Measuring neutron star mass and radius with three mass-radius relations

Measuring Neutron Star Mass and Radius with Three Mass-Radius Relations

We propose to determine the mass and the radius of a neutron star (NS) using three measurable mass-radius relationships, namely the “apparent” radius inferred from neutron star thermal emission, the gravitational redshift inferred from the absorption lines, as well as the averaged stellar mass density inferred from the orbital Keplerian frequency derived from the kilohertz quasi periodic oscill...

Radius Mass Position of Radius

Star cluster life-times: dependence on mass, radius and environment

The dissolution time (tdis) of clusters in a tidal field does not scale with the “classical” expression for the relaxation time. First, the scaling with N , and hence cluster mass, is shallower due to the finite escape time of stars. Secondly, the cluster half-mass radius is of little importance. This is due to a balance between the relative tidal field strength and internal relaxation, which h...

Towards a Mass and Radius Determination of the Nearby Isolated Neutron Star Rx J185635-3754

We discuss efforts to determine the mass, radius, and surface composition of the nearby compact object RX J185635-3754 from its multi-wavelength spectral energy distribution. We compute non-magnetized model atmospheres and emergent spectra for selected compositions and gravities, and discuss efforts to fit existing and new observational data from ROSAT, EUVE and the HST. The spectral energy dis...

Constraining the Mass & Radius of Neutron Stars in Globular Clusters

We analyze observations of eight quiescent low-mass X-ray binaries in globular clusters and combine them to determine the neutron star mass-radius curve and the equation of state of dense matter. We determine the effect that several uncertainties may have on our results, including uncertainties in the distance, the atmosphere composition, the neutron star maximum mass, the neutron star mass dis...