Variable and Transient Radio Sources in the FIRST Survey
Abstract
A comprehensive search for variable and transient radio sources has been conducted using ~55,000 snapshot images of the Faint Images of the Radio Sky at Twenty-cm survey. We present an analysis leading to the discovery of 1627 variable and transient objects down to mJy levels over a wide range of timescales (a few minutes to years). Variations observed range from 20% to a factor of 25. Multi-wavelength matching for counterparts reveals the diverse classes of objects exhibiting variability, ranging from nearby stars and pulsars to galaxies and distant quasars. Interestingly, more than half of the objects in the sample have either no classified counterparts or no corresponding sources at any other wavelength and require multi-wavelength follow-up observations. We discuss these classes of variables and speculate on the identity of objects that lack multi-wavelength counterparts.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 2011
- DOI:
- 10.1088/0004-637X/742/1/49
- arXiv:
- arXiv:1107.5901
- Bibcode:
- 2011ApJ...742...49T
- Keywords:
-
- catalogs;
- methods: data analysis;
- methods: statistical;
- radio continuum: general;
- surveys;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 63 pages, 18 encapsulated postscript figures (19 if individual subfigures are counted), 3 tables. LaTeX style file fltpage.sty used. Submitted, accepted and "in press" for publication in the Astrophysical Journal. Full electronic version of table 1 (tab1.txt) has been uploaded and can be obtained after extracting the zipped source file