Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Average power density spectrum of Swift long gamma-ray bursts in the
  observer and in the source rest frames   We calculate the average power density spectra (PDS) of 244 long gamma-ray
bursts detected with the Swift Burst Alert Telescope in the 15-150 keV band
from January 2005 to August 2011. For the first time we derived the average PDS
in the source rest frame of 97 GRBs with known redshift. For 49 of them an
average PDS was also obtained in a common source-frame energy band to account
for the dependence of time profiles on energy. Previous results obtained on
BATSE GRBs with unknown redshift showed that the average spectrum in the
25-2000 keV band could be modelled with a power-law with a 5/3 index over
nearly two decades of frequency with a break at ~1 Hz. Depending on the
normalisation and on the subset of GRBs considered, our results show analogous
to steeper slopes (between 1.7 and 2.0) of the power-law. However, no clear
evidence for the break at ~1 Hz was found, although the softer energy band of
BAT compared with BATSE might account for that. We instead find a break at
lower frequency corresponding to a typical source rest frame characteristic
time of a few seconds. We furthermore find no significant differences between
observer and source rest frames. Notably, no distinctive PDS features are found
for GRBs with different intrinsic properties of the prompt emission either.
Finally, the average PDS of GRBs at higher redshifts shows possibly shallower
power-law indices than that of low-z GRBs. It is not clear whether this is due
to an evolution with z of the average PDS.

13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int