Early-type galaxies with core collapse supernovae

¹ Byurakan Astrophysical Observatory and Isaac Newton Institute of Chile, Armenian Branch, Byurakan 378433, Armenia e-mail: hakartur@rambler.ru
² Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
³ Institut d'Astrophysique de Paris (UMR 7095: CNRS & Université Pierre et Marie Curie), 98bis Bd Arago, 75014 Paris, France
⁴ INAF, Osservatorio Astrofisico di Catania via Santa Sofia 78, 95123 Catania, Italy
⁵ Dipartimento di Astronomia, Università di Padova, vicolo dell'Osservatorio 2, 35122 Padova, Italy

Received: 20 March 2008
Accepted: 16 June 2008

Abstract

Aims. It is widely accepted that the progenitors of core collapse SNe are young massive stars and therefore their host galaxies are mostly spiral or irregular galaxies dominated by a young stellar population. Surprisingly, among morphologically classified hosts of core collapse SNe, we find 22 cases where the host has been classified as an Elliptical or S0 galaxy.

Methods. To clarify this apparent contradiction, we carry out a detailed morphological study and an extensive literature search for additional information on the sample objects.

Results. Our results are as follows: 1. Of 22 “early type” objects, 17 are in fact misclassified spiral galaxies, one is a misclassified irregular, and one is a misclassified ring galaxy. 2. Of the 3 objects maintaining the early type classification, one (NGC 2768) is a suspected merger remnant, another (NGC 4589) is definitely a merger, and the third (NGC 2274) is in close interaction. The presence of some amount of young stellar population in these galaxies is therefore not unexpected.

Conclusions. These results confirm the presence of a limited, but significant, number of core collapse SNe in galaxies generally classified as early-type. In all cases, anyway, there are independent indicators of the presence in host galaxies of recent star formation due to merging or gravitational interaction.