Gibbs Point Process Model for Young Star Clusters in M33

Abstract

We demonstrate the power of Gibbs point process models from the spatial statistics literature when applied to studies of resolved galaxies. We conduct a rigorous analysis of the spatial distributions of objects in the star formation complexes of M33, including giant molecular clouds (GMCs) and young stellar cluster candidates (YSCCs). We choose a hierarchical model structure from GMCs to YSCCs based on the natural formation hierarchy between them. This approach circumvents the limitations of the empirical two-point correlation function analysis by naturally accounting for the inhomogeneity present in the distribution of YSCCs. We also investigate the effects of GMCs' properties on their spatial distributions. We confirm that the distribution of GMCs and YSCCs are highly correlated. We found that the spatial distributions of YSCCs reaches a peak of clustering pattern at ~250 pc scale compared to a Poisson process. This clustering mainly occurs in regions where the galactocentric distance >~4.5 kpc. Furthermore, the galactocentric distance of GMCs and their mass have strong positive effects on the correlation strength between GMCs and YSCCs. We outline some possible implications of these findings for our understanding of the cluster formation process.

MNRAS in press; 22 pages

References in corpus (9)

• The lifecycle of molecular clouds in nearby star-forming disc galaxies
• Fast and inefficient star formation due to short-lived molecular clouds and rapid feedback
• Markov Chain Monte Carlo Methods for Bayesian Data Analysis in Astronomy
• The Fractal Density Structure in Supersonic Isothermal Turbulence: Solenoidal versus Compressive Energy Injection
• Studying the YMC population of M83: how long clusters remain embedded, their interaction with the ISM and implications for GC formation theories
• The Spatial Relation between Young Star Clusters and Molecular Clouds in M 51 with LEGUS
• Kinematics and Structure of Star-forming Regions: Insights from Cold Collapse Models
• The molecular gas mass of M33
• Rise and fall of molecular clouds across the M33 disk

Cited by in corpus (2)

• Clusters, Clouds, and Correlations: Relating Young Clusters to Giant Molecular Clouds in M33 and M31
• Discovery of Two Ultra-Diffuse Galaxies with Unusually Bright Globular Cluster Luminosity Functions via a Mark-Dependently Thinned Point Process (MATHPOP)