We investigate the gravitational waves (GWs) at low frequencies produced by neutrinos that are emitted anisotropically from the proto-neutron star (PNS) during its cooling phase that lasts about a minute. We first give a formulation based on the spherical-harmonic expansion of the neutrino luminosity to obtain the gravitational waveform as well as the characteristic strain. In the absence of multi-dimensional simulations of PNS cooling, from which we can extract reliable data on the neutrino luminosities as a function of solid angle, we construct them by hand. In the first model, the time evolution is approximated by piece-wise exponential functions (PEFs); in the second model we employ the time evolution obtained in a 1D cooling simulation for all harmonic components for simplicity; In both cases, we consider not only axisymmetric components but also non-axisymmetric ones; for the latter, in particular, we consider as the third model axisymetric neutrino emissions that are misaligned with the rotation axis and, as a result, rotate with the PNS. We find from the first model that the decay times in PEF at late phases can be inferred from the positions of bumps and dips in the characteristic strain of the GW in the case of a slow cooling, whereas it may be obtained by identifying the positions of slope change in the case of rapid cooling, which may be induced by convections in PNS. We also find from the first model that the rotation of PNS can be reflected in GW waveforms. Finally, we compared the characteristic strains with sensitivity curves GW detectors, finding that above phenomena are expected to be detected by DECIGO if the PNS is located at 10kpc.
Asymmetric emissions of neutrinos in the cooling of rotating proto-neutron stars
Graduate School of Advanced Science and Engineering, Waseda University（早稻田大学先进理工学研究科）；Department of Liberal Arts, Tokyo University of Technology（东京工业大学教养学部）；Faculty of Science and Engineering, Waseda University（早稻田大学理工学府）；National Astronomical Observatory of Japan（日本国立天文台）；Advanced Research Institute for Science and Engineering, Waseda University（早稻田大学理工学高等研究院）
我们研究了孤立中子星的冷却，特别是考虑到核配对间隙的重要性。采用Brueckner-Hartree-Fock方法导出的微观核物质状态方程，并结合相容的中子和质子对能隙。然后，我们研究了修改的差距最终推导出的中子星质量分布的影响。我们发现，利用质子1 S 0 Bardeen-Cooper-Schrieffer（BCS）能隙（约减少40%）和没有中子3 P2配对，可以实现对当前所有冷却数据的一致描述，并可以预测合理的中子星质量分布.
Cooling of Isolated Neutron Stars with Hyperon-mixed Kaon-Condensation Matter
The University of Manchester（曼彻斯特大学）；Indian Institute of Technology, Roorkee（印度理工学院鲁尔基分校）；RIKEN（理化学研究所）；Chiba Institute of Technology（千叶工业大学）；Kurume Institute of Technology（久留米工业大学）
Fudan University（复旦大学）；INFN Sezione di Catania, Dipartimento di Fisica, Universitá di Catania（意大利国家核物理研究所卡塔尼亚分部、物理学系、卡塔尼亚大学）；University of Geosciences, Wuhan（武汉地球科学学院）；Shanghai Research Center for Theoretical Nuclear Physics, NSFC, Fudan University（国家自然科学基金委上海理论核物理研究中心，复旦大学）
