Letter to the Editor

The X-ray afterglows of gamma-ray bursts GRB 001025A and GRB 010220 observed with XMM-Newton

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

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

Received: 18 June 2002
Accepted: 2 August 2002

Abstract

The X-ray afterglows of GRB 001025A and GRB 010220 were detected by XMM-Newton with an average 0.2–10.0 keV flux of 4.4 and  erg cm^-2 s^-1 respectively; the afterglow of GRB 001025A is observed to decay. Afterglows at other wavelengths were not detected for either burst. A set of broadened soft X-ray emission lines are detected in the afterglow of GRB 001025A, at  significance above a Galactic-absorbed power-law continuum. The spectra of both afterglows are significantly better fit by a variable abundance thermal plasma model than by an absorbed power-law and are consistent with the observations of GRB 011211, indicating that thermal emission from light elements may be common in the early X-ray afterglows of GRBs.