Volume 399, Number 3, March I 2003
|913 - 918
|14 February 2003
Thermal components in the early X-ray afterglow of GRBs
Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
Corresponding author: email@example.com
Accepted: 11 December 2002
The presence of thermal components in the early X-ray afterglows of γ-ray bursts is investigated. We discuss both the presence of a thermal continuum and, in particular, of collisional X-ray emission lines. We compute the predicted luminosity by a thin plasma for a range of metallicities for the continuum and the Kα lines of the elements Mg, Si, S, Ar, Ca and Fe. We show that light travel effects are dominant in the determination of the thermal continuum and line luminosities, and derive the relevant equations. We conclude that thermal lines and continua are unlikely to dominate the early afterglow of GRBs, unless the explosion site is surrounded by a very massive and extremely clumped shell of material. Such conditions are difficult to envisage in the close environment of the GRB progenitor, unless they are excited by some strong precursor activity, like in the Supranova scenario.
Key words: gamma-rays: burst / line: formation / radiation mechanisms: thermal
© ESO, 2003
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.