Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Spectral Lags of the Short Gamma-Ray Bursts   We present a detail analysis on the spectral lags of the short gamma-ray
bursts (GRBs) and compare them with that of the long GRBs by using the
CGRO/BATSE GRB Catalog. Our results are as follows. (1)The spectral lag
distribution of the short GRBs is significantly different from that of the long
GRBs. Excluding the statistical fluctuation effect, a proportion of ~17% of the
short GRBs have a negative spectral lag, i.e., the hard photons being lag
behind the soft photons. We do not find any peculiar features from their light
curves to distinguish these bursts from those with a positive spectral lag. We
argue that a more physical mechanism dominated the hard lag may be hid behind
the morphological features of the light curves. This should be a great
challenge to the current GRB models. We notice that this proportion is
consistent with the proportion of short GRBs correlated with nearby galaxies
newly discovered by Tanvir et al., although it is unclear if these short GRBs
are indeed associated with the sources originated at low redshift. (2)While the
spectral lags of the long GRBs are strongly correlated with the pulse
durations, they are not for the short GRBs. However, the ratios of the spectral
lag to the pulse duration for the short and long GRBs normally distributed at
0.023 and 0.046, respectively, with the sample width, indicating that the
curvature effect alone could not explain the difference of the spectral lags
between the two types of GRBs. The hydrodynamic timescales of the outflows and
the radiative processes at work in GRBs might also play an important role as
suggested by Daigne and Mochkovitch.

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The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
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The categories of this paper are: stat
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The categories of this paper are: cmp-lg
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The categories of this paper are: adap-org
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The categories of this paper are: supr-con
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The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: q-alg
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The categories of this paper are: math
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The categories of this paper are: chao-dyn
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The categories of this paper are: gr-qc
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The categories of this paper are: ao-sci
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The categories of this paper are: cond-mat