Pan-STARRS1 DISCOVERY OF TWO ULTRALUMINOUS SUPERNOVAE AT z Almost-Equal-To 0.9

Journal Article · Mon Dec 19 23:00:00 EST 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/743/2/114· OSTI ID:22004469

Chomiuk, L ^[1]; Chornock, R; Soderberg, A M; Berger, E; Foley, R J; Kirshner, R P; Czekala, I ^[2]; Chevalier, R A ^[3]; Huber, M E; Gezari, S; Riess, A; Rodney, S A ^[4]; Narayan, G; Stubbs, C W ^[5]; Rest, A ^[6]; Smartt, S J ^[7]; Tonry, J L; Burgett, W S; Chambers, K C ^[8]; others, and

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1. National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States)
2. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
3. Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)
4. Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)
5. Department of Physics, Harvard University, Cambridge, MA 02138 (United States)
6. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
7. Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom)
8. Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

We present the discovery of two ultraluminous supernovae (SNe) at z Almost-Equal-To 0.9 with the Pan-STARRS1 Medium Deep Survey. These SNe, PS1-10ky and PS1-10awh, are among the most luminous SNe ever discovered, comparable to the unusual transients SN 2005ap and SCP 06F6. Like SN 2005ap and SCP 06F6, they show characteristic high luminosities (M{sub bol} Almost-Equal-To -22.5 mag), blue spectra with a few broad absorption lines, and no evidence for H or He. We have constructed a full multi-color light curve sensitive to the peak of the spectral energy distribution in the rest-frame ultraviolet, and we have obtained time series spectroscopy for these SNe. Given the similarities between the SNe, we combine their light curves to estimate a total radiated energy over the course of explosion of (0.9-1.4) Multiplication-Sign 10{sup 51} erg. We find photospheric velocities of 12,000-19,000 km s{sup -1} with no evidence for deceleration measured across {approx}3 rest-frame weeks around light curve peak, consistent with the expansion of an optically thick massive shell of material. We show that, consistent with findings for other ultraluminous SNe in this class, radioactive decay is not sufficient to power PS1-10ky, and we discuss two plausible origins for these events: the initial spin-down of a newborn magnetar in a core-collapse SN, or SN shock breakout from the dense circumstellar wind surrounding a Wolf-Rayet star.

• OSTI ID: 22004469
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 743; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION
COLOR
ENERGY SPECTRA
EXPLOSIONS
LUMINOSITY
NUCLEAR DECAY
SPECTROSCOPY
SUPERNOVAE
ULTRAVIOLET RADIATION
WOLF-RAYET STARS