Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: X-ray spectral features from GRBs: Predictions of progenitor models   We investigate the potentially observable prompt or delayed X-ray spectral
features from the currently popular gamma-ray burst (GRB) models. During the
evolution of many GRB progenitors, a disk around the central GRB source is
produced. Shock heating as the GRB ejecta collide with the disk may produce
observable X-ray features. We first summarize predictions deduced from previous
calculations which invoke photoionization and relativistic blast waves. We then
calculate the quasi-thermal X-ray line features produced assuming the ejecta
are nonrelativistic (which is more likely for the disk interactions of many GRB
models). In the framework of the Hypernova/Collapsar model, delayed (a few days
- several months after the GRB) bursts of line-dominated, thermal X-ray
emission may be expected. The He-merger scenario predicts similar X-ray
emission line bursts <~ a few days after the GRB. These X-ray signatures should
be observable with Chandra and XMM-Newton out to at least z ~ 1. Weak emission
line features <~ a few days after the GRB may also result from the supranova
GRB scenario. In all three cases, significant X-ray absorption features, in
particular during the prompt GRB phase, are expected. No significant X-ray
spectral features might result from compact-object binary mergers.

15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
2
The categories of this paper are: math