Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The BMW X-ray Cluster Survey   We describe the main features of the BMW survey of serendipitous X-ray
clusters, based on the still unexploited ROSAT-HRI archival observations. The
sky coverage, surface density and first deep optical CCD images of the
candidates indicate that this sample can represent an excellent complement to
the existing PSPC deep cluster surveys and will provide us with a fully
independent probe of the evolution of the cluster abundance, in addition to
significantly increasing the number of clusters known at z>0.6.

20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci