2007/11/28 by S. Taubenberger, S. Hachinger, G. Pignata +24 · 141 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Cosmic Phenomena #Carbon fibers #Gamma-ray bursts and supernovae #Luminosity #Metallicity #Pair-instability supernova #Range (aeronautics) #Spectral line #Supernova #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2008.12843.x
published in Monthly Notices of the Royal Astronomical Society 385(1), 75-96 (Oxford University Press) · 24 pages, 24 figures, accepted for publication in MNRAS
arxiv created 2007/11/28 · openalex publication_date 2008/02/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Optical observations of the Type Ia supernova (SN Ia) 2005bl in NGC 4070, obtained from -6 to +66 d with respect to the B-band maximum, are presented. The photometric evolution is characterized by rapidly declining light curves [ m 15 (B) true = 1.93] and red colours at peak and soon thereafter. With M B,max = -17.24 the SN is an underluminous SN Ia, similar to the peculiar SNe 1991bg and 1999by. This similarity also holds for the spectroscopic appearance, the only remarkable difference being the likely presence of carbon in pre-maximum spectra of SN 2005bl. A comparison study among underluminous SNe Ia is performed, based on a number of spectrophotometric parameters. Previously reported correlations of the light-curve decline rate with peak luminosity and R(Si) are confirmed, and a large range of post-maximum Si II 6355 velocity gradients is encountered. 1D synthetic spectra for SN 2005bl are presented, which confirm the presence of carbon and suggest an overall low burning efficiency with a significant amount of leftover unburned material. Also, the Fe content in pre-maximum spectra is very low, which may point to a low metallicity of the precursor. Implications for possible progenitor scenarios of underluminous SNe Ia are briefly discussed.