A NICER View of the Nearest and Brightest Millisecond Pulsar: PSR J0437–4715

Abstract We report Bayesian inference of the mass, radius, and hot X-ray emitting region properties—using data from the Neutron Star Interior Composition ExploreR (NICER)—for the brightest rotation-powered millisecond X-ray pulsar, PSR J0437−4715. Our modeling is conditional on informative tight priors on mass, distance, and binary inclination obtained from radio pulsar timing using the Parkes Pulsar Timing Array (PPTA; Reardon et al.), and we use NICER background models to constrain the nonsource background, cross-checking with data from XMM-Newton. We assume two distinct hot emitting regions and various parameterized hot region geometries that are defined in terms of overlapping circles; while simplified,…

• NA
  National Aeronautics and Space Administration

  Awards: 80NSSC22K0092, 80NSSC22K0728, 80NSSC23K0078, 80NSSC20K0275
• AR
  Australian Research Council

  Award: CE230100016