Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Smoking Guns Of Neutron Stars Mergers   The short hard gamma ray burst (SHB) 170817A that followed GW170817A, the
first neutron stars merger (NSM) detected in gravitational waves (GWs), has
shown beyond doubt that NSMs produce beamed SHBs. Its low luminosity and other
properties that differ from those of ordinary SHBs were predicted by the
cannonball model of gamma ray bursts. Low luminosity (LL) SHBs are mainly
ordinary SHBs viewed far off-axis. They are produced mainly by nearby NSMs.
Because of beaming, most of the NSMs, including those within the current
horizon of Ligo-Virgo, produce SHBs most of which are invisible from Earth.
But, their pulsar wind nebula powered by the spin down of the remnant neutron
star produces an early-time isotropic afterglow with a universal temporal
shape. This smoking gun of NSMs is detectable independent of whether the SHB
was visible, or was invisible from Earth because of being beamed away.

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The categories of this paper are: chao-dyn
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The categories of this paper are: alg-geom
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The categories of this paper are: comp-gas
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The categories of this paper are: eess
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The categories of this paper are: q-fin
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The categories of this paper are: supr-con
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The categories of this paper are: patt-sol
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The categories of this paper are: chem-ph
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The categories of this paper are: physics
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The categories of this paper are: gr-qc
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The categories of this paper are: dg-ga
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The categories of this paper are: nlin
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The categories of this paper are: solv-int
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The categories of this paper are: math
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The categories of this paper are: cs
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The categories of this paper are: nucl-th