Heat release in accreting neutron stars

Observed thermal emission from accreting neutron stars (NSs) in a quiescent state is believed to be powered by nonequilibrium nuclear reactions that heat the stellar crust (deep crustal heating paradigm). We derive simple universal formula for efficiency, assuming an NS has fully accreted crust. further show that, within recently proposed thermodynamically consistent approach crust, release can parametrized only one parameter---the pressure ${P}_{\mathrm{oi}}$ at outer-inner interface (as we argue, this should not necessarily coincide with neutron-drip pressure). discuss possible values of selection models account shell effects, and determine net its distribution as function ${P}_{\mathrm{oi}}$. conclude reduced factor few comparison previous works.