The Host Galaxy of the Super-luminous SN 2010gx and Limits on Explosive 56Ni Production
Abstract
Super-luminous supernovae have a tendency to occur in faint host galaxies which are likely to have low mass and low metallicity. While these extremely luminous explosions have been observed from z = 0.1 to 1.55, the closest explosions allow more detailed investigations of their host galaxies. We present a detailed analysis of the host galaxy of SN 2010gx (z = 0.23), one of the best studied super-luminous type Ic supernovae. The host is a dwarf galaxy (Mg = -17.42 ± 0.17) with a high specific star formation rate. It has a remarkably low metallicity of 12 + log (O/H) = 7.5 ± 0.1 dex as determined from the detection of the [O III] λ4363 line. This is the first reliable metallicity determination of a super-luminous stripped-envelope supernova host. We collected deep multi-epoch imaging with Gemini + GMOS between 240 and 560 days after explosion to search for any sign of radioactive 56Ni, which might provide further insights on the explosion mechanism and the progenitor's nature. We reach griz magnitudes of m AB ~ 26, but do not detect SN 2010gx at these epochs. The limit implies that any 56Ni production was similar to or below that of SN 1998bw (a luminous type Ic SN that produced around 0.4 M ⊙ of 56Ni). The low volumetric rates of these supernovae (~10-4 of the core-collapse population) could be qualitatively matched if the explosion mechanism requires a combination of low-metallicity (below 0.2 Z ⊙), high progenitor mass (>60 M ⊙) and high rotation rate (fastest 10% of rotators).
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2013
- DOI:
- 10.1088/2041-8205/763/2/L28
- arXiv:
- arXiv:1210.4027
- Bibcode:
- 2013ApJ...763L..28C
- Keywords:
-
- supernovae: general;
- supernovae: individual: SN 2010gx;
- Astrophysics - Cosmology and Extragalactic Astrophysics
- E-Print:
- 6 pages, 3 figures, 2 tables. Published in Astrophysical Journal Letters