Letter to the Editor

The X-ray afterglow of GRB 020322

¹ X-ray Astronomy Group, Dept. of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK
² XMM-Newton Science Operations Centre, European Space Agency, PO Box 50727, 28080 Madrid, Spain

Corresponding author: D. Watson, wat@star.le.ac.uk

Received: 27 September 2002
Accepted: 14 October 2002

Abstract

The spectrum of the afterglow of GRB 020322 is the highest-quality X-ray spectrum of a GRB afterglow available to date. It was detected by XMM-Newton in an observation starting fifteen hours after the GRB with a mean 0.2–10.0 keV observed flux of  erg cm^-2 s^-1, making it the brightest X-ray afterglow observed so far with XMM-Newton. The source faded; its lightcurve was well fit by a power-law with a decay index of . The spectrum is adequately fit with a power-law absorbed with neutral or ionised gas significantly in excess of the foreground Galactic column, at redshift or with low metal abundances. No spectral line or edge features are detected at high significance, in particular, a thermal emission model fits the data poorly, the upper limit on its contribution to the spectrum is  erg cm^-2 s^-1, or ~10% of the total flux. No spectral variability is observed.