Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Distributions of the Hardness Ratio of short and Long Gamma-Ray Bursts
  in Different Time Intervals within the First 2 Seconds   In the present paper, we investigated the distribution of hardness ratio (HR)
for short and long gamma-ray bursts (GRBs) in different time scales for the
first two seconds. After including and subtracting the background count, we
performed a Kolmogorov--Smirnov (K-S) test to the HR distributions of the two
classes of GRBs in each time interval. Our analysis shows that the
probabilities of the KS test to the distributions are very small, suggesting
that the two classes of bursts are unlikely to arise from the same HR
distributions, and indicating that they probably originate from the different
physical processes and central engine. In addition, we found that the hardness
ratio of short bursts within the time interval of 0$-$0.96 seconds changes
hard-to-soft, on the other hand long bursts do not. The two kinds of bursts
have different characteristics in the first 2 seconds which might be associated
with different physical mechanisms.

21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
19
The categories of this paper are: eess
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con