The nature of the prompt X-ray and radio emission from SN 2002ap^*

¹ Department of Physics and Astronomy, The Open University, Milton Keynes, UK
² Tata Institute of Fundamental Research, Bombay 400 005, India
³ Joint Astronomy Programme, Indian Institute of Science, Bangalore 560 012, India
⁴ National Centre for Radio Astrophysics, Pune 411 007, India
⁵ National Radio Astronomy Observatory, Socorro, NM 87801, USA

Corresponding author: F. K. Sutaria, F.K.Sutaria@open.ac.uk

Received: 3 July 2002
Accepted: 30 October 2002

Abstract

We report on the combined X-ray and radio observations of the type Ic SN 2002ap, using XMM-Newton TOO observation of M 74 and the Giant Metrewave Radio Telescope (GMRT). We account for the presence of a nearby source in the pre-supernova Chandra field of view in our measurements of the X-ray flux ( KeV) 5.2 days after the explosion. The X-ray spectrum is well fitted by a power law spectrum with photon index . Our results suggest that the prompt X-ray emission originates from inverse Compton scattering of photospheric thermal emission by energetic electrons. Radio observations with the GMRT at 610 MHz (8 days after the explosion) and 1420 MHz (70 days after the explosion) are combined with the high frequency VLA observations of SN 2002ap reported by Berger et al. 2002), and the early radiospheric properties of SN 2002ap are compared with similar data from two other supernovae. Finally, the GMRT radio map reveals four other X-ray sources in the field of view of M 74 with radio counterparts.