Optical and ultraviolet spectroscopic analysis of SN 2011fe at late times

Journal Article · Mon Feb 27 00:00:00 EST 2017 · Monthly Notices of the Royal Astronomical Society

DOI:https://doi.org/10.1093/mnras/stx241· OSTI ID:1393113

Friesen, Brian ^[1]; Baron, E. ^[2]; Parrent, Jerod T. ^[3]; Thomas, R. C. ^[4]; Branch, David ^[5]; Nugent, Peter E. ^[4]; Hauschildt, Peter H. ^[6]; Foley, Ryan J. ^[7]; Wright, Darryl E. ^[8]; Pan, Yen-Chen ^[9]; Filippenko, Alexei V. ^[10]; Clubb, Kelsey I. ^[10]; Silverman, Jeffrey M. ^[11]; Maeda, Keiichi ^[12]; Shivvers, Isaac ^[10]; Kelly, Patrick L. ^[10]; Cohen, Daniel P. ^[10]; Rest, Armin ^[13]; Kasen, Daniel ^[14]

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1. Homer L. Dodge Department of Physics and Astronomy, Norman, OK (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2. Homer L. Dodge Department of Physics and Astronomy, Norman, OK (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hamburger Stenwarte, Hamburg (Germany)
3. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
4. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
5. Homer L. Dodge Department of Physics and Astronomy, Norman, OK (United States)
6. Hamburger Stenwarte, Hamburg (Germany)
7. Univ. of Illinois, Urbana-Champaign, IL (United States); Univ. of California, Santa Cruz, CA (United States)
8. Queen's Univ., Belfast, Northern Ireland (United Kingdom)
9. Univ. of Illinois, Urbana-Champaign, IL (United States)
10. Univ. of California, Berkeley, CA (United States)
11. Univ. of Texas, Austin, TX (United States)
12. Kyoto Univ. (Japan); Univ. of Tokyo (Japan). Kavli Inst. for the Physics and Mathematics of the Universe
13. Harvard Univ., Cambridge, MA (United States); Space Telescope Science Inst., Baltimore, MD (United States)
14. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

This paper presents optical spectra of the nearby Type Ia supernova SN 2011fe at 100, 205, 311, 349 and 578 d post-maximum light, as well as an ultraviolet (UV) spectrum obtained with the Hubble Space Telescope at 360 d post-maximum light. We compare these observations with synthetic spectra produced with the radiative transfer code PHOENIX. The day +100 spectrum can be well fitted with models that neglect collisional and radiative data for forbidden lines. Curiously, including these data and recomputing the fit yields a quite similar spectrum, but with different combinations of lines forming some of the stronger features. At day +205 and later epochs, forbidden lines dominate much of the optical spectrum formation; however, our results indicate that recombination, not collisional excitation, is the most influential physical process driving spectrum formation at these late times. Consequently, our synthetic optical and UV spectra at all epochs presented here are formed almost exclusively through recombinationdriven fluorescence. Furthermore, our models suggest that the UV spectrum even as late as day +360 is optically thick and consists of permitted lines from several iron-peak species. These results indicate that the transition to the 'nebular' phase in Type Ia supernovae is complex and highly wavelength dependent.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1393113
• Journal Information: Monthly Notices of the Royal Astronomical Society, Vol. 467, Issue 2; ISSN 0035-8711
• Publisher: Royal Astronomical Society
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS