Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: CHANDRA/VLA Follow-up of TeV J2032+4131, the Only Unidentified TeV
  Gamma-ray Source   The HEGRA Cherenkov telescope array group recently reported a steady and
extended unidentified TeV gamma-ray source lying at the outskirts of Cygnus
OB2. This is the most massive stellar association known in the Galaxy,
estimated to contain ~2600 OB type members alone. It has been previously argued
that the large scale shocks and turbulence induced by the multiple interacting
supersonic winds from the many young stars in such associations may play a role
in accelerating Galactic cosmic rays. Indeed, Cyg OB2 also coincides with the
non-variable MeV-GeV range unidentified EGRET source, 3EG 2033+4118. We report
on the near-simultaneous follow-up observations of the extended TeV source
region with the CHANDRA X-ray Observatory and the Very Large Array (VLA) radio
telescope obtained in order to explore this possibility. Analysis of the CO,
HI, and IRAS 100 micron emissions shows that the TeV source region coincides
with an outlying sub-group of powerful OB stars which have evacuated or
destroyed much of the ambient atomic, molecular and dust material, and which
may be related to the very high-energy emissions. An interesting SNR-like
structure is also revealed near the TeV source region in the CO, HI and radio
emission maps. Applying a numerical simulation which accurately tracks the
radio to gamma-ray emission from primary hadrons as well as primary and
secondary e+/-, we find that the broadband spectrum of the TeV source region
favors a predominantly nucleonic - rather than electronic - origin of the
high-energy flux, though deeper X-ray and radio observations are needed to
confirm this. A very reasonable, ~0.1%, conversion efficiency of Cyg OB2's
extreme stellar wind mechanical luminosity to nucleonic acceleration to ~PeV
(10^15 eV) energies is sufficient to explain the multifrequency emissions.

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The categories of this paper are: math
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The categories of this paper are: math-ph
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The categories of this paper are: cs
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The categories of this paper are: q-bio
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: cmp-lg
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The categories of this paper are: funct-an
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The categories of this paper are: quant-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: mtrl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: solv-int
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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: hep-ex