A moment-based hierarchy (zeroth, first, second order) diagnoses convergence of Lyman-alpha MCRT momentum-transfer estimators, showing that core-skipping biases internal forces and that statistical precision, cost, and physical accuracy must be evaluated separately.
The Lyman-alpha signature of the first galaxies
4 Pith papers cite this work. Polarity classification is still indexing.
4
Pith papers citing it
abstract
We present the Cosmic Lyman-$\alpha$ Transfer code (COLT), a massively parallel Monte-Carlo radiative transfer code, to simulate Lyman-$\alpha$ (Ly$\alpha$) resonant scattering through neutral hydrogen as a probe of the first galaxies. We explore the interaction of centrally produced Ly$\alpha$ radiation with the host galactic environment. Ly$\alpha$ photons emitted from the luminous starburst region escape with characteristic features in the line profile depending on the density distribution, ionization structure, and bulk velocity fields. For example, anisotropic ionization exhibits a tall peak close to line centre with a skewed tail that drops off gradually. Idealized models of first galaxies explore the effect of mass, anisotropic H II regions, and radiation pressure driven winds on Ly$\alpha$ observables. We employ mesh refinement to resolve critical structures. We also post-process an ab initio cosmological simulation and examine images captured at various escape distances within the 1 Mpc$^3$ comoving volume. Finally, we discuss the emergent spectra and surface brightness profiles of these objects in the context of high-$z$ observations. The first galaxies will likely be observed through the red damping wing of the Ly$\alpha$ line. Observations will be biased toward galaxies with an intrinsic red peak located far from line centre that reside in extensive H II super bubbles, which allows Hubble flow to sufficiently redshift photons away from line centre and facilitate transmission through the intergalactic medium (IGM). Even with gravitational lensing to boost the luminosity this preliminary work indicates that Ly$\alpha$ emission from stellar clusters within haloes of $M_{\rm vir}<10^9~{\rm M}_\odot$ is generally too faint to be detected by the James Webb Space Telescope (JWST).
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astro-ph.GA 4representative citing papers
Analytical and fitting formulae for Lyα radiative-transfer spectra under slab, cylindrical and spherical geometries, including recoil and constant velocity gradients, verified against Monte Carlo simulations.
A source 660 million years after the Big Bang is interpreted as a black hole star with a dust-free dense gas atmosphere, implying Little Red Dots have black hole masses overestimated by orders of magnitude.
Deep JWST spectroscopy of Maisie's Galaxy at z=11.4 reveals moderate star formation, metallicity, and ionization consistent with a typical galaxy on the early star-formation main sequence rather than an extreme source.
citing papers explorer
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Force convergence in Monte Carlo Lyman-alpha radiative transfer
A moment-based hierarchy (zeroth, first, second order) diagnoses convergence of Lyman-alpha MCRT momentum-transfer estimators, showing that core-skipping biases internal forces and that statistical precision, cost, and physical accuracy must be evaluated separately.
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Analytical and fitting formulae for solutions to Lyman-alpha radiative transfer equations: the effects of geometry, recoil, and velocity gradients
Analytical and fitting formulae for Lyα radiative-transfer spectra under slab, cylindrical and spherical geometries, including recoil and constant velocity gradients, verified against Monte Carlo simulations.
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A "Black Hole Star" Reveals the Remarkable Gas-Enshrouded Hearts of the Little Red Dots
A source 660 million years after the Big Bang is interpreted as a black hole star with a dust-free dense gas atmosphere, implying Little Red Dots have black hole masses overestimated by orders of magnitude.
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Deep Spectroscopic Follow-Up of Maisie's Galaxy -- A Typical Galaxy in the Early Universe
Deep JWST spectroscopy of Maisie's Galaxy at z=11.4 reveals moderate star formation, metallicity, and ionization consistent with a typical galaxy on the early star-formation main sequence rather than an extreme source.