Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Half Million Quasars (HMQ) Catalogue   A quasar catalogue is presented with a total of 510764 objects including
424748 type 1 QSOs and 26623 type 1 AGN complete from the literature to 25
January 2015. Also included are 25015 high-confidence SDSS-based photometric
quasars with radio/X-ray associations, 1595 BL Lac objects, and 32783 type 2
objects. Each object is displayed with arcsecond-accurate astrometry, red and
blue photometry, redshift, citations, and radio and X-ray associations where
present. Also, 114 new spectroscopically confirmed quasars are presented.

16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
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The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin