Long-term multi-frequency monitoring of microquasars

TL;DR

This study presents a detailed multi-frequency radio monitoring of microquasars SS433, GRS1915+105, and Cyg X-3 over nearly two years, revealing correlations between radio flares and X-ray activity, and providing insights into jet dynamics.

Contribution

It provides the first extensive daily multi-frequency radio monitoring of these microquasars, capturing their variability and jet activity in correlation with X-ray emissions.

Findings

Cyg X-3 showed a transition from quiescent to flaring states with fluxes up to 20 Jy.

Detected short-term flares in GRS 1915+105 associated with soft X-ray events.

Observed massive ejections in SS433 during powerful flares.

Abstract

We discuss the results of the radio studies of the X-ray binaries with relativistic jets. We carried out a multi-frequency (1-30 GHz) daily monitoring of the radio flux variability of the microquasars SS433, GRS1915+105, and Cyg X-3 with the RATAN-600 radio telescope during the recent sets from 1 November 2006 to 31 August 2008. From December 2005 radio emission of Cyg X-3 after four years relatively quiescent levels (100-200 mJy) dropped down to $\sim$20 mJy, and then we detected a lot of bright radio flaring events (1-20 Jy) followed the very variable (from 0 to 0.5 crabs) 15-50 keV X-ray emission, which was monitored in the Swift/BAT ASM program. Again from December 2007 to March 2008 we have daily measured almost quiescent fluxes from Cyg X-3 but in April 2008 a bright radio flare with clear synchrotron self-absorption was detected. We detected several bright short-term flares from GRS 1915+105 which could be associated with active soft X-ray events. In intense measurements of SS433 fluxes (often mutually with X-ray and optical observations) we detected massive ejections during powerful flares. We discuss the various spectral and temporal characteristics of the light curves from the microquasars. Monitoring of the flaring radio emission is a good tracer of jet activity X-ray binaries.