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Forming disc galaxies in ΛCDM simulations

Governato, F. ; Willman, B. ; Mayer, L. ; Brooks, A. ; Stinson, G. ; Valenzuela, O. ; Wadsley, J. ; Quinn, T.

In: Monthly Notices of the Royal Astronomical Society, 2007, vol. 374, no. 4, p. 1479-1494

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    Title
    • Forming disc galaxies in ΛCDM simulations
    Author
    • Governato, F.. Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195, USA
    • Willman, B.. NYU, Department of Physics, 4 Washington Place, New York, NY 10003, USA
    • Mayer, L.. ETH, Ramistrasse 101, CH-8092 Zurich, Switzerland
    • Brooks, A.. Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195, USA
    • Stinson, G.. Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195, USA
    • Valenzuela, O.. Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195, USA
    • Wadsley, J.. Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L88 4M1, Canada
    • Quinn, T.. Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195, USA
    Document Type
    • Postprint
    OAI-PMH Identifier
    • oai:doc.rero.ch:293156
    Summary
    We used fully cosmological, high-resolution N-body + smooth particle hydrodynamic (SPH) simulations to follow the formation of disc galaxies with rotational velocities between 135 and 270 km s−1 in a Λ cold dark matter (CDM) universe. The simulations include gas cooling, star formation, the effects of a uniform ultraviolet (UV) background and a physically motivated description of feedback from supernovae (SNe). The host dark matter haloes have a spin and last major merger redshift typical of galaxy-sized haloes as measured in recent large-scale N-body simulations. The simulated galaxies form rotationally supported discs with realistic exponential scalelengths and fall on both the I band and baryonic Tully-Fisher relations. An extended stellar disc forms inside the Milky Way (MW)-sized halo immediately after the last major merger. The combination of UV background and SN feedback drastically reduces the number of visible satellites orbiting inside a MW-sized halo, bringing it in fair agreement with observations. Our simulations predict that the average age of a primary galaxy's stellar population decreases with mass, because feedback delays star formation in less massive galaxies. Galaxies have stellar masses and current star formation rates as a function of total mass that are in good agreement with observational data. We discuss how both high mass and force resolution and a realistic description of star formation and feedback are important ingredients to match the observed properties of galaxies