Bignall, Hayley E.Jauncey, David L.Kedziora-Chudczer, LucynaLovell, James E. J.Macquart, Jean-PierreOjha, RoopeshRickett, Barnaby J.2020-03-102020-03-102009Bignall, Hayley E.; Jauncey, David L.; Kedziora-Chudczer, Lucyna; Lovell, James E. J.; Macquart, Jean-Pierre; Ojha, Roopesh; Rickett, Barnaby J.; Intraday Radio Variability and Micro-Arcsecond Resolution; Approaching Micro-Arcsecond Resolution with VSOP-2: Astrophysics and Technology; ASP Conference Series, Vol. 402, ©2009; http://aspbooks.org/custom/publications/paper/402-0256.htmlhttp://hdl.handle.net/11603/17515Approaching Micro-Arcsecond Resolution with VSOP-2: Astrophysics and Technology ASP Conference Series, Vol. 402, ©2009 Y. Hagiwara, E. Fomalont, M. Tsuboi, and Y. Murata, eds.Intraday variability (IDV) of AGN at centimeter wavelengths has been shown to be predominantly due to interstellar scintillation (ISS). Recent VLBI observations have shown that IDV sources are more compact than non-IDVs on milliarcsecond scales, and a significant fraction are completely unresolved with ground-based VLBI. Additionally, very rapid IDV due to ISS has been observed in some extragalactic water masers at 22 GHz, implying masers ∼ 10 micro-arcseconds in angular size. Such bright, compact sources will be excellent targets for observation with VSOP-2 in order to study the sub-pc scale regions of AGN.6 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 work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore 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.Text