Fermi Gamma-ray Space Telescope

Modeling the synchrotron radio emission from gamma-ray novae

A. D. Vlasov
B. D. Metzger, I. Vurm

Abstract:

The discovery by Fermi LAT of GeV gamma-rays from classical novae illustrates that shocks and high energy particle acceleration are common in nova outflows. Many novae also display an early sharp maximum in the radio light curve on timescales of months, in clear excess of that expected from freely-expanding photo-ionized ejecta. We have developed a detailed 1D model for the synchrotron radio emission from nova shocks, which includes for the first time important effects such as radiative cooling of the post-shock gas and free-free absorption. We apply our model to the radio data on several novae, including V1723 Aql and V1324 Sco, the latter of which was detected by Fermi. We infer acceleration efficiencies of relativistic electrons which are consistent with the gamma-ray and radio emission originating from the same shocks, potentially from the same population of accelerated particles. We discuss the implications of our work for disentangling hadronic versus leptonic scenarios.