Gas around galaxy haloes: methodology comparisons using hydrodynamical simulations of the intergalactic medium

We perform cosmological simulations of the intergalactic medium (IGM) at redshift z ∼ 3 using the numerical gravity-hydrodynamics codes gadget-3 and enzo for the purpose of modelling the gaseous environments of galaxies. We identify haloes in the simulations using three different algorithms. Differe...

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Main Authors: Meiksin, Avery, Bolton, James S., Tittley, Eric R.
Format: Article
Published: Oxford University Press 2014
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Online Access:https://eprints.nottingham.ac.uk/42507/
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author Meiksin, Avery
Bolton, James S.
Tittley, Eric R.
author_facet Meiksin, Avery
Bolton, James S.
Tittley, Eric R.
author_sort Meiksin, Avery
building Nottingham Research Data Repository
collection Online Access
description We perform cosmological simulations of the intergalactic medium (IGM) at redshift z ∼ 3 using the numerical gravity-hydrodynamics codes gadget-3 and enzo for the purpose of modelling the gaseous environments of galaxies. We identify haloes in the simulations using three different algorithms. Different rank orderings of the haloes by mass result, introducing a limiting factor, in identifying haloes with observed galaxies. We also compare the physical properties of the gas between the two codes, focusing primarily on the gas outside the virial radius, motivated by recent H i absorption measurements of the gas around z ∼ 2–3 galaxies. The internal dispersion velocities of the gas in the haloes have converged for a box size of 30 comoving Mpc, but the centre-of-mass peculiar velocities of the haloes have not up to a box size of 60 comoving Mpc. The density and temperature of the gas within the instantaneous turn-around radii of the haloes are adequately captured for box sizes of 30 Mpc on a side, but the results are highly sensitive to the treatment of unresolved, rapidly cooling gas, with the gas mass fraction within the virial radius severely depleted by star formation in the gadget-3 simulations. Convergence of the gas peculiar velocity field on large scales requires a box size of at least 60 Mpc. Outside the turn-around radius, the physical state of the gas agrees to 30 per cent or better both with box size and between simulation methods. We conclude that generic IGM simulations make accurate predictions for the intergalactic gas properties beyond the halo turn-around radii, but the gas properties on smaller scales are highly dependent on star formation and feedback implementations.
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spelling nottingham-425072020-05-04T16:55:31Z https://eprints.nottingham.ac.uk/42507/ Gas around galaxy haloes: methodology comparisons using hydrodynamical simulations of the intergalactic medium Meiksin, Avery Bolton, James S. Tittley, Eric R. We perform cosmological simulations of the intergalactic medium (IGM) at redshift z ∼ 3 using the numerical gravity-hydrodynamics codes gadget-3 and enzo for the purpose of modelling the gaseous environments of galaxies. We identify haloes in the simulations using three different algorithms. Different rank orderings of the haloes by mass result, introducing a limiting factor, in identifying haloes with observed galaxies. We also compare the physical properties of the gas between the two codes, focusing primarily on the gas outside the virial radius, motivated by recent H i absorption measurements of the gas around z ∼ 2–3 galaxies. The internal dispersion velocities of the gas in the haloes have converged for a box size of 30 comoving Mpc, but the centre-of-mass peculiar velocities of the haloes have not up to a box size of 60 comoving Mpc. The density and temperature of the gas within the instantaneous turn-around radii of the haloes are adequately captured for box sizes of 30 Mpc on a side, but the results are highly sensitive to the treatment of unresolved, rapidly cooling gas, with the gas mass fraction within the virial radius severely depleted by star formation in the gadget-3 simulations. Convergence of the gas peculiar velocity field on large scales requires a box size of at least 60 Mpc. Outside the turn-around radius, the physical state of the gas agrees to 30 per cent or better both with box size and between simulation methods. We conclude that generic IGM simulations make accurate predictions for the intergalactic gas properties beyond the halo turn-around radii, but the gas properties on smaller scales are highly dependent on star formation and feedback implementations. Oxford University Press 2014-10-18 Article PeerReviewed Meiksin, Avery, Bolton, James S. and Tittley, Eric R. (2014) Gas around galaxy haloes: methodology comparisons using hydrodynamical simulations of the intergalactic medium. Monthly Notices of the Royal Astronomical Society, 445 (3). pp. 2462-2475. ISSN 1365-2966 methods: numerical galaxies: formation intergalactic medium large-scale structure of Universe https://academic.oup.com/mnras/article/445/3/2462/1050611/Gas-around-galaxy-haloes-methodology-comparisons doi:10.1093/mnras/stu1938 doi:10.1093/mnras/stu1938
spellingShingle methods: numerical
galaxies: formation
intergalactic medium
large-scale structure of Universe
Meiksin, Avery
Bolton, James S.
Tittley, Eric R.
Gas around galaxy haloes: methodology comparisons using hydrodynamical simulations of the intergalactic medium
title Gas around galaxy haloes: methodology comparisons using hydrodynamical simulations of the intergalactic medium
title_full Gas around galaxy haloes: methodology comparisons using hydrodynamical simulations of the intergalactic medium
title_fullStr Gas around galaxy haloes: methodology comparisons using hydrodynamical simulations of the intergalactic medium
title_full_unstemmed Gas around galaxy haloes: methodology comparisons using hydrodynamical simulations of the intergalactic medium
title_short Gas around galaxy haloes: methodology comparisons using hydrodynamical simulations of the intergalactic medium
title_sort gas around galaxy haloes: methodology comparisons using hydrodynamical simulations of the intergalactic medium
topic methods: numerical
galaxies: formation
intergalactic medium
large-scale structure of Universe
url https://eprints.nottingham.ac.uk/42507/
https://eprints.nottingham.ac.uk/42507/
https://eprints.nottingham.ac.uk/42507/