Fermi Gamma-ray Space Telescope

Fermi Reveals New Light on Novae in Gamma rays

C. C. Cheung
P. Jean, S. N. Shore, J. E. Grove, M. Leising, on behalf of the Fermi-LAT Collaboration

Abstract:

Novae are now firmly established as a high-energy (>100 MeV) gamma-ray source class by the Fermi Large Area Telescope (LAT). In symbiotic-like binary systems such as V407 Cyg 2010, there is a clear theoretical framework for the production of accelerated particles in the nova ejecta from passage of the shock through the dense wind of the red giant companion as was previously proposed for RS Oph 2006. The high-energy gamma-ray emission detected in classical novae, sited in compact binary systems with less evolved stellar companions cannot be explained in the same way. It could, instead, be produced in internal shocks in the ejecta. We summarize the Fermi-LAT gamma-ray observations of novae, highlighting the main properties that will guide further studies. Additionally, we report on the soft gamma-ray (~0.1 MeV) continuum detection of the oxygen-neon type classical nova V382 Vel 1999 with the OSSE detector aboard the Compton Gamma Ray Observatory in light of its Fermi-era analog, V959 Mon 2012.