Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Initial results from a systematic search for changing-look active
  galactic nuclei selected via mid-infrared variability   Changing look active-galatic-nuclei (CL AGNs) can yield considerable insight
into accretion physics as well as the co-evolution of black holes and their
host galaxies. A large sample of these CL AGNs is essential to achieve the
latter goal. We propose an effective method to select CL candidates from
spectroscopic quasar catalogs using the mid-infrared (MIR) variability
information derived from ALL-WISE/NEOWISE data releases. Our primary selection
criteria include both a large amplitude flux variation and a transition of MIR
color from an AGN to a normal galaxy. A pilot spectroscopic follow-up of 7
candidates among about 300 candidates selected from Sloan Digital Sky Survey
low-redshift (z<0.5) AGN sample results in 6 new turn-off CL AGNs. We expect to
obtain hundreds of CL AGNs once full spectroscopic follow-up of the sample is
carried out.

21
The categories of this paper are: adap-org
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg