Evidence for periodic accretion-ejection in LSI+61303

TL;DR

This study presents simultaneous multiwavelength observations of LS I +61303, confirming two accretion-ejection events per orbit and revealing the correlation between radio, X-ray, and gamma-ray emissions, supporting accretion theory.

Contribution

First simultaneous multiwavelength campaign confirming the two accretion-ejection events predicted by theory in LS I +61303.

Findings

Radio and gamma-ray peaks coincide with X-ray dips.

Two accretion-ejection events observed per orbit.

Results support accretion-ejection physical models.

Abstract

The stellar binary system LS I +61303, composed of a compact object in an eccentric orbit around a B0 Ve star, emits from radio up to gamma-ray energies. The orbital modulation of radio spectral index, X-ray, and GeV gamma-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 +61303 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 gamma-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 gamma-ray peaks are coincident with X-ray dips as expected for radio and gamma-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 +61303.