Cosmic Reionization On Computers: The Faint End of the Galaxy Luminosity Function

Abstract

Using numerical cosmological simulations completed under the "Cosmic Reionization On Computers" (CROC) project, I explore theoretical predictions for the faint end of the galaxy UV luminosity functions at $z\ge 6$. A commonly used Schechter function approximation with the magnitude cut at $M_{\mathrm{CUT}}\sim -13$ provides a reasonable fit to the actual luminosity function of simulated galaxies. When the Schechter functional form is forced on the luminosity functions from the simulations, the magnitude cut $M_{\mathrm{CUT}}$ is found to vary between $-12$ and $-14$ with a mild redshift dependence. An analytical model of reionization from Madau, Haardt & Rees (1997), as used by Robertson et al. (2015), provides a good description of the simulated results, but only if the redshift dependence of the effective escape fraction (induced by physical processes not captured by the Madau, Haardt & Rees model) is accounted for.

Published in ApJ Letters

References in corpus (10)

• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• Cosmic Reionization and Early Star-Forming Galaxies: A Joint Analysis of New Constraints from Planck and Hubble Space Telescope
• Cosmic Reionization On Computers I. Design and Calibration of Simulations
• New Constraints on the Faint-end of the UV Luminosity Function at z~7-8 using the Gravitational Lensing of the Hubble Frontier Fields Cluster A2744
• Cosmic Reionization On Computers II. Reionization History and Its Back Reaction on Early Galaxies
• The Efficiency of Stellar Reionization: Effects of Rotation, Metallicity, and Initial Mass Function
• The Very Faint End of the UV Luminosity Function over Cosmic Time: Constraints from the Local Group Fossil Record
• The ionizing background at the end of overlap
• Cosmic Reionization On Computers: Numerical and Physical Convergence
• Cosmic Reionization On Computers. Ultraviolet Continuum Slopes and Dust Opacities in High Redshift Galaxies

Cited by in corpus (43)

• The Dearth of z~10 Galaxies in all HST Legacy Fields -- The Rapid Evolution of the Galaxy Population in the First 500 Myr
• Directly Observing the Galaxies Likely Responsible for Reionization
• A Long Time Ago in a Galaxy Far, Far Away: A Candidate z ~ 12 Galaxy in Early JWST CEERS Imaging
• Conditions for Reionizing the Universe with A Low Galaxy Ionizing Photon Escape Fraction
• Rapid Reionization by the Oligarchs: The Case for Massive, UV-Bright, Star-Forming Galaxies with High Escape Fractions
• The z~6 Luminosity Function Fainter than -15 mag from the Hubble Frontier Fields: The Impact of Magnification Uncertainties
• The Extreme Faint End of the UV Luminosity Function at $z\sim 6$ Through Gravitational Telescopes: a comprehensive assessment of strong lensing uncertainties
• Introducing the THESAN project: radiation-magnetohydrodynamic simulations of the epoch of reionization
• Great Optically Luminous Dropout Research Using Subaru HSC (GOLDRUSH). I. UV Luminosity Functions at $z\sim 4-7$ Derived with the Half-Million Dropouts on the 100 deg${}^2$ Sky
• Simulating galaxies in the reionization era with FIRE-2: galaxy scaling relations, stellar mass functions, and luminosity functions
• Semi-analytic forecasts for JWST - I. UV luminosity functions at z = 4 - 10
• Star cluster formation in cosmological simulations. I. Properties of young clusters
• No missing photons for reionization: moderate ionizing photon escape fractions from the FIRE-2 simulations
• A Census of the Bright z=8.5-11 Universe with the Hubble and Spitzer Space Telescopes in the CANDELS Fields
• z~2-9 Galaxies Magnified by the Hubble Frontier Field Clusters II: Luminosity Functions and Constraints on a Faint-End Turnover
• The Lyman Continuum escape fraction of faint galaxies at z~3.3 in the CANDELS/GOODS-North, EGS, and COSMOS fields with LBC
• Semi-analytic forecasts for JWST -- IV. Implications for cosmic reionization and LyC escape fraction
• Introducing the FirstLight project: UV luminosity function and scaling relations of primeval galaxies
• Escape of ionizing radiation from high redshift dwarf galaxies: role of AGN feedback
• A Minimalist Feedback-Regulated Model for Galaxy Formation During the Epoch of Reionization
• The Little Engines That Could? Globular Clusters Contribute Significantly to Reionization-era Star Formation
• UV absorption lines and their potential for tracing the Lyman continuum escape fraction
• Local Group Ultra-Faint Dwarf Galaxies in the Reionization Era
• Sizes of Lensed Lower-luminosity z=4-8 Galaxies from the Hubble Frontier Field Program
• Cosmic Reionization After Planck and Before JWST: An Analytic Approach
• ETHOS -- an effective theory of structure formation: predictions for the high-redshift Universe -- abundance of galaxies and reionization
• Roll of the Dice: A Stochastically Sampled IMF Alters the Stellar Content of Simulated Dwarf Galaxies
• How robustly can we constrain the low-mass end of the $z\sim 6-7$ stellar mass function? -- The limits of lensing models and stellar population assumptions in the Hubble Frontier Fields
• On the faint-end of the high-$z$ galaxy luminosity function
• Winds of change: reionization by starburst galaxies
• Supermassive Dark Star candidates seen by JWST?
• On the faint-end of the galaxy luminosity function in the Epoch of Reionization: updated constraints from the HST Frontier Fields
• Warm Dark Matter and Cosmic Reionization
• Models of the Cosmological 21 cm Signal from the Epoch of Reionization Calibrated with Lyman-alpha and CMB Data
• Globular Clusters in High-Redshift Dwarf Galaxies: A Case Study from the Local Group
• SCORCH. II. Radiation-Hydrodynamic simulations of reionization with varying radiation escape fractions
• On the Reionization-Era Globular Cluster in Low-Mass Galaxy Eridanus II
• Detectability of Supermassive Dark Stars with the Roman Space Telescope
• Studying neutral hydrogen structures during the epoch of reionization using fractal dimensions
• Impact of the turnover in the high-z galaxy luminosity function on the 21-cm signal during Cosmic Dawn and Epoch of Reionization
• Dust-UV offsets in high-redshift galaxies in the Cosmic Dawn III simulation
• A quantitative assessment of completeness correction methods and public release of a versatile simulation code
• Probing power spectrum enhancement at small scales with the SKA