Evolution of CIV Absorbers I. The Cosmic Incidence

Abstract

We present a large high-resolution study of the distribution and evolution of CIV absorbers, including the weakest population with equivalent widths $W_r<0.3$~Å. By searching 369 high-resolution, high signal-to-noise spectra of quasars at $1.1\le z_{em}\le 5.3$ from Keck/HIRES and VLT/UVES, we find $1268$ CIV absorbers with $W_r\ge 0.05$~Å (our $\sim 50\%$ completeness limit) at redshifts $1\le z\le 4.75$. A Schechter function describes the observed equivalent width distribution with a transition from power-law to exponential decline at $W_r\gtrsim 0.5$~Å. The power-law slope $\alpha$ rises by $\sim 7\%$ and transition equivalent width $W_{\star }$ falls by $\sim 20\%$ from $⟨z⟩=1.7$ to $⟨z⟩=3.6$. We find that the co-moving redshift path density, $dN/dX$, of $W_r\ge 0.05$~Å absorbers rises by $\sim 1.8$ times from $z\simeq 4.0$ to $z\simeq 1.3$, while the $W_r\ge 0.6$~Å $dN/dX$ rises by a factor of $\sim 8.5$. We quantify the observed evolution by a model in which $dN/dX$ decreases linearly with redshift. The model suggests that populations with larger $W_r$ thresholds evolve faster with redshift and appear later in the universe. The cosmological Technicolor Dawn simulations at $z=3-5$ over-produce the observed abundance of absorbers with $W_r<0.3$~Å, while yielding better agreement at higher $W_r$. Our empirical linear model successfully describes {CIV evolution in the simulations and the observed evolution of $W_r\ge 0.6$~Å CIV for the past $\sim 12$ Gyr. Combining our measurements with the literature gives us a picture of CIV-absorbing structures becoming more numerous and/or larger in physical size over the last $\approx 13$ Gyr of cosmic time ($z\sim 6$ to $z\sim 0$).

arXiv comment27 pages, 13 figures, 7 tables; submitted to ApJ on July 22, 2020; revised September 28, 2020; accepted October 2, 2020

References in corpus (122)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• The Sloan Digital Sky Survey: Technical Summary
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Cosmic Star Formation History
• The Average Star Formation Histories of Galaxies in Dark Matter Halos from z=0-8
• Physical Models of Galaxy Formation in a Cosmological Framework
• In the Beginning: The First Sources of Light and the Reionization of the Universe
• Properties of galaxies reproduced by a hydrodynamic simulation
• UniverseMachine: The Correlation between Galaxy Growth and Dark Matter Halo Assembly from z=0-10
• Radiative transfer in a clumpy universe: IV. New synthesis models of the cosmic UV/X-ray background
• The Circumgalactic Medium
• Introducing the Illustris Project: the evolution of galaxy populations across cosmic time
• The Structure and Kinematics of the Circum-Galactic Medium from Far-UV Spectra of z~2-3 Galaxies
• Gas-regulation of galaxies: the evolution of the cosmic sSFR, the metallicity-mass-SFR relation and the stellar content of haloes
• The Diversity and Similarity of Simulated Cold Dark Matter Halos
• A New Calculation of the Ionizing Background Spectrum and the Effects of HeII Reionization
• Gusty, gaseous flows of FIRE: galactic winds in cosmological simulations with explicit stellar feedback
• The Large, Oxygen-Rich Halos of Star-Forming Galaxies Are A Major Reservoir of Galactic Metals
• New Constraints on Cosmic Reionization from the 2012 Hubble Ultra Deep Field Campaign
• Mass, Metal, and Energy Feedback in Cosmological Simulations
• Reionization of the Universe and the Early Production of Metals
• Self-Consistent Models of the AGN and Black Hole Populations: Duty Cycles, Accretion Rates, and the Mean Radiative Efficiency
• The Illustris Simulation: Public Data Release
• Feedback and Recycled Wind Accretion: Assembling the z=0 Galaxy Mass Function
• The Low Redshift Lyman Alpha Forest in Cold Dark Matter Cosmologies
• The Cosmic Baryon Cycle and Galaxy Mass Assembly in the FIRE Simulations
• Metallicity of the intergalactic medium using pixel statistics. II. The distribution of metals as traced by C IV
• Cosmological Reionization by Stellar Sources
• 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 Evolution of the Intergalactic Medium
• Detection of Extended He II Reionization in the Temperature Evolution of the Intergalactic Medium
• The Bolometric Quasar Luminosity Function at z = 0-7
• New Measurements of the Ionizing Ultraviolet Background over 2 < z < 5 and Implications for Hydrogen Reionization
• Metallicity Evolution of Damped Lyman-alpha Systems out to z~5
• The Connection Between Galaxies and Intergalactic Absorption Lines at Redshift 2<z<3
• Spatial variation in the fine-structure constant -- new results from VLT/UVES
• HeII Reionization and its Effect on the IGM
• The Minimum Universal Metal Density Between Redshifts of 1.5 and 5.5
• The COS-Dwarfs Survey: The Carbon Reservoir Around sub-L* Galaxies
• Evolution of the Intergalactic Opacity: Implications for the Ionizing Background, Cosmic Star Formation, and Quasar Activity
• Evolution of the AGN UV luminosity function from redshift 7.5
• The Low-z Intergalactic Medium. III. HI and Metal Absorbers at z<0.4
• Tracing Outflows and Accretion: A Bimodal Azimuthal Dependence of MgII Absorption
• In-N-Out: the gas cycle from dwarfs to spiral galaxies
• The spectral evolution of the first galaxies. II. Spectral signatures of Lyman continuum leakage from galaxies in the reionization epoch
• The JHU-SDSS metal absorption line catalog: redshift evolution and properties of Mg II absorbers
• Consistent modelling of the meta-galactic UV background and the thermal/ionization history of the intergalactic medium
• Tracing Inflows and Outflows with Absorption Lines in Circumgalactic Gas
• Metal flows of the circumgalactic medium, and the metal budget in galactic halos
• The Population of Weak Mg II Absorbers I. A Survey of 26 QSO HIRES/Keck Spectra
• The Origin of C IV Absorption Systems at Redshifts z<1---Discovery of Extended C IV Envelopes Around Galaxies
• An analytic solution for the minimal bathtub toy model: challenges in the star-formation history of high-z galaxies
• Halo Gas Cross Sections And Covering Fractions of MgII Absorption Selected Galaxies
• Reionization and high-redshift galaxies: the view from quasar absorption lines
• A large population of metal-rich, compact, intergalactic C IV absorbers - Evidence for poor small-scale metal mixing
• Mining Circumgalactic Baryons in the Low-Redshift Universe
• An Accounting of the Dust-Obscured Star Formation and Accretion Histories Over the Last ~11~Billion Years
• Damped Lyman-alpha absorbers as a probe of stellar feedback
• The C IV Mass Density of the Universe at Redshift 5
• MAGIICAT I. The MgII Absorber-Galaxy Catalog
• Early and Extended Helium Reionization Over More Than 600 Million Years of Cosmic Time
• The galaxy UV luminosity function at z ~ 2 - 4; new results on faint-end slope and the evolution of luminosity density
• The drop in the cosmic star formation rate below redshift 2 is caused by a change in the mode of gas accretion and by AGN feedback
• A Review of Recent Observations of Galactic Winds Driven by Star Formation
• Cosmic distribution of highly ionized metals and their physical conditions in the EAGLE simulations
• A Deep Search For Faint Galaxies Associated With Very Low-redshift C IV Absorbers: III. The Mass- and Environment-dependent Circumgalactic Medium
• High Redshift Metals I.: The Decline of C IV at z > 5.3
• Metals in the IGM approaching the re-ionization epoch: results from X-shooter at the VLT
• The UVES Spectral Quasar Absorption Database (SQUAD) Data Release 1: The first 10 million seconds
• Tracing the Reionization-Epoch Intergalactic Medium with Metal Absorption Lines
• The Sources of Intergalactic Metals
• Probing star formation across cosmic time with absorption line systems
• Constraints on the Universal CIV Mass Density at z~6 from Early IR Spectra Obtained with the Magellan FIRE Spectrograph
• The Kinematics of Intermediate Redshift Mg II Absorbers
• The Properties of Intergalactic C IV and Si IV Absorption, I: Optimal Analysis of an Extremely High S/N Quasar Sample
• The formation of massive, quiescent galaxies at cosmic noon
• The cosmic evolution of dust-corrected metallicity in the neutral gas
• MAGIICAT V. Orientation of Outflows and Accretion Determine the Kinematics and Column Densities of the Circumgalactic Medium
• Star Formation Feedback and Metal Enrichment History Of The Intergalactic Medium
• The First Data Release of the KODIAQ Survey
• The Evolution of O I over 3.2 < z < 6.5: Reionization of the Circumgalactic Medium
• C IV absorption in damped and sub-damped Lyman-alpha systems: correlations with metallicity and implications for galactic winds at z~2-3
• The Cosmic Evolution of the Metallicity Distribution of Ionized Gas Traced by Lyman Limit Systems
• Temperature and Kinematics of CIV Absorption Systems
• The rise of the C IV mass density at z<2.5
• The Last Eight-Billion Years of Intergalactic CIV Evolution
• The MaGICC Baryon Cycle: The Enrichment History of Simulated Disc Galaxies
• Reionization in Technicolor
• A Survey of MgII Absorption at 2 < z < 6 with Magellan / FIRE: I: Sample and Evolution of the MgII Frequency
• Precious Metals in SDSS Quasar Spectra I: Tracking the Evolution of Strong, 1.5 < z < 4.5 CIV Absorbers with Thousands of Systems
• Tracing the Cosmic Metal Evolution in the Low-Redshift Intergalactic Medium
• Heavy Element Absorption Systems at $5.0<z<6.8$: Metal-Poor Neutral Gas and a Diminishing Signature of Highly Ionized Circumgalactic Matter
• MAGIICAT VI. The MgII Intragroup Medium is Kinematically Complex
• Direct Insights into Observational Absorption Line Analysis Methods of the Circumgalactic Medium Using Cosmological Simulations
• The Carbon Content of Intergalactic Gas at z=4.25 and its Evolution Toward z=2.4
• Testing the effect of galactic feedback on the IGM at z ~ 6 with metal-line absorbers
• 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 Soft, Fluctuating UVB at $z\sim 6$ as Traced by C IV, SiIV, and CII
• The Reionization of Carbon
• The Unchanging Circumgalactic Medium Over the Past 11 Billion Years
• Precise limits on cosmological variability of the fine-structure constant with zinc and chromium quasar absorption lines
• A Deep Search For Faint Galaxies Associated With Very Low-redshift C IV Absorbers: II. Program Design, Absorption-line Measurements, and Absorber Statistics
• The CGM and IGM at z$\sim$5: metal budget and physical connection
• The Highly Ionized Circumgalactic Medium is Kinematically Uniform Around Galaxies
• The Impact of the Group Environment on the OVI Circumgalactic Medium
• Fluctuations in the Ionizing Background During and After Helium Reionization
• The Properties of Intergalactic CIV Absorption II: Which Systems Are Associated With Galaxy Outflows?
• The HI Mass Density in Galactic Halos, Winds, and Cold Accretion as Traced by MgII Absorption
• The Relation Between Galaxy ISM and Circumgalactic OVI Gas Kinematics Derived from Observations and $\Lambda$CDM Simulations
• MAGIICAT IV. Kinematics of the Circumgalactic Medium and Evidence for Quiescent Evolution Around Red Galaxies
• A Survey of Analogs to Weak MgII Absorbers in the Present
• The Faint Host Galaxies of C IV Absorbers at z > 5
• Evolution of Neutral Oxygen During the Epoch of Reionization and its Use in Estimating the Neutral Hydrogen Fraction
• Kinematics of the OVI Circumgalactic Medium: Halo Mass Dependence and Outflow Signatures
• Aligned metal absorbers and the ultraviolet background at the end of reionization
• Simulating the Carbon Footprint of Galactic Halos
• Gas Accretion and Galactic Chemical Evolution: Theory and Observations
• Testing Galaxy Formation Simulations with Damped Lyman-$\alpha$ Abundance and Metallicity Evolution
• Probing Inhomogeneity in the Helium Ionizing UV Background
• CIV Absorbers in z>4 Quasars: Tracing Early Galactic Halos Evolution

Cited by in corpus (14)

• Metal-enriched halo gas across galaxy overdensities over the last 10 billion years
• The evolution of the Si IV content in the Universe from the epoch of reionization to cosmic noon
• MUSE Analysis of Gas around Galaxies (MAGG) -- V: Linking ionized gas traced by CIV and SiIV absorbers to Ly$\alpha$ emitting galaxies at $z\approx 3.0-4.5$
• Examining the Decline in the C IV Content of the Universe over 4.3 < z < 6.3 using the E-XQR-30 Sample
• The COS-legacy survey of C IV absorbers: properties and origins of the intervening systems
• Constraining IGM enrichment and metallicity with the C IV forest correlation function
• Evolution of CIV Absorbers. II. Where does CIV live?
• A framework to measure the properties of intergalactic metal systems with two-point flux statistics
• The environments and hosts of metal absorption at z>5
• Probing the He II re-Ionization ERa via Absorbing C IV Historical Yield (HIERACHY) I: A Strong Outflow from a z~4.7 Quasar
• The Cosmic Evolution of CIV Absorbers at $1.4<z<4.5$: Insights from $100,000$ Systems in DESI Quasars
• The multiple coherence scales of C IV at cosmic noon
• Mapping the z>=5 SiIV Column Density Distribution onto the Galaxy Stellar Mass Function Using the Cumulative Absorption Cross Section
• Constraining the Size of the Circumgalactic Medium Using the Transverse Autocorrelation Function of C IV Absorbers in Paired Quasar Spectra