Document Type
Article
Publication Date
6-20-2012
Publication Title
Letters of the Astrophysical Journal
Department
Department of Physics and Astronomy
Abstract
The nearby Type Ia supernova SN 2011fe in M101 (cz=241 km s^-1) provides a unique opportunity to study the early evolution of a "normal" Type Ia supernova, 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 7774 absorption features detected within five days post-explosion indicate 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.
DOI
10.1088/2041-8205/752/2/L26
Original Citation
J. T. Parrent et al 2012 ApJL 752 L26
Dartmouth Digital Commons Citation
Parrent, J. T.; Howell, D. A.; Friesen, B.; and Thomas, R. C., "Analysis of the Early-Time Optical Spectra of SN 2011fe in M101" (2012). Dartmouth Scholarship. 1790.
https://digitalcommons.dartmouth.edu/facoa/1790
