Long-term NIR Variability in the UKIDSS Ultra Deep Survey: a new probe of AGN activity at high redshift.
Date
2019
Type:
Article
item.page.extent
item.page.accessRights
item.contributor.advisor
ORCID:
Journal Title
Journal ISSN
Volume Title
Publisher
item.page.isbn
item.page.issn
item.page.issne
item.page.doiurl
item.page.other
item.page.references
Abstract
We present the first attempt to select AGN using long-term NIR variability. By
analysing the K-band light curves of all the galaxies in the UKIDSS Ultra Deep
Survey, the deepest NIR survey over ∼ 1 sq degree, we have isolated 393 variable
AGN candidates. A comparison to other selection techniques shows that only half
of the variable sources are also selected using either deep Chandra X-ray imaging or
IRAC colour selection, suggesting that using NIR variability can locate AGN that are
missed by more standard selection techniques. In particular, we find that long-term
NIR variability identifies AGN at low luminosities and in host galaxies with low stellar
masses, many of which appear relatively X-ray quiet.
Description
item.page.coverage.spatial
item.page.sponsorship
Citation
Monthly Notices of the Royal Astronomical Society, 2019:1-11
Keywords
Galaxies: active, Infrared: galaxies, Surveys, X-rays: galaxies