Is the bowshock of the runaway massive star HD 195592 a Fermi source?

TL;DR

This study models the non-thermal emission from the bowshock of the runaway star HD 195592 and suggests it could be the source of a nearby Fermi gamma-ray detection, marking a potential first for such objects.

Contribution

It provides the first detailed spectral energy distribution modeling linking a runaway star's bowshock to gamma-ray emission observed by Fermi.

Findings

The gamma-ray emission can be explained by inverse Compton scattering in the bowshock.

HD 195592's bowshock is a plausible gamma-ray source under certain energetic conditions.

This supports the hypothesis that runaway massive stars can be gamma-ray emitters.

Abstract

HD 195592 is an O-type super-giant star, known as a well-established runaway. Recently, a Fermi gamma-ray source (2FGL J2030.7+4417) with a position compatible with that of HD 195592 has been reported. Our goal is to explore the scenario where HD 195592 is the counterpart of the Fermi gamma-ray source modeling the non-thermal emission produced in the bowshock of the runaway star. We calculate the spectral energy distribution of the radiation produced in the bowshock of HD 195592 and we compare it with Fermi observations of 2FGL J2030.7+4417. We present relativistic particle losses and the resulting radiation of the bowshock of HD 195592 and show that the latter is compatible with the detected gamma-ray emission. We conclude that the Fermi source 2FGL J2030.7+4417 might be produced, under some energetic assumptions, by inverse Compton up-scattering of photons from the heated dust in the bowshock of the runaway star. HD 195592 might therefore be the very first object detected belonging to the category of gamma-ray emitting runaway massive stars, whose existence has been recently predicted.