XMM-Newton observations of two transient millisecond X-ray pulsars in   quiescence
  We report on XMM-Newton observations of two X-ray transient millisecond pulsars (XRTMSPs). We detected XTE J0929-314 with an unabsorbed luminosity of \~7x10^{31} erg/s. (0.5-10 keV) at a fiducial distance of 10 kpc. The quiescent spectrum is consistent with a simple power law spectrum. The upper limit on the flux from a cooling neutron star atmosphere is about 20% of the total flux. XTE J1807-294 instead was not detected. We can put an upper limit on the source quiescent 0.5-10 keV unabsorbed luminosity <4x10^{31} erg/s at 8 kpc. These observations strenghten the idea that XRTMSPs have quiescent luminosities significantly lower than classical neutron star transients. 
S. Campana (Brera Obs.), N. Ferrari (Brera Obs. & Milano Univ.), L.   Stella (Roma Obs.), G.L. Israel (Roma Obs.)