Study Explores Factors Behind Star Formation Cessation in Nearby Galaxies

A recent study titled "On the Origin of Quenched but Gas-rich Regions at Kiloparsec Scales in Nearby Galaxies" investigates the factors contributing to the cessation of star formation in specific regions of galaxies. The research, conducted by Tao Jing and Cheng Li, utilizes resolved spectroscopy from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey to analyze isolated disk galaxies. The study identifies quenched regions, areas where star formation has stopped, and categorizes them into gas-rich quenched regions (GRQRs) and gas-poor quenched regions (GPQRs) based on the surface density of cold gas.

Key findings indicate that both GRQRs and GPQRs are typically found in non-active galactic nucleus (non-AGN) galaxies with high mass (greater than 10 billion solar masses) and red colors. These regions also exhibit low star formation rates and high central densities. The study highlights that the conditions leading to quenching in gas-rich regions are largely independent of the global properties of the galaxies.

The researchers employed random forest classifiers and regressors to predict quenching using 15 local and global properties. The surface density of stars (Σ_*) emerged as the most significant factor for quenching, particularly in GRQRs. The study suggests that low-mass hot evolved stars play a crucial role in these quenched regions by providing substantial radiation pressure to prevent gas from collapsing under gravity.

This research provides new insights into the mechanisms behind star formation cessation in galaxies and underscores the importance of local properties over global characteristics in these processes.

For more detailed information, the full study can be accessed at arXiv:2408.12348.