# Effects of infall and outflow on massive star-forming regions

## TL;DR

This study analyzes the evolution of outflows in massive star-forming regions, revealing how outflow activity varies across different stages and impacts the environment, with implications for star formation processes.

## Contribution

It provides a comprehensive statistical analysis of outflow detection rates across evolutionary stages and their relationship with infall, masers, and environmental influence.

## Key findings

- Outflow detection rate peaks at the protostellar and H II stages.
- Outflows are less common during the PDR stage, indicating they are being switched off.
- Outflow activity influences the local environment and diminishes over time.

## Abstract

A total of 188 high-mass outflows have been identified from a sample of 694 clumps from the Millimetre Astronomy Legacy Team 90 GHz survey, representing a detection rate of approximately 27%. The detection rate of outflows increases from the protostellar stage to the H II stage, but decreases again at the photodissociation (PDR) stage suggesting that outflows are being switched off during the PDR stage. An intimate relationship is found between outflow action and the presence of masers, and water masers appear together with 6.7 GHz methanol masers. Comparing the infall detection rate of clumps with and without outflows, we find that outflow candidates have a lower infall detection rate. Finally, we find that outflow action has some influence on the local environment and the clump itself, and this influence decreases with increasing evolutionary time as the outflow action ceases.