Results From Core-Collapse Simulations with Multi-Dimensional, Multi-Angle Neutrino Transport
We present new results from the only two-dimensional multi-group, multi-angle calculations of core-collapse supernova evolution. The first set of results from these calculations was published in 2008 by Ott et al. We have followed a nonrotating and a rapidly rotating 20M_⊙ model for ~400 ms after bounce. We show that the radiation fields vary much less with angle than the matter quantities in the region of net neutrino heating. This happens because most neutrinos are emitted from inner radiative regions and because the specific intensity is an integral over sources from many angles at depth. The latter effect can only be captured by multi-angle transport. We then compute the phase relationship between dipolar oscillations in the shock radius and in matter and radiation quantities throughout the post-shock region. We demonstrate a connection between variations in neutrino flux and the hydrodynamical shock oscillations, and use a variant of the Rayleigh test to estimate the detectability of these neutrino fluctuations in IceCube and Super-Kamiokande. Neglecting flavor oscillations, fluctuations in our nonrotating model would be detectable to ~10 kpc in IceCube, and a detailed power spectrum could be measured out to ~5 kpc. These distances are considerably lower in our rapidly rotating model or with significant flavor oscillations. Finally, we measure the impact of rapid rotation on detectable neutrino signals. Our rapidly rotating model has strong, species-dependent asymmetries in both its peak neutrino flux and its light curves. The peak flux and decline rate show pole–equator ratios of up to ~3 and ~2, respectively.
Additional Information© 2011 American Astronomical Society. Received 2010 September 23; accepted 2010 November 24; published 2011 January 13. The authors acknowledge fruitful ongoing and past collaborations with, conversations with, or input from Jason Nordhaus, Emmanouela Rantsiou, and Evan O'Connor. This material is based upon work supported under a National Science Foundation Graduate Research Fellowship to T.D.B. A.B. is supported by the Scientific Discovery through Advanced Computing (Sci- DAC) program of the DOE, under grant number DE-FG02- 08ER41544, the NSF under the subaward number ND201387 to the Joint Institute for Nuclear Astrophysics (JINA, NSF PHY-0822648), and the NSF PetaApps program, under award OCI-0905046 via a subaward number 44592 from Louisiana State University to Princeton University. C.D.O. is partially supported by the NSF under grant numbers AST-0855535 and OCI-0905046. Computational resources were provided by the TIGRESS high-performance computer center at Princeton University, which is jointly supported by the Princeton Institute for Computational Science and Engineering (PICSciE) and the Princeton University Office of Information Technology. Other computational resources used include the NSF TeraGrid under award TG-PHY100033, the Caltech NSF MRI-R^2 cluster Zwicky (PHY-1057238), and the Louisiana Optical Network Infrastructure compute clusters under award loni_numrel05.
Published - Brandt2011p13006Astrophys_J.pdf