Comptonization, the X-ray-radio correlation and the long-term   periodicity in the chi-states of GRS 1915+105
  We analyzed 139 chi-state observations of GRS 1915+105 with RXTE from 1997 to 2000 and found i) that the observations fall into two groups with different Comptonization behavior, ii) that the slope of the hard X-ray component correlates with the radio flux, thus revealing the interaction of jet and corona, and iii) a 590 days long term periodicity in the hard X-ray and radio components. 
Arne Rau, Jochen Greiner