PHANGS: constraining star formation time-scales using the spatial correlations of star clusters and giant molecular clouds
Abstract
In the hierarchical view of star formation, giant molecular clouds (GMCs) undergo fragmentation to form small-scale structures made up of stars and star clusters. Here we study the connection between young star clusters and cold gas across a range of extragalactic environments by combining the high resolution (1″) PHANGS-ALMA catalogue of GMCs with the star cluster catalogues from PHANGS-HST. The star clusters are spatially matched with the GMCs across a sample of 11 nearby star-forming galaxies with a range of galactic environments (centres, bars, spiral arms, etc.). We find that after 4 - 6 Myr the star clusters are no longer associated with any gas clouds. Additionally, we measure the autocorrelation of the star clusters and GMCs as well as their cross-correlation to quantify the fractal nature of hierarchical star formation. Young (≤10 Myr) star clusters are more strongly autocorrelated on kpc and smaller spatial scales than the $\gt \, 10$ Myr stellar populations, indicating that the hierarchical structure dissolves over time.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 2022
- DOI:
- 10.1093/mnras/stac2559
- arXiv:
- arXiv:2209.02872
- Bibcode:
- 2022MNRAS.516.4612T
- Keywords:
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- galaxies: star clusters;
- galaxies: star formation;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 15 pages, 11 figures, 4 tables. Accepted to MNRAS Sept 6 2022