Simulation study of optical turbulence in interstellar medium by phase screens.

The interstellar medium (ISM) is the most widely interested in astronomical fields. Understanding the behavior of the interstellar medium is needed for the concept of the evolution of stars. The variation of the interstellar medium's refractive index, density, temperature, and pressure leads to turbulence. The turbulence has the main role in the star formation. In this paper, by using phase screen methods, the different turbulence models for the interstellar medium are simulated. Using two simulation methods, random processes and the phase spectral density, the different ISM patterns of phase screens are simulated in MATLAB programming. These patterns are phase power spectrum of the Kolmogorov, non-Kolmogorov, von-Karman, and Modified models for the turbulent medium as Giant Molecular Clouds, Cores, Nebulae, and Filaments. The results show that the Kolmogorov, von-Karman, and Modified turbulence models have more visibility than the non-Kolmogorov turbulence model. Then, by using of optical setup, laser beam propagates in a different medium that are simulated. Using the obtained results, the Fried parameter and the Strehl ratio were determined. [ABSTRACT FROM AUTHOR]