The radio counterpart of the likely TeV binary HESS J0632+057

J. L. Skilton , M. Pandey-Pommier , J. A. Hinton , C. C. Cheung , F. A. Aharonian , J. Brucker , G. Dubus (1) , Armand Fiasson (2, 3) , S. Funk , Yves Gallant (2) , Alexandre Marcowith (2) , O. Reimer

1 LAOG - Laboratoire d'Astrophysique de Grenoble
2 LPTA - Laboratoire de Physique Théorique et Astroparticules
3 LAPP - Laboratoire d'Annecy de Physique des Particules

The few known gamma-ray binary systems are all associated with variable radioand X-ray emission. The TeV source HESS J0632+057, apparently associated withthe Be star MWC148, is plausibly a new member of this class. Following theidentification of a variable X-ray counterpart to the TeV source we conductedGMRT and VLA observations in June-September 2008 to search for the radiocounterpart of this object. A point-like radio source at the position of thestar is detected in both 1280 MHz GMRT and 5 GHz VLA observations, with anaverage spectral index, alpha, of ~0.6. In the VLA data there is significantflux variability on ~month timescales around the mean flux density of ~0.3 mJy.These radio properties (and the overall spectral energy distribution) areconsistent with an interpretation of HESS J0632+057 as a lower power analogueof the established gamma-ray binary systems.

Mots clés: radio-continuum:stars; X-rays:binaries

Domaines: Phénomènes cosmiques de haute energie [astro-ph.HE]

J. L. Skilton, M. Pandey-Pommier, J. A. Hinton, C. C. Cheung, F. A. Aharonian, et al.. The radio counterpart of the likely TeV binary HESS J0632+057. Monthly Notices of the Royal Astronomical Society, 2009, 399 (1), pp.317 - 322. ⟨10.1111/j.1365-2966.2009.15272.x⟩. ⟨hal-00398778⟩