Star cluster formation in a turbulent molecular cloud self-regulated by photoionization feedback

Elena Gavagnin, Andreas Bleuler, Joakim Rosdahl, Romain Teyssier

Research output: Contribution to journalArticlepeer-review

70 Scopus citations


Most stars in the Galaxy are believed to be formed within star clusters from collapsing molecular clouds. However, the complete process of star formation, from the parent cloud to a gas-free star cluster, is still poorly understood. We perform radiation-hydrodynamical simulations of the collapse of a turbulent molecular cloud using the RAMSES-RT code. Stars are modelled using sink particles, from which we self-consistently follow the propagation of the ionizing radiation. We study how different feedback models affect the gas expulsion from the cloud and how they shape the final properties of the emerging star cluster.We find that the star formation efficiency is lower for stronger feedback models. Feedback also changes the high-mass end of the stellar mass function. Stronger feedback also allows the establishment of a lower density star cluster, which can maintain a virial or sub-virial state. In the absence of feedback, the star formation efficiency is very high, as well as the final stellar density. As a result, high-energy close encounters make the cluster evaporate quickly. Other indicators, such as mass segregation, statistics of multiple systems and escaping stars confirm this picture. Observations of young star clusters are in best agreement with our strong feedback simulation.

Original languageEnglish (US)
Pages (from-to)4155-4172
Number of pages18
JournalMonthly Notices of the Royal Astronomical Society
Issue number4
StatePublished - 2017
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • Galaxies: star clusters: general
  • Galaxies: star clusters: individual: (NGC 3603 YC, Arches)
  • Stars: formation
  • Stars: kinematics and dynamics -HII regions
  • Ultraviolet: stars


Dive into the research topics of 'Star cluster formation in a turbulent molecular cloud self-regulated by photoionization feedback'. Together they form a unique fingerprint.

Cite this