X1658-298: unveiling the emission mechanismopenParsclosePar of quiescent X-ray transients

Different mechanisms may power the quiescent emission of soft Xray transients, impacting on the physics of fast spinning, weakly magnetic neutron stars subject to low mass inflow rates: a. the accretion regime; b. the propellerregime c. the radio pulsar regime. The emission location and spectrum should be: close to the neutron star and soft in cases a. and b.; from an extendedshock and powerlaw like in case c. Additional soft emission may originate fromneutron star cooling. We propose an 80 ks observation of the eclipsing systemX1658298, covering 3 orbits. This will yield the source quiescent spectrum and exploit the Xray eclipses to determine where the emission components originate. Only XMM 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]