Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: What's Emitting the Broad Emission Lines?   I present a brief review about our ideas concerning the origin and nature of
the broad line emitting gas. This is one of the outstanding problems in quasar
research. I suggest the establishment of a central data base of high quality
quasar spectra as a means to realize an understanding of quasars.

29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph