Radio spectral properties of cores and extended regions in blazars in
  the MHz regime
  Low-frequency radio surveys allow in-depth studies and new analyses of
classes of sources previously known and characterised only in other bands. In
recent years, low radio frequency observations of blazars have been available
thanks to new surveys, such as the GaLactic and Extragalactic All-sky MWA
Survey (GLEAM). We search for gamma-ray blazars in a low frequency (${\nu}$ <
240MHz) survey, to characterise the spectral properties of the spatial
components. We cross-correlate GLEAM with the fourth catalogue of active
galactic nuclei (4LAC) detected by the Fermi satellite. This improves over
previous works using a low frequency catalogue that is wider, deeper, with a
better spectral coverage and the latest and most sensitive gamma-ray source
list. In comparison to the previous study based on the commissioning survey,
the detection rate increased from 35% to 70%. We include Australia Telescope
20GHz (AT20G) Survey data to extract high-frequency high-angular resolution
information on the radio cores of blazars. We find low radio frequency
counterparts for 1274 out of 1827 blazars in the 72-231 MHz range. Blazars have
at spectrum at $\sim$ 100MHz regime, with a mean spectral index ${\alpha}$ =
-0.44 +-0.01 (assuming S $\propto$ ${\nu}^ {\alpha}$ ). Low synchrotron peaked
objects have a scatter spectrum than high synchrotron peaked objects. Low
frequency radio and gamma-ray emission show a significant but scattered
correlation. The ratio between lobe and core radio emission in gamma-ray
blazars is smaller than previously estimated.
