Luminosity distributions of Type Ia supernovae
Luminosity distributions of Type Ia supernovae
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DOI：
10.1093/mnras/stw1214
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发表时间：
2016-05
影响因子：
4.8
通讯作者：
C. Ashall;P. Mazzali;M. Sasdelli;S. Prentice
中科院分区：
文献类型：
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作者：
C. Ashall;P. Mazzali;M. Sasdelli;S. Prentice
我们收集了165颗低红移，$z<$ 0.06，公开可用的Ia型超新星（SNe Ia）的数据集。我们生成了超新星Ia的最大光等（$M_{B}$和$M_{V}$）分布，以探索它们可以填充的参数空间的多样性。在校正主星系消光之前，我们发现Ia超新星的平均$M_{B}$和$M_{V}$分别为$-18.58\pm0.07$等和$-18.72\pm0.05$等。采用一种基于SN谱的新方法对宿主星系消光进行校正。修正后，Ia号SNe的$M_{B}$和$M_{V}$的平均值分别为$-19.10\pm0.06$和$-19.10\pm0.05$。在对宿主星系消光进行校正后，“正常”超新星（$\Delta m_{15}(B)<1.6$等）在宽度-光度关系（WLR）中占据的参数空间比之前提出的要大，并且有证据表明超新星Ia具有较大的$\Delta m_{15}(B)$。我们在$\Delta m_{15}(B)$中发现了双峰分布，在$\Delta m_{15}(B)$ =1.6等处明显缺乏过渡事件。我们证实了更快、低光度的超新星往往来自被动星系。将样本按宿主星系类型划分，来自恒星形成（S-F）星系的Ia型超新星的平均星等为$M_{B}=-19.20 \pm 0.05$，而来自被动星系的Ia型超新星的平均星等为$M_{B}=-18.57 \pm 0.24$。即使排除快速衰减的超新星，S-F和被动星系的Ia型超新星的“正常”（$M_{B}<-18$等）也是不同的。在$V$ -波段，来自被动星系和S-F星系的“正常”Ia型超新星群的中位数（$M_{V}$）值之间存在0.4 $ \pm $ 0.13等的差异。这与（$\sim 15 \pm $ 10）一致% of `normal' SNe Ia from S-F galaxies coming from an old stellar population.
We have assembled a dataset of 165 low redshift, $z<$0.06, publicly available type Ia supernovae (SNe Ia). We produce maximum light magnitude ($M_{B}$ and $M_{V}$) distributions of SNe Ia to explore the diversity of parameter space that they can fill. Before correction for host galaxy extinction we find that the mean $M_{B}$ and $M_{V}$ of SNe Ia are $-18.58\pm0.07$mag and $-18.72\pm0.05$mag respectively. Host galaxy extinction is corrected using a new method based on the SN spectrum. After correction, the mean values of $M_{B}$ and $M_{V}$ of SNe Ia are $-19.10\pm0.06$ and $-19.10\pm0.05$mag respectively. After correction for host galaxy extinction, `normal' SNeIa ($\Delta m_{15}(B)<1.6$mag) fill a larger parameter space in the Width-Luminosity Relation (WLR) than previously suggested, and there is evidence for luminous SNe Ia with large $\Delta m_{15}(B)$. We find a bimodal distribution in $\Delta m_{15}(B)$, with a pronounced lack of transitional events at $\Delta m_{15}(B)$=1.6 mag. We confirm that faster, low-luminosity SNe tend to come from passive galaxies. Dividing the sample by host galaxy type, SNe Ia from star-forming (S-F) galaxies have a mean $M_{B}=-19.20 \pm 0.05$ mag, while SNe Ia from passive galaxies have a mean $M_{B}=-18.57 \pm 0.24$ mag. Even excluding fast declining SNe, `normal' ($M_{B}<-18$ mag) SNe Ia from S-F and passive galaxies are distinct. In the $V$-band, there is a difference of 0.4$ \pm $0.13 mag between the median ($M_{V}$) values of the `normal' SN Ia population from passive and S-F galaxies. This is consistent with ($\sim 15 \pm $10)% of `normal' SNe Ia from S-F galaxies coming from an old stellar population.