Mid-infrared Variability of Changing-look AGNs

Creators: Sheng, Zhenfeng; Wang, Tinggui; Jiang, Ning; Yang, Chenwei; Yan, Lin; Dou, Liming; Peng, Bo

Abstract

It is known that some active galactic nuclei (AGNs) transit from Type 1 to Type 2 or vice versa. There are two explanations for the so-called changing-look AGNs: one is the dramatic change of the obscuration along the line of sight, and the other is the variation of accretion rate. In this Letter, we report the detection of large amplitude variations in the mid-infrared luminosity during the transitions in 10 changing-look AGNs using the Wide-field Infrared Survey Explorer (WISE) and newly released Near-Earth Object WISE Reactivation data. The mid-infrared light curves of 10 objects echo the variability in the optical band with a time lag expected for dust reprocessing. The large variability amplitude is inconsistent with the scenario of varying obscuration, rather it supports the scheme of dramatic change in the accretion rate.

Additional Information

© 2017 The American Astronomical Society. Received 2017 May 23; revised 2017 July 10; accepted 2017 August 10; published 2017 August 29. We acknowledge the anonymous referee for valuable comments that helped to improve the Letter. And we acknowledge Andrew Drake for providing the unreleased CRTS data (Drake et al. 2009) of J155440. Also, we acknowledge Jordan N. Runco for helpful information on J081319 (Runco et al. 2016). We thank Luming Sun for discussion and Zhihao Zhong for his perfect spectrum reduction skill. This project is supported by National Basic Research Program of China (grant No. 2015CB857005), the NSFC through NSFC-11233002, NSFC-11421303, NSFC-116203021, and U1431229, jointly supported by the Chinese Academy of Science and NSF. This research has made use of the NASA/IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. The CSS survey is funded by the National Aeronautics and Space Administration under grant No. NNG05GF22G issued through the Science Mission Directorate Near-Earth Objects Observations Program. The CRTS survey is supported by the U.S. National Science Foundation under grant No. AST-0909182. This research made use of Astropy, a community-developed core Python package for Astronomy (Astropy Collaboration et al. 2013).

Attached Files

Published - Sheng_2017_ApJL_846_L7.pdf

Submitted - 1707.02686.pdf

Files

1707.02686.pdf

Files (1.3 MB)

Name	Size	Download all
1707.02686.pdf md5:983ac0fc3ebc742dcc4c75bae96e9cc9	605.2 kB	Preview Download
Sheng_2017_ApJL_846_L7.pdf md5:2b5abc897c5e6a1e37da544872f64659	707.0 kB	Preview Download

Additional details

	All versions	This version
Views	0	0
Downloads	0	0
Data volume	0 Bytes	0 Bytes