Monitoring Sgr A* X-ray flaring activity to measure quasi periodic modulation

Building on the great successes of the monitoring program of Sgr A* flaringactivity we initiated and fostered in the last years, we propose to continueextended observations of the Galactic nucleus with XMMNewton in order tofurther test the supermassive black hole paradigm while studying the accretionflow and radiation mechanisms associated with this unique system at the centreof the Galaxy. Thanks to the unique capabilities of XMMNewton we will tacklecrucial questions that remain unanswered: 1) are Xray flares from Sgr A* causedby blobs of hot, orbiting plasma in the accretion flow close to the eventhorizon of the black hole, truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]