Two years of INTEGRAL monitoring of the Soft Gamma-Ray Repeater SGR   1806-20: from quiescence to frenzy
  SGR 1806-20 has been observed for more than 2 years with the INTEGRAL satellite. In this period the source went from a quiescent state into a very active one culminating in a giant flare on December 27 2004. Here we report on the properties of all the short bursts detected with INTEGRAL before the giant flare. We derive their number-intensity distribution and confirm the hardness-intensity correlation for the bursts found by Gotz et al. (2004a). Our sample includes a very bright outburst that occurred on October 5 2004, during which over one hundred bursts were emitted in 10 minutes, involving an energy release of 3 x 1E42 erg. We present a detailed analysis of it and discuss our results in the framework of the magnetar model. 
D. Gotz, S. Mereghetti, S. Molkov, K. Hurley, I.F. Mirabel, R.   Sunyaev, G. Weidenspointner, S. Brandt, M. Del Santo, M. Fe...