Identifying the principal mechanism of star formation feedback
- Chong Li
- Rouyu Li
- Keping Qiu
- Marko Krco
- Di Li
- Hongchi Wang
- Xin Lyu
- Yan Duan
- Min Fang
- Xuepeng Chen
- Lile Wang
- Haoran Feng
- Shuinai Zhang
- Miaomiao Zhang
- Shaobo Zhang
- Yue Cao
- Yao Wang
- Yan Gong
- Fujun Du
- Zhiwei Chen
- Yang Su
- Yuehui Ma
- Yuchen Xing
- Yinghui Zheng
- Tianwei Zhang
- Shu Niu
- Chenrui Li
- Jiawei Liu
- Zhijun Zhang
- Yulian Guo
2026-09-04
Feedback from massive stars regulates the formation of next-generation stars and planets and thus shapes the evolution of galaxies, yet observational evidence capable of determining which mechanism dominates the feedback process has long been lacking. Here, we present a large-scale H I survey toward Orion A. With an unprecedented sensitivity and superior resolution, FAST (Five-hundred-meter Aperture Spherical radio Telescope) reveals a well-defined heart-shaped expanding H I bubble, enshrouding the well-known “Veil” bubble of ionized gas. The photoionization-driven and wind-driven gas expands at 10.9 and 13.8 kilometers per second, respectively, with a kinetic energy ratio of 1:2 assuming a spherical symmetry and a uniform H I -to-H 2 ratio. This first direct comparison within a single bubble shows that radiation does not dominate the feedback process as predicted by classical theories; instead, stellar winds contribute a comparable share of the injected kinetic energy.