Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Where are Swift Gamma-ray bursts beyond the "synchrotron deathline"?   We study time-resolved spectra of the prompt emission of Swift Gamma-ray
bursts (GRB). Our goal is to see if previous BATSE claims of the existence of a
large amount of spectra with the low energy photon indices harder than 2/3 are
consistent with Swift data. We perform a systematic search of the episodes of
the spectral hardening down to the photon indices below 2/3 in the prompt
emission spectra of Swift GRBs. We show that the data of the BAT instrument on
board of Swift are consistent with BATSE data, if one takes into account
differences between the two instruments. Much lower statistics of the very hard
spectra in Swift GRBs is explained by the smaller field of view and narrower
energy band of the BAT telescope.

30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
19
The categories of this paper are: eess
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg