First high resolution spectral studies from marginally stable nuclear burning

We propose to perform the first high spectral resolution studies of the recentlyfound milihertz quasiperiodic oscillations in the Xray time variability of twoneutron star systems. These phenomena are very likely due to a marginally stablenuclear burning on the neutron star surface which means that by measuring thegravitational redshift of the spectral lines we will be able to constrain themasstoradius ratio. Furthermore, the resulting spectrum can give us furtherinformation about the emitting area, and particularly, the temperature obtainedfrom the spectral fits will confirm if the local accretion rate onto the star isvirgulL_E as the simulations suggest. This could prove, for the first time, theextent to which the accreted material spreads over the surface. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]