High energy neutrinos from novae in symbiotic binaries: The case of V407 Cygni

Abstract

Detection of high-energy ($\ensuremath{\gtrsim}100\text{ }\text{ }\mathrm{MeV}$) $\ensuremath{\gamma}$ rays by the Fermi Large Area Telescope from a nova in the symbiotic binary system V407 Cygni has opened the possibility of high-energy neutrino detection from this type of source. A thermonuclear explosion on the white dwarf surface sets off a nova shell in motion that expands and slows down in a dense surrounding medium provided by the red giant companion. Particles are accelerated in the shocks of the shell and interact with the surrounding medium to produce observed $\ensuremath{\gamma}$ rays. We show that proton-proton interaction, which is most likely responsible for producing $\ensuremath{\gamma}$ rays via neutral pion decay, produces $\ensuremath{\gtrsim}0.1\text{ }\text{ }\mathrm{GeV}$ neutrinos that can be detected by the current and future experiments at $\ensuremath{\gtrsim}10\text{ }\text{ }\mathrm{GeV}$.