A Missing-Link in the Supernova-GRB Connection: The Case of SN 2012ap
Abstract
Gamma Ray Bursts (GRBs) are characterized by ultra-relativistic outflows, while supernovae are generally characterized by non-relativistic ejecta. GRB afterglows decelerate rapidly usually within days, because their low-mass ejecta rapidly sweep up a comparatively larger mass of circumstellar material. However supernovae, with heavy ejecta, can be in nearly free expansion for centuries. Supernovae were thought to have non-relativistic outflows except for few relativistic ones accompanied by GRBs. This clear division was blurred by SN 2009bb, the first supernova with a relativistic outflow without an observed GRB. Yet the ejecta from SN 2009bb was baryon loaded, and in nearly-free expansion for a year, unlike GRBs. We report the first supernova discovered without a GRB, but with rapidly decelerating mildly relativistic ejecta, SN 2012ap. We discovered a bright and rapidly evolving radio counterpart driven by the circumstellar interaction of the relativistic ejecta. However, we did not find any coincident GRB with an isotropic fluence of more than a sixth of the fluence from GRB 980425. This shows for the first time that central engines in type Ic supernovae, even without an observed GRB, can produce both relativistic and rapidly decelerating outflows like GRBs.
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Cite
@article{arxiv.1402.6336,
title = {A Missing-Link in the Supernova-GRB Connection: The Case of SN 2012ap},
author = {Sayan Chakraborti and Alicia Soderberg and Laura Chomiuk and Atish Kamble and Naveen Yadav and Alak Ray and Kevin Hurley and Raffaella Margutti and Dan Milisavljevic and Michael Bietenholz and Andreas Brunthaler and Giuliano Pignata and Elena Pian and Paolo Mazzali and Claes Fransson and Norbert Bartel and Mario Hamuy and Emily Levesque and Andrew MacFadyen and Jason Dittmann and Miriam Krauss and M. S. Briggs and V. Connaughton and K. Yamaoka and T. Takahashi and M. Ohno and Y. Fukazawa and M. Tashiro and Y. Terada and T. Murakami and J. Goldsten and S. Barthelmy and N. Gehrels and J. Cummings and H. Krimm and D. Palmer and S. Golenetskii and R. Aptekar and D. Frederiks and D. Svinkin and T. Cline and I. G. Mitrofanov and D. Golovin and M. L. Litvak and A. B. Sanin and W. Boynton and C. Fellows and K. Harshman and H. Enos and A. von Kienlin and A. Rau and X. Zhang and V. Savchenko},
journal= {arXiv preprint arXiv:1402.6336},
year = {2015}
}
Comments
8 pages, 5 figures, 1 table, accepted for publication in ApJ