Interplanetary scintillation observations of an unbiased sample of 90 Ooty occultation radio sources at 326.5~MHz

We present 327-MHz interplanetary scintillation (IPS) observations of an unbiased sample of 90 extragalactic radio sources selected from the ninth Ooty lunar occultation list. The sources are brighter than 0.75 Jy at 327 MHz and lie outside the Galactic Plane (|b| >= 10 degrees). We derive values of mu, the fraction of scintillating flux density, and psi, the equivalent Gausian diamete for the scintillating structure. Various correlations are found between the observed parameters. In particular, the scintillating component weakens and broadens with increasing largest angular size (LAS), and stronger scintillators have more compact scintillating components. The correlation between mu and the total source flux density found by previous workers is extended to smaller flux densities, but the three new points do not permit a distinction between a continuing upward trend or a levelling off of mu in the relation between the median values.