1. Thermal Instability and Turbulence in the ISM Alexei Kritsuk CASS/UCSD

2. Outline TI basics TI basics TI-induced turbulence TI-induced turbulence Sustaining turbulence with variable heating source Sustaining turbulence with variable heating source Scaling relations for multiphase turbulence Scaling relations for multiphase turbulence Thermal pancakes with AMR Thermal pancakes with AMR

3. TI Theory Highlights Linear stability of thermal equilibrium [Field 1965] 546 Linear stability of thermal equilibrium [Field 1965] 546 Generic linear stability [Hunter 1970,71] 10 Generic linear stability [Hunter 1970,71] 10 Phase equilibrium [Zel’dovich & Pikel’ner 1969] (62) Phase equilibrium [Zel’dovich & Pikel’ner 1969] (62) Nonlinear thermal waves [Doroshkevich & Zel’dovich 1981] 12 Nonlinear thermal waves [Doroshkevich & Zel’dovich 1981] 12 Thermal pancakes [Sasorov 1988] (10) Thermal pancakes [Sasorov 1988] (10) Complexity from TI [Elphick et al. 1991] 16 Complexity from TI [Elphick et al. 1991] 16 Two-phase model [FGH 1969] 419 Two-phase model [FGH 1969] 419 Three-phase model [McKee & Ostriker 1977] 973 Three-phase model [McKee & Ostriker 1977] 973 ADS citations ( … ) Web of Knowledge

4. TI Equations

5. TI-induced Turbulence ApJL 569, L127 (2002)

6. TI-induced Turbulence low-density

7. What’s Happening?

8. Phase Diagram

9. Phase Diagrams

10. Mach number vs. Density

11. Phase Transitions Stimulated by Time-dependent Heating ApJL 580, L51 (2002)

12. Interstellar Phase Transitions response to time-dependent local FUV field Low-density region High-density region

13. Time Evolution of Global Variables

14. Phase Diagram low-density

15. Phase Fractions low-density

16. Phase Diagram high-density

17. Energy Exchange high-density

18. Scaling Relations for Turbulence in Multiphase ISM ApJL in press (Jan 2004)

19. TI-induced Turbulence high-density

20. Phase Diagram

21. Phase Fractions

22. Velocity Power Spectra at 0.12, 0.56, 1.5, and 2.5 Myr totalcompressionalsolenoidal Kolmogorov Burgers

23. Velocity Structure Functions

24. Velocity Structure Functions at 0.5 Myr (order 1, …, 6) longitudinaltransverse

25. Scaling Exponents for velocity structure functions

26. Initial Rapid Cooling Stage

27. Structures within a slice at 0.12 Myr Log densityDiv uLog(|rot u|)

28. Structures at 0.12 Myr density vorticity divergence pressure

29. Structures at 0.12 and 0.56 Myr 0.12 2.5 Log densityLog | rot (u) |

30. Mach number vs. density at 0.56 Myr Threshold density

31. Scaling Exponents at 0.56 Myr

32. Work in progress…

33. Thermal Pancakes with AMR