ANALYSIS OF THE EARLY-TIME OPTICAL SPECTRA OF SN 2011fe IN M101

作者：Parrent J T^*; Howell D A; Friesen B; Thomas R C; Fesen R A; Milisavljevic D; Bianco F B; Dilday B; Nugent P; Baron E; Arcavi I; Ben Ami S; Bersier D; Bildsten L; Bloom J; Cao Y; Cenko S B; Filippenko A V; Gal Yam A; Kasliwal M M; Konidaris N; Kulkarni S R; Law N M; Levitan D; Maguire K; Mazzali P A; Ofek E O; Pan Y; Polishook D; Poznanski D; Quimby R M; Silverman J M; Sternberg A; Sullivan M; Walker E S

来源：Astrophysical Journal Letters, 2012, 752(2): L26.

DOI：10.1088/2041-8205/752/2/L26

• supernovae: general
• supernovae: individual (SN 2011fe)

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 %26quot;normal%26quot; 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 highlyDoppler-shifted OI lambda 7774 absorption features detected within 5 days post-explosion indicates the presence of OI with expansion velocities from 11,500 to 21,000 km s(-1). The fact that some OI 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.

• 出版日期2012-6-20
• 单位MIT