Evidence for periodic accretion-ejection in LS I +61°303
Migliari, S.; Readhead, A. C. S.; Kraus, A.; Kiehlmann, S.; Chernyakova, M.; Malyshev, D.; Dzib, S. A.; Massi, M.; Sharma, R.; Jaron, F.
Germany, Ireland, Greece, United States, Spain
Abstract
The stellar binary system LS I +61°303, composed of a compact object in an eccentric orbit around a B0 Ve star, emits from radio up to γ-ray energies. The orbital modulation of radio spectral index, X-ray, and GeV γ-ray data suggests the presence of two peaks. This two-peaked profile is in line with the accretion theory predicting two accretion-ejection events for LS I +61°303 along the 26.5 d orbit. However, the existing multiwavelength data are not simultaneous. In this paper, we report the results of a campaign covering radio, X-ray, and γ-ray observations of the system along one single orbit. Our results confirm the two predicted events along the orbit and in addition show that the positions of radio and γ-ray peaks are coincident with X-ray dips as expected for radio and γ-ray emitting ejections depleting the X-ray emitting accretion flow. We discuss future observing strategies for a systematic study of the accretion-ejection physical processes in LS I +61°303.