Angular clustering of point sources at 150 MHz in the TGSS survey
  We study the angular clustering of point sources in The GMRT (Giant Meter
Wave Telescope) Sky Survey (TGSS). The survey at 150 MHz with delta > -53.5
degrees has a sky coverage of 3.6 pi steradians, i.e., 90% of the whole sky. We
created subsamples by applying different total flux thresholds limit (S >> 5
sigma) for good completeness and measured the angular correlation function
omega(theta) of point sources at large scales ( >= 1 degree). We find that the
amplitude of angular clustering is higher for brighter subsamples, this
indicates that higher threshold flux samples are hosted by massive halos and
cluster strongly: this conclusions is based on the assumption that the redshift
distribution of sources does not change with flux and this is supported by
models of radio sources. We compare our results with other low-frequency
studies of clustering of point sources and verify that the amplitude of
clustering varies with the flux limit. We quantify this variation as a power
law dependence of the amplitude of correlation function with the flux limit.
This dependence can be used to estimate foreground contamination due to
clustering of point sources for low frequency HI intensity mapping surveys for
studying the epoch of reionisation.
