General-relativistic Simulations of Three-dimensional Core-collapse Supernovae
We study the three-dimensional (3D) hydrodynamics of the post-core-bounce phase of the collapse of a 27 M_☉ star and pay special attention to the development of the standing accretion shock instability (SASI) and neutrino-driven convection. To this end, we perform 3D general-relativistic simulations with a three-species neutrino leakage scheme. The leakage scheme captures the essential aspects of neutrino cooling, heating, and lepton number exchange as predicted by radiation-hydrodynamics simulations. The 27 M_☉ progenitor was studied in 2D by Müller et al., who observed strong growth of the SASI while neutrino-driven convection was suppressed. In our 3D simulations, neutrino-driven convection grows from numerical perturbations imposed by our Cartesian grid. It becomes the dominant instability and leads to large-scale non-oscillatory deformations of the shock front. These will result in strongly aspherical explosions without the need for large-scale SASI shock oscillations. Low-ℓ-mode SASI oscillations are present in our models, but saturate at small amplitudes that decrease with increasing neutrino heating and vigor of convection. Our results, in agreement with simpler 3D Newtonian simulations, suggest that once neutrino-driven convection is started, it is likely to become the dominant instability in 3D. Whether it is the primary instability after bounce will ultimately depend on the physical seed perturbations present in the cores of massive stars. The gravitational wave signal, which we extract and analyze for the first time from 3D general-relativistic models, will serve as an observational probe of the postbounce dynamics and, in combination with neutrinos, may allow us to determine the primary hydrodynamic instability.
Additional Information© 2013 American Astronomical Society. Received 2012 November 20; accepted 2013 March 19; published 2013 April 19. We acknowledge helpful discussions with Dave Arnett, Adam Burrows, Sean Couch, Luc Dessart, Thierry Foglizzo, Uschi C. T. Gamma, Sarah Gossan, Raph Hix, H.-Thomas Janka, Peter Kalmus, Hannah Klion, Io Kleiser, Jim Lattimer, Bernhard Müller, Jeremiah Murphy, David Radice, Luke Roberts, Jason Nordhaus, Ken Nomoto, Jerome Novak, Tony Piro, Sherwood Richers, and members of our Simulating eXtreme Spacetimes (SXS) collaboration (http://www.blackholes. org). This research is partially supported by NSF grant Nos. AST-0855535, AST-1212170, PHY-0904015, PHY-1151197, OCI-0905046, and OCI-0941653, by the Sloan Research Foundation, and by the Sherman Fairchild Foundation. C.R. acknowledges support by NASA through Einstein Postdoctoral Fellowship grant No. PF2-130099 awarded by the Chandra X-ray center, which is operated by the Smithsonian Astrophysical Observatory for NASA under contract NAS8-03060. R.H. acknowledges support by the Natural Sciences and Engineering Council of Canada. The simulations were performed on the Caltech compute cluster "Zwicky" (NSF MRI award No. PHY-0960291), on supercomputers of the NSF XSEDE network under computer time allocation TG-PHY100033, on machines of the Louisiana Optical Network Initiative under grant loni_numrel07, and at the National Energy Research Scientific Computing Center (NERSC), which is supported by the Office of Science of the US Department of Energy under contract DE-AC02-05CH11231. The multi-dimensional visualizations were generated with the open-source VisIt visualization package (https://wci.llnl.gov/codes/visit/). All other figures were generated with the Python-based matplotlib package (http://matplotlib.org/).
Published - 0004-637X_768_2_115.pdf
Submitted - 1210.6674v2.pdf