标题： Ia 型超新星前身系统的年龄？ GALEX 对时间延迟分布的新观测限制 显示英文标题

标题： How old are SN Ia Progenitor Systems? New Observational Constraints on the Distribution of Time Delays from GALEX

摘要： Ia型超新星（SNe Ia）前身系统形成与其引爆之间的时间延迟是区分针对它们提出的不同前身情景的关键判据。 我们利用21个近邻SNe Ia的早期类型宿主星系的SDSS光学和GALEX紫外观测数据，量化了年轻恒星群体的存在与否，以限制每个超新星的最小时间延迟。 我们发现早期类型的宿主星系缺乏时间延迟<1亿年的“快速”SNe Ia，并且约70%的SNe Ia具有275百万年至12.5亿年的最小时间延迟，其中位数为650百万年，而至少20%的SNe Ia在95%置信度下具有至少1亿年的最小时间延迟，其中这四个SNe Ia中有两个很可能超过20亿年。 观察到的最小时间延迟分布与单简并通道的预期最为接近，该通道的供体处于主序阶段。 此外，我们并未发现任何证据表明次亮SNe Ia与长时延有关联。 显示英文摘要

摘要： The time delay between the formation of the progenitor systems of Type Ia supernovae (SNe Ia) and their detonation is a vital discriminant between the various progenitor scenarios that have been proposed for them. We use SDSS optical and GALEX ultraviolet observations of the early-type host galaxies of 21 nearby SNe Ia and quantify the presence or absence of any young stellar population to constrain the minimum time delay for each supernova. We find that early-type host galaxies lack `prompt' SNe Ia with time delays of <100 Myr and that ~70% SNe Ia have minimum time delays of 275 Myr -- 1.25 Gyr, with a median of 650 Myr, while at least 20% SNe Ia have minimum time delays of at least 1 Gyr at 95% confidence and two of these four SNe Ia are are likely older than 2 Gyr. The distribution of minimum time delays observed matches most closely the expectation for the single-degenerate channel with a main sequence donor. Furthermore, we do not find any evidence that sub-luminous SNe Ia are associated with long time delays.