Metallicity from Type II supernovae from the (i)PTF
- Stockholm Univ. (Sweden)
- Weizmann Inst. of Science, Rehovot (Israel)
- Weizmann Inst. of Science, Rehovot (Israel); Univ. of Copenhagen (Denmark)
- Las Cumbres Observatory Global Telescope, Goleta, CA (United States); Univ. of California, Santa Barbara, CA (United States)
- California Inst. of Technology (CalTech), Pasadena, CA (United States)
- Univ. of California, Berkeley, CA (United States)
- Liverpool John Moores Univ., Liverpool (United Kingdom); Max Planck Inst. for Astrophysics, Garching (Germany)
- Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Univ. of Illinois, Urbana, IL (United States)
- Univ. of Texas, Austin, TX (United States)
- Chinese Academy of Sciences (CAS), Beijing (China)
Type IIP supernovae (SNe IIP) have recently been proposed as metallicity (Z) probes. The spectral models of Dessart et al. (2014, MNRAS, 440, 1856) showed that the pseudo-equivalent width of Fe ii λ5018 (pEW5018) during the plateau phase depends on the primordial Z, but there was a paucity of SNe IIP exhibiting pEW5018 that were compatible with Z < 0.4 Z⊙. This lack might be due to some physical property of the SN II population or to the fact that those SNe have been discovered in luminous, metal-rich targeted galaxies. In this paper, we use SN II observations from the untargeted (intermediate) Palomar Transient Factory [(i)PTF] survey, aiming to investigate the pEW5018 distribution of this SN population and, in particular, to look for the presence of SNe II at lower Z. We perform pEW5018 measurements on the spectra of a sample of 39 (i)PTF SNe II, selected to have well-constrained explosion epochs and light-curve properties. Based on the comparison with the pEW5018 spectral models, we subgrouped our SNe into four Z bins from Z ≈ 0.1 Z⊙ up to Z ≈ 2 Z⊙. We also independently investigated the Z of the hosts by using their absolute magnitudes and colors and, in a few cases, using strong-line diagnostics from spectra. We searched for possible correlations between SN observables, such as their peak magnitudes and the Z inferred from pEW5018. We found 11 events with pEW5018 that were small enough to indicate Z ≈ 0.1 Z⊙. The trend of pEW5018 with Z matches the Z estimates obtained from the host-galaxy photometry, although the significance of the correlation is weak. Finally, we also found that SNe with brighter peak magnitudes have smaller pEW5018 and occur at lower Z.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); National Science Foundation (NSF); Swedish Research Council (SRC); European Research Council (ERC); Israel Science Foundation (ISF)
- Grant/Contract Number:
- AC02-05CH11231; AST-1211916; AST-1302771; 307260
- OSTI ID:
- 1393032
- Journal Information:
- Astronomy and Astrophysics, Vol. 587; ISSN 0004-6361
- Publisher:
- EDP SciencesCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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