Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Black Holes, Galaxy Formation and the Large-scale Structure of the
  Universe   A new model for the formation of active galaxies is described. A key feature
of this model is the idea that the birth of black holes in the centers of
supergiant galaxies is strongly influenced by the large-scale distribution of
matter in the universe. This conjecture can successfully explain two observed
phenomena: the alignment of the radio, optical and infrared axes of
high-redshift radio galaxies, and the alignment of present-day cD galaxies with
their environs. Other recent observational tests of this theory are also
discussed.

18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th