{
  "id": "1602.01433",
  "version": "v1",
  "published": "2016-02-02T16:10:30.000Z",
  "updated": "2016-02-02T16:10:30.000Z",
  "title": "Metallicity from Type II Supernovae from the (i)PTF",
  "authors": [
    "F. Taddia",
    "P. Moquist",
    "J. Sollerman",
    "A. Rubin",
    "G. Leloudas",
    "A. Gal-Yam",
    "I. Arcavi",
    "Y. Cao",
    "A. V. Filippenko",
    "M. L. Graham",
    "P. A. Mazzali",
    "P. E. Nugent",
    "Y. -C. Pan",
    "J. M. Silverman",
    "D. Xu",
    "O. Yaron"
  ],
  "comment": "Letter to the editor, submitted to Astronomy and Astrophysics on Dec. 16th, 2015",
  "categories": [
    "astro-ph.HE",
    "astro-ph.CO"
  ],
  "abstract": "Type IIP supernovae (SNe IIP) have recently been proposed as metallicity ($Z$) probes. The spectral models of Dessart et al. (2014) showed that the pseudo-equivalent width of Fe II $\\lambda$5018 (pEW$_{5018}$) during the plateau phase depends on the primordial $Z$, but there was a paucity of SNe IIP exhibiting pEW$_{5018}$ compatible with $Z < 0.4 {\\rm Z}_{\\odot}$. This lack might be due to some physical property of the SN II population, or to the fact that those SNe were discovered in luminous, metal-rich targeted galaxies. Here we use SN II observations from the untargeted (intermediate) Palomar Transient Factory [(i)PTF] survey, aiming to investigate the pEW$_{5018}$ distribution of this SN population and in particular to look for the presence of SNe II at lower $Z$. We perform pEW$_{5018}$ measurements on the spectra of a sample of 39 (i)PTF SNe II, selected to have well-constrained explosion epochs and light-curve properties (Rubin et al. 2015). Based on the comparison with the pEW$_{5018}$ spectral models we subgrouped our SNe into four $Z$ bins, from $Z \\approx 0.1$ $Z_{\\odot}$ up to $Z \\approx 2$ $Z_{\\odot}$. We also independently investigated the $Z$ of the hosts by using their absolute magnitudes and colors, and in a few cases with strong-line diagnostics from spectra. We searched for possible correlations between SN observables such as their peak magnitudes and the $Z$ inferred from pEW$_{5018}$. We found 11 events with pEW$_{5018}$ sufficiently small to indicate $Z \\approx 0.1$ $Z_{\\odot}$. The trend of pEW$_{5018}$ with $Z$ matches the $Z$ estimates obtained from the host-galaxy photometry, although the significance of the correlation is weak. We also found that SNe with brighter peak magnitudes have smaller pEW$_{5018}$ and occur at lower $Z$.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2016-02-02T16:10:30.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "metallicity",
      "spectral models",
      "palomar transient factory",
      "brighter peak magnitudes",
      "type iip supernovae"
    ],
    "publication": {
      "doi": "10.1051/0004-6361/201527983"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1419225
    }
  }
}