The merger of two neutron stars launches a relativistic jet, which must be driven by a strong large-scale magnetic field. However, the magnetohydrodynamical mechanism required to build up this magnetic field remains uncertain. By performing an ab initio super-high-resolution neutrino-radiation magnetohydrodynamics merger simulation in full general relativity, we show that the αΩ dynamo mechanism, driven by the magnetorotational instability, builds up the large-scale magnetic field inside the long-lived remnant of the binary neutron star merger. As a result, the magnetic field induces a Poynting-flux-dominated relativistic outflow with an isotropic equivalent luminosity of ~10⁵² erg s⁻¹ and a magnetically driven post-merger mass ejection of ~0.1 M_⊙. Therefore, the magnetar hypothesis, in which an ultra-strongly magnetized neutron star drives a relativistic jet in binary neutron star mergers, is possible. Magnetars can be the engines of short, hard gamma-ray bursts, and they should be associated with very bright kilonovae, which current telescopes could observe. Therefore, this scenario is testable in future observations.

两颗中子星的合并会发射相对论性喷流，该喷流必须由强大的大尺度磁场驱动。然而，建立该磁场所需的磁流体动力学机制仍然不确定。通过在完全广义相对论中进行从头算超高分辨率中微子辐射磁流体动力学合并模拟，我们表明，在磁旋转不稳定性的驱动下， αΩ发电机机制在长寿命残余物内部建立了大规模磁场。双中子星合并。结果，磁场引起了坡印廷通量主导的相对论流出，其各向同性等效光度约为 10 ⁵²  erg s ^-1，磁力驱动的合并后质量抛射约为 0.1  M _⊙。因此，磁星假说是可能的，其中超强磁化的中子星在双中子星合并中驱动相对论性喷流。磁星可以是短而强的伽马射线爆发的引擎，它们应该与非常明亮的千新星有关，目前的望远镜可以观测到。因此，这种情况可以在未来的观察中进行检验。