Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The First Fermi Large Area Telescope Catalog of Gamma-ray Pulsars   The dramatic increase in the number of known gamma-ray pulsars since the
launch of the Fermi Gamma-ray Space Telescope (formerly GLAST) offers the first
opportunity to study a population of these high-energy objects. This catalog
summarizes 46 high-confidence pulsed detections using the first six months of
data taken by the Large Area Telescope (LAT), Fermi's main instrument. Sixteen
previously unknown pulsars were discovered by searching for pulsed signals at
the positions of bright gamma-ray sources seen with the LAT, or at the
positions of objects suspected to be neutron stars based on observations at
other wavelengths. Pulsed gamma-ray emission was discovered from twenty-four
known pulsars by using ephemerides (timing solutions) derived from monitoring
radio pulsars. Eight of these new gamma-ray pulsars are millisecond pulsars.
The pulsed energy spectra can be described by a power law with an exponential
cutoff, with cutoff energies in the range 1 to 5 GeV. The rotational energy
loss rate (\dot{E}) of these neutron stars spans 5 decades, from ~3x10^{33}
erg/s to 5x10^{38} erg/s, and the apparent efficiencies for conversion to
gamma-ray emission range from ~0.1% to unity, although distance uncertainties
complicate efficiency estimates. The pulse shapes show substantial diversity,
but roughly 75% of the gamma-ray pulse profiles have two peaks, separated by
>0.2 of rotational phase. For most of the pulsars, gamma-ray emission appears
to come mainly from the outer magnetosphere, while polar-cap emission remains
plausible for a remaining few. Finally, these discoveries suggest that
gamma-ray-selected young pulsars are born at a rate comparable to that of their
radio-selected cousins and that the birthrate of all young gamma-ray-detected
pulsars is a substantial fraction of the expected Galactic supernova rate.

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The categories of this paper are: chem-ph
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The categories of this paper are: hep-th
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The categories of this paper are: eess
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The categories of this paper are: atom-ph
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The categories of this paper are: funct-an
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The categories of this paper are: hep-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: nlin
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The categories of this paper are: nucl-ex
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The categories of this paper are: stat
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The categories of this paper are: physics
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The categories of this paper are: mtrl-th
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The categories of this paper are: comp-gas
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-th
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The categories of this paper are: ao-sci