J plots: a new method for characterizing structures in the interstellar medium

TL;DR

This paper introduces J plots, a novel automated method using principal moments of inertia to classify and analyze structures like cores, filaments, and rings in 2D interstellar medium data from observations and simulations.

Contribution

The paper presents a new inertia-based classification method for structures in the interstellar medium, applicable to 2D data from surveys and simulations.

Findings

Successfully applied to Hi-GAL surface-density data

Effectively distinguishes cores, filaments, and rings

Demonstrates potential for automated structure analysis

Abstract

Large scale surveys have brought about a revolution in astronomy. To analyse the resulting wealth of data, we need automated tools to identify, classify, and quantify the important underlying structures. We present here a method for classifying and quantifying a pixelated structure, based on its principal moments of inertia. The method enables us to automatically detect, and objectively compare, centrally condensed cores, elongated filaments and hollow rings. We illustrate the method by applying it to (i) observations of surface-density from Hi-GAL, and (ii) simulations of filament growth in a turbulent medium. We limit the discussion here to 2D data; in a future paper we will extend the method to 3D data.