0740013

We propose a Target of Opportunity Observation whenever one of the Known Accreting Pulsars enters an outburst. Part of the proposal are also the New Accreting Pulsars discovered by INTEGRAL or any othercurrent High Energy mission. We request a total of 800 ksec divided into: (a) three deep observations 400 ksec in total to be performed at the rise (100 ks) at the peak (100 ks) and at low luminosity in the declining phase of the outburst (200 ks) (b) a series of eight pointings (50 ksec each) to monitor the source along the outburst. The science goals of the proposal are: (1) The understanding of the accretion regime super- vs. sub-Eddington through the monitoring of the spectral parameters (mainly the cyclotron line parameters) along the outburst. (2) The study of magnetospheric instabilities through the observations of the recently discovered flares in the rising part of the outburst. (3) The study of the geometry/physics of the emission through the observation with high statistics at different luminosities of the phase dependence of the spectral parameters as well as of the energy dependent pulse profiles. This allows the measurement of the line shapes of the CRSFs (fundamental and harmonics) to test the theoretical models proposed for line formation. [truncated! Please see actual data for full text]