A search for the progenitors of two Type Ia Supernovae in NGC 1316

作者：Maoz Dan^*; Mannucci Filippo

来源：Monthly Notices of the Royal Astronomical Society, 2008, 388(1): 421-428.

DOI：10.1111/j.1365-2966.2008.13403.x

• supernovae : general
• supernovae : individual : SN2006dd
• supernovae : individual : SN2006mr
• galaxies : individual : NGC 1316

Recent evidence of a young progenitor population for many Type Ia supernovae (SNe Ia) raises the possibility that evolved intermediate-mass progenitor stars may be detected in pre-explosion images. NGC 1316, a radio galaxy in the Fornax cluster, is a prolific producer of SNe Ia, with four detected since 1980. We analyse Hubble Space Telescope (HST) pre-explosion images of the sites of two of the SNe Ia that exploded in this galaxy, SN2006dd (a normal Type Ia) and SN2006mr (likely a subluminous, 1991bg-like, SN Ia). Astrometric positions are obtained from optical and near-infrared ground-based images of the events. We find no candidate point sources at either location, and set upper limits on the flux in B, V and I from any such progenitors. We also estimate the amount of extinction that could be present, based on analysis of the surface-brightness inhomogeneities in the HST images themselves. At the distance of NGC 1316, the limits correspond to absolute magnitudes of similar to -5.5, -5.4 and -6.0 mag in M(B), M(V) and MI, respectively. Comparison to stellar evolution models argues against the presence at the supernova sites, 3 yr prior to the explosion, of normal stars with initial masses greater than or similar to 6 M(circle dot) at the tip of their asymptotic-giant branch (AGB) evolution, young post-AGB stars that had initial masses greater than or similar to 4 M(circle dot) and post-red giant stars of initial masses greater than or similar to 9 M(circle dot).

• 出版日期2008-7-21