SN 2012au: A GOLDEN LINK BETWEEN SUPERLUMINOUS SUPERNOVAE AND THEIR LOWER-LUMINOSITY COUNTERPARTS

作者：Milisavljevic Dan^*; Soderberg Alicia M; Margutti Raffaella; Drout Maria R; Marion Howie; Sanders Nathan E; Hsiao Eric Y; Lunnan Ragnhild; Chornock Ryan; Fesen Robert A; Parrent Jerod T; Levesque Emily M; Berger Edo; Foley Ryan J; Challis Pete; Kirshner Robert P; Dittmann Jason; Bieryla Allyson; Kamble Atish; Chakraborti Sayan; De Rosa Gisella; Fausnaugh Michael; Hainline Kevin N; Chen Chien Ting; Hickox Ryan C; Morrell Nidia; Phillips Mark M

来源：Astrophysical Journal Letters, 2013, 770(2): L38.

DOI：10.1088/2041-8205/770/2/L38

• supernovae: general
• supernovae: individual (SN 2012au)

We present optical and near-infrared observations of SN 2012au, a slow-evolving supernova (SN) with properties that suggest a link between subsets of energetic and H-poor SNe and superluminous SNe. SN 2012au exhibited conspicuous Type-Ib-like He I lines and other absorption features at velocities reaching approximate to 2x10(4) km s(-1) in its early spectra, and a broad light curve that peaked at M-B = -18.1 mag. Models of these data indicate a large explosion kinetic energy of similar to 10(52) erg and Ni-56 mass ejection of M-Ni approximate to 0.3 M-circle dot on par with SN 1998bw. SN 2012au%26apos;s spectra almost one year after explosion show a blend of persistent Fe II P-Cyg absorptions and nebular emissions originating from two distinct velocity regions. These late-time emissions include strong [Fe II], [Ca II], [O I], Mg I], and Na I lines at velocities greater than or similar to 4500 km s(-1), as well as O I and Mg I lines at noticeably smaller velocities less than or similar to 2000 km s(-1). Many of the late-time properties of SN 2012au are similar to the slow-evolving hypernovae SN 1997dq and SN 1997ef, and the superluminous SN 2007bi. Our observations suggest that a single explosion mechanism may unify all of these events that span -21 less than or similar to M-B less than or similar to -17 mag. The aspherical and possibly jetted explosion was most likely initiated by the core collapse of a massive progenitor star and created substantial high-density, low-velocity Ni-rich material.

• 出版日期2013-6-20