Eclipse Mapping of EXO 0748-676: Evidence for a Massive Neutron Star

Understand

Determining the maximum possible neutron star (NS) mass places limits on the equation of state (EoS) of ultra-dense matter.

• The mass of NSs in low mass X-ray binaries can be determined from the binary mass function, providing independent constraints are placed on both the binary inclination and mass ratio.
• In eclipsing systems, they relate via the totality duration.
• EXO 0748-676 is an eclipsing NS low mass X-ray binary with a binary mass function estimated using stellar emission lines from the irradiated face of the companion.