research

Observations of the X-ray Afterglows of GRB011211 and GRB001025 by XMM-Newton

Abstract

We present the XMM-Newton observations of X-ray afterglows of the gamma-ray bursts GRB 011211 and GRB 001025. For GRB 011211 XMM detected fading X-ray object with an average flux in 0.2-10 keV declining from 2.7Γ—10βˆ’13\times10^{-13} erg cmβˆ’2^{-2} sβˆ’1^{-1} during the first 5 ks of 27-ks observation to 1.0Γ—10βˆ’13\times10^{-13} erg cmβˆ’2^{-2} sβˆ’1^{-1} toward the end of the observation. The spectrum of the afterglow can be fit to a power law with alpha=2.16Β±\pm0.03 modified for the Galactic absorption. No significant evolution of spectral parameters has been detected during the observation. Similar X-ray spectrum with alpha=2.01Β±\pm0.09 has been observed by the XMM from the GRB 001025. The non-detection of any extra absorption in these spectra above the Galactic value is an interesting fact and may impose restrictions to the favorable GRB models involving burst origin in star-forming regions. Finally we discuss soft X-ray lines from GRB 011211 reported by Reeves et al.(2002) and conclude that there is no definitive evidence for the presense of these lines in the spectrum.Comment: submitted to ApJL (7 pages, 4 figures, 2 tables, emulateapj.sty

    Similar works

    Full text

    thumbnail-image

    Available Versions

    Last time updated on 11/12/2019