The delay-time distribution of Type Ia supernovae: a comparison between theory and observation
The delay-time distribution of Type Ia supernovae: a comparison between theory and observation
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DOI：
10.1051/0004-6361/201014115
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发表时间：
2010-03
影响因子：
6.5
通讯作者：
N. Mennekens;D. Vanbeveren;D. Vanbeveren;J. D. Greve;E. D. Donder;E. D. Donder
中科院分区：
文献类型：
--
作者：
N. Mennekens;D. Vanbeveren;D. Vanbeveren;J. D. Greve;E. D. Donder;E. D. Donder
目标。我们研究了椭圆星系中Ia型超新星的不同形成情景的贡献。单简并假说(从晚期主序或红巨星伴星吸积而来的白矮星)与双简并假说(两颗白矮星通过发射引力波辐射螺旋进入并合并)进行了对比测试。方法：研究方法。我们使用种群数合成代码，它结合了二进制进化中的最新物理结果，并允许我们区分某些物理场景(例如，共同包络进化的描述)和进化参数(例如，罗氏瓣溢出期间的传质效率)。将得到的Ia型超新星延迟时间的理论分布从形态和绝对事件数两个方面与实际观测结果进行了比较。这些分布对某些参数的临界依赖性被用来约束后者的值。结果。我们发现，单简并情景不能单独解释观测延迟时间分布的形态，而双简并情景(或两者的组合)可以解释观测延迟时间分布的形态。这些双简并Ia型超新星大多是通过正常的准保守罗氏波瓣溢出和公共包络相位产生的，而不是通过两个连续的公共包络相位产生的。这可能会让人对在其他研究中使用分析形式主义来确定延误时间产生怀疑。就绝对数而言，旧椭圆星系的理论超新星Ia率至少比观测到的低三倍。我们提出了一个包含旋转对中等质量双星演化影响的解决方案。
Aims. We investigate the contribution of different formation scenarios for type Ia supernovae in elliptical galaxies. The single-degenerate scenario (a white dwarf accreting from a late main-sequence or red giant companion) is tested against the double-degenerate scenario (the spiral-in and merging of two white dwarfs through the emission of gravitational wave radiation). Methods. We use a population-number synthesis code that incorporates the latest physical results in binary evolution and allows us to differentiate between certain physical scenarios (e.g. description of common-envelope evolution) and evolutionary parameters (e.g. mass-transfer efficiency during Roche-lobe overflow). The obtained theoretical distributions of the delay times of type Ia supernovae are compared, both in morphological shape and in absolute number of events, to those which are observed. The critical dependency of these distributions on certain parameters is used to constrain the values of the latter. Results. We find that the single-degenerate scenario alone cannot explain the morphological shape of the observational delay-time distribution, while the double-degenerate scenario (or a combination of both) can. Most of these double-degenerate type Ia supernovae are created through a normal quasi-conservative Roche-lobe overflow followed by a common-envelope phase, not through two successive common-envelope phases. This may cast doubt on the use in other studies of analytical formalisms to determine delay times. In terms of absolute number, theoretical supernova Ia rates in old elliptical galaxies lie a factor of at least three below the observed ones. We propose a solution involving the effect of rotation on the evolution of intermediate mass binaries.