Nikolaj A. Nizhelskij

What do we understand from multi-frequency monitoring of microquasars?

Peter A. Voitsik Moscow State University, Physical department, Moscow, Russia E-mail: voitsik@gmail.com We discuss the results of the monitoring programs of the X-ray binaries with relativistic jets studies. We carried out a multi-frequency (1-30 GHz) daily monitoring of the radio flux variability of the microquasars SS433, GRS1915+105, V4641 Sgr and Cyg X-3 with RATAN-600 radio telescope during the recent sets in 2002-2006. We detected a lot of bright short-time flares from GRS 1915+105 which could be associated with active X-ray events. In 2004 we have detected two flares from V4641 Sgr, which followed after recurrent X-ray activity of the transient. From September 2005 to May 2006 and then in July we have daily measured flux densities from Cyg X-3. In January 2006 we detected a drop down of its quiescent fluxes (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 quasisimultaneous observations at 110 GHz with the RT45m telescope and the NMA millimeter array of the Nobeyama Radio Observatory 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. We discuss the various spectral and temporal characteristics of the light curves from the microquasars. Thus we conclude that monitoring of the flaring radio emission is a good tracer of jet activity X-ray binaries. VI Microquasar Workshop: Microquasars and Beyond September 18-22 2006 Societa del Casino, Como, Italy

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 progr...

Flaring activity of microquasars from multi-frequency daily monitoring program with RATAN-600 radio telescope

We report about the multi-frequency (1–30 GHz) daily monitoring of the radio flux variability of the three microquasars: SS433, GRS1915+105 and Cyg X-3 during 2005–2006. After a quiescent radio emission we have detected a drop down of the fluxes (∼20 mJy) from Cyg X-3, a sign of the following bright flare, and indeed a 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 was found flat from 2 to 110 GHz, using the quasi-simultaneous observations at 109 GHz with the RT45m telescope and the NMA millimeter array of Nobeyama Radio Observatory in Japan. Several bright radio flaring events (1–15 Jy) followed during the state of highly variable and intense 1–12 keV X-ray emission (∼0.5 Crab), monitored in the RXTE ASM program. We discussed various spectral and temporal characteristics of the detected 180 day light curves from three microquasars in comparison with the Rossi XTE ASM data.

Discovery of the Small Scale Sky Anisotropy at 2.7cm: Radio Sources or Relic Emission?

We present new limits on the small scale 3K emission anisotropy. At the scales of 1° ÷ 3.°3 all 7 harmonics have at λ = 7.6cm amplitudes below 10-5 in ΔT/T. At l from 6.1 103 to 17.5 103 (rad -1) scale this limit is about 2.8 10-4 at a wavelength of 2.7cm and may be fully explained by a discrete source contribution.The low baryonic content of the Universe and present limit on ΔT/T at the horizon scale suggest that (ΔM/M)gravitating ≪ (ΔM/M)baryonic. We speculate that 3K anisotropy measurements demonstrate a) the existence of the dark matter, b) the nonbaryonic nature of this dark matter and c) that the spatial distribution of this matter is much more homogeneous than that of the visible one.