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Oscar Agertz. Profile photo.

Oscar Agertz

Assistant Professor / Associate senior university lecturer / Wallenberg Academy Fellow

Oscar Agertz. Profile photo.

On the interplay between star formation and feedback in galaxy formation simulations

Author

  • Oscar Agertz
  • Andrey V. Kravtsov

Summary, in English

We investigate the star formation-feedback cycle in cosmological galaxy formation simulations, focusing on the progenitors of Milky Way (MW)-sized galaxies. We find that in order to reproduce key properties of the MW progenitors, such as semi-empirically derived star formation histories (SFHs) and the shape of rotation curves, our implementation of star formation and stellar feedback requires (1) a combination of local early momentum feedback via radiation pressure and stellar winds, and subsequent efficient supernovae feedback, and (2) an efficacy of feedback that results in the self-regulation of the global star formation rate on kiloparsec scales. We show that such feedback-driven self-regulation is achieved globally for a local star formation efficiency per free fall time of . Although this value is larger that the value usually inferred from the Kennicutt-Schmidt (KS) relation, we show that it is consistent with direct observational estimates of in molecular clouds. Moreover, we show that simulations with local efficiency of reproduce the global observed KS relation. Such simulations also reproduce the cosmic SFH of the MW-sized galaxies and satisfy a number of other observational constraints. Conversely, we find that simulations that a priori assume an inefficient mode of star formation, instead of achieving it via stellar feedback regulation, fail to produce sufficiently vigorous outflows and do not reproduce observations. This illustrates the importance of understanding the complex interplay between star formation and feedback, and the detailed processes that contribute to the feedback-regulated formation of galaxies.

Publishing year

2015-05-01

Language

English

Publication/Series

Astrophysical Journal

Volume

804

Issue

1

Document type

Journal article

Publisher

American Astronomical Society

Topic

  • Astronomy, Astrophysics and Cosmology

Keywords

  • galaxies: evolution
  • galaxies: formation
  • galaxies: high-redshift
  • galaxies: star formation
  • galaxies: stellar content
  • methods: numerical

Status

Published

ISBN/ISSN/Other

  • ISSN: 0004-637X