Effects of Spatial Discretization in Lyman-alpha Line Radiation Transfer Simulations

Abstract

We describe the addition of Lyman-alpha resonant line transfer to our dust continuum radiation transfer code SKIRT, verifying our implementation with published results for spherical problems and using some self-designed three-dimensional setups. We specifically test spatial discretization through various grid types, including hierarchical octree grids and unstructured Voronoi tessellations. We then use a radiation transfer post-processing model for one of the spiral galaxies produced by the Auriga cosmological zoom simulations to investigate the effect of spatial discretization on the synthetic observations. We find that the calculated Lyman-alpha line profiles exhibit an extraordinarily strong dependence on the type and resolution of the spatial grid, rendering the results untrustworthy at best. We attribute this effect to the large gradients in the hydrogen density distribution over small distances, which remain significantly under-resolved in the input model. We therefore argue that further research is needed to determine the required spatial resolution of a hydrodynamical simulation snapshot to enable meaningful Lyman-alpha line transfer post-processing.

Accepted for publication in The Astrophysical Journal

References in corpus (29)

• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• The EAGLE simulations of galaxy formation: calibration of subgrid physics and model variations
• Simba: Cosmological Simulations with Black Hole Growth and Feedback
• The Auriga Project: the properties and formation mechanisms of disc galaxies across cosmic time
• 3D Lyman-alpha radiation transfer. I. Understanding Lyman-alpha line profile morphologies
• SKIRT: an Advanced Dust Radiative Transfer Code with a User-Friendly Architecture
• Lyman Alpha Emitting Galaxies as a Probe of Reionization
• Sunrise: Polychromatic Dust Radiative Transfer in Arbitrary Geometries
• Modelling the Pan-Spectral Energy Distribution of Starburst Galaxies: IV The Controlling Parameters of the Starburst SED
• Environmental Dependence of the Kennicutt-Schmidt Relation in Galaxies
• Observations of the Lyman-$\alpha$ Universe
• Synthetic Galaxy Images and Spectra from the Illustris Simulation
• Dust attenuation, dust emission, and dust temperature in galaxies at z>=5: a view from the FIRE-2 simulations
• Far-infrared and dust properties of present-day galaxies in the EAGLE simulations
• Atomic and molecular gas in IllustrisTNG galaxies at low redshift
• Lyman alpha Radiative Transfer in Cosmological Simulations using Adaptive Mesh Refinement
• The distribution of interstellar dust in CALIFA edge-on galaxies via oligochromatic radiative transfer fitting
• Lyman alpha Emitting Galaxies in the Nearby Universe
• The Lyman-alpha signature of the first galaxies
• Properties of HI discs in the Auriga cosmological simulations
• The Polarization of Scattered Lyman Alpha Radiation Around High-Redshift Galaxies
• Lyα emission from galaxies in the Epoch of Reionization
• Large and small-scale structures and the dust energy balance problem in spiral galaxies
• Ly-alpha Radiative Transfer: Monte-Carlo Simulation of the Wouthuysen-Field Effect
• The impact of modified gravity on the Sunyaev-Zel'dovich effect
• Infrared luminosity functions and dust mass functions in the EAGLE simulation
• The scattering order problem in Monte Carlo radiative transfer
• Radiative transfer in disc galaxies $-$ V. The accuracy of the KB approximation
• SEURAT: SPH scheme extended with ultraviolet line radiative transfer

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• TODDLERS: A new UV-mm emission library for star-forming regions. 1. Integration with SKIRT and public release
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• TODDLERS: A New UV to Millimeter Emission Library for Star-Forming Regions. II. Star Formation Rate Indicators Using Auriga Zoom Simulations