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8/27/03LSU - AEI Astrophysics1 The Nonlinear Development of Instabilities in Rotating Stars and Binary Star Systems Joel E. Tohline & Juhan Frank Kevin.

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Presentation on theme: "8/27/03LSU - AEI Astrophysics1 The Nonlinear Development of Instabilities in Rotating Stars and Binary Star Systems Joel E. Tohline & Juhan Frank Kevin."— Presentation transcript:

1 8/27/03LSU - AEI Astrophysics1 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

2 8/27/03LSU - AEI Astrophysics2 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

3 8/27/03LSU - AEI Astrophysics3 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

4 8/27/03LSU - AEI Astrophysics4 Movies

5 8/27/03LSU - AEI Astrophysics5 Principal Governing Equations

6 8/27/03LSU - AEI Astrophysics6 Numerical Simulations Initial Models: Self- Consistent-Field Technique Explicit Time-Integration Finite-Difference Scheme –Uniform, Cylindrical Lattice [typically, ] –Rotating Frame –van Leer Advection Heterogeneous Computing Environment SuperMike: LSU’s 1024-processor, 2.2 TeraFlop Supercomputer

7 8/27/03LSU - AEI Astrophysics7 Regions of Instability & Possible Evolutions

8 8/27/03LSU - AEI Astrophysics8 Regions of Instability & Possible Evolutions Movie #1 & Movie #2 [Dynamical Barmode]

9 8/27/03LSU - AEI Astrophysics9 Regions of Instability & Possible Evolutions

10 8/27/03LSU - AEI Astrophysics10 Hanford Observatory Livingston Observatory Laser Interferometer Gravitational-wave Observatory (LIGO)

11 8/27/03LSU - AEI Astrophysics11

12 8/27/03LSU - AEI Astrophysics12 Principal Governing Equations

13 8/27/03LSU - AEI Astrophysics13  GR for (Dedekind) f-mode

14 8/27/03LSU - AEI Astrophysics14  GR for (Dedekind) f-mode l = m = 2 5 th derivative! c5c5

15 8/27/03LSU - AEI Astrophysics15 F GR for (Rossby) r-mode [Lindblom, Tohline & Vallisneri (2001, 2002)]

16 8/27/03LSU - AEI Astrophysics16 F GR for (Rossby) r-mode [Lindblom, Tohline & Vallisneri (2001, 2002)] (l = m = 2) c 7 !

17 8/27/03LSU - AEI Astrophysics17 r-mode amplitude vs. time [Lindblom, Tohline & Vallisneri (2001, 2002)]

18 8/27/03LSU - AEI Astrophysics18 r-mode amplitude vs. time [Lindblom, Tohline & Vallisneri (2001, 2002)] Movie #3

19 8/27/03LSU - AEI Astrophysics19 r-mode velocity field

20 8/27/03LSU - AEI Astrophysics20 r-mode amplitude vs. time [Lindblom, Tohline & Vallisneri (2001, 2002)] Movie #4

21 8/27/03LSU - AEI Astrophysics21 Neutron Star’s Angular Momentum, E rot, & Mass

22 8/27/03LSU - AEI Astrophysics22 Sample Binaries Example Binary Systems

23 8/27/03LSU - AEI Astrophysics23 Roche Potential for Unequal-Mass Binary

24 8/27/03LSU - AEI Astrophysics24 Sample Binaries Example Binary Systems

25 8/27/03LSU - AEI Astrophysics25 Movie #5 (top) Movie #6 (side) Movie #7 (vectors)


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