Dust-UV offsets in high-redshift galaxies in the Cosmic Dawn III simulation

Abstract

Recent observations have revealed puzzling spatial disparities between ALMA dust continuum and UV emission as seen by HST and JWST in galaxies at $z=5-7$ (e.g. ALPINE and REBELS surveys), compelling us to propose a physical interpretation of such offsets. We investigate these offsets using the Cosmic Dawn III (CoDa III) simulation, a state-of-the-art fully coupled radiation-hydrodynamics cosmological simulation, which incorporates a dynamical dust model. First of all, we find that our simulated dust masses, while calibrated to match observed ones, yield unrealistically large UV attenuations. In fact, the bright-end galaxy UV Luminosity function is best reproduced using only 7.5\% of the dust content of CoDa III galaxies. With this recalibration, we obtain populations of massive galaxies matching ALPINE and REBELS magnitudes and UV slopes, but with smaller dust masses than observed. In this framework, we also find significant dust-UV offsets in massive, UV-bright galaxies (${\mathrm{M}}_{\mathrm{DM}}>10^{11.5}$ M${}_{\odot }$, M${}_{\ast }>10^{10}$ M${}_{\odot }$, M${}_{AB1600}<-21.5$), reaching up to $\sim 2$ pkpc for the most massive systems. Our analysis reveals that these offsets primarily result from severe dust extinction in galactic centers rather than a misalignment between dust and stellar mass distributions. At the spatial resolution of CoDa III (1.65 pkpc at z=6), the dust remains in majority well-aligned with the bulk stellar component, and we predict the dust continuum should therefore align well with the stellar rest-frame NIR component, less affected by dust attenuation. This study highlights the importance of dust in shaping the appearance of early galaxies at UV wavelengths, even as early as in the Epoch of Reionization.

12 pages, 9 figures, first revision submitted to A&A

References in corpus (63)

• Array Programming with NumPy
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Interstellar Dust Grains
• Cosmological Hydrodynamics with Adaptive Mesh Refinement: a new high resolution code called RAMSES
• In the Beginning: The First Sources of Light and the Reionization of the Universe
• Binary Population and Spectral Synthesis Version 2.1: construction, observational verification and new results
• Infrared Emission from Interstellar Dust. I. Stochastic Heating of Small Grains
• New Determinations of the UV Luminosity Functions from z~9 to z~2 show a remarkable consistency with halo growth and a constant star formation efficiency
• SKIRT: an Advanced Dust Radiative Transfer Code with a User-Friendly Architecture
• Hydrogen reionisation ends by $z=5.3$: Lyman-$\alpha$ optical depth measured by the XQR-30 sample
• The halo mass function through the cosmic ages
• The ALPINE-ALMA [CII] Survey: data processing, catalogs, and statistical source properties
• Cosmic Dawn (CoDa): the First Radiation-Hydrodynamics Simulation of Reionization and Galaxy Formation in the Local Universe
• Reionization Era Bright Emission Line Survey: Selection and Characterization of Luminous Interstellar Medium Reservoirs in the z>6.5 Universe
• The Evolution of the IR Luminosity Function and Dust-obscured Star Formation in the Last 13 Billion Years
• The Dust-to-Gas and Dust-to-Metals Ratio in Galaxies from z=0-6
• Cosmic Reionization On Computers I. Design and Calibration of Simulations
• The VLA-COSMOS 3 GHz Large Project: The cosmic star formation history since z~5
• The overdensity and masses of the friends-of-friends halos and universality of the halo mass function
• Dust Formation in Milky Way-like Galaxies
• The dust mass in z > 6 normal star forming galaxies
• A radiative transfer scheme for cosmological reionization based on a local Eddington tensor
• Galaxy Simulation with Dust Formation and Destruction
• Dusty galaxies in the Epoch of Reionization: simulations
• The REBELS ALMA Survey: cosmic dust temperature evolution out to z $\sim$ 7
• A Theory for the Variation of Dust Attenuation Laws in Galaxies
• The ALMA REBELS Survey: Dust Continuum Detections at z > 6.5
• The THESAN project: properties of the intergalactic medium and its connection to Reionization-era galaxies
• The ALPINE-ALMA [CII] survey: Dust attenuation properties and obscured star formation at z~4.4-5.8
• The ALMA REBELS Survey: the dust content of $z\sim 7$ Lyman Break Galaxies
• The assembly of dusty galaxies at $z\ge 4$: statistical properties
• Coevolution of dust, gas, and stars in galaxies - I. Spatial distributions and scaling-relations of dust and molecular hydrogen
• The ALMA REBELS Survey. Epoch of Reionization giants: properties of dusty galaxies at $z\approx 7$
• The ALPINE-ALMA [CII] Survey: Obscured Star Formation Rate Density and Main Sequence of star-forming galaxies at z>4
• Predictions for the spatial distribution of the dust continuum emission in 1<z<5 star-forming galaxies
• Introducing the FirstLight project: UV luminosity function and scaling relations of primeval galaxies
• LoTSS jellyfish galaxies: I. Radio tails in low redshift clusters
• Accurate dust temperature determination in a $z=7.13$ galaxy
• Warm dust in high-z galaxies: origin and implications
• Early results from GLASS-JWST. V: the first rest-frame optical size-luminosity relation of galaxies at $z>7$
• RASCAS: RAdiation SCattering in Astrophysical Simulations
• Powderday: Dust Radiative Transfer for Galaxy Simulations
• The discovery of rest-frame UV colour gradients and a diversity of dust morphologies in bright z ~ 7 Lyman-break galaxies
• The short ionizing photon mean free path at z=6 in Cosmic Dawn III, a new fully-coupled radiation-hydrodynamical simulation of the Epoch of Reionization
• Cosmic Reionization On Computers: The Faint End of the Galaxy Luminosity Function
• An Introductory Review on Cosmic Reionization
• Dust Evolution in Galaxy Cluster Simulations
• PHEW: a parallel segmentation algorithm for three-dimensional AMR datasets - application to structure detection in self-gravitating flows
• Dust evolution in zoom-in cosmological simulations of galaxy formation
• The Galactic Dust-Up: Modeling Dust Evolution in FIRE
• Observational and theoretical constraints on the formation and early evolution of the first dust grains in galaxies at 5 < z < 10
• Impact of the reduced speed of light approximation on ionization front velocities in cosmological simulations of the epoch of reionization
• The Photometric Properties of Galaxies in the Early Universe
• Radiative properties of the first galaxies: rapid transition between blue and red
• Impact of the reduced speed of light approximation on the post-overlap neutral hydrogen fraction in numerical simulations of the epoch of reionization
• Galaxies with grains: unraveling dust evolution and extinction curves with hydrodynamical simulations
• Galaxy clusters in simulations of the local Universe: a matter of constraints
• The Origin of the Dust Extinction Curve in Milky Way-like Galaxies
• Radiative transfer of ionizing radiation through gas and dust: stellar source case
• A Dusty Locale: Evolution of Galactic Dust Populations from Milky Way to Dwarf-Mass Galaxies
• DUSTiER (DUST in the Epoch of Reionization): dusty galaxies in cosmological radiation-hydrodynamical simulations of the Epoch of Reionization with RAMSES-CUDATON
• Dust in High-Redshift Galaxies: Reconciling UV Attenuation and IR Emission
• First Light And Reionisation Epoch Simulations (FLARES) XVI: Size Evolution of Massive Dusty Galaxies at Cosmic Dawn from UV to IR

Cited by in corpus (3)

• A Galactic Transformation -- Understanding the SMC's Structural and Kinematic Disequilibrium
• Bright [CII]158$\mu$m Streamers as a Beacon for Giant Galaxy Formation in SPT2349$-$56 at $z=4.3$
• Double-Peaked Ly$\alpha$ Emission during Reionization Requires Nearby Voids and a Favorable Local Ionizing Background