Thursday 10/12/2020 @ 11:30, JAC, Sala IV piano Battiferro (remote)
Elise Egron (INAF-OAC), "Investigating the mini and giant radio flares of the enigmatic microquasar Cygnus X-3"
Microquasars are ideal targets to study the accretion-ejection processes on human timescales. Cygnus X-3 is the brightest X-ray binary at radio wavelengths. It is the only known binary system in our Galaxy composed of a compact object wind-fed by a Wolf-Rayet star. This high-mass X-ray binary system has a very short orbital period of 4.8 hrs, which implies a very tight orbit and strong interactions between the compact object and the stellar wind from the donor. Cyg X-3 is characterized by a highly variable radio emission spanning from 1-30 mJy in the quenched radio state up to 20 Jy during giant flaring states. We present single-dish (SRT and Medicina) and VLBI observations performed during giant and mini flare episodes of Cyg X-3. We study the evolution of the radio flux and spectral index in a multi-wavelength context. We provide evidence of radio orbital modulation during specific episodes of Cyg X-3, the giant flare and mini flares, where the jet characteristics and morphologies are very different.