The Photon Underproduction Crisis

Abstract

We examine the statistics of the low-redshift Lyman-alpha forest from smoothed particle hydrodynamic simulations in light of recent improvements in the estimated evolution of the cosmic ultraviolet background (UVB) and recent observations from the Cosmic Origins Spectrograph (COS). We find that the value of the metagalactic photoionization rate required by our simulations to match the observed properties of the low-redshift Lyman-alpha forest is a factor of 5 larger than the value predicted by state-of-the art models for the evolution of this quantity. This mismatch results in the mean flux decrement of the Lyman-alpha forest being underpredicted by at least a factor of 2 (a 10-sigma discrepancy with observations) and a column density distribution of Lyman-alpha forest absorbers systematically and significantly elevated compared to observations over nearly two decades in column density. We examine potential resolutions to this mismatch and find that either conventional sources of ionizing photons (galaxies and quasars) must be significantly elevated relative to current observational estimates or our theoretical understanding of the low-redshift universe is in need of substantial revision.

Submitted to ApJ Letters; 6 pages including 3 figures

References in corpus (41)

• The cosmological simulation code GADGET-2
• Radiative Transfer in a Clumpy Universe: II. The Utraviolet Extragalactic Background
• Radiative transfer in a clumpy universe: IV. New synthesis models of the cosmic UV/X-ray background
• An Observational Determination of the Bolometric Quasar Luminosity Function
• Cosmological Simulations with TreeSPH
• Equation of State of the Photoionized Intergalactic Medium
• A New Calculation of the Ionizing Background Spectrum and the Effects of HeII Reionization
• Cosmological Simulations of Intergalactic Medium Enrichment from Galactic Outflows
• Mass, Metal, and Energy Feedback in Cosmological Simulations
• Gravitational Collapse of Small-Scale Structure as the Origin of the Lyman Alpha Forest
• The Lyman-alpha Forest in the Cold Dark Matter Model
• The Lyman-alpha Forest Power Spectrum from the Sloan Digital Sky Survey
• The Opacity of the Lyman Alpha Forest and Implications for Omega_{baryon} and the Ionizing Background
• The Lyman Alpha Forest from Gravitational Collapse in the CDM+Lambda Model
• The observed ionization rate of the intergalactic medium and the ionizing emissivity at z >5: Evidence for a photon starved and extended epoch of reionization
• The Direct Detection of Lyman-Continuum Emission from Star-forming Galaxies at z~3
• A Multi-Species Model for Hydrogen and Helium Absorbers in Lyman-Alpha Forest Clouds
• The Cosmological Impact of Luminous TeV Blazars I: Implications of Plasma Instabilities for the Intergalactic Magnetic Field and Extragalactic Gamma-Ray Background
• A Direct Precision Measurement of the Intergalactic Lyman-alpha Opacity at 2<z<4.2
• The Evolution of Optical Depth in the Ly-alpha Forest: Evidence Against Reionization at z~6
• A Lower Bound on the Cosmic Baryon Density
• The Great Observatories Origins Deep Survey: Constraints on the Lyman Continuum Escape Fraction Distribution of Lyman--Break Galaxies at 3.4<z<4.5
• HST-COS Observations of AGN. I. Ultraviolet Composite Spectra of the Ionizing Continuum and Emission Lines
• Physical Properties, Baryon Content, and Evolution of the LyαForest: New Insights from High Resolution Observations at z < 0.4
• The intergalactic medium over the last 10 billion years I: Lyman alpha absorption and physical conditions
• The Metagalactic Ionizing Radiation Field at Low Redshift
• Measuring the Sources of the Intergalactic Ionizing Flux
• Voigt-Profile Analysis of the Lyman-alpha Forest in a Cold Dark Matter Universe
• The Statistical and Physical Properties of the Low Redshift Lyman Alpha Forest Observed with HST/STIS
• A Hubble Space Telescope Study of Lyman Limit Systems: Census and Evolution
• A Spectroscopic Search for Leaking Lyman Continuum at z~0.7
• A low escape fraction of ionizing photons of L>L* Lyman break galaxies at z=3.3
• The Lyman-alpha forest in a blazar-heated Universe
• A Uniform Analysis of the Ly-alpha Forest at z=0 - 5: V. The extragalactic ionizing background at low redshift
• Pressure Support vs. Thermal Broadening in the Lyman-alpha Forest I: Effects of the Equation of State on Longitudinal Structure
• Lyman Break Galaxies and the Lyman-alpha Forest
• Continuous statistics of the Lyman-alpha forest at 0 < z < 1.6: the mean flux, flux distribution, and autocorrelation from HST FOS spectra
• Warm Ionized Gas Revealed in the Magellanic Bridge Tidal Remnant: Constraining the Baryon Content and the Escaping Ionizing Photons around Dwarf Galaxies
• Galactic Wind Effects on the Lyman-alpha Absorption in the Vicinity of Galaxies
• A new z=0 metagalactic UV background limit
• Pressure Support vs. Thermal Broadening in the Lyman-alpha Forest II: Effects of the Equation of State on Transverse Structure

Cited by in corpus (77)

• Simba: Cosmological Simulations with Black Hole Growth and Feedback
• Cosmic Reionization after Planck: Could Quasars Do It All?
• MUFASA: Galaxy Formation Simulations With Meshless Hydrodynamics
• Radiation Backgrounds at Cosmic Dawn: X-Rays from Compact Binaries
• The COS-Halos Survey: Metallicities in the Low-Redshift Circumgalactic Medium
• Evolution of the AGN UV luminosity function from redshift 7.5
• A Cosmic UV/X-ray Background Model Update
• The Lyman-$\alpha$ forest in optically-thin hydrodynamical simulations
• An HST/COS Survey of the Low-Redshift IGM. I. Survey, Methodology, & Overall Results
• Consistent modelling of the meta-galactic UV background and the thermal/ionization history of the intergalactic medium
• Characterizing Circumgalactic Gas around Massive Ellipticals at z~0.4 - II. Physical Properties and Elemental Abundances
• New synthesis models of consistent extragalactic background light over cosmic time
• On the Origin of Near-Infrared Extragalactic Background Light Anisotropy
• The redshift evolution of escape fraction of hydrogen ionizing photons from galaxies
• A Universal Density Structure for Circum-Galactic Gas
• Early and Extended Helium Reionization Over More Than 600 Million Years of Cosmic Time
• The photoheating of the intergalactic medium in synthesis models of the UV background
• Photon underproduction crisis: Are QSOs sufficient to resolve it?
• Characterizing the Circumgalactic Medium of Nearby Galaxies with HST/COS and HST/STIS Absorption-Line Spectroscopy: II. Methods and Models
• The Metagalactic Ionizing Background: A Crisis in UV Photon Production or Incorrect Galaxy Escape Fractions?
• Constraining the UV emissivity of AGN throughout cosmic time via X-ray surveys
• Tracing the Cosmic Metal Evolution in the Low-Redshift Intergalactic Medium
• NIHAO VIII: Circum-galactic medium and outflows - The puzzles of HI and OVI gas distributions
• The Spectral Slope and Escape Fraction of Bright Quasars at $z\sim 3.8$: the Contribution to the Cosmic UV Background
• Ambient Column Densities of Highly Ionized Oxygen in Precipitation-Limited Circumgalactic Media
• Intergalactic Lyman continuum photon budget in the past 5 billion years
• A measurement of the z = 0 UV background from H$\alpha$ fluorescence
• VoIgt profile Parameter Estimation Routine (VIPER): H I photoionization rate at z<0.5
• Does circumgalactic OVI trace low-pressure gas beyond the accretion shock? Clues from HI and low-ion absorption, line kinematics, and dust extinction
• Properties of QSO Metal Line Absorption Systems at High Redshifts: Nature and Evolution of the Absorbers and New Evidence on Escape of Ionizing Radiation from Galaxies
• The Low Redshift Circumgalactic Medium in Simba
• How Do Supernovae Impact the Circumgalactic Medium? I. Large-Scale Fountains Around a Milky Way-Like Galaxy
• HST/COS Observations of Ionized Gas Accretion at the Disk-halo Interface of M33
• Diagnosing galactic feedback with the line broadening in the low redshift Lyman-alpha forest
• Fast Winds Drive Slow Shells: A Model for the Circumgalactic Medium as Galactic Wind-Driven Bubbles
• The COS Absorption Survey of Baryon Harbors: Unveiling the Physical Conditions of Circumgalactic Gas through Multiphase Bayesian Ionization Modeling
• The Power Spectrum of the Lyman-$\alpha$ Forest at z < 0.5
• Jet Feedback and the Photon Underproduction Crisis in Simba
• The Mystery of the Cosmic Diffuse Ultraviolet Background Radiation
• Empirically Constrained Predictions for Metal-Line Emission from the Circumgalactic Medium
• Observations of metals in the $z\approx 3.5$ intergalactic medium and comparison to the EAGLE simulations
• The Effect Of AGN Heating On The Low-Redshift Lyα Forest
• In search of cool flow accretion onto galaxies $-$ where does the disk gas end?
• Not So Heavy Metals: Black Hole Feedback Enriches The Circumgalactic Medium
• Mapping the Escape Fraction of Ionizing Photons Using Resolved Stars: A Much Higher Escape Fraction for NGC 4214
• Emission from the circumgalactic medium: from cosmological zoom-in simulations to multiwavelength observables
• HST-COS Observations of AGNs. III. Spectral Constraints in the Lyman Continuum from Composite COS/G140L Data
• An HST/COS legacy survey of intervening SiIII absorption in the extended gaseous halos of low-redshift galaxies
• A Pair of O VI and Broad Ly-alpha Absorbers Probing Warm Gas in a Galaxy Group Environment at z ~ 0.4
• The Escape Fraction of Ionizing Photons During the Epoch of Reionization: observability with the Square Kilometre Array
• The COS-AGN survey: Revealing the nature of circum-galactic gas around hosts of active galactic nuclei
• Implications of an updated ultraviolet background for the ionization mechanisms of intervening Ne VIII absorbers
• The effect of stellar and AGN feedback on the low redshift Lyman-$\alpha$ forest in the Sherwood simulation suite
• Gauging Metallicity of Diffuse Gas Under An Uncertain Ionizing Radiation Field
• Detection of Two Intervening Ne VIII Absorbers Probing Warm Gas at z~0.6
• Limits on non-canonical heating and turbulence in the intergalactic medium from the low redshift Lyman-alpha forest
• Efficient long-range AGN feedback affects the low redshift Lyman-$\alpha$ forest
• Warm Gas in and Around Simulated Galaxy Clusters as Probed by Absorption Lines
• The Indirect Influence of Quasars on Reionization
• The low redshift Lyman-$\alpha$ Forest as a constraint for models of AGN feedback
• Efficient adiabatic hydrodynamical simulations of the high-redshift intergalactic medium
• The evolution of the low-density HI intergalactic medium from z=3.6 to 0: Data, transmitted flux and HI column density
• Probing the Dependence of the Intergalactic Medium on Large Scale Environment Using the Low Redshift Lyman Alpha Forest
• The Robustness of Cosmological Hydrodynamic Simulation Predictions to Changes in Numerics and Cooling Physics
• How Robust are the Inferred Density and Metallicity of the Circumgalactic Medium?
• Multicomponent H2 in DLA at zabs = 2.05: physical conditions through observations and numerical models
• Role of ionizing background on the statistics of metal absorbers in hydrodynamical simulations
• The Far Ultraviolet Background
• Circumgalactic gas at its extreme: tidal gas streams around the Whale galaxy NGC 4631 explored with HST/COS
• Flux sensitivity requirements for the detection of Lyman continuum radiation drop-ins from star-forming galaxies below redshifts of 3
• Detection of Low Metallicity Warm Plasma in a Galaxy Overdensity Environment at z ~ 0.2
• Can the Low Redshift Lyman Alpha Forest Constrain AGN Feedback Models?
• Evidence of bimodal physical properties of intervening, optically-thin CIII absorbers at z ~ 2.5
• A population of high-velocity absorption-line systems residing in the Local Group
• Far-UV Emission Properties of FR1 Radio Galaxies
• Excess Ultraviolet Emission at High Galactic Latitudes: A New Horizons View
• Physical conditions and redshift evolution of optically thin C III absorbers: Low-z sample