XMM-Newton study of hard X-ray sources in IC 443

¹ INAF, Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, 90134 Palermo, Italy
² AF Ioffe Institute for Physics and Technology, St. Petersburg, 194021, Russia

Corresponding author: F. Bocchino, bocchino@astropa.unipa.it

Received: 20 August 2002
Accepted: 16 December 2002

Abstract

We present XMM-Newton observations of hard X-ray emission from the field of IC 443, a supernova remnant interacting with a molecular cloud. The hard emission from the field is dominated by 12 isolated sources having 2–10 keV flux . Only a fraction of the sources are expected to be extragalactic or stars on statistical grounds, while the others may be associated with the remnant. We have analyzed near-infrared K band and also DSS optical data for all of the detected sources, finding that six X-ray sources are located in a relatively small region where there is strong 2.2 infrared emission, indicating interaction with a molecular cloud. The source 1SAX J0618.0+2227, the brightest in this region (excluding the plerion), is resolved with XMM-Newton into two sources, one of which is extended and has a hard power law spectrum photon index 1.5) and shows some indications of spectral line signatures (e.g. Si), while the other is point-like and has a featureless spectrum of steeper photon index ~2.2. Possible interpretations of some of the discrete sources in terms of interaction between the SNR and the molecular cloud are discussed.