Radio spectra of protostellar jets: Thermal and non-thermal emission
  Protostellar jets and outflows are pointers of star-formation and serve as
important sources of momentum and energy transfer to the interstellar medium.
Radio emission from ionized jets have been detected towards a number of
protostellar objects. In few cases, negative spectral indices and polarized
emission have also been observed suggesting the presence of synchrotron
emission from relativistic electrons. In this work, we develop a numerical
model that incorporates both thermal free-free and non-thermal synchrotron
emission mechanisms in the jet geometry. The flux densities include
contribution from an inner thermal jet, and a combination of emission from
thermal and non-thermal distributions along the edges and extremities, where
the jet interacts with the interstellar medium. We also include the effect of
varying ionization fraction laterally across the jet. An investigation of radio
emission and spectra along the jet shows the dependence of the emission process
and optical depth along the line of sight. We explore the effect of various
parameters on the turnover frequencies and the radio spectral indices (between
10 MHz and 300 GHz) associated with them.
