The physics of the intergalactic medium

2007/11/30 by Avery Meiksin, Avery A. Meiksin · 349 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Context (archaeology) #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Intergalactic medium #Intergalactic travel #Physics #Redshift #Reionization #Stars #Stellar, planetary, and galactic studies #Structure formation #astro-ph #physics.gen-ph

paper · pdf · doi:10.1103/revmodphys.81.1405

published in Reviews of Modern Physics 81(4), 1405-1469 (American Physical Society) · 69 pages; accepted version to appear in Reviews of Modern Physics; text and equation typos corrected; all figures included

arxiv created 2008/12/15 · openalex publication_date 2009/10/05 · arxiv updated 2014/11/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

Intergalactic space is filled with a pervasive medium of ionized gas, the intergalactic medium (IGM). A residual neutral fraction is detected in the spectra of quasistellar objects at both low and high redshifts, revealing a highly fluctuating medium with temperatures characteristic of photoionized gas. The statistics of the fluctuations are well reproduced by numerical gravity-hydrodynamics simulations within the context of standard cosmological structure formation scenarios. Thus, the study of the IGM offers an opportunity to probe the nature of the primordial density fluctuations on scales unavailable to other methods. The simulations also suggest that the IGM is the dominant reservoir of baryons produced by the Big Bang, and so the principal source of the matter from which galaxies formed. The detection of metal systems within the IGM shows that it was enriched by evolved stars early in its history, demonstrating an intimate connection between galaxy formation and the IGM. A comprehensive review of the current understanding of the structure and physical properties of the IGM and its relation to galaxies is presented, concluding with comments on prospects for furthering the study of the IGM using future ground-based facilities and space-based experiments.

Citations

• Hydrodynamical Simulations of the Lyα Forest: Model Comparisons
• Small‐Scale Cosmic Microwave Background Temperature and Polarization Anisotropies Due to Patchy Reionization
• Ionizing Radiation Fluctuations and Large‐Scale Structure in the Lyα Forest
• Searching for Low Surface Brightness Galaxies in the Hubble Ultra Deep Field: Implications for the Star Formation Efficiency in Neutral Gas at \documentclassaastex \usepackageamsbsy \usepackageamsfonts \usepackageamssymb \usepackagebm \usepackagemathrsfs \usepackagepifont \usepackagestmaryrd \usepackagetextcomp \usepackageportland,xspace \usepackageamsmath,amsxtra \usepackage[OT2,OT1]fontenc \newcommand\cyr \renewcommand\rmdefaultwncyr \renewcommand\sfdefaultwncyss \renewcommand\encodingdefaultOT2 \normalfont \selectfont \DeclareTextFontCommand\textcyr\cyr \pagestyleempty \DeclareMathSizes10976 \begindocument \landscape z∼ 3 \enddocument
• A New Measurement of the Primordial Abundance of Deuterium: Toward Convergence with the Baryon Density from the Cosmic Microwave Background?
• The Observability of Metal Lines Associated with the Lyα Forest
• Characterizing the Warm‐Hot Intergalactic Medium at High Redshift: A High‐Resolution Survey for Oviatz= 2.5
• The N/S[CLC]i[/CLC] Abundance Ratio in 15 Damped L[CLC]y[/CLC]α Galaxies: Implications for the Origin of Nitrogen
• 21 Centimeter Tomography of the Intergalactic Medium at High Redshift
• The Subaru/XMM‐NewtonDeep Survey (SXDS). IV. Evolution of Lyα Emitters from \documentclassaastex \usepackageamsbsy \usepackageamsfonts \usepackageamssymb \usepackagebm \usepackagemathrsfs \usepackagepifont \usepackagestmaryrd \usepackagetextcomp \usepackageportland,xspace \usepackageamsmath,amsxtra \usepackage[OT2,OT1]fontenc \newcommand\cyr \renewcommand\rmdefaultwncyr \renewcommand\sfdefaultwncyss \renewcommand\encodingdefaultOT2 \normalfont \selectfont \DeclareTextFontCommand\textcyr\cyr \pagestyleempty \DeclareMathSizes10976 \begindocument \landscape z=3.1 \enddocument to 5.7 in the 1 deg2Field: Luminosity Functions and AGN
• The evolution of ΩH iand the epoch of formation of damped Lyman α absorbers
• A new measure of Δα/α at redshift z = 1.84 from very high resolution spectra of Q 1101–264
• A Survey of [CLC][ITAL]z[/ITAL][/CLC] > 5.8 Quasars in the Sloan Digital Sky Survey. I. Discovery of Three New Quasars and the Spatial Density of Luminous Quasars at [CLC][ITAL]z[/ITAL][/CLC] ∼ 6
• The evolution of Lyman αabsorbers in the redshift range 0.5<z<1.9
• ChandraDetection of the First X‐Ray Forest along the Line of Sight to Markarian 421
• The Sensitivity of First‐Generation Epoch of Reionization Observatories and Their Potential for Differentiating Theoretical Power Spectra
• QSO Metal Absorption Systems at High Redshift and the Signature of Hierarchical Galaxy Formation
• Measuring the Small-Scale Power Spectrum of Cosmic Density Fluctuations through 21 cm Tomography Prior to the Epoch of Structure Formation
• Cross-correlation of Lyman absorbers with gas-rich galaxies
• Lyman-alpha absorption and tidal debris
• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• Search for Time Variation of the Fine Structure Constant
• The Keck+Magellan Survey for Lyman Limit Absorption. I. The Frequency Distribution of Super Lyman Limit Systems
• Constraining the Metallicity of the Low‐Density Lyα Forest Using OviAbsorption
• Physical effects on the Lyα forest flux power spectrum: damping wings, ionizing radiation fluctuations and galactic winds
• The Kinetic Sunyaev‐Zel’dovich Effect from Reionization
• A Study of the Reionization History of Intergalactic Helium withFUSEand the Very Large Telescope
• The Direct Detection of Lyman Continuum Emission from Star‐forming Galaxies atz∼3
• Gravitational collapse of small-scale structure as the origin of the Lyman-alpha forest
• Resolving the Helium Lyman-alpha Forest: Mapping Intergalactic Gas and Ionizing Radiation at z~3
• Atomic Data for Astrophysics. I. Radiative Recombination Rates for H-like, He-like, Li-like, and Na-like Ions over a Broad Range of Temperature
• Cosmological H II regions and the photoionization of the intergalactic medium
• The distribution of Lyman-alpha absorption lines in the spectra of six QSOs - Evidence for an intergalactic origin
• Scattered Lyα Radiation around Sources before Cosmological Reionization
• The association between gas and galaxies - II. The two-point correlation function
• Lyα Absorption in the Quasar Triplet Q0107-025A, Q0107-025B, and Q0107-0232: Data Calibration and Line Selection
• Surveys forz > 3 Damped Lyα Absorption Systems: The Evolution of Neutral Gas
• Spectroscopy of the double quasars Q1343+266A, B: A new determination of the size of Lyman-alpha forest absorbers
• Detecting X-ray filaments in the low-redshift Universe with XEUS and Constellation-X
• The Major Sources of the Cosmic Reionizing Background at z 6
• PC 1643+4631A, B: THE LYMAN-α FOREST AT THE EDGE OF COHERENCE
• The Deuterium to Hydrogen Abundance Ratio toward a Fourth QSO: HS 0105+1619
• Recovery of the Power Spectrum of Mass Fluctuations from Observations of the Lyα Forest
• The Local Lyα Forest. IV. Space Telescope Imaging Spectrograph G140M Spectra and Results on the Distribution and Baryon Content of H i Absorbers
• Implications for Cosmic Reionization from the Optical Afterglow Spectrum of the Gamma-Ray Burst 050904 at z = 6.3
• Measuring the equation of state of the intergalactic medium
• HeII Reionization and its Effect on the IGM
• Abundance of damped Lyman α absorbers in cosmological smoothed particle hydrodynamics simulations
• A galaxy at a redshift z = 6.96
• The Power Spectrum of Mass Fluctuations Measured from the Lyα Forest at Redshiftz = 2.5
• ThebDistribution of the Lyα Forest: Probing Cosmology and the Intergalactic Medium
• The Deuterium-to-Hydrogen Abundance Ratio toward the QSO SDSS J155810.16-003120.0
• The star formation rate of the Universe atz≈ 6 from theHubble Ultra-Deep Field
• Limits on Variations in Fundamental Constants from 21-cm and Ultraviolet Quasar Absorption Lines
• Starburst99: Synthesis Models for Galaxies with Active Star Formation
• Colour corrections for high-redshift objects due to intergalactic attenuation
• Detection of Neviiiin the Low‐Redshift Warm‐Hot Intergalactic Medium
• The Minimum Universal Metal Density between Redshifts of 1.5 and 5.5
• New Observations of the Interstellar Medium in the Lyman Break Galaxy MS 1512−cB58
• Atomic data for resonance absorption lines. I - Wavelengths longward of the Lyman limit
• The Temperature Structure of the Warm-Hot Intergalactic Medium
• X-ray pre-ionization powered by accretion on the first black holes - I. A model for theWMAPpolarization measurement
• The Observed Probability Distribution Function, Power Spectrum, and Correlation Function of the Transmitted Flux in the Lyα Forest
• Radiative Transfer in a Clumpy Universe. III. The Nature of Cosmological Ionizing Sources
• Particle-mesh simulations of the Ly forest
• Was Star Formation Suppressed in High‐Redshift Minihalos?
• The physics and early history of the intergalactic medium
• Plausible Fluorescent Lyα Emitters around thez= 3.1 QSO 0420−388
• The Properties of Intergalactic Civand SiivAbsorption. I. Optimal Analysis of an Extremely High Signal-to-Noise Quasar Sample
• MgiiAbsorption Systems in Sloan Digital Sky Survey QSO Spectra
• Radiative transfer through the intergalactic medium
• CLOUDY 90: Numerical Simulation of Plasmas and Their Spectra
• Large scale structure and galaxy disks as Lyman-alpha clouds
• The HeII Lyman alpha forest and the thermal state of the IGM
• The discovery of a galaxy-wide superwind from a young massive galaxy at redshift z ≈ 3
• The Linear Theory Power Spectrum from the Lyα Forest in the Sloan Digital Sky Survey
• Simulations of Damped Lyα and Lyman Limit Absorbers in Different Cosmologies: Implications for Structure Formation at High Redshift
• The Ultraviolet Spectroscopic Properties of Local Starbursts: Implications at High Redshift
• Mission: impossible (escape from the Lyman limit)
• Spectral shape of the UV ionizing background and He II absorption at redshifts 1.8 < z < 2.9
• Voigt‐Profile Analysis of the Lyα Forest in a Cold Dark Matter Universe
• 3C 273 : A Star-Like Object with Large Red-Shift
• Mapping Neutral Hydrogen during Reionization with the Lyα Emission from Quasar Ionization Fronts
• Resolving the Structure of Ionized Helium in the Intergalactic Medium with the Far Ultraviolet Spectroscopic Explorer
• Monte Carlo inversion of hydrogen and metal lines from QSO absorption\n spectra
• Photoevaporation of cosmological minihaloes during reionization
• DAMPED LYα SYSTEMS
• The Escape of Ionizing Photons from OB Associations in Disk Galaxies: Radiation Transfer through Superbubbles
• X‐Ray Absorption by the Low‐Redshift Intergalactic Medium: A Numerical Study of the Λ Cold Dark Matter Model
• Power Spectra for Cold Dark Matter and Its Variants
• Cosmic dynamics in the era of Extremely Large Telescopes
• Probing reionization with Lyman α emission lines
• The amplitude of mass density fluctuations at z 3.25 from the Ly forest of Q1422+231
• Where Are the Baryons?
• Intergalactic HeII absorption towards QSO 1157+3143
• The cosmic microwave background radiation fluctuations from H i perturbations prior to reionization
• Cosmological simulations of intergalactic medium enrichment from galactic outflows
• SIMULATIONS OF STRUCTURE FORMATION IN THE UNIVERSE
• Three‐YearWilkinson Microwave Anisotropy Probe(WMAP) Observations: Implications for Cosmology
• The Age-Metallicity Relation of the Universe in Neutral Gas: The First 100 Damped Ly Systems
• FIVE-YEARWILKINSON MICROWAVE ANISOTROPY PROBEOBSERVATIONS: COSMOLOGICAL INTERPRETATION
• 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
• A deep search for 21-cm absorption in high redshift damped Lyman-αsystems
• Small‐Scale Structure at High Redshift. II. Physical Properties of the CivAbsorbing Clouds
• FIVE-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE OBSERVATIONS: DATA PROCESSING, SKY MAPS, AND BASIC RESULTS
• On the Putative Detection ofz> 0 X‐Ray Absorption Features in the Spectrum of Mrk 421
• Mapping Low-Density Intergalactic Gas: A Third Helium [CLC]Ly[/CLC]α Forest
• The Local Lyα Forest. II. Distribution of HiAbsorbers, Doppler Widths, and Baryon Content
• The James Webb Space Telescope
• On the Quantum Theory of Radiation
• Galactic Winds
• Lyman Break Galaxies at z>4 and the Evolution of the UV Luminosity Density at High Redshift
• The Implications of a High Allelic Frequency of CYP2B6 G516T in Ethnic Chinese Persons

Cited by

• Cosmological-model independent limits on photon mass from FRB and SNe data
• The Lyα forest flux correlation function: a perturbation theory perspective
• urchin: a reverse ray tracer for astrophysical applications
• Probing primordial non-Gaussianity with fast radio bursts
• Suite of hydrodynamical simulations for the Lyman-αforest with massive neutrinos
• Prospects for observing the low-density cosmic web in Lyman-αemission
• Spectral Signatures of Quasar Ages at z ≈ 3
• Resolving the high redshift Lyα forest in smoothed particle hydrodynamics simulations
• On estimating Lyα forest correlations between multiple sightlines
• Possible features of galactic halo with electric field and observational constraints
• Narrow absorption line variability in repeat quasar observations from the Sloan Digital Sky Survey

Related

• The Intergalactic Medium
• Simulations of the Intergalactic Medium
• The Evolution of the Intergalactic Medium
• The Intergalactic Medium
• Observations of the Intergalactic Medium and the Cosmic Web in the SKA era