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H 2 O and CH 3 OH Masers provide information on:

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. H 2 O and CH 3 OH Masers provide information on:.

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H 2 O and CH 3 OH Masers provide information on:

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  1. Turbulent AU Structures Revealed by H2O and CH3OH MasersV. StrelnitskiMaria Mitchell ObservatoryIn collaboration with: J. Alexander, S. Gezari, B. Holder, N. Nezhdanova, J. Moran, M. Reed, V. ShishovSINS, Socorro, May 21-24, 2006

  2. H2O and CH3OH Masersprovide information on: • Physics of natural masing • Spatial and kinematical structure of the surroundings of new-born stars • Physics of supersonic turbulence

  3. CH3OH Masers in OMC-1 Johnston et al. 1997

  4. 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)

  5. Are H2O & H2CO Masers Spooks orThings?

  6. The Model (Holder et al. 2006): • Random Kolmogorov velocity field in a 5123 grid point box • Unsaturated and saturated maser amplification I = I0 eτ I = I0τ • Random fractalization of the medium (d = 1)

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

  8. Dimensional Approach • Relevant parameters for dissipation: ε = U3/L cs • Dissipation scale: η = cs3/ε = L / M3 • H2O Masers: L ~ 104 A.U.; M ~ 20 → η ~ 1 A.U.

  9. Physical Approach tl ~ l / ul ts ~ l/cs ul = uL (l / L)1/3 ts > tl as long as l > L/M3 η ~ L/M3 vs ~ cs L uL= M cs

  10. Conclusions • H2O 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

  11. pl = (η/l)3-d

  12. Typical Model (Sobolev et al. 1998) • Random Kolmogorov velocity field in a N3 grid point box • Unsaturated (exponential) maser amplification I = I0 eτ • Synthetic spectra and maps to be compared with observations • Result: CH3OH hot spots may be an optical effect

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

  14. Required Maser Gains H2O: T = T0 eτ ~ 1015 K τ ≈ 35 T0 ~ 1K H2CO:τ ≈ 10

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