Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Constraints on the Nature of Jets from kpc Scale X-ray Data   Motivated by the large number of jets detected by the Chandra X-ray
Observatory, and by the inverse Compton X-ray emission model (IC/CMB) for
relativistic jets, we revisit two basic questions: ``If the medium that carries
the jet's energy consists of hot electrons, can we use the physical length of
the jet to constrain the maximum electron energy?'' and ``Why do jets have
knots?'' Based on the two non-thermal emission processes for X-rays from jets,
we consider constraints on the jet medium and other properties from these two
simple questions. We argue that hot pairs cannot be the dominant constituent of
the medium responsible for the jet's momentum flux and that some mechanisms for
producing fluctuating brightness along jets (rather than a monotonically
decreasing intensity) are precluded by observed jet morphologies.

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The categories of this paper are: hep-th
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The categories of this paper are: physics
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The categories of this paper are: comp-gas
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The categories of this paper are: adap-org
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The categories of this paper are: dg-ga
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The categories of this paper are: cs
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The categories of this paper are: q-fin
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The categories of this paper are: q-alg
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The categories of this paper are: q-bio
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The categories of this paper are: stat
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The categories of this paper are: chem-ph
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The categories of this paper are: math-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: quant-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: atom-ph