Constraining the Nuclear Equation of State with a Quiescent Neutron Star in M13

Measuring the spectrum of quiescent neutron stars in globular clusters allowsstrong constraints on their mass and radius, with implications for the physicsof matter at high densities. We identify the quiescent neutron star in M13 asthe ideal candidate to study with XMMNewton, due to its high observed Xrayflux, low N_H, and angular separation from contaminating sources. A 100ks EPICexposure will allow us to constrain the fitted neutron star radius within <1 km,for a 1.4 M mass.