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X-Ray Emission from Supernovae in Dense Circumstellar Matter Environments: A Search for Collisionless Shocks

Ofek, E. O. and Fox, D. and Cenko, S. B. and Sullivan, M. and Gnat, O. and Frail, D. A. and Horesh, A. and Corsi, A. and Quimby, R. M. and Gehrels, N. and Kulkarni, S. R. and Gal-Yam, A. and Nugent, P. E. and Yaron, O. and Filippenko, A. V. and Kasliwal, M. M. and Bildsten, L. and Bloom, J. S. and Poznanski, D. and Arcavi, I. and Laher, R. R. and Levitan, D. and Sesar, B. and Surace, J. (2013) X-Ray Emission from Supernovae in Dense Circumstellar Matter Environments: A Search for Collisionless Shocks. Astrophysical Journal, 763 (1). Art. No. 42. ISSN 0004-637X.

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The optical light curve of some supernovae (SNe) may be powered by the outward diffusion of the energy deposited by the explosion shock (the so-called shock breakout) in optically thick (τ ≳ 30) circumstellar matter (CSM). Recently, it was shown that the radiation-mediated and radiation-dominated shock in an optically thick wind must transform into a collisionless shock and can produce hard X-rays. The X-rays are expected to peak at late times, relative to maximum visible light. Here we report on a search, using Swift/XRT and Chandra, for X-ray emission from 28 SNe that belong to classes whose progenitors are suspected to be embedded in dense CSM. Our sample includes 19 Type IIn SNe, one Type Ibn SN, and eight hydrogen-poor superluminous SNe (SLSN-I such as SN 2005ap). Two SNe (SN 2006jc and SN 2010jl) have X-ray properties that are roughly consistent with the expectation for X-rays from a collisionless shock in optically thick CSM. However, the X-ray emission from SN 2006jc can also be explained as originating in an optically thin region. Thus, we propose that the optical light curve of SN 2010jl is powered by shock breakout in CSM. We suggest that two other events (SN 2010al and SN 2011ht) were too X-ray bright during the SN maximum optical light to be explained by the shock-breakout model. We conclude that the light curves of some, but not all, SNe IIn/Ibn are powered by shock breakout in CSM. For the rest of the SNe in our sample, including all of the SLSN-I events, our X-ray limits are not deep enough and were typically obtained too early (i.e., near the SN maximum light) for definitive conclusions about their nature. Late-time X-ray observations are required in order to further test whether these SNe are indeed embedded in dense CSM. We review the conditions required for a shock breakout in a wind profile. We argue that the timescale, relative to maximum light, for the SN to peak in X-rays is a probe of the column density and the density profile above the shock region. In SNe whose X-ray emission slowly rises, and peaks at late times, the optical light curve is likely powered by the diffusion of shock energy in a dense CSM. We note that if the CSM density profile falls faster than a constant-rate wind-density profile, then X-rays may escape at earlier times than estimated for the wind-profile case. Furthermore, if the CSM has a region in which the density profile is very steep relative to a steady wind-density profile, or if the CSM is neutral, then the radio free-free absorption may be sufficiently low for radio emission to be detected.

Item Type:Article
Related URLs:
URLURL TypeDescription
Ofek, E. O.0000-0002-6786-8774
Cenko, S. B.0000-0003-1673-970X
Corsi, A.0000-0001-8104-3536
Quimby, R. M.0000-0001-9171-5236
Kulkarni, S. R.0000-0001-5390-8563
Gal-Yam, A.0000-0002-3653-5598
Nugent, P. E.0000-0002-3389-0586
Filippenko, A. V.0000-0003-3460-0103
Kasliwal, M. M.0000-0002-5619-4938
Arcavi, I.0000-0001-7090-4898
Sesar, B.0000-0002-0834-3978
Surace, J.0000-0001-7291-0087
Additional Information:© 2013 American Astronomical Society. Received 2012 May 30; accepted 2012 October 18; published 2013 January 4. We thank Ehud Nakar, Boaz Katz, and Nir Sapir for many discussions, and the anonymous referee for constructive comments. This paper is based on observations obtained with the Samuel Oschin Telescope as part of the Palomar Transient Factory project, a scientific collaboration between the California Institute of Technology, Columbia University, Las Cumbres Observatory, the Lawrence Berkeley National Laboratory, the National Energy Research Scientific Computing Center, the University of Oxford, and the Weizmann Institute of Science. E.O.O. is incumbent of the Arye Dissentshik career development chair and is grateful to support by a grant from the Israeli Ministry of Science. M.S. acknowledges support from the Royal Society. A.C. acknowledges support from LIGO, which was constructed by the California Institute of Technology and the Massachusetts Institute of Technology with funding from the National Science Foundation and operates under cooperative agreement PHY-0757058. S.R.K. and his group are partially supported by the NSF grant AST-0507734. A.G. acknowledges support by the Israeli, German–Israeli, and the U.S.–Israel Binational Science Foundations, a Minerva grant, and the Lord Sieff of Brimpton fund. The National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, provided staff, computational resources, and data storage for the PTF project. P.E.N. acknowledges support from the U.S. Department of Energy Scientific Discovery through Advanced Computing program under contract DE-FG02-06ER06-04. J.S.B.’s work on PTF was supported by NSF/OIA award AST-0941742 (“Real-Time Classification of Massive Time-Series Data Streams”). L.B. is supported by the NSF under grants PHY 05-51164 and AST 07-07633. M.M.K. acknowledges generous support from the Hubble Fellowship and Carnegie-Princeton Fellowship. A.V.F.’s supernova group at UC Berkeley is supported by Gary & Cynthia Bengier, the Richard & Rhoda Goldman Fund, the Christopher R. Redlich Fund, the TABASGO Foundation, and NSF grants AST-0908886 and AST-1211916. KAIT and its ongoing operation were made possible by donations from Sun Microsystems, Inc., the Hewlett-Packard Company, Auto-Scope Corporation, Lick Observatory, the NSF, the University of California, the Sylvia & Jim Katzman Foundation, and the TABASGO Foundation.
Group:Space Radiation Laboratory, IPTF, Infrared Processing and Analysis Center (IPAC), LIGO
Funding AgencyGrant Number
Ministry of Science (Israel)UNSPECIFIED
Israel Science FoundationUNSPECIFIED
German-Israeli Foundation for Research and DevelopmentUNSPECIFIED
Binational Science Foundation (USA-Israel)UNSPECIFIED
Lord Sieff of Brimpton FundUNSPECIFIED
Department of Energy (DOE)DE-AC02-05CH11231
Department of Energy (DOE)DE-FG02-06ER06-04
NSFPHY 05-51164
NSFAST 07-07633
Carnegie-Princeton FellowshipUNSPECIFIED
Gary and Cynthia BengierUNSPECIFIED
Richard and Rhoda Goldman FundUNSPECIFIED
Christopher R. Redlich FundUNSPECIFIED
Sun Microsystems, Inc.UNSPECIFIED
Hewlett-Packard CompanyUNSPECIFIED
Auto-Scope Corporation UNSPECIFIED
Lick ObservatoryUNSPECIFIED
University of CaliforniaUNSPECIFIED
Sylvia and Jim Katzman FoundationUNSPECIFIED
Subject Keywords:stars: mass-loss; supernovae: general; supernovae: individual (SN 2006jc, SN 2010jl)
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory2009-65
Record Number:CaltechAUTHORS:20130215-140729372
Persistent URL:
Official Citation:X-Ray Emission from Supernovae in Dense Circumstellar Matter Environments: A Search for Collisionless Shocks E. O. Ofek et al. 2013 ApJ 763 42
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:36964
Deposited By: Ruth Sustaita
Deposited On:15 Feb 2013 22:43
Last Modified:22 Nov 2017 17:07

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