Galactic synchrotron distribution derived from 152 HII region absorption
  features in the full GLEAM survey
  We derive the synchrotron distribution in the Milky Way disk from HII region
absorption observations over -40{\deg} < l < 40{\deg} at six frequencies of
76.2, 83.8, 91.5, 99.2, 106.9, and 114.6 MHz with the GaLactic and
Extragalactic All-sky Murchison widefield array survey (GLEAM). We develop a
new method of emissivity calculation by taking advantage of the Haslam et al.,
(1981) map and known spectral indices, which enable us to simultaneously derive
the emissivity and the optical depth of HII regions at each frequency. We show
our derived synchrotron emissivities based on 152 absorption features of HII
regions using both the method previously adopted in the literature and our
improved method. We derive the synchrotron emissivity from HII regions to the
Galactic edge along the line of sight and, for the first time, derive the
emissivity from HII regions to the Sun. These results provide direct
information on the distribution of the Galactic magnetic field and cosmic-ray
electrons for future modelling.
