Determining the Fractal Dimension of the Interstellar Medium

TL;DR

This paper investigates the fractal dimension of the interstellar medium using simulations and real data, revealing a higher value than previously assumed, and discusses factors affecting its measurement.

Contribution

It introduces a method to reliably estimate the fractal dimension of the interstellar medium considering observational distortions.

Findings

Fractal dimension of the interstellar medium is between 2.6 and 2.8.

The estimated Df is higher than the commonly assumed 2.3.

Factors like projection and noise significantly influence Df measurement.

Abstract

The Interstellar Medium seems to have an underlying fractal structure, which can be characterized through its fractal dimension (Df). However, several factors may affect the determination of Df, such as distortions due to projection, low image resolution, opacity of the cloud, and low signal-to-noise ratio. Here we use both simulated clouds and real molecular cloud maps to study these effects in order to estimate Df in a reliable way. Our results indicate in a self-consistent way that the fractal dimension of the Interstellar Medium is in the range 2.6 < Df < 2.8, which is significantly higher than the value Df = 2.3 usually assumed in the literature.