Shock-cloud interaction in the Vela SNR observed with XMM-Newton

¹ Dipartimento di Scienze Fisiche ed Astronomiche, Sezione di Astronomia, Università di Palermo, Piazza del Parlamento 1, 90134 Palermo, Italy e-mail: miceli@astropa.unipa.it
² INAF - Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, 90134 Palermo, Italy

Received: 27 August 2004
Accepted: 8 June 2005

Abstract

We analyzed an XMM-Newton EPIC observation of a bright knot, named FilD, in the northern rim of the Vela SNR, where the shock has encountered a cloud. The good combination of sensitivity, spectral, and spatial resolution allowed us to describe the internal structure of the observed ISM clouds and to obtain estimates of their temperature, density, O, Ne, and Fe abundances, and of their extension along the line of sight. We also examined the interaction of the shock with the FilD knot and estimated that the time elapsed from the shock impact is about one cloud crushing time. Our analysis allowed us to conclude that the observed X-ray emission is best explained by the propagation of transmitted shocks through ISM inhomogeneities with an inward increasing density profile. We found that the interaction with the shock determines the heating of the inner part of the clouds and the evaporation of the outer part.