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The Nonlinear Development of Instabilities in Rotating Stars and Binary Star Systems. Joel E. Tohline & Juhan Frank Kevin Pearson Shangli Ou, Mario D’Souza, Ravi Kopparapu, Vayu Gokhale (Hopefully: Xiaomeng Peng & Ilsoon Park)
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The Nonlinear Development of Instabilities in Rotating Stars and Binary Star Systems Joel E. Tohline & Juhan Frank Kevin Pearson Shangli Ou, Mario D’Souza, Ravi Kopparapu, Vayu Gokhale (Hopefully: Xiaomeng Peng & Ilsoon Park) Former students: Kim New; John Cazes, Howard Cohl, Patrick Motl, Eric Barnes LSU - AEI Astrophysics
Recent Focus • Isolated, rotating stars • Dynamical, barmode instability • (Secular) barmode instability in young Neutron Stars • (Secular) r-mode instability in young Neutron Stars • Binary star systems (late stages of evolution) • Tidal instability (stiff equations of state) • Mass-transferring instabilities • Formation of binary stars LSU - AEI Astrophysics
Recent Focus • Isolated, rotating stars • Dynamical, barmode instability • (Secular) barmode instability in young Neutron Stars • (Secular) r-mode instability in young Neutron Stars • Binary star systems (late stages of evolution) • Tidal instability (stiff equations of state) • Mass-transferring instabilities • Formation of binary stars LSU - AEI Astrophysics
Movies http://baton.phys.lsu.edu/tohline/LSUAEI.movies.html LSU - AEI Astrophysics
Principal Governing Equations LSU - AEI Astrophysics
Numerical Simulations • Initial Models: Self-Consistent-Field Technique • Explicit Time-Integration • Finite-Difference Scheme • Uniform, Cylindrical Lattice [typically, 1283 - 2563] • Rotating Frame • van Leer Advection • Heterogeneous Computing Environment SuperMike: LSU’s 1024-processor, 2.2 TeraFlop Supercomputer LSU - AEI Astrophysics
Regions of Instability & Possible Evolutions LSU - AEI Astrophysics
Regions of Instability & Possible Evolutions Movie #1 & Movie #2 [Dynamical Barmode] http:// http:// LSU - AEI Astrophysics
Regions of Instability & Possible Evolutions LSU - AEI Astrophysics
Laser Interferometer Gravitational-wave Observatory (LIGO) Hanford Observatory Livingston Observatory LSU - AEI Astrophysics
Principal Governing Equations LSU - AEI Astrophysics
FGR for (Dedekind) f-mode LSU - AEI Astrophysics
l = m = 2 FGR for (Dedekind) f-mode 5th derivative! c5 LSU - AEI Astrophysics
FGR for (Rossby) r-mode [Lindblom, Tohline & Vallisneri (2001, 2002)] LSU - AEI Astrophysics
(l = m = 2) FGR for (Rossby) r-mode c7 ! [Lindblom, Tohline & Vallisneri (2001, 2002)] LSU - AEI Astrophysics
r-mode amplitude vs. time [Lindblom, Tohline & Vallisneri (2001, 2002)] LSU - AEI Astrophysics
r-mode amplitude vs. time Movie #3 [Lindblom, Tohline & Vallisneri (2001, 2002)] LSU - AEI Astrophysics
r-mode velocity field LSU - AEI Astrophysics
r-mode amplitude vs. time Movie #4 [Lindblom, Tohline & Vallisneri (2001, 2002)] LSU - AEI Astrophysics
Neutron Star’s Angular Momentum, Erot, & Mass LSU - AEI Astrophysics
Sample Binaries Example Binary Systems LSU - AEI Astrophysics
Roche Potential for Unequal-Mass Binary LSU - AEI Astrophysics
Sample Binaries Example Binary Systems LSU - AEI Astrophysics
Movie #5 (top) Movie #6 (side) Movie #7 (vectors) LSU - AEI Astrophysics