng et al., effectively rules out progenitor systems for these supernovae with secondaries close enough to the white dwarf to be experiencing Roche lobe overflow at the time of explosion. Alternative explanations for the absence of Hα emission, along with suggestions for future investigations necessary to confidently exclude them as possibilities, are critically evaluated.