{
  "id": "1605.05507",
  "version": "v1",
  "published": "2016-05-18T10:32:33.000Z",
  "updated": "2016-05-18T10:32:33.000Z",
  "title": "Luminosity distributions of Type Ia Supernovae",
  "authors": [
    "Chris Ashall",
    "Paolo Mazzali",
    "Michele Sasdelli",
    "Simon Prentice"
  ],
  "comment": "Accepted for publication in MNRAS",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "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.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2016-05-18T10:32:33.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "sne ia",
      "type ia supernovae",
      "host galaxy extinction",
      "luminosity distributions",
      "passive galaxies"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1460811
    }
  }
}