AI Insight
This study uses high-resolution radiation magnetohydrodynamic simulations to compare star formation in the Milky Way's Central Molecular Zone (CMZ) with the solar neighborhood. The research reveals that the CMZ's extreme conditions—particularly strong orbital shear and short orbital times—cause young stars to rapidly separate from their parent gas clouds, preventing the combined effects of stellar radiation and supernovae from efficiently disrupting molecular clouds. This fundamentally alters how stellar feedback regulates star formation in the CMZ, where feedback acts more as a background turbulence source rather than directly destroying molecular clouds.
Why it matters
Understanding star formation in extreme environments like the CMZ is crucial for developing universal theories of how stars form across different galactic regions. These findings challenge classical star formation models and have implications for interpreting observations of star formation in galactic centers and other high-density regions throughout the universe.
arXiv:2512.09981v2 Announce Type: replace
Abstract: The Central Molecular Zone (CMZ) is an extreme star formation environment, characterized by higher density, higher turbulence, stronger orbital shear, and stronger magnetic field strength than the solar neighborhood. It is still debated whether classical theories of star formation hold within this extreme environment. In order to assess the impact of these different conditions on the interstellar medium (ISM) and on star formation, we present radiation magnetohydrodynamic {sc arepo} simulations of a Milky Way-type galaxy. We set up a high-resolution ($M_{rm cell}=20$~Msun) region in a ring around the solar radius and in the barred region of the Galaxy to have a coherent comparison between the CMZ and the solar neighborhood. Although the high densities and strong levels of turbulence affect star formation and feedback, a key difference in the regulation of star formation between the two environments comes from the short orbital times and the strong shear in the CMZ. In particular, we highlight the role of the quick dynamical decoupling of stars and gas, which leads to periodic re-embedding events in the early lifetimes of radiating O stars. Young stellar associations are efficiently sheared apart, such that the ISM is deprived of the compounding effect of radiation and supernovae in disrupting molecular clouds. This dramatically changes the evolution of giant molecular clouds and how feedback can regulate star formation in the CMZ. Stellar feedback is no longer directly coupled to the molecular cloud from which they formed, and no strong and disruptive superbubbles can develop. The feedback instead rather acts as a background source of turbulence.