A pre-launch low frequency VLBI survey for radio astron

Abstract

Preliminary results from two low frequency Very Long Baseline Interferometry (VLBI) observations (EA009 and INTAS1) at 327 MHz are described. Sixty one sources were observed. Twenty five sources are recommended for further detailed investigation. Only two sources (3C345 and 3C309.1) could be mapped. These experiments are part of a long term pre-launch RadioAstron survey at 327 MHz that has two objectives: (i) to establish a suitable list of candidates for low frequency Space VLBI (SVLBI) observations and (ii) to study the limitations on SVLBI due to scattering effects in the interstellar and interplanetary medium.