Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The jet and counterjet of 3C 270 (NGC 4261) viewed in the X-ray with
  Chandra   The radio source 3C 270, hosted by NGC 4261, is the brightest known example
of counterjet X-ray emission from a low-power radio galaxy. We report on the
X-ray emission of the jet and counterjet from 130 ks of Chandra data. We argue
that the X-ray emission is synchrotron radiation and that the internal
properties of the jet and counterjet are remarkably similar. We find a smooth
connection in X-ray hardness and X-ray to radio ratio between the jet and one
of the X-ray components within the core spectrum. We observe wedge-like
depressions in diffuse X-ray surface brightness surrounding the jets, and
interpret them as regions where an aged population of electrons provides
pressure to balance the interstellar medium of NGC 4261. About 20% of the mass
of the interstellar medium has been displaced by the radio source. Treating 3C
270 as a twin-jet system, we find an interesting agreement between the ratio of
jet-to-counterjet length in X-rays and that expected if X-rays are observed
over the distance that an outflow from the core would have traveled in ~6x10^4
yr. X-ray synchrotron loss times are shorter than this, and we suggest that
most particle acceleration arises as a result of turbulence and dissipation in
a stratified flow. We speculate that an episode of activity in the central
engine beginning ~6x10^4 yr ago has led to an increased velocity shear. This
has enhanced the ability of the jet plasma to accelerate electrons to
X-ray-synchrotron-emitting energies, forming the X-ray jet and counterjet that
we see today.

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The categories of this paper are: solv-int
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The categories of this paper are: atom-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: q-alg
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The categories of this paper are: eess
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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: hep-th
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The categories of this paper are: plasm-ph
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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: comp-gas
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: stat
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The categories of this paper are: chem-ph