Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The last stages of evolution of close binaries composed of compact
  companions   Gamma-ray bursts (GRB) are the most powerful transient phenomena in the
Universe. Nowadays dozens of speculations on the origin of GRB were undertaken,
but so far a single model for the origin of, in particular, short GRBs does not
exist. The black hole (BH) - neutron star (NS) coalescence is a promising
candidate source for short GRBs. Most of binary mergers numerical simulations
were carried out with the purpose of investigating the emission of
gravitational waves. Such a scenario consists of an inspiral, merging and
ringdown phase. In this paper we present the comparison of the observational
results and analytical predictions for a test particle in a quasicircular orbit
around the BH. The emission of gravitational waves causes a rapid decrease of
the orbital radius and a rise of a {\it chirp} of radiation. Matter orbiting
the black hole would be expected to produce high-frequency oscillations (HFO).
Timescales of the coalescence process are of the order of milliseconds and
oscillation frequencies of hundreds Hz for a system with a solar mass BH
companion. We report on the detection of HFO in two short gamma-ray bursts in
this paper. The frequencies and durations of the oscillations are in agreement
with the predicted values. A {\it chirp} phenomenon is identified also. We
therefore argue in favor of BH-NS mergers as a scenario for the production of
short gamma-ray bursts.

32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat