X1658-298: UNVEILING THE EMISSION MECHANISMopenParSclosePar OF QUIESCENT SOFT X-RAY TRANSIENT

Different mechanisms may power the quiescent emission of soft Xray transients,impacting on the physics of fast spinning, weakly magnetic neutron stars subjectto low mass inflow rates: a) the accretion regime; b) the propeller regime; c)the radio pulsar regime. The emission location and spectrum should be: close tothe neutron star and soft in cases a) and b); from an extended shock andpowerlaw like in case c). Additional soft emission may originate from neutronstar cooling. We propose an 80 ks observation of the eclipsing system X1658298,covering 3 orbits. This will yield the source quiescent spectrum and exploit theXray eclipses to determine where the emission components originate. OnlyXMMNewton has the sensitivity and throughput to carry out this study. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]