Oral Presentation Astronomical Society of Australia Annual Scientific Meeting including HWWS 2013

Disk-jet coupling in Galactic black hole X-ray binaries. (#90)

Thomas D Russell 1
  1. ICRAR, Perth, WA, Australia
There is a universal connection between the accretion and ejection phenomena; a relationship that is observed in black holes of all masses. Quantifying this connection is the first step to understanding how jets are launched, accelerated and collimated. X-ray binaries (or microquasars) are ideal systems to study this relation, as they evolve on human timescales. In occasional outbursts, their luminosities increase by several orders of magnitude, with the thermal X-ray emission from the accretion disk and the radio emission from the relativistic jets undergoing dramatic changes. I present recent results from an intensive, multi-wavelength observing campaign of the microquasar MAXI J1836-194 during its 2011 outburst. Broadband radio to X-ray data taken over the course of the outburst show dramatic changes in the jet spectrum, closely linked to the evolution of the accretion disk. During the peak of the outburst we see that the inner radius of the accretion disk moves inwards to ~85 km, the disk temperature peaks and the jet luminosity decreases. Then, as the outburst declines, the inner disk radius returns to much larger radii, the disk cools and the jet luminosity recovers to pre-outburst levels. These simultaneous, high cadence observations provide an unprecedented insight into the accretion processes occurring during an outburst, allowing us to observe an evolving compact jet and the corresponding changes within the accretion regime. This has implications for the launching of jets on all scales, from microquasars to their larger-scale analogues, AGN.