Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Chandra imaging of the X-ray core of Abell 1795   We report the discovery of a 40 arcsec long X-ray filament in the core of the
cluster of galaxies A1795. The feature coincides with an Halpha+NII filament
found by Cowie et al in the early 1980s and resolved into at least 2 U-band
filaments by McNamara et al in the mid 1990s. The (emission-weighted)
temperature of the X-ray emitting gas along the filament is 2.5-3 keV, as
revealed by X-ray colour ratios. The deprojected temperature will be less. A
detailed temperature map of the core of the cluster presented. The cD galaxy at
the head of the filament is probably moving through or oscillating in the
cluster core. The radiative cooling time of the X-ray emitting gas in the
filament is about 3x10^8 yr which is similar to the age of the filament
obtained from its length and velocity. This suggests that the filament is
produced by cooling of the gas from the intracluster medium. The filament, much
of which is well separated from the body of the cD galaxy and its radio source,
is potentially of great importance in helping to understand the energy and
ionization source of the optical nebulosity common in cooling flows.

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The categories of this paper are: stat
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The categories of this paper are: quant-ph
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The categories of this paper are: funct-an
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The categories of this paper are: cs
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The categories of this paper are: dg-ga
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-th
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ph
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The categories of this paper are: solv-int
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The categories of this paper are: math-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: q-fin
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The categories of this paper are: eess