Abstract

Contributed Talk - Splinter GalaxyEvol

Thursday, 12 September 2024, 17:21   (S21)

Quantifying GMC spatial distribution with two-point correlation function

Hao He
Argelander-Institut für Astronomie

Giant molecular clouds are the major sites of star formation and therefore crucial to understanding of star formation process. While the properties and evolutionary stage of individual GMCs have been extensively studied, the organization of GMCs across different spatial scales, which involves hierachical gravitational collapse and various dynamical process, is less well understood. In this study, we present the noval application of two-point correlation function on the homogenious GMC catalogs (~ 1,8000 GMCs) in 52 PHANGS galaxies to quantify GMC spatial distribution. We find that the average GMC spacing (distance between two nearest GMCs) has a strong anti-correlation with kpc-scale CO intensity, which suggests GMC clustering is dependent on large-scale CO distribution. By removing the contribution from the large-scale structure, we only find a moderate clustering (20% excess above the random source catalog) of GMCs with no preferred scale. However, the clustering behavior varies among different environments. Specifically, GMCs in spiral arms show a significant clustering (100% excess) at ~300 pc, which is comparable to the median of Jeans length in our sample. These comparisons suggest that GMC collapse in different environments might be dominated by different physical mechanisms.