Simulating jets from a neutron star companion hours after a core-collapse supernova

We conduct three-dimensional hydrodynamical simulations to explore the interaction of the jets that a neutron star (NS) companion to a type Ic or type Ib core-collapse supernova (CCSN) launches a few hours after explosion with the ejecta of the CCSN. We assume that an NS companion at 5 R_☉ from the exploding star accretes mass from the slower inner ejecta through an accretion disk, and that the disk launches two opposite jets. Although the energy of the jets is only about one percent of the total energy of the ejecta, it is comparable to the energy of the slower inner part of the ejecta. We find that the jets inflate one low-density hot bubble to one side of the ejecta, and that this bubble expands to influence ejecta gas up to expansion velocities of v_ej ≃ 3500 km s^-1. The postshock jets' material develops a large meridional flow and small vortexes. The boundary between the ejecta and jets' postshock gases is unstable. The instabilities and vortexes mix jets' gas with the ejecta. We expect such a hot bubble to contribute to the light curve of CCSNe that are progenitors of binary NS systems, in particular to observers on the side of the bubble.