Structure of 194 southern declination radio sources from interplanetary scintillations

Abstract

Interplanetary scintillation observations of 194 southern declination radio sources have been made at 327MHz. The angular size and the fraction of the flux present in the scintillating component have been estimated. More than half of the observed sources scintillate and contain ≥10% of their flux in angular size smaller than 0.5. About 75% of the quasers and 50% of the galaxies and the blank field objects scintillate. For quasers the spectral index seems to be correlated with the strenght of scintillation; most of the flat spectrum quasers are strong scintillators and are unresolved. The scintillating properties of blank field objects are consistent with Bolton's hypothesis that most of these are galaxies beyoud the plate limit of the sky survey.