Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: X-ray Scaling Properties of Early-type Galaxies   We present an analysis of 39 X-ray luminous early-type galaxies observed with
the ROSAT PSPC. Using multi-component spectral and spatial fits to these data
we have measured halo abundance, temperature, luminosity and surface brightness
profile. We compare these measurements to similar results from galaxy groups
and clusters, fitting a number of relations commonly used in the study of these
larger objects. In particular, we find that the sigma:Tx relation for our
sample is similar to that reported for clusters, consistent with beta_{spec}=1,
and that the Lx:Tx relation has a steep slope (gradient 4.8+-0.7) comparable
with that found for galaxy groups. Assuming isothermality, we construct
3-dimensional models of our galaxies, allowing us to measure gas entropy. We
find no correlation between gas entropy and system mass, but do find a trend
for low temperature systems to have reduced gas fractions. We conclude that the
galaxies in our sample are likely to have developed their halos through galaxy
winds, influenced by their surrounding environment.

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The categories of this paper are: math
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
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The categories of this paper are: econ
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The categories of this paper are: cmp-lg
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The categories of this paper are: cond-mat
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The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
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The categories of this paper are: hep-th
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The categories of this paper are: hep-ex
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The categories of this paper are: atom-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: adap-org
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The categories of this paper are: chao-dyn