Non-thermal radiation from a runaway massive star
Instituto Argentino de Radioastronomía, CCT-La Plata, CONICET, C.C.5, (1894) Villa Elisa, Buenos Aires, Argentina, and Facultad de Ciencias Astronómicas y Geofísicas UNLP, Paseo del Bosque S/N, B1900FWA La Plata, Argentina
Instituto Argentino de Radioastronomía, CCT-La Plata, CONICET, C.C.5, (1894) Villa Elisa, Buenos Aires, Argentina, et
Facultad de Ciencias Astronómicas y Geofísicas UNLP, Paseo del Bosque S/N, B1900FWA La Plata, Argentina
Instituto Argentino de Radioastronomía, CCT-La Plata, CONICET, C.C.5, (1894) Villa Elisa, Buenos Aires, Argentina, and Facultad de Ciencias Astronómicas y Geofísicas UNLP, Paseo del Bosque S/N, B1900FWA La Plata, Argentina
Departamento de Física (EPS), Universidad de Jaén, Campus Las Lagunillas s/n, 23071 Jaén, Spain
Abstract
We present a study of the radio emission from a massive runaway star. The star forms a bow shock that is clearly observed in the infrared. We have performed VLA observations under the assumption that the reverse shock in the stellar wind might accelerate charged particles up to relativistic energies. Non-thermal radio emission of synchrotron origin has been detected, confirming the hypothesis. We have then modeled the system and we predict a spectral energy distribution that extends up to gamma-rays. Under some simplifying assumptions, we find that the intensity at high energies is too low to be detected by current instruments, but the future Cherenkov Telescope Array might detect the source.