Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multiplicity Functions and X-ray emission of Clusters and Groups versus
  Galaxies and Quasars   We use a unified analytical formulation for the multiplicity functions of
clusters and galaxies which is free from the cloud-in-cloud problem encountered
in earlier approaches and well adapted to the description of the non-linear
clustering features. It is especially suited to simultaneously describe rich
clusters, groups and galaxies, consistently with the hierarchical picture of
gravitational clustering and their evolution in time. Using a simple model for
the X-ray luminosity (taking into account entropy considerations), we obtain
the X-ray luminosity distribution of groups and clusters. Then, using the same
formalism we derive the galaxy and quasar multiplicity functions. In
particular, we show that the use of the standard Press-Schechter prescription
leads to erroneous conclusions at low redshifts while our approach provides a
reasonable agreement with observations in a natural fashion because it is able
to distinguish galactic halos from groups or clusters. Thus, we obtain a global
and consistent picture of the X-ray emissions from all structures. In
particular, we show that future observations (e.g., from AXAF) could provide
interesting information on galaxy evolution. Indeed, they will constrain the
importance of a possible hot diffuse gaseous phase in galactic halos and they
could reveal massive galaxies which are just being formed, through the X-ray
emission of their cooling gas.

12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg