The effect of accretion on the measurement of neutron star mass and radius in the low-mass X-ray binary 4U 1608-52

Understand

Spectral measurements of thermonuclear (type-I) X-ray bursts from low mass X-ray binaries have been used to measure neutron star (NS) masses and radii.

• A number of systematic issues affect such measurements and have raised concerns as to the robustness of the methods.
• We present analysis of the X-ray emission from bursts observed from 4U 1608-52 at various persistent fluxes.
• We find a strong dependence of the burst properties on the flux and spectral hardness of the persistent emission before burst.