Title: NIR imaging of late-type galaxies to identify progenitors of future core-collapse supernovae
Abstract: We propose to obtain pre-supernova-explosion IR imaging of nearby <10Mpc late-type galaxies in order to identify and define the nature of the progenitor after a core-collapse SN (Type Ib/c and II) has occurred. Optical imaging data from an approved and completed HST 'snapshot' program, and completed VLT ISAAC imaging of a southern hemisphere sample will complement this project. Current core-collapse SNe rates suggest that 1 SN each 1-2 years will occur in the full sample. After discovery we will determine if the progenitor star was a red supergiant, as stellar evolutionary models still predict. NIRI observations will allow us to cover the main star-forming regions in each galaxy and to confidently detect M0-M4 Ia-b supergiants with Mv <= -5.5. We have been allocated time in previous semesters to build this archive, and now request a final NIRI allocation to complete the sample. We managed to gather pre-explosion NIRI images of the recent type II-P supernova 2005cs in M51 and have shown how combining the NIR images with HST optical data allows the mass and spectral type of the progenitor to be determined. The images will be available in the archive for other studies such as the distribution of red supergiant stars in these galaxies and hence sites of starbursts.
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