5 research outputs found
Flaring variability of Microquasars
We discuss flaring variability of radio emission of microquasars, measured in
monitoring programs with the RATAN-600 radio telescope. 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 during the recent sets in
2005-2007. A lot of bright short-time flares were detected from GRS 1915+105
and they could be associated with active X-ray events. In January 2006 we
detected a drop down of the quiescent fluxes from Cyg X-3 (from 100 to 20
mJy), then the 1 Jy-flare was detected on 2 February 2006 after 18 days of
quenched radio emission. The daily spectra of the flare in the maximum were
flat from 2 to 110 GHz, using the quasi-simultaneous observations at 110 GHz
with the RT45m telescope and the NMA millimeter array of NRO in Japan. Several
bright radio flaring events (1-15 Jy) followed during the continuing state of
very variable and intensive 1-12 keV X-ray emission (0.5 Crab), which was
monitored in the RXTE ASM program. Swift/BAT ASM hard X-ray fluxes correlated
strongly with flaring radio data. The various spectral and temporal
characteristics of the light curves from the microquasars could be determined
from such comparison. We conclude that monitoring of the flaring radio emission
is a good tracer of jet activity X-ray binaries.Comment: 6 pages, 8 figures, published in the proceedings of the Second
Kolkata conference on Observational Evidence for Black Holes in the Universe,
ed. S.K. Chakrabarti (AIP