Spectra of the spreading layers on the neutron star surface and constraints on the neutron star equation of state

摘要: Spectra of the spreading layers on neutron star surface are calculated basis Inogamov-Sunyaev model taking into account general relativity correction to grav- ity and considering various chemical composition accreting matter. Local (at a given latitude) spectra similar X-ray burst described by diluted blackbody. Total layer integrated accounting for light bending, gravitational red- shift relativistic Doppler effect aberration. They depend slightly inclination angle luminosity. These also can be fitted blackbody with colour temperature depending mainly compactness. Owing fact that flux from is close critical Eddington, we put constraints radius without need know precisely emitting region area or distance source. The boundary observed in luminous low-mass binaries, T c = 2.4 ± 0.1 keV, restrict radii R 14.8 1.5 km (for 1.4-M ⊙ solar matter), which corresponds hard equation state.