# Initial results from a systematic search for changing-look active galactic nuclei selected via mid-infrared variability

## TL;DR

This study introduces a new method to identify changing-look AGNs using mid-infrared variability data, successfully discovering new candidates and promising to expand the known sample significantly.

## Contribution

The paper presents an effective MIR variability-based selection technique for CL AGNs and reports the discovery of six new turn-off CL AGNs from a pilot spectroscopic follow-up.

## Key findings

- Six new turn-off CL AGNs identified.
- High success rate in pilot follow-up (6 out of 7 candidates).
- Potential to find hundreds of CL AGNs with full follow-up.

## Abstract

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.