Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Marriage \`a-la-MOND: Baryonic dark matter in galaxy clusters and the
  cooling flow puzzle   I start with a brief introduction to MOND phenomenology and its possible
roots in cosmology--a notion that may turn out to be the most far reaching
aspect of MOND. Next I discuss the implications of MOND for the dark matter
(DM) doctrine: MOND's successes imply that baryons determine everything. For DM
this would mean that the puny tail of leftover baryons in galaxies wags the
hefty DM dog. This has to occur in many intricate ways, and despite the
haphazard construction history of galaxies--a very tall order. I then
concentrate on galaxy clusters in light of MOND, which still requires some yet
undetected cluster dark matter, presumably in some baryonic form (CBDM). This
CBDM might contribute to the heating of the x-ray emitting gas and thus
alleviate the cooling-flow puzzle. MOND, qua theory of dynamics, does not
directly enter the microphysics of the gas; however, it does force a new
outlook on the role of DM in shaping the cluster gasdynamics: MOND tells us
that the cluster DM is not cold dark matter, is not so abundant, and is not
expected in galaxies; it is thus not subject to constraints on baryonic DM in
galaxies. The mass in CBDM required in a whole cluster is, typically, similar
to that in hot gas, but is rather more centrally concentrated, totally
dominating the core. The CBDM contribution to the baryon budget in the universe
is thus small. Its properties, deduced for isolated clusters, are consistent
with the observations of the ``bullet cluster''. Its kinetic-energy reservoir
is much larger than that of the hot gas in the core, and would suffice to keep
the gas hot for many cooling times. Heating can be effected in various ways
depending on the exact nature of the CBDM, from very massive black holes to
cool, compact gas clouds.

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The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
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The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: stat
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The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
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The categories of this paper are: solv-int
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The categories of this paper are: quant-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
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The categories of this paper are: atom-ph