Three-dimensional hydrodynamics simulations of shell burning in Si/O-rich layer of pre-collapse massive stars

We perform three-dimensional (3D)hydrodynamics simulations of shell burning in the silicon-and oxygen-rich layers in pre-collapse massive stars.Weadoptanon-rotating27 M⊙ starhaving anextended O/Si/Ne layer and afast-rotating 38 M⊙ star having a Si/Olayer, that has experienced chemically homogeneousevolution. Both pre-collapse stars showlarge-scale turbulent motion with a maximum Mach number of ~0.1 in the convective layers activated byneonand oxygenshellburning.The radialproflieoftheangle-averaged mass fraction distributioninO/Si/Ne layer is more homogeneous in the 3D simulation compared to the 1D evolution for the 27 M⊙ star. The angle-averaged specific angular momentum in the Si/O layer of the fast-rotating 38 M⊙ star tends to become roughly constant in the convective layer of the 3D simulation, which is not considered in the 1D evolution.