Bignall, Hayley E.Jauncey, David L.Lovell, James E. J.Ojha, RoopeshReynolds, Cormac2020-04-302020-04-302010Bignall, Hayley E.; Jauncey, David L.; Lovell, James E. J.; Ojha, Roopesh; Reynolds, Cormac; Finding Extremely Compact Sources Using the ASKAP VAST Survey; IVS 2010 General Meeting Proceedings, p.325–329 (2010); https://ivscc.gsfc.nasa.gov/publications/gm2010/bignall.pdfhttp://hdl.handle.net/11603/18386IVS 2010 General Meeting ProceedingsVLBI observations of intraday variable (IDV) quasars found in the MASIV (Micro-Arcsecond Scintillation-Induced Variability) 5 GHz VLA Survey of 500 flat-spectrum sources in the northern sky have shown that these sources are extremely compact, often unresolved, on milliarcsecond scales, and more core-dominated than their non-IDV counterparts. VAST: an ASKAP Survey for Variables and Slow Transients, proposes to observe 10,000 square degrees of southern sky daily for 2 years in the VAST-Wide survey component. This is expected to reveal of order 30,000 compact sources brighter than 10 mJy showing refractive interstellar scintillation (the cause of centimeter-wavelength IDV) at the survey frequency of about 1.4 GHz. Many of these sources may be suitable astrometric calibrators for VLBI at higher frequencies.5 pagesen-USThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.Public Domain Mark 1.0This is a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.http://creativecommons.org/publicdomain/mark/1.0/Text