* Astronomy

Title: PS1-10bzj: A Fast, Hydrogen-Poor Superluminous Supernova in a Metal Poor Host Galaxy
Authors: R. Lunnan, R. Chornock, E. Berger, D. Milisavljevic, M. Drout, N. E. Sanders, P. M. Challis, I. Czekala, R. J. Foley, W. Fong, M. E. Huber, R. P. Kirshner, C. Leibler, G. H. Marion, M. McCrum, G. Narayan, A. Rest, K. C. Roth, D. Scolnic, S. J. Smartt, K. Smith, A. M. Soderberg, C. W. Stubbs, J. L. Tonry, W. S. Burgett, K. C. Chambers, R.-P. Kudritzki, E. A. Magnier, P. A. Price

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 (ECDF-S) and the host galaxy is imaged in a number of surveys, including with the Hubble Space Telescope. The host is a compact dwarf galaxy (M_B ~ -18 mag, diameter < 800 pc), with a low stellar mass (M_* ~ 2.4 * 10^7 solar masses), young stellar population (\tau_* ~ 5 Myr), and a star formation rate of ~ 2-3 solar masses/yr. The specific star formation rate is the highest seen in a SLSN host so far (~ 100 Gyr^{-1}). We detect the [O III]\lambda 4363 line, and find a low metallicity: 12+(O/H) = 7.8 ± 0.2 (~ 0.1 Z_sun). Together, this indicates that at least some of the progenitors of SLSNe come from young, low-metallicity populations.

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