Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A model-driven search for extreme BL Lacs among LAT BCU   The emission of very-high-energy photons (VHE, E$>$100 GeV) in active
galactic nuclei (AGN) is closely connected with the production of
ultra-relativistic particles. Among AGN, the subclass of extreme BL Lacertae
are of particular interest because they challenge state-of-art models on how
these cosmic particle accelerators operate. By cross-matching two gamma-ray
catalogs (this is, 4FGL-DR2 and 2BIGB), we identified 23
high-synchrotron-peaked (HSP) blazar candidates with photometric or
spectroscopic redshifts, good multi-wavelength coverage, that are possibly
detectable by VHE instruments. We performed a new analysis of Fermi Large Area
Telescope data including the effects of attenuation from the extragalactic
background light and complemented these results by collecting multiwavelength
data from optical, radio and X-ray archival observations. Their broadband
spectral energy distributions were interpreted in terms of
synchrotron-self-Compton models with external-Compton components and compared
with the properties of prototypical extreme HSP blazars. Finally, we test their
detectability with imaging atmospheric Cherenkov telescopes (IACTs) and propose
a new method for selecting these extreme targets for these ground-based
telescopes.

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The categories of this paper are: cond-mat
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The categories of this paper are: gr-qc
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The categories of this paper are: q-bio
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The categories of this paper are: hep-lat
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-ex
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The categories of this paper are: solv-int
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The categories of this paper are: q-alg
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The categories of this paper are: econ
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The categories of this paper are: physics
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The categories of this paper are: alg-geom
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The categories of this paper are: chem-ph
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The categories of this paper are: nlin
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The categories of this paper are: plasm-ph
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The categories of this paper are: cs
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The categories of this paper are: chao-dyn