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Oscar Agertz. Profile photo.

Oscar Agertz

Assistant Professor / Associate senior university lecturer / Wallenberg Academy Fellow

Oscar Agertz. Profile photo.

THE AGORA HIGH-RESOLUTION GALAXY SIMULATIONS COMPARISON PROJECT. II. ISOLATED DISK TEST

Author

  • Ji Hoon Kim
  • Oscar Agertz
  • Romain Teyssier
  • Michael J. Butler
  • Daniel Ceverino
  • Jun Hwan Choi
  • Robert Feldmann
  • Ben W. Keller
  • Alessandro Lupi
  • Thomas Quinn
  • Yves Revaz
  • Spencer Wallace
  • Nickolay Y. Gnedin
  • Samuel N. Leitner
  • Sijing Shen
  • Britton D. Smith
  • Robert Thompson
  • Matthew J. Turk
  • Tom Abel
  • Kenza S. Arraki
  • Samantha M. Benincasa
  • Sukanya Chakrabarti
  • Colin Degraf
  • Avishai Dekel
  • Nathan J. Goldbaum
  • Philip F. Hopkins
  • Cameron B. Hummels
  • Anatoly Klypin
  • Hui Li
  • Piero Madau
  • Nir Mandelker
  • Lucio Mayer
  • Kentaro Nagamine
  • Sarah Nickerson
  • Brian W. O'Shea
  • Joel R. Primack
  • Santi Roca-Fàbrega
  • Vadim Semenov
  • Ikkoh Shimizu
  • Christine M. Simpson
  • Keita Todoroki
  • James W. Wadsley
  • John H. Wise

Summary, in English

Using an isolated Milky Way-mass galaxy simulation, we compare results from nine state-of-the-art gravito-hydrodynamics codes widely used in the numerical community. We utilize the infrastructure we have built for the AGORA High-resolution Galaxy Simulations Comparison Project. This includes the common disk initial conditions, common physics models (e.g., radiative cooling and UV background by the standardized package Grackle) and common analysis toolkit yt, all of which are publicly available. Subgrid physics models such as Jeans pressure floor, star formation, supernova feedback energy, and metal production are carefully constrained across code platforms. With numerical accuracy that resolves the disk scale height, we find that the codes overall agree well with one another in many dimensions including: gas and stellar surface densities, rotation curves, velocity dispersions, density and temperature distribution functions, disk vertical heights, stellar clumps, star formation rates, and Kennicutt-Schmidt relations. Quantities such as velocity dispersions are very robust (agreement within a few tens of percent at all radii) while measures like newly formed stellar clump mass functions show more significant variation (difference by up to a factor of ∼3). Systematic differences exist, for example, between mesh-based and particle-based codes in the low-density region, and between more diffusive and less diffusive schemes in the high-density tail of the density distribution. Yet intrinsic code differences are generally small compared to the variations in numerical implementations of the common subgrid physics such as supernova feedback. Our experiment reassures that, if adequately designed in accordance with our proposed common parameters, results of a modern high-resolution galaxy formation simulation are more sensitive to input physics than to intrinsic differences in numerical schemes.

Department/s

  • Lund Observatory

Publishing year

2016-12-20

Language

English

Publication/Series

Astrophysical Journal

Volume

833

Issue

2

Document type

Journal article

Publisher

American Astronomical Society

Topic

  • Astronomy, Astrophysics and Cosmology

Keywords

  • galaxies: evolution
  • galaxies: formation
  • galaxies: kinematics and dynamics
  • ISM: structure
  • methods: numerical
  • theory

Status

Published

ISBN/ISSN/Other

  • ISSN: 0004-637X