Optimized Multi-Frequency Spectra for Applications in Radiative Feedback and Cosmological Reionization

Abstract

The recent implementation of radiative transfer algorithms in numerous hydrodynamics codes has led to a dramatic improvement in studies of feedback in various astrophysical environments. However, because of methodological limitations and computational expense, the spectra of radiation sources are generally sampled at only a few evenly-spaced discrete emission frequencies. Using one-dimensional radiative transfer calculations, we investigate the discrepancies in gas properties surrounding model stars and accreting black holes that arise solely due to spectral discretization. We find that even in the idealized case of a static and uniform density field, commonly used discretization schemes induce errors in the neutral fraction and temperature by factors of two to three on average, and by over an order of magnitude in certain column density regimes. The consequences are most severe for radiative feedback operating on large scales, dense clumps of gas, and media consisting of multiple chemical species. We have developed a method for optimally constructing discrete spectra, and show that for two test cases of interest, carefully chosen four-bin spectra can eliminate errors associated with frequency resolution to high precision. Applying these findings to a fully three-dimensional radiation-hydrodynamic simulation of the early universe, we find that the HII region around a primordial star is substantially altered in both size and morphology, corroborating the one-dimensional prediction that discrete spectral energy distributions can lead to sizable inaccuracies in the physical properties of a medium, and as a result, the subsequent evolution and observable signatures of objects embedded within it.

15 pages, 13 figures, 2 tables, accepted for publication in the Astrophysical Journal

References in corpus (16)

• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• Protostellar Feedback Halts the Growth of the First Stars in the Universe
• Accretion onto the First Stellar Mass Black Holes
• Radiative transfer simulations of cosmic reionization I: methodology and initial results
• Cosmological Radiative Transfer Codes Comparison Project I: The Static Density Field Tests
• The HII Region of a Primordial Star
• A radiative transfer scheme for cosmological reionization based on a local Eddington tensor
• Imprint of Inhomogeneous Hydrogen Reionization on the Temperature Distribution of the Intergalactic Medium
• Radiation Feedback and Fragmentation in Massive Protostellar Cores
• Ionization Front Instabilities in Primordial H II Regions
• An implementation of radiative transfer in the cosmological simulation code GADGET
• Time-evolution of ionization and heating around first stars and miniquasars
• The effect of intergalactic helium on hydrogen reionisation: implications for the sources of ionising photons at z > 6
• A New Moment Method for Continuum Radiative Transfer in Cosmological Reionization
• Constraints on First-Light Ionizing Sources from Optical Depth of the Cosmic Microwave Background
• Radiative transfer of energetic photons: X-rays and helium ionization in C2-Ray

Cited by in corpus (32)

• Enzo: An Adaptive Mesh Refinement Code for Astrophysics
• The First Billion Years Project: The escape fraction of ionizing photons in the epoch of reionization
• A scheme for radiation pressure and photon diffusion with the M1 closure in RAMSES-RT
• The THESAN project: properties of the intergalactic medium and its connection to Reionization-era galaxies
• Bayesian constraints on the global 21-cm signal from the Cosmic Dawn
• Constraining Non-Cold Dark Matter Models with the Global 21-cm Signal
• Radiative Feedback from high mass X-ray binaries on the formation of the first galaxies and early reionization
• Decoding the X-ray Properties of Pre-Reionization Era Sources
• First Insights into the ISM at $z>8$ with JWST: Possible Physical Implications of a High [O III]$\lambda 4363$/[O III]$\lambda 5007$
• Turbulence and cooling in galaxy cluster cores
• Interpreting the Global 21-cm Signal from High Redshifts. II. Parameter Estimation for Models of Galaxy Formation
• Quasar Ionization Front Lyα Emission in an Inhomogeneous Intergalactic Medium
• RAMSES-RTZ: Non-Equilibrium Metal Chemistry and Cooling Coupled to On-The-Fly Radiation Hydrodynamics
• Global 21-cm Signal Extraction from Foreground and Instrumental Effects II: Efficient and Self-Consistent Technique for Constraining Nonlinear Signal Models
• Rise of the First Super-Massive Stars
• Forming Super-Massive Black Hole Seeds under the Influence of a Nearby Anisotropic Multi-Frequency Source
• Radiation Hydrodynamical Simulations of the Birth of Intermediate-Mass Black Holes in the First Galaxies
• Fully-Coupled Simulation of Cosmic Reionization. I: Numerical Methods and Tests
• Urchin: A Reverse Ray Tracer for Astrophysical Applications
• Constraining Warm Dark Matter and Pop III stars with the Global 21-cm Signal
• Positive or Negative? The Impact of X-ray Feedback on the Formation of Direct Collapse Black Hole Seeds
• Using Artificial Neural Networks to extract the 21-cm Global Signal from the EDGES data
• Late-end reionization with ATON-HE: towards constraints from Lyman-$\alpha$ emitters observed with JWST
• Radiation-driven turbulent accretion onto massive black holes
• 21cm Global Signal Extraction: Extracting the 21cm Global Signal using Artificial Neural Networks
• Extracting the Global 21-cm signal from Cosmic Dawn and Epoch of Reionization in the presence of Foreground and Ionosphere
• Constraining structure formation using EDGES
• Massive black hole formation in Population III star clusters
• Simulation-Based Inference of the sky-averaged 21-cm signal from CD-EoR with REACH
• Direct Parameter Inference from Global EoR Signal with Bayesian Statistics
• Exploring Machine Learning Regression Models for Advancing Foreground Mitigation and Global 21cm Signal Parameter Extraction
• On the accuracy of posterior recovery with neural network emulators