The X-ray afterglows of gamma-ray bursts GRB001025A and GRB010220 observed with XMM-Newton
journal contributionposted on 08.12.2009, 16:25 by D. Watson, J.N. Reeves, Julian P. Osborne, Paul T. O'Brien, Kenneth A. Pounds, Jonathan A. Tedds, M. Santos-Lleó, M. Ehle
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 3.3 X 10[superscript -14] erg cm[superscript -2] s[superscript -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 5.0 σ 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.