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EDGE : A new approach to suppressing numerical diffusion in adaptive mesh simulations of galaxy formation

Pontzen, Andrew ; Rey, Martin P. LU ; Cadiou, Corentin ; Agertz, Oscar LU ; Teyssier, Romain ; Read, Justin and Orkney, M. D. (2021) In Monthly Notices of the Royal Astronomical Society 501(2). p.1755-1765
Abstract

We introduce a new method to mitigate numerical diffusion in adaptive mesh refinement (AMR) simulations of cosmological galaxy formation, and study its impact on a simulated dwarf galaxy as part of the 'EDGE' project. The target galaxy has a maximum circular velocity of 21 km s-1 but evolves in a region that is moving at up to 90 km s-1 relative to the hydrodynamic grid. In the absence of any mitigation, diffusion softens the filaments feeding our galaxy. As a result, gas is unphysically held in the circumgalactic medium around the galaxy for 320 Myr, delaying the onset of star formation until cooling and collapse eventually triggers an initial starburst at z = 9. Using genetic modification, we produce 'velocity-zeroed' initial... (More)

We introduce a new method to mitigate numerical diffusion in adaptive mesh refinement (AMR) simulations of cosmological galaxy formation, and study its impact on a simulated dwarf galaxy as part of the 'EDGE' project. The target galaxy has a maximum circular velocity of 21 km s-1 but evolves in a region that is moving at up to 90 km s-1 relative to the hydrodynamic grid. In the absence of any mitigation, diffusion softens the filaments feeding our galaxy. As a result, gas is unphysically held in the circumgalactic medium around the galaxy for 320 Myr, delaying the onset of star formation until cooling and collapse eventually triggers an initial starburst at z = 9. Using genetic modification, we produce 'velocity-zeroed' initial conditions in which the grid-relative streaming is strongly suppressed; by design, the change does not significantly modify the large-scale structure or dark matter accretion history. The resulting simulation recovers a more physical, gradual onset of star formation starting at z = 17. While the final stellar masses are nearly consistent (4.8 × 106 M⊙ and 4.4 × 106 M⊙ for unmodified and velocity-zeroed, respectively), the dynamical and morphological structure of the z = 0 dwarf galaxies are markedly different due to the contrasting histories. Our approach to diffusion suppression is suitable for any AMR zoom cosmological galaxy formation simulations, and is especially recommended for those of small galaxies at high redshift.

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author
; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
cosmology: miscellaneous, galaxies: dwarf, methods: numerical
in
Monthly Notices of the Royal Astronomical Society
volume
501
issue
2
pages
11 pages
publisher
Oxford University Press
external identifiers
  • scopus:85100301562
ISSN
0035-8711
DOI
10.1093/mnras/staa3645
language
English
LU publication?
yes
id
359e8c09-6688-471f-ad84-b4da2af9a987
date added to LUP
2021-02-11 09:29:00
date last changed
2024-04-18 01:48:56
@article{359e8c09-6688-471f-ad84-b4da2af9a987,
  abstract     = {{<p>We introduce a new method to mitigate numerical diffusion in adaptive mesh refinement (AMR) simulations of cosmological galaxy formation, and study its impact on a simulated dwarf galaxy as part of the 'EDGE' project. The target galaxy has a maximum circular velocity of 21 km s-1 but evolves in a region that is moving at up to 90 km s-1 relative to the hydrodynamic grid. In the absence of any mitigation, diffusion softens the filaments feeding our galaxy. As a result, gas is unphysically held in the circumgalactic medium around the galaxy for 320 Myr, delaying the onset of star formation until cooling and collapse eventually triggers an initial starburst at z = 9. Using genetic modification, we produce 'velocity-zeroed' initial conditions in which the grid-relative streaming is strongly suppressed; by design, the change does not significantly modify the large-scale structure or dark matter accretion history. The resulting simulation recovers a more physical, gradual onset of star formation starting at z = 17. While the final stellar masses are nearly consistent (4.8 × 106 M⊙ and 4.4 × 106 M⊙ for unmodified and velocity-zeroed, respectively), the dynamical and morphological structure of the z = 0 dwarf galaxies are markedly different due to the contrasting histories. Our approach to diffusion suppression is suitable for any AMR zoom cosmological galaxy formation simulations, and is especially recommended for those of small galaxies at high redshift. </p>}},
  author       = {{Pontzen, Andrew and Rey, Martin P. and Cadiou, Corentin and Agertz, Oscar and Teyssier, Romain and Read, Justin and Orkney, M. D.}},
  issn         = {{0035-8711}},
  keywords     = {{cosmology: miscellaneous; galaxies: dwarf; methods: numerical}},
  language     = {{eng}},
  number       = {{2}},
  pages        = {{1755--1765}},
  publisher    = {{Oxford University Press}},
  series       = {{Monthly Notices of the Royal Astronomical Society}},
  title        = {{EDGE : A new approach to suppressing numerical diffusion in adaptive mesh simulations of galaxy formation}},
  url          = {{http://dx.doi.org/10.1093/mnras/staa3645}},
  doi          = {{10.1093/mnras/staa3645}},
  volume       = {{501}},
  year         = {{2021}},
}