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Title: Optical and ultraviolet observations of the narrow-lined type Ia SN 2012fr in NGC 1365

Extensive optical and ultraviolet (UV) observations of the type Ia supernova (SN Ia) 2012fr are presented in this paper. It has a relatively high luminosity, with an absolute B-band peak magnitude of about –19.5 mag and a smaller post-maximum decline rate than normal SNe Ia (e.g., Δm {sub 15}(B) =0.85 ± 0.05 mag). Based on the UV and optical light curves, we derived that a {sup 56}Ni mass of about 0.88 M {sub ☉} was synthesized in the explosion. The earlier spectra are characterized by noticeable high-velocity features of Si II λ6355 and Ca II with velocities in the range of ∼22, 000-25, 000 km s{sup –1}. At around the maximum light, these spectral features are dominated by the photospheric components which are noticeably narrower than normal SNe Ia. The post-maximum velocity of the photosphere remains almost constant at ∼12,000 km s{sup –1} for about one month, reminiscent of the behavior of some luminous SNe Ia like SN 1991T. We propose that SN 2012fr may represent a subset of the SN 1991T-like SNe Ia viewed in a direction with a clumpy or shell-like structure of ejecta, in terms of a significant level of polarization reported in Maund et al. inmore » 2013.« less
Authors:
; ; ;  [1] ; ; ;  [2] ;  [3]
  1. Yunnan Observatories (YNAO), Chinese Academy of Sciences, Kunming 650011 (China)
  2. Physics Department and Tsinghua Center for Astrophysics (THCA), Tsinghua University, Beijing 100084 (China)
  3. National Astronomical Observatories of China (NAOC), Chinese Academy of Sciences, Beijing 100012 (China)
Publication Date:
OSTI Identifier:
22342310
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (New York, N.Y. Online); Journal Volume: 148; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; EXPLOSIONS; LUMINOSITY; MASS; PHOTOSPHERE; POLARIZATION; SPECTRA; SUPERNOVAE; ULTRAVIOLET RADIATION; VELOCITY; VISIBLE RADIATION