TY - JOUR
T1 - Optical and ultraviolet spectroscopic analysis of SN 2011fe at late times
AU - Friesen, Brian
AU - Baron, E.
AU - Parrent, Jerod T.
AU - Thomas, R. C.
AU - Branch, David
AU - Nugent, Peter E.
AU - Hauschildt, Peter H.
AU - Foley, Ryan J.
AU - Wright, Darryl E.
AU - Pan, Yen Chen
AU - Filippenko, Alexei V.
AU - Clubb, Kelsey I.
AU - Silverman, Jeffrey M.
AU - Maeda, Keiichi
AU - Shivvers, Isaac
AU - Kelly, Patrick L.
AU - Cohen, Daniel P.
AU - Rest, Armin
AU - Kasen, Daniel
N1 - Publisher Copyright:
© 2017 The Authors.
PY - 2017
Y1 - 2017
N2 - We present 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.
AB - We present 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.
KW - Supernovae: general
KW - Supernovae: individual: SN 2011fe
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U2 - 10.1093/mnras/stx241
DO - 10.1093/mnras/stx241
M3 - Article
AN - SCOPUS:85018326258
SN - 0035-8711
VL - 467
SP - 2392
EP - 2411
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 2
ER -