The Distance, Mass, and Radius of the Neutron Star in 4U 1608-52

Understand

Low mass X-ray binaries that show thermonuclear bursts are ideal sources for constraining the equation of state of neutron star matter.

• The lack of independent distance measurements for most of these sources, however, prevents a systematic exploration of the masses and radii of the neutron stars, hence limiting the equation of state studies.
• We present here a measurement of the distance to the low mass X-ray binary 4U 1608-52 that is based on the study of the interstellar extinction towards the source.
• We first model the individual absorption edges of the elements Ne and Mg in the high resolution X-ray spectrum obtained with XMM-Newton.