Quasi-periodic X-ray brightness fluctuations in an accreting millisecond pulsar

摘要: The relativistic plasma flows onto neutron stars that are accreting material from stellar companions can be used to probe strong-field gravity as well the physical conditions in supra-nuclear-density interiors of stars. Plasma inhomogeneities orbiting a few kilometres above observable X-ray brightness fluctuations on millisecond dynamical timescale flows1,2,3. Two frequencies kilohertz range dominate these fluctuations: twin quasi-periodic oscillations (kHz QPOs). Competing models for origins (based orbital motions) all predict they should related spin frequency4,5,6,7,8,9,10, but tests have been difficult because spins were not unambiguously known. Here we report detection kHz QPOs pulsar whose frequency is Our measurements establish clear link between and spin, one predicted by any current model. A new approach understanding now required. We suggest resonance general epicyclic could provide observed relation spin.