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Analysis of the Early-time Optical Spectra of SN 2011fe in M101

Parrent, J. T. and Cao, Y. and Konidaris, N. and Kulkarni, S. R. and Levitan, D. (2012) Analysis of the Early-time Optical Spectra of SN 2011fe in M101. Astrophysical Journal Letters, 752 (2). Art. No. L26. ISSN 2041-8205. doi:10.1088/2041-8205/752/2/L26.

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The nearby Type Ia supernova (SN Ia) SN 2011fe in M101 (cz = 241 km s^(–1)) provides a unique opportunity to study the early evolution of a "normal" SN Ia, its compositional structure, and its elusive progenitor system. We present 18 high signal-to-noise spectra of SN 2011fe during its first month beginning 1.2 days post-explosion and with an average cadence of 1.8 days. This gives a clear picture of how various line-forming species are distributed within the outer layers of the ejecta, including that of unburned material (C+O). We follow the evolution of C II absorption features until they diminish near maximum light, showing overlapping regions of burned and unburned material between ejection velocities of 10,000 and 16,000 km s^(–1). This supports the notion that incomplete burning, in addition to progenitor scenarios, is a relevant source of spectroscopic diversity among SNe Ia. The observed evolution of the highly Doppler-shifted O I λ7774 absorption features detected within 5 days post-explosion indicates the presence of O I with expansion velocities from 11,500 to 21,000 km s^(–1). The fact that some O I is present above C II suggests that SN 2011fe may have had an appreciable amount of unburned oxygen within the outer layers of the ejecta.

Item Type:Article
Related URLs:
URLURL TypeDescription
Cao, Y.0000-0002-8036-8491
Konidaris, N.0000-0003-1905-2815
Kulkarni, S. R.0000-0001-5390-8563
Additional Information:© 2012 American Astronomical Society. Received 2012 April 18; accepted 2012 May 15; published 2012 May 31. This work was supported by the Las Cumbres Observatory Global Telescope Network. This research used resources of 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. Observations were obtained as part of the Palomar Transient Factory project. The TNG is operated by the Fundacion Galileo Galilei—INAF (Istituto Nazionale di Astrofisica). The LT and WHT are operated by the Isaac Newton Group. The three telescopes are located in the Spanish Observatorio of the Roque de Los Muchachos of the Instituto de Astrofisica de Canarias. Some observations were obtained at the Gemini Observatory (GN-2011B-Q-215), which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership. Other observations were obtained with the 200 inch telescope at Palomar Observatory, the UH 2.2 m telescope, which is part of the Nearby Supernova Factory II project, and the Lick 3 m telescope, which is operated by the University of California. Some of the data presented herein were obtained at the W. M. Keck Observatory.
Group:Space Radiation Laboratory, Palomar Transient Factory
Funding AgencyGrant Number
Las Cumbres Observatory Global Telescope NetworkUNSPECIFIED
Department of Energy (DOE)DE-AC02-05CH11231
Subject Keywords:supernovae: general; supernovae: individual (SN 2011fe)
Issue or Number:2
Record Number:CaltechAUTHORS:20120716-133338149
Persistent URL:
Official Citation:Analysis of the Early-time Optical Spectra of SN 2011fe in M101 J. T. Parrent et al. 2012 ApJ 752 L26
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:32481
Deposited By: Jason Perez
Deposited On:16 Jul 2012 20:59
Last Modified:09 Nov 2021 21:27

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