%0 Generic %1 hopkins2017fire2 %A Hopkins, Philip F %A Wetzel, Andrew %A Keres, Dusan %A Faucher-Giguere, Claude-Andre %A Quataert, Eliot %A Boylan-Kolchin, Michael %A Murray, Norman %A Hayward, Christopher C. %A Garrison-Kimmel, Shea %A Hummels, Cameron %A Feldmann, Robert %A Torrey, Paul %A Ma, Xiangcheng %A Angles-Alcazar, Daniel %A Su, Kung-Yi %A Orr, Matthew %A Schmitz, Denise %A Escala, Ivanna %A Sanderson, Robyn %A Grudic, Michael Y. %A Hafen, Zachary %A Kim, Ji-Hoon %A Fitts, Alex %A Bullock, James S. %A Wheeler, Coral %A Chan, T. K. %A Elbert, Oliver D. %A Narananan, Desika %D 2017 %K fire numerical simulations %T FIRE-2 Simulations: Physics versus Numerics in Galaxy Formation %U http://arxiv.org/abs/1702.06148 %X The Feedback In Realistic Environments (FIRE) project explores the role of feedback in cosmological simulations of galaxy formation. Previous FIRE simulations used an identical source code (FIRE-1) for consistency. Now, motivated by the development of more accurate numerics (hydrodynamic solvers, gravitational softening, supernova coupling) and the exploration of new physics (e.g. magnetic fields), we introduce FIRE-2, an updated numerical implementation of FIRE physics for the GIZMO code. We run a suite of simulations and show FIRE-2 improvements do not qualitatively change galaxy-scale properties relative to FIRE-1. We then pursue an extensive study of numerics versus physics in galaxy simulations. Details of the star-formation (SF) algorithm, cooling physics, and chemistry have weak effects, provided that we include metal-line cooling and SF occurs at higher-than-mean densities. We present several new resolution criteria for high-resolution galaxy simulations. Most galaxy-scale properties are remarkably robust to the numerics that we test, provided that: (1) Toomre masses (cold disk scale heights) are resolved; (2) feedback coupling ensures conservation and isotropy, and (3) individual supernovae are time-resolved. As resolution increases, stellar masses and profiles converge first, followed by metal abundances and visual morphologies, then properties of winds and the circumgalactic medium. The central (~kpc) mass concentration of massive (L*) galaxies is sensitive to numerics, particularly how winds ejected into hot halos are trapped, mixed, and recycled into the galaxy. Multiple feedback mechanisms are required to reproduce observations: SNe regulate stellar masses; OB/AGB mass loss fuels late-time SF; radiative feedback suppresses instantaneous SFRs and accretion onto dwarfs. We provide tables, initial conditions, and the numerical algorithms required to reproduce our simulations.

@misc{hopkins2017fire2, abstract = {The Feedback In Realistic Environments (FIRE) project explores the role of feedback in cosmological simulations of galaxy formation. Previous FIRE simulations used an identical source code (FIRE-1) for consistency. Now, motivated by the development of more accurate numerics (hydrodynamic solvers, gravitational softening, supernova coupling) and the exploration of new physics (e.g. magnetic fields), we introduce FIRE-2, an updated numerical implementation of FIRE physics for the GIZMO code. We run a suite of simulations and show FIRE-2 improvements do not qualitatively change galaxy-scale properties relative to FIRE-1. We then pursue an extensive study of numerics versus physics in galaxy simulations. Details of the star-formation (SF) algorithm, cooling physics, and chemistry have weak effects, provided that we include metal-line cooling and SF occurs at higher-than-mean densities. We present several new resolution criteria for high-resolution galaxy simulations. Most galaxy-scale properties are remarkably robust to the numerics that we test, provided that: (1) Toomre masses (cold disk scale heights) are resolved; (2) feedback coupling ensures conservation and isotropy, and (3) individual supernovae are time-resolved. As resolution increases, stellar masses and profiles converge first, followed by metal abundances and visual morphologies, then properties of winds and the circumgalactic medium. The central (~kpc) mass concentration of massive (L*) galaxies is sensitive to numerics, particularly how winds ejected into hot halos are trapped, mixed, and recycled into the galaxy. Multiple feedback mechanisms are required to reproduce observations: SNe regulate stellar masses; OB/AGB mass loss fuels late-time SF; radiative feedback suppresses instantaneous SFRs and accretion onto dwarfs. We provide tables, initial conditions, and the numerical algorithms required to reproduce our simulations.}, added-at = {2017-02-22T10:35:22.000+0100}, author = {Hopkins, Philip F and Wetzel, Andrew and Keres, Dusan and Faucher-Giguere, Claude-Andre and Quataert, Eliot and Boylan-Kolchin, Michael and Murray, Norman and Hayward, Christopher C. and Garrison-Kimmel, Shea and Hummels, Cameron and Feldmann, Robert and Torrey, Paul and Ma, Xiangcheng and Angles-Alcazar, Daniel and Su, Kung-Yi and Orr, Matthew and Schmitz, Denise and Escala, Ivanna and Sanderson, Robyn and Grudic, Michael Y. and Hafen, Zachary and Kim, Ji-Hoon and Fitts, Alex and Bullock, James S. and Wheeler, Coral and Chan, T. K. and Elbert, Oliver D. and Narananan, Desika}, biburl = {https://www.bibsonomy.org/bibtex/2a724fa977439ce1856a74c773d3ddbf7/miki}, description = {[1702.06148] FIRE-2 Simulations: Physics versus Numerics in Galaxy Formation}, interhash = {9ee46ef6aefc34733bc836fb3c6b73c5}, intrahash = {a724fa977439ce1856a74c773d3ddbf7}, keywords = {fire numerical simulations}, note = {cite arxiv:1702.06148Comment: 66 pages, 39 figures. Simulation animations and visualizations available at http://www.tapir.caltech.edu/~phopkins/Site/animations and http://fire.northwestern.edu Paper includes complete FIRE algorithms and public ICs (http://www.tapir.caltech.edu/~phopkins/publicICs)}, timestamp = {2017-02-22T10:35:22.000+0100}, title = {FIRE-2 Simulations: Physics versus Numerics in Galaxy Formation}, url = {http://arxiv.org/abs/1702.06148}, year = 2017 }