RAMSES-RTZ: Non-Equilibrium Metal Chemistry and Cooling Coupled to On-The-Fly Radiation Hydrodynamics

Abstract

Emission and absorption lines from elements heavier than helium (metals) represent one of our strongest probes of galaxy formation physics across nearly all redshifts accessible to observations. The vast majority of simulations that model these metal lines often assume either collisional or photoionisation equilibrium, or a combination of the two. For the few simulations that have relaxed these assumptions, a redshift-dependent meta-galactic UV background or fixed spectrum is often used in the non-equilibrium photoionisation calculation, which is unlikely to be accurate in the interstellar medium where the gas can self-shield as well as in the high-redshift circumgalactic medium where locally emitted radiation may dominate over the UV background. In this work, we relax this final assumption by coupling the ionisation states of individual metals to the radiation hydrodynamics solver present in RAMSES-RT. Our chemical network follows radiative recombination, dielectronic recombination, collisional ionisation, photoionisation, and charge transfer and we use the ionisation states to compute non-equilibrium optically-thin metal-line cooling. The fiducial model solves for the ionisation states of C, N, O, Mg, Si, S, Fe, and Ne in addition to H, He, and H${}_2$, but can be easily extended for other ions. We provide interfaces to two different ODE solvers that are competitive in both speed and accuracy. The code has been benchmarked across a variety of gas conditions to reproduce results from CLOUDY when equilibrium is reached. We show an example isolated galaxy simulation with on-the-fly radiative transfer that demonstrates the utility of our code for translating between simulations and observations without the use of idealised photoionisation models.

18 pages, 14 figures, resubmitted to MNRAS after first referee report

References in corpus (35)

• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• The Circumgalactic Medium
• The effect of photo-ionization on the cooling rates of enriched, astrophysical plasmas
• A Unified Representation of Gas-Phase Element Depletions in the Interstellar Medium
• Galactic chemical evolution: Carbon through Zinc
• PyNeb: a new tool for analyzing emission lines. I. Code description and validation of results
• Understanding Galaxy Evolution through Emission Lines
• The effect of massive binaries on stellar populations and supernova progenitors
• Time-Dependent Ionization in Radiatively Cooling Gas
• Grackle: a Chemistry and Cooling Library for Astrophysics
• New fully empirical calibrations of strong-line metallicity indicators in star forming galaxies
• CHIANTI - an atomic database for emission lines - Paper XV: Version 9, improvements for the X-ray satellite lines
• Cosmological Radiative Transfer Codes Comparison Project I: The Static Density Field Tests
• Radiative recombination data for modelling dynamic finite-density plasmas
• A scheme for radiation pressure and photon diffusion with the M1 closure in RAMSES-RT
• Feedback-regulated star formation and escape of LyC photons from mini-haloes during reionisation
• Star formation at very low metallicity. I: Chemistry and cooling at low densities
• VINTERGATAN I: The origins of chemically, kinematically and structurally distinct discs in a simulated Milky Way-mass galaxy
• Metal and molecule cooling in simulations of structure formation
• Metal and molecule cooling in simulations of structure formation
• Galaxies that Shine: radiation-hydrodynamical simulations of disk galaxies
• Radiative cooling rates, ion fractions, molecule abundances and line emissivities including self-shielding and both local and metagalactic radiation fields
• The effect of magnetic fields on properties of the circumgalactic medium
• Probing Cosmic Dawn with Emission Lines: Predicting Infrared and Nebular Line Emission for ALMA and JWST
• Optically-Thin Spatially-Resolved Mg II Emission Maps the Escape of Ionizing Photons
• Non-equilibrium chemistry and cooling in the diffuse interstellar medium - II. Shielded gas
• Impact of Lyman alpha pressure on metal-poor dwarf galaxies
• Introducing SPHINX-MHD: The Impact of Primordial Magnetic Fields on the First Galaxies, Reionization, and the Global 21cm Signal
• UV absorption lines and their potential for tracing the Lyman continuum escape fraction
• New Methods for Identifying Lyman Continuum Leakers and Reionization-Epoch Analogues
• Tracing the simulated high-redshift circum-galactic medium with Lyman alpha emission
• An analytic model for OIII fine structure emission from high redshift galaxies
• Atomic Chemistry In Turbulent Astrophysical Media I: Effect of Atomic Cooling
• A new ionisation network and radiation transport module in PLUTO

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• The Pandora project. I: the impact of radiation and cosmic rays on baryonic and dark matter properties of dwarf galaxies
• Galaxies with grains: unraveling dust evolution and extinction curves with hydrodynamical simulations
• SPICE: the connection between cosmic reionisation and stellar feedback in the first galaxies
• Boosting galactic outflows with enhanced resolution
• DUSTiER (DUST in the Epoch of Reionization): dusty galaxies in cosmological radiation-hydrodynamical simulations of the Epoch of Reionization with RAMSES-CUDATON
• LIMFAST. II. Line Intensity Mapping as a Probe of High-Redshift Galaxy Formation
• The effects of local stellar radiation and dust depletion on non-equilibrium interstellar chemistry
• The THESAN-ZOOM project: central starbursts and inside-out quenching govern galaxy sizes in the early Universe
• Hybrid-chimes: A model for radiative cooling and the abundances of ions and molecules in simulations of galaxy formation
• Population III star formation in the presence of turbulence, magnetic fields and ionizing radiation feedback
• Spectral reconstruction for radiation hydrodynamic simulations of galaxy evolution
• Gas phase Elemental abundances in Molecular cloudS (GEMS). X. Observational effects of turbulence on the chemistry of molecular clouds
• The ionization structure and chemical history in isolated H II regions of dwarf galaxies with IFU I. The Sagittarius Dwarf Irregular Galaxy
• Effect of cosmic rays and ionizing radiation on observational ultraviolet plasma diagnostics in the circumgalactic medium
• Recovering the properties of the interstellar medium through integrated spectroscopy: application to the z~0 ECO volume-limited star-forming galaxy sample
• The ionization structure and chemical history in isolated H ii regions of dwarf galaxies with VIMOS/IFU II. The Leo A galaxy