Tsallis statistics as a tool for studying interstellar turbulence

TL;DR

This paper demonstrates that Tsallis distributions effectively model the PDFs of density, velocity, and magnetic field increments in interstellar turbulence, with parameters varying according to turbulence regimes, offering a new diagnostic tool.

Contribution

It introduces the use of Tsallis statistics to analyze interstellar turbulence and links distribution parameters to turbulence properties, extending previous solar wind studies.

Findings

Tsallis distributions fit the PDFs of interstellar turbulence data.

Distribution parameters vary with sonic and Alfvén Mach numbers.

Potential for using Tsallis parameters to diagnose interstellar gas states.

Abstract

We used magnetohydrodynamic (MHD) simulations of interstellar turbulence to study the probability distribution functions (PDFs) of increments of density, velocity, and magnetic field. We found that the PDFs are well described by a Tsallis distribution, following the same general trends found in solar wind and Electron MHD studies. We found that the PDFs of density are very different in subsonic and supersonic turbulence. In order to extend this work to ISM observations we studied maps of column density obtained from 3D MHD simulations. From the column density maps we found the parameters that fit to Tsallis distributions and demonstrated that these parameters vary with the sonic and Alfv\'en Mach numbers of turbulence. This opens avenues for using Tsallis distributions to study the dynamical and perhaps magnetic states of interstellar gas.