Quasar Lenses and Galactic Streams: Outlier Selection and GAIA Multiplet Detection [GA]

http://arxiv.org/abs/1705.08900


I describe two novel techniques originally devised to select strongly lensed quasar candidates in wide-field surveys. The first relies on outlier selection in optical and mid-infrared magnitude space; the second combines mid-infrared colour selection with GAIA spatial resolution, to identify multiplets of objects with quasar-like colours. Both methods have already been applied successfully to the SDSS, ATLAS and DES footprints: besides recovering known lenses from previous searches, they have led to new discoveries, including quadruply lensed quasars, which are rare within the rare-object class of quasar lenses. As a serendipitous by-product, at least four candidate Galactic streams in the South have been identified among foreground contaminants. There is considerable scope for tailoring the WISE-GAIA multiplet search to stellar-like objects, instead of quasar-like, and to automatically detect Galactic streams.

Read this paper on arXiv…

A. Agnello
Fri, 26 May 17
-39/63

Comments: MNRAS subm. 21/04, revised version after referee report. 10 pages, 5 figures