The Exceptionally Luminous Type Ia Supernova 2007if
Abstract
SN 2007if was the third over-luminous Type Ia supernova (SN Ia) detected after 2003fg and 2006gz. We present the photometric and spectroscopic observations of the SN and its host by ROTSE-III, HET, and Keck. From the H_α line identified in the host spectra, we determine a redshift of 0.0736. At this distance, the SN reached an absolute magnitude of –20.4, brighter than any other SNe Ia ever observed. If the source of luminosity is radioactive decay, a large amount of radioactive nickel (~1.5 M_☉) is required to power the peak luminosity, more than can be produced realistically in a Chandrasekhar mass progenitor. Low expansion velocity, similar to that of 2003fg, is also measured around the maximum light. The observations may suggest that SN 2007if was from a massive white dwarf progenitor, plausibly exploding with mass well beyond 1.4 M_☉. Alternatively, we investigate circumstellar interaction that may contribute to the excess luminosity.
Additional Information
© 2010 The American Astronomical Society. Received 2009 December 22; accepted 2010 April 13; published 2010 May 10. The authors gratefully acknowledge M. Kasliwal for the data taken at Keck, and C. S. Peters and J. R. Thorstensen for the data taken at the 2.4 m Hiltner telescope. Special thanks to the McDonald Observatory staff and the H.E.S.S. staff, especially David Doss and Toni Hanke. We also thank the staff of Hobby- Eberly Telescope for their support. F.Y. is supported by the NASA Swift Guest Investigator grants NNX-08AN25G. J.C.W. is supported in part by NSF AST-0707769. ROTSE-III has been supported by NASA grant NNX-08AV63G, NSF grant PHY- 0801007, the Australian Research Council, the University of New South Wales, the University of Texas, and the University of Michigan. The authors thank the anonymous referee for the valuable comments.Attached Files
Published - Yuan2010p10224Astrophys_J.pdf
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Additional details
- Eprint ID
- 18670
- Resolver ID
- CaltechAUTHORS:20100614-140415579
- NNX-08AN25G
- NASA
- AST-0707769
- NSF
- NNX-08AV63G
- NASA
- PHY-0801007
- NSF
- Australian Research Council
- University of New South Wales
- University of Texas
- University of Michigan
- Created
-
2010-06-14Created from EPrint's datestamp field
- Updated
-
2021-11-08Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences