1. Turbulent AU Structures Revealed by H 2 O and CH 3 OH Masers V. Strelnitski Maria Mitchell Observatory In collaboration with: J. Alexander, S. Gezari, B. Holder, N. Nezhdanova, J. Moran, M. Reed, V. Shishov SINS, Socorro, May 21-24, 2006 Turbulent AU Structures Revealed by H 2 O and CH 3 OH Masers V. Strelnitski Maria Mitchell Observatory In collaboration with: J. Alexander, S. Gezari, B. Holder, N. Nezhdanova, J. Moran, M. Reed, V. Shishov SINS, Socorro, May 21-24, 2006

2. H 2 O and CH 3 OH Masers provide information on: Physics of natural masing Physics of natural masing Spatial and kinematical structure of the surroundings of new-born stars Spatial and kinematical structure of the surroundings of new-born stars Physics of supersonic turbulence Physics of supersonic turbulence

9. CH 3 OH Masers in OMC-1 Johnston et al. 1997

11. Two Competing Interpretations: Maser “hot spots” are the result of a lucky coincidence of radial velocities in a homogeneous turbulent medium The “hot spots” are physical condensations with special conditions (density, temperature, abundances, etc)

12. Are H 2 O & H 2 CO Masers or Things ?

13. The Model (Holder et al. 2006): Random Kolmogorov velocity field in a 512 3 grid point box Random Kolmogorov velocity field in a 512 3 grid point box Unsaturated and saturated maser amplification Unsaturated and saturated maser amplification I = I 0 e τ I = I 0 τ Random fractalization of the medium Random fractalization of the medium (d = 1) (d = 1)

16. Does Supersonic Turbulence have a Shock-Wave Dissipation Scale?

17. Relevant parameters for dissipation: ε = U 3 /L cs cs Dissipation scale: η = c s 3 /ε = L / M 3 H 2 O Masers: L ~ 10 4 A.U.; M ~ 20 → η ~ 1 A.U. Dimensional Approach

18. Physical Approach u L = M c s v s ~ c s t l ~ l / u l t s ~ l/c s u l = u L (l / L) 1/3 t s > t l as long as l > L/M 3 η ~ L/M 3 L

19. Conclusions H 2 O masers are “things” and they may be ideal probes of supersonic turbulence They point to: - High degree of intermittency of turbulence - Lack of energy dissipation at large scales They may be intimately connected with the shock- wave dissipation scale of turbulence More computer simulations are needed to investigate the dependence of energy dissipation on scale for supersonic turbulence

20. p l = (η/l) 3-d

21. Typical Model (Sobolev et al. 1998) Random Kolmogorov velocity field in a N 3 grid point box Random Kolmogorov velocity field in a N 3 grid point box Unsaturated (exponential) maser amplification Unsaturated (exponential) maser amplification I = I 0 e τ Synthetic spectra and maps to be compared with observations Synthetic spectra and maps to be compared with observations Result: Result: CH 3 OH hot spots may be an optical effect CH 3 OH hot spots may be an optical effect

22. Unsaturated Amplification (Analytical Solution) Mean Intensity = C exp[ + 0.5 ] The most probable realizations are within ± [ ] 1/2 If >> 1, only a few bright spots Δτ τ

23. H 2 O: T = T 0 e τ ~ 10 15 K τ ≈ 35 T 0 ~ 1K H 2 CO: τ ≈ 10 Required Maser Gains