Abstract
We present spectroscopic observations of the host galaxies of 82
low-redshift Type Ia supernovae (SNe Ia) discovered by the Palomar
Transient Factory. We determine star formation rates, gas-phase/stellar
metallicities, and stellar masses and ages of these objects. As
expected, strong correlations between the SN Ia light-curve width
(stretch) and the host age/mass/metallicity are found: fainter, faster
declining events tend to be hosted by older/massive/metal-rich galaxies.
There is some evidence that redder SNe Ia explode in higher metallicity
galaxies, but we found no relation between the SN colour and host galaxy
extinction based on the Balmer decrement, suggesting that the colour
variation of these SNe does not primarily arise from this source. SNe Ia
in higher mass/metallicity galaxies also appear brighter after
stretch/colour corrections than their counterparts in lower mass hosts,
and the stronger correlation is with gas-phase metallicity suggesting
this may be the more important variable. We also compared the host
stellar mass distribution to that in galaxy-targeted SN surveys and the
high-redshift untargeted Supernova Legacy Survey (SNLS). SNLS has many
more low-mass galaxies, while the targeted searches have fewer. This can
be explained by an evolution in the galaxy stellar mass function,
coupled with an SN delay-time distribution proportional to
t-1. Finally, we found no significant difference in the
mass-metallicity relation of our SN Ia hosts compared to field galaxies,
suggesting any metallicity effect on the SN Ia rate is small.
Original language | English |
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Pages (from-to) | 1391-1416 |
Number of pages | 26 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 438 |
Issue number | 2 |
Early online date | 20 Dec 2013 |
DOIs | |
Publication status | Published - 21 Feb 2014 |
Externally published | Yes |
Keywords
- supernovae: general
- cosmology: observations
- distance scale