Constraint on nuclear symmetry energy imposed by f-mode oscillation of neutron stars

摘要

Due to improvements in the sensitivity of gravitational wave (GW) detectors, the detection of GWs originating from the fundamental quasi-normal mode (f-mode) of neutron stars has become possible. The future detection of GWs originating from the f-mode of neutron stars will provide a potential way to improve our understanding of the nature of nuclear matter inside neutron stars. In this work, we investigate the constraint imposed by the f-mode oscillation of neutron stars on the symmetry energy of nuclear matter using Bayesian analysis and parametric EOS. It is shown that if the frequency of the f-mode of a neutron star of known mass is observed precisely, the symmetry energy at twice the saturation density (E-sym(2(rho 0))) of nuclear matter can be constrained within a relatively narrow range. For example, when all the following parameters are within the given intervals: 220 <= K-0 <= 260 MeV, 28 <= E-sym(rho(0)) <= 36 MeV, 30 <= L <= 90 MeV, -800 <= J(0) <= 400 MeV, - 400 <= K-sym <= 100 MeV, -200 <= J(sym) <= 800 MeV, E-sym(2(rho 0)) will be constrained to within 48.8(-5.5)(+6.6) MeV if the f-mode frequency of a canonical neutron star (1.4 M-circle dot) is observed to be 1.720 kHz with a 1% relative error. Furthermore, if only f-mode frequency detection is available, i.e. there is no stellar mass measurement, a precisely detected f-mode frequency can also impose an accurate constraint on the symmetry energy. For example, given the same parameter space and the same assumed observed f-mode frequency mentioned above, and assuming that the stellar mass is in the range of 1.2-2.0 M-circle dot, E-sym(2(rho 0)) will be constrained to within 49.5(-6.8)(+8.1) MeV. In addition, it is shown that a higher slope of 69 <= L <= 143 MeV will give a higher posterior distribution of E-sym(2(rho 0)), 53.8(-6.4)(+7.0) MeV.

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