arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1106.6301astro-ph.SRgr-qc
收藏

中微子驱动的超新星爆炸的参数化3D模型:中微子发射不对称性和引力波信号

Parametrized 3D models of neutrino-driven supernova explosions: Neutrino emission asymmetries and gravitational-wave signals

E. Müller, H. -Th. Janka, A. Wongwathanarat

摘要:

本文给出了一组参数化的、中微子驱动的太阳质量为15和20的非自转恒星超新星爆炸的三维流体动力学模型的中微子和引力波的时间和方向特征。我们采用近似处理中微子输运。由于切除了原中子星的高密度核心,并使用了无轴重叠网格,模型可以从反弹后吸积阶段进行一秒钟以上的计算,而不施加任何对称性限制。GW和中微子发射表现出从2D模型已知的一般的时间依赖性的功能。吸积层中的非径向流体动力学质量运动及其与原中子星外层的相互作用,加上各向异性中微子发射,产生了振幅约5-20厘米、频率100- 500赫兹的GW信号。质量运动产生的GW辐射在爆炸开始前达到最大值。之后的GW信号表现出低频调制,在某些情况下描述的准单调增长,与爆炸冲击波的非球形膨胀和逃逸中微子流的大尺度各向异性。新生中子星内部对流活动引起的质量四极矩的变化在爆炸后阶段对GW信号产生了高频分量。GW信号在两种极化、不同爆炸模拟和不同观测方向之间表现出很强的可变性,并且不具有任何模板特征。中微子发射特性显示了中子星表面在空间和时间尺度上的波动,反映了不同类型的非球形质量运动。可测量的中微子光度和平均能量的调制幅度显着小于预测的二维模拟。

英文摘要:

Time-dependent and direction-dependent neutrino and gravitational-wave (GW) signatures are presented for a set of 3D hydrodynamic models of parametrized, neutrino-driven supernova explosions of non-rotating 15 and 20 solar mass stars. We employ an approximate treatment of neutrino transport. Due to the excision of the high-density core of the proto-neutron star and the use of an axis-free overset grid, the models can be followed from the post-bounce accretion phase for more than one second without imposing any symmetry restrictions. GW and neutrino emission exhibit the generic time-dependent features known from 2D models. Non-radial hydrodynamic mass motions in the accretion layer and their interaction with the outer layers of the proto-neutron star together with anisotropic neutrino emission give rise to a GW signal with an amplitude of ~5-20 cm and frequencies 100--500 Hz. The GW emission from mass motions reaches a maximum before the explosion sets in. Afterwards the GW signal exhibits a low-frequency modulation, in some cases describing a quasi-monotonic growth, associated with the non-spherical expansion of the explosion shock wave and the large-scale anisotropy of the escaping neutrino flow. Variations of the mass-quadrupole moment due to convective activity inside the nascent neutron star contribute a high-frequency component to the GW signal during the post-explosion phase. The GW signals exhibit strong variability between the two polarizations, different explosion simulations and different observer directions, and does not possess any template character. The neutrino emission properties show fluctuations over the neutron star surface on spatial and temporal scales that reflect the different types of non-spherical mass motions. The modulation amplitudes of the measurable neutrino luminosities and mean energies are significantly smaller than predicted by 2D simulations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑