LS I +61°303 is an X-ray binary with a radio outburst every ̃27 d. Previous studies of the stellar system revealed radio microflares superimposed on the large radio outburst. We present here new radio observations of LS I +61°303 at 2.2 GHz with the Westerbork Synthesis Radio Telescope (WSRT). Using various timing analysis methods, we find significant quasi-periodic oscillations (QPOs) of 55 min stable over the duration of 4 d. We also use archival data obtained from the Suzaku satellite at X-ray wavelengths. We report here for the first time significant X-ray QPOs of about 2 h present over the time span of 21 h. We compare our results with the previously reported QPO observations and we conclude that the QPOs seem to be associated with the radio outburst, independent of the amplitude of the outburst. Finally, the different QPO time-scales are discussed in the context of magnetic reconnection.
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- May 2018
- radio continuum: stars;
- X-rays: binaries;
- X-rays: individual: LS I +61°303;
- Astrophysics - High Energy Astrophysical Phenomena