Details

Autor(en) / Beteiligte

• Mazzali, Paolo A.
• Maurer, I.
• Stritzinger, M.
• Taubenberger, S.
• Benetti, S.
• Hachinger, S.

Titel

The nebular spectrum of the Type Ia supernova 2003hv: evidence for a non-standard event

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2011-09, Vol.416 (2), p.881-892

Ort / Verlag

Oxford, UK: Blackwell Publishing Ltd

Erscheinungsjahr

2011

Quelle

Wiley Blackwell Single Titles

Beschreibungen/Notizen

• The optical and near-infrared (near-IR) late-time spectra of the under-luminous Type Ia supernova 2003hv are analysed with a code that computes the nebular emission from a supernova nebula. Synthetic spectra based on the classical explosion model W7 are unable to reproduce the large Fe iii/Fe ii ratio and the low IR flux at ∼1 year after the explosion, although the optical spectrum of SN 2003hv is reproduced reasonably well for a supernova of luminosity intermediate between normal and subluminous (SN 1991bg-like) ones. A possible solution is that the inner layers of the supernova ejecta (v≲ 8000 km s−1) contain less mass than predicted by classical explosion models like W7. If this inner region contains ∼ 0.5 M⊙ of material, as opposed to ∼ 0.9 M⊙ in Chandrasekhar-mass models developed within the single-degenerate scenario, the low density inhibits recombination, favouring the large Fe iii/Fe ii ratio observed in the optical, and decreases the flux in the [Fe ii] lines which dominate the IR spectrum. The most likely scenario may be an explosion of a sub-Chandrasekhar-mass white dwarf. Alternatively, the violent/dynamical merger of two white dwarfs with the combined mass exceeding the Chandrasekhar limit also shows a reduced inner density.