Understanding High-Density Matter Through Analysis of Surface Spectral   Lines and Burst Oscillations from Accreting Neutron Stars
  We discuss millisecond period brightness oscillations and surface atomic spectral lines observed during type I X-ray bursts from a neutron star in a low mass X-ray binary system. We show that modeling of these phenomena can constrain models of the dense cold matter at the cores of neutron stars. We demonstrate that, even for a broad and asymmetric spectral line, the stellar radius-to-mass ratio can be inferred to better than 5%. We also fit our theoretical models to the burst oscillation data of the low mass X-ray binary XTE J1814-338, and find that the 90% confidence lower limit of the neutron star's dimensionless radius-to-mass ratio is 4.2. 
Sudip Bhattacharyya, M. Coleman Miller, Tod E. Strohmayer, Frederick   K. Lamb, and Craig B. Markwardt