Browsing by Subject "ic supernova"

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    Multi-Color Optical and Near-Infrared Light Curves of 64 Stripped-Envelope Core-Collapse Supernovae
    (2014-08) Bianco, F. B.; Modjaz, M.; Hicken, M.; Friedman, A.; Kirshner, R. P.; Bloom, J. S.; Challis, P.; Marion, G. H.; Wood-Vasey, W. M.; Rest, A.; Marion, G. H.
    We present a densely sampled, homogeneous set of light curves of 64 low-redshift (z less than or similar to 0.05) stripped-envelope supernovae (SNe of Type IIb, Ib, Ic, and Ic-BL). These data were obtained between 2001 and 2009 at the Fred L. Whipple Observatory (FLWO) on Mount Hopkins in Arizona, with the optical FLWO 1.2 m and the near-infrared (NIR) Peters Automated Infrared 1.3 m telescopes. Our data set consists of 4543 optical photometric measurements on 61 SNe, including a combination of UBVRI, UBVr'i', and u'BVr'i', and 1919 JHK(s) NIR measurements on 25 SNe. This sample constitutes the most extensive multi-color data set of stripped-envelope SNe to date. Our photometry is based on template-subtracted images to eliminate any potential host-galaxy light contamination. This work presents these photometric data, compares them with data in the literature, and estimates basic statistical quantities: date of maximum, color, and photometric properties. We identify promising color trends that may permit the identification of stripped-envelope SN subtypes from their photometry alone. Many of these SNe were observed spectroscopically by the Harvard-Smithsonian Center for Astrophysics (CfA) SN group, and the spectra are presented in a companion paper. A thorough exploration that combines the CfA photometry and spectroscopy of stripped-envelope core-collapse SNe will be presented in a follow-up paper.
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    Rapidly Evolving And Luminous Transients From Pan-STARRS1
    (2014-10) Drout, M. R.; Chornock, Ryan; Soderberg, Alicia M.; Sanders, N. E.; McKinnon, R.; Rest, A.; Foley, Ryan J.; Milisavljevic, Dan; Margutti, R.; Berger, E.; Calkins, M.; Fong, W.; Gezari, S.; Huber, M. E.; Kankare, E.; Kirshner, Robert P.; Leibler, C.; Lunnan, R.; Mattila, S.; Marion, G. H.; Narayan, G.; Riess, Adam G.; Roth, K. C.; Scolnic, D.; Smartt, S. J.; Tonry, J. L.; Burgett, W. S.; Chambers, K. C.; Hodapp, K. W.; Jedicke, R.; Kaiser, N.; Magnier, E. A.; Metcalfe, N.; Morgan, J. S.; Price, P. A.; Waters, C.; Marion, G. H.
    In the past decade, several rapidly evolving transients have been discovered whose timescales and luminosities are not easily explained by traditional supernovae (SNe) models. The sample size of these objects has remained small due, at least in part, to the challenges of detecting short timescale transients with traditional survey cadences. Here we present the results from a search within the Pan-STARRS1 Medium Deep Survey (PS1-MDS) for rapidly evolving and luminous transients. We identify 10 new transients with a time above half-maximum (t(1/2)) of less than 12 days and -16.5 > M> -20 mag. This increases the number of known events in this region of SN phase space by roughly a factor of three. The median redshift of the PS1-MDS sample is z = 0.275 and they all exploded in star-forming galaxies. In general, the transients possess faster rise than decline timescale and blue colors at maximum light (g(P1) - r(P1) less than or similar to -0.2). Best-fit blackbodies reveal photospheric temperatures/radii that expand/cool with time and explosion spectra taken near maximum light are dominated by a blue continuum, consistent with a hot, optically thick, ejecta. We find it difficult to reconcile the short timescale, high peak luminosity (L> 10(43) erg s(-1)), and lack of UV line blanketing observed in many of these transients with an explosion powered mainly by the radioactive decay of56Ni. Rather, we find that many are consistent with either (1) cooling envelope emission from the explosion of a star with a low-mass extended envelope that ejected very little (<0.03 M-circle dot) radioactive material, or (2) a shock breakout within a dense, optically thick, wind surrounding the progenitor star. After calculating the detection efficiency for objects with rapid timescales in the PS1-MDS we find a volumetric rate of 4800-8000 events yr(-1) Gpc(-3) (4%-7% of the core-collapse SN rate at z = 0.2).