标题： Ia型超新星光谱特征与其宿主星系属性的背景 显示英文标题

标题： Type Ia Supernova Spectral Features in the Context of Their Host Galaxy Properties

摘要： 我们分析了由帕洛马瞬变工厂发现的122个Ia型超新星（SNe Ia）的光谱测量数据，重点研究了$z<0.09$的特性以及\Siii 和\Caii 的“近红外三重吸收”特征。 我们在恒星质量（\mstellar ）和超新星宿主星系的恒星形成率（SFR）以及超新星在其宿主星系中的位置的背景下，检查了光球层\Siii 的速度，以及光球层和高速\Caii 的速度和强度。 我们发现，具有更快 \Siii 的超新星 Ia 更倾向于在质量更大的星系中爆发，最高速度事件仅出现在 $\mstellar>3\times10^9$ \msun 的星系中。 我们还发现一些证据表明，这些最高速度的超新星 Ia 在其宿主星系的内部区域爆发，类似于 \citet{2013Sci...340..170W} 的研究，尽管在我们的数据中这种趋势并不那么显著。 我们表明，这些趋势与某些超新星 Ia 光谱模型是一致的，如果将宿主星系恒星质量解释为宿主星系金属量的代理指标的话。 我们研究了 \Caii 近红外吸收的高速度成分的强度，并表明相对于光球层成分具有更强高速度成分的超新星 Ia 所在的星系具有低 \mstellar 、蓝色和高 sSFR。 因此，这些超新星很可能来自最年轻的前身系统。 这反驳了高速度特征纯粹由取向效应引起的观点，并且与其他研究结合时，与高速度特征与超新星爆发物质和局部超新星周围的介质（CSM）之间相互作用相关的场景一致。 显示英文摘要

摘要： We analyse spectroscopic measurements of 122 type Ia supernovae (SNe Ia) with $z<0.09$ discovered by the Palomar Transient Factory, focusing on the properties of the \Siii\ and \Caii\ `near-infrared triplet' absorptions. We examine the velocities of the photospheric \Siii, and the velocities and strengths of the photospheric and high-velocity \Caii, in the context of the stellar mass (\mstellar) and star-formation rate (SFR) of the SN host galaxies, as well as the position of the SN within its host. We find that SNe Ia with faster \Siii\ tend to explode in more massive galaxies, with the highest velocity events only occuring in galaxies with $\mstellar>3\times10^9$\,\msun. We also find some evidence that these highest velocity SNe Ia explode in the inner regions of their host galaxies, similar to the study of \citet{2013Sci...340..170W}, although the trend is not as significant in our data. We show that these trends are consistent with some SN Ia spectral models, if the host galaxy stellar mass is interpreted as a proxy for host galaxy metallicity. We study the strength of the high-velocity component of the \Caii\ near-IR absorption, and show that SNe Ia with stronger high-velocity components relative to photospheric components are hosted by galaxies with low \mstellar, blue colour, and a high sSFR. Such SNe are therefore likely to arise from the youngest progenitor systems. This argues against a pure orientation effect being responsible for high-velocity features in SN Ia spectra and, when combined with other studies, is consistent with a scenario where high-velocity features are related to an interaction between the SN ejecta and circumstellar medium (CSM) local to the SN.