A Flexible Analytic Model of Cosmic Variance in the First Billion Years

Abstract

Cosmic variance is the intrinsic scatter in the number density of galaxies due to fluctuations in the large-scale dark matter density field. In this work, we present a simple analytic model of cosmic variance in the high redshift Universe ($z\sim 5-15$). We assume that galaxies grow according to the evolution of the halo mass function, which we allow to vary with large-scale environment. Our model produces a reasonable match to the observed ultraviolet luminosity functions in this era by regulating star formation through stellar feedback and assuming that the UV luminosity function is dominated by recent star formation. We find that cosmic variance in the UVLF is dominated by the variance in the underlying dark matter halo population, and not by differences in halo accretion or the specifics of our stellar feedback model. We also find that cosmic variance dominates over Poisson noise for future high-$z$ surveys except for the brightest sources or at very high redshifts ($z\gtrsim 12$). We provide a linear approximation of cosmic variance for a variety of redshifts, magnitudes, and survey areas through the public Python package galcv. Finally, we introduce a new method for incorporating priors on cosmic variance into estimates of the galaxy luminosity function and demonstrate that it significantly improves constraints on that important observable.

arXiv comment16 pages, 15 figures, accepted by MNRAS

References in corpus (54)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• The NumPy array: a structure for efficient numerical computation
• Planck 2015 results. XIII. Cosmological parameters
• Cosmic Star Formation History
• Baryonic Features in the Matter Transfer Function
• Toward a halo mass function for precision cosmology: the limits of universality
• An analytic model for the spatial clustering of dark matter haloes
• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• UniverseMachine: The Correlation between Galaxy Growth and Dark Matter Halo Assembly from z=0-10
• Wide-Field InfrarRed Survey Telescope-Astrophysics Focused Telescope Assets WFIRST-AFTA 2015 Report
• 21cmFAST: A Fast, Semi-Numerical Simulation of the High-Redshift 21-cm Signal
• The Evolution of the Galaxy Rest-Frame Ultraviolet Luminosity Function Over the First Two Billion Years
• The Merger Rates and Mass Assembly Histories of Dark Matter Haloes in the Two Millennium Simulations
• Linking halo mass to galaxy luminosity
• The Dearth of z~10 Galaxies in all HST Legacy Fields -- The Rapid Evolution of the Galaxy Population in the First 500 Myr
• Assembly bias in the clustering of dark matter haloes
• Directly Observing the Galaxies Likely Responsible for Reionization
• Cosmic Variance and Its Effect on the Luminosity Function Determination in Deep High z Surveys
• A Unified Model for Galactic Discs: Star Formation, Turbulence Driving, and Mass Transport
• Cosmic Variance in the Great Observatories Origins Deep Survey
• Unusually Large Fluctuations in the Statistics of Galaxy Formation at High Redshift
• A Cosmic Variance Cookbook
• The Baryonic Assembly of Dark Matter Halos
• The Galaxy UV Luminosity Function Before the Epoch of Reionization
• The high redshift galaxy population in hierarchical galaxy formation models
• The Extreme Faint End of the UV Luminosity Function at $z\sim 6$ Through Gravitational Telescopes: a comprehensive assessment of strong lensing uncertainties
• How stellar feedback simultaneously regulates star formation and drives outflows
• A lack of evolution in the very bright-end of the galaxy luminosity function from z = 8-10
• The bright end of the galaxy luminosity function at z ~ 7: before the onset of mass quenching?
• Mass Accretion Rates and Histories of Dark Matter Haloes
• Feedback-regulated star formation in molecular clouds and galactic discs
• Constraints on the Star Formation Efficiency of Galaxies During the Epoch of Reionization
• The Wide Field Infrared Survey Telescope: 100 Hubbles for the 2020s
• An analytic solution for the minimal bathtub toy model: challenges in the star-formation history of high-z galaxies
• High redshift JWST predictions from IllustrisTNG: Dust modelling and galaxy luminosity functions
• The Global 21-cm Signal in the Context of the High-z Galaxy Luminosity Function
• An excursion set model for the distribution of dark matter and dark matter haloes
• The Bright End of the z~9 and z~10 UV Luminosity Functions using all five CANDELS Fields
• First Light And Reionisation Epoch Simulations (FLARES) I: Environmental Dependence of High-Redshift Galaxy Evolution
• SCORCH I: The Galaxy-Halo Connection in the First Billion Years
• Coming of Age in the Dark Sector: How Dark Matter Haloes grow their Gravitational Potential Wells
• Statistics of Voids in the 2dF Galaxy Redshift Survey
• A Minimalist Feedback-Regulated Model for Galaxy Formation During the Epoch of Reionization
• Measuring the Cosmic Equation of State with Counts of Galaxies II: Error Budget for the DEEP2 Redshift Survey
• An Empirically-Calibrated Model For Interpreting the Evolution of Galaxies During the Reionization Era
• Estimating Luminosity Function Constraints from High-Redshift Galaxy Surveys
• Cosmic variance of $z>7$ galaxies: Prediction from BlueTides
• Accounting for Cosmic Variance in Studies of Gravitationally-Lensed High-Redshift Galaxies in the Hubble Frontier Field Clusters
• Astraeus II: Quantifying the impact of cosmic variance during the Epoch of Reionization
• Distribution of streaming rates into high-redshift galaxies
• Effects of self-consistent rest-ultraviolet colours in semi-empirical galaxy formation models
• A prescription for the conditional mass function of dark matter haloes
• Testing the conditional mass function of dark matter halos against numerical N-body simulations
• Galaxy Statistics in Pencil-beam Surveys at High Redshifts

Cited by in corpus (20)

• COSMOS2020: The Galaxy Stellar Mass Function: the assembly and star formation cessation of galaxies at $0.2<z\le 7.5$
• Life beyond 30: probing the -20<M_UV<-17 luminosity function at 8<z<13 with the NIRCam parallel field of the MIRI Deep Survey
• Balancing the efficiency and stochasticity of star formation with dust extinction in z > 10 galaxies observed by JWST
• Probing Cosmic Reionization and Molecular Gas Growth with TIME
• The Prevalence of Galaxy Overdensities Around UV-Luminous Lyman $\alpha$ Emitters in the Epoch of Reionization
• GALLUMI: A Galaxy Luminosity Function Pipeline for Cosmology and Astrophysics
• Constraints on the End of Reionization from the Density Fields Surrounding Two Highly Opaque Quasar Sightlines
• Deep Realistic Extragalactic Model (DREaM) Galaxy Catalogs: Predictions for a Roman Ultra-Deep Field
• JWST UNCOVER: The Overabundance of Ultraviolet-luminous Galaxies at $z>9$
• On the Significance of Rare Objects at High Redshift: The Impact of Cosmic Variance
• The importance of stochasticity in determining galaxy emissivities and UV LFs during cosmic dawn and reionization
• Lyman-alpha Emitters in Ionized Bubbles: Constraining the Environment and Ionized Fraction
• The first GLIMPSE of the faint galaxy population at Cosmic Dawn with JWST: The evolution of the ultraviolet luminosity function across z~9-15
• The impact of medium-width bands on the selection, and subsequent luminosity function measurements, of high-z galaxies
• Efficient simulation of discrete galaxy populations and associated radiation fields during the first billion years
• A Framework for Simultaneously Measuring Field Densities and the High-z Luminosity Function
• First Light and Reionisation Epoch Simulations (FLARES) X: Environmental Galaxy Bias and Survey Variance at High Redshift
• An X-ray-Emitting Proto-Cluster at $z\approx 5.7$ Reveals Rapid Structure Growth
• Finding High-Redshift Galaxies with JWST
• A joint measurement of galaxy luminosity functions and large-scale field densities during the Epoch of Reionization