A search for radio supernovae and supernova remnants in the region of NGC 1569's super star clusters

¹ Institut de Radio Astronomie Millimétrique, 300 rue de la Piscine, 38406 St. Martin d'Hères, France
² Astronomisches Institut der Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany
³ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
⁴ Astronomisches Institut der Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum, Germany
⁵ Onsala Space Observatory, 43920 Onsala, Sweden
⁶ Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
⁷ Kapteyn Astronomical Instituut, Postbus 800, 9700 AV Groningen, The Netherlands
⁸ Nuffield Radio Astronomy Laboratories, Jodrell Bank, Macclesfield Cheshire SK11 9DL, UK

Corresponding author: A. Greve, greve@iram.fr

Received: 20 April 2001
Accepted: 22 October 2001

Abstract

We have used MERLIN, at 1.4 and 5 GHz, to search for radio supernovae (RSNe) and supernova remnants (SNRs) in the unobscured irregular dwarf galaxy NGC 1569, and in particular in the region of its super star clusters (SSCs) A and B. Throughout NGC 1569 we find some 5 RSNe and SNRs but the SSCs and their immediate surroundings are largely devoid of non-thermal radio sources. Even though many massive stars in the SSCs are expected to have exploded already, when compared with M 82 and its many SSCs the absence of RSNe and SNRs in and near A and B may seem plausible on statistical arguments. The absence of RSNe and SNRs in and near A and B may, however, also be due to a violent and turbulent outflow of stellar winds and supernova ejected material, which does not provide a quiescent environment for the development of SNRs within and near the SSCs.