The Bulletin of The Korean Astronomical Society (천문학회보)
- Volume 39 Issue 1
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- Pages.57.2-57.2
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- 2014
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- 1226-2692(pISSN)
Density distributions and Power spectra of outflow-driven turbulence
- Kim, Jongsoo (Korea Astronomy and Space Science Institute) ;
- Moraghan, Anthony (Academia Sinica Institute of Astronomy and Astrophysics)
- Published : 2014.04.10
Abstract
Protostellar jets and outflows are signatures of star formation and promising mechanisms for driving supersonic turbulence in molecular clouds. We quantify outflow-driven turbulence through three-dimensional numerical simulations using an isothermal version of the total variation diminishing code. We drive turbulence in real space using a simplified spherical outflow model, analyze the data through density probability distribution functions (PDFs), and investigate density and velocity power spectra. The real-space turbulence-driving method produces a negatively skewed density PDF possessing an enhanced tail on the low-density side. It deviates from the log-normal distributions typically obtained from Fourier-space turbulence driving at low densities, but can provide a good fit at high densities, particularly in terms of mass-weighted rather than volume-weighted density PDF. We find shallow density power-spectra of -1.2. It is attributed to spherical shocks of outflows themselves or shocks formed by the interaction of outflows. The total velocity power-spectrum is found to be -2.0, representative of the shock dominated Burger's turbulence model. Our density weighted velocity power spectrum is measured as -1.6, slightly less that the Kolmogorov scaling values found in previous works.
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