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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 observed diversity of star formation efficiencies in Giant Molecular Clouds

Author

  • Kearn Grisdale
  • Oscar Agertz
  • Florent Renaud
  • Alessandro B. Romeo
  • Julien Devriendt
  • Adrianne Slyz

Summary, in English

Observations find a median star formation efficiency per free-fall time in Milky Way Giant Molecular Clouds (GMCs) of the order of ϵff∼1 per cent with dispersions of ∼0.5dex⁠. The origin of this scatter in ϵff is still debated and difficult to reproduce with analytical models. We track the formation, evolution and destruction of GMCs in a hydrodynamical simulation of a Milky Way-like galaxy and by deriving cloud properties in an observationally motivated way, we measure the distribution of star formation efficiencies which are in excellent agreement with observations. We find no significant link between ϵff and any measured global property of GMCs (e.g. gas mass, velocity dispersion). Instead, a wide range of efficiencies exist in the entire parameter space. From the cloud evolutionary tracks, we find that each cloud follows a unique evolutionary path which gives rise to a wide diversity in all properties. We argue that it is this diversity in cloud properties, above everything else, that results in the dispersion of ϵff.

Department/s

  • eSSENCE: The e-Science Collaboration
  • Lund Observatory

Publishing year

2019-07-01

Language

English

Pages

5482-5491

Publication/Series

Monthly Notices of the Royal Astronomical Society

Volume

486

Issue

4

Document type

Journal article

Publisher

Oxford University Press

Topic

  • Astronomy, Astrophysics and Cosmology
  • Polymer Chemistry

Keywords

  • ISM: clouds, galaxies: evolution, galaxies: ISM, galaxies: star formation, galaxies:structure, Astrophysics - Astrophysics of Galaxies

Status

Published

ISBN/ISSN/Other

  • ISSN: 1365-2966