PS1-12sk IS A PECULIAR SUPERNOVA FROM A He-RICH PROGENITOR SYSTEM IN A BRIGHTEST CLUSTER GALAXY ENVIRONMENT

Journal Article · Mon May 20 00:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/769/1/39· OSTI ID:22126652

Sanders, N. E.; Soderberg, A. M.; Foley, R. J.; Chornock, R.; Milisavljevic, D.; Margutti, R.; Drout, M. R.; Moe, M.; Berger, E.; Brown, W. R.; Lunnan, R. ^[1]; Smartt, S. J.; Fraser, M.; Kotak, R.; Magill, L.; Smith, K. W.; Wright, D. ^[2]; Huang, K. ^[3]; Urata, Y. ^[4]; others, and

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1. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
2. Astrophysics Research Centre, School of Maths and Physics, Queens University, Belfast BT7 1NN (United Kingdom)
3. Academia Sinica Institute of Astronomy and Astrophysics, Taipei 106, Taiwan (China)
4. Institute of Astronomy, National Central University, Chung-Li 32054, Taiwan (China)

We report on our discovery and observations of the Pan-STARRS1 supernova (SN) PS1-12sk, a transient with properties that indicate atypical star formation in its host galaxy cluster or pose a challenge to popular progenitor system models for this class of explosion. The optical spectra of PS1-12sk classify it as a Type Ibn SN (SN Ibn; cf. SN 2006jc), dominated by intermediate-width (3 Multiplication-Sign 10{sup 3} km s{sup -1}) and time variable He I emission. Our multi-wavelength monitoring establishes the rise time dt {approx} 9-23 days and shows an NUV-NIR spectral energy distribution with temperature {approx}> 17 Multiplication-Sign 10{sup 3} K and a peak magnitude of M{sub z} = -18.88 {+-} 0.02 mag. SN Ibn spectroscopic properties are commonly interpreted as the signature of a massive star (17-100 M{sub Sun }) explosion within an He-enriched circumstellar medium. However, unlike previous SNe Ibn, PS1-12sk is associated with an elliptical brightest cluster galaxy, CGCG 208-042 (z = 0.054) in cluster RXC J0844.9+4258. The expected probability of an event like PS1-12sk in such environments is low given the measured infrequency of core-collapse SNe in red-sequence galaxies compounded by the low volumetric rate of SN Ibn. Furthermore, we find no evidence of star formation at the explosion site to sensitive limits ({Sigma}{sub H{alpha}} {approx}< 2 Multiplication-Sign 10{sup -3} M{sub Sun} yr{sup -1} kpc{sup -2}). We therefore discuss white dwarf binary systems as a possible progenitor channel for SNe Ibn. We conclude that PS1-12sk represents either a fortuitous and statistically unlikely discovery, evidence for a top-heavy initial mass function in galaxy cluster cooling flow filaments, or the first clue suggesting an alternate progenitor channel for SNe Ibn.

• OSTI ID: 22126652
• Journal Information: Astrophysical Journal, Vol. 769, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
EMISSION
ENERGY SPECTRA
ENVIRONMENT
GALAXIES
GALAXY CLUSTERS
MASS
MONITORING
PROBABILITY
PULSE RISE TIME
SUPERNOVAE
WAVELENGTHS
WHITE DWARF STARS