PS1-10bzj: A Fast, Hydrogen-poor Superluminous Supernova in a Metal-poor Host Galaxy
Price, P. A.; Berger, E.; Kirshner, R. P.; Rest, A.; Foley, R. J.; Smartt, S. J.; Chambers, K. C.; Stubbs, C. W.; Huber, M. E.; Magnier, E. A.; Chornock, R.; Lunnan, R.; Tonry, J. L.; Smith, K.; Scolnic, D.; Fong, W.; Burgett, W. S.; Soderberg, A. M.; Challis, P. M.; Sanders, N. E.; Milisavljevic, D.; Marion, G. H.; Czekala, I.; Drout, M.; Narayan, G.; Kudritzki, R. -P.; Leibler, C.; McCrum, M.; Roth, K. C.
United States, United Kingdom
Abstract
We present observations and analysis of PS1-10bzj, a superluminous supernova (SLSN) discovered in the Pan-STARRS Medium Deep Survey at a redshift z = 0.650. Spectroscopically, PS1-10bzj is similar to the hydrogen-poor SLSNe 2005ap and SCP 06F6, though with a steeper rise and lower peak luminosity (M bol ~= -21.4 mag) than previous events. We construct a bolometric light curve, and show that while PS1-10bzj's energetics were less extreme than previous events, its luminosity still cannot be explained by radioactive nickel decay alone. We explore both a magnetar spin-down and circumstellar interaction scenario and find that either can fit the data. PS1-10bzj is located in the Extended Chandra Deep Field South and the host galaxy is imaged in a number of surveys, including with the Hubble Space Telescope. The host is a compact dwarf galaxy (MB ≈ -18 mag, diameter <~ 800 pc), with a low stellar mass (M * ≈ 2.4 × 107 M ⊙), young stellar population (τ* ≈ 5 Myr), and a star formation rate of ~2-3 M ⊙ yr-1. The specific star formation rate is the highest seen in an SLSN host so far (~100 Gyr-1). We detect the [O III] λ4363 line, and find a low metallicity: 12 + (O/H) = 7.8 ± 0.2 (sime 0.1 Z ⊙). Together, this indicates that at least some of the progenitors of SLSNe come from young, low-metallicity populations.