The Cosmic Evolution of CIV Absorbers at $1.4<z<4.5$: Insights from $100,000$ Systems in DESI Quasars

Abstract

We present the largest catalog to date of triply ionized carbon (CIV) absorbers detected in quasar spectra from the Dark Energy Spectroscopic Instrument. Using an automated matched-kernel convolution method with adaptive signal-to-noise thresholds, we identify $101,487$ CIV systems in the redshift range $1.4<z<4.5$ from $300,637$ quasar spectra. Completeness is estimated via Monte Carlo simulations and catalog is $50\%$ complete at ${\mathrm{EW}}_{\mathrm{CIV}}\ge 0.4$ Angstroms. The differential equivalent width frequency distribution declines exponentially and shows weak redshift evolution. The absorber incidence per unit comoving path increases by a factor of $2-5$ from $z\approx 4.5$ to $z\approx 1.4$, with stronger redshift evolution for strong systems. Using column densities derived from the apparent optical depth method, we constrain the cosmic mass density of CIV, ${\Omega }_{\mathrm{CIV}}$, which increases by a factor of $\sim 3.8$ from $(0.82\pm 0.05)\times 10^{-8}$ at $z\approx 4.5$ to $(3.16\pm 0.2)\times 10^{-8}$ at $z\approx 1.4$. From ${\Omega }_{\mathrm{CIV}}$, we estimate a lower limit on intergalactic medium metallicity $\log (Z_{\mathrm{IGM}}/Z_{\odot })\gtrsim -3.25$ at $z\sim 2.3$, with a smooth decline at higher redshifts. These trends trace the cosmic star formation history and HeII photoheating rate, suggesting a link between CIV enrichment, star formation, and UV background over $\sim 3$ Gyr. The catalog also provides a critical resource for future studies connecting circumgalactic metals to galaxy evolution, especially near cosmic noon.

Matches Published version, the catalog is publicly available at https://data.desi.lbl.gov/doc/releases/dr1/vac/civ-absorber/

References in corpus (37)

• Array Programming with NumPy
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Cosmic Star Formation History
• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• The Circumgalactic Medium
• Cosmological Simulations of Intergalactic Medium Enrichment from Galactic Outflows
• Mass, Metal, and Energy Feedback in Cosmological Simulations
• Overview of the Instrumentation for the Dark Energy Spectroscopic Instrument
• JADES NIRSpec Spectroscopy of GN-z11: Lyman-$\alpha$ emission and possible enhanced nitrogen abundance in a $z=10.60$ luminous galaxy
• The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Baryon acoustic oscillations with Lyman-$\alpha$ forests
• The Early Data Release of the Dark Energy Spectroscopic Instrument
• The Cosmic Baryon and Metal Cycles
• The Spectroscopic Data Processing Pipeline for the Dark Energy Spectroscopic Instrument
• Target Selection and Validation of DESI Luminous Red Galaxies
• Target Selection and Validation of DESI Quasars
• Resolving small-scale cold circumgalactic gas in TNG50
• DESI 2024 VII: Cosmological Constraints from the Full-Shape Modeling of Clustering Measurements
• A downturn in intergalactic CIV as redshift 6 is approached
• Tracing the Cosmic Metal Evolution in the Low-Redshift Intergalactic Medium
• Characterizing the abundance, properties, and kinematics of the cool circumgalactic medium of galaxies in absorption with SDSS DR16
• 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
• Seven wonders of Cosmic Dawn: JWST confirms a high abundance of galaxies and AGNs at z $\simeq$ 9-11 in the GLASS field
• A Deep Narrowband Imaging Search for CIV and He II Emission from Ly$\alpha$ Blobs
• Line-driven radiative outflows in luminous quasars
• Deep Extragalactic VIsible Legacy Survey (DEVILS): Consistent multi-wavelength photometry for the DEVILS regions (COSMOS, XMMLSS & ECDFS)
• Damped Lyman-alpha Absorbers from Sloan Digital Sky Survey DR16Q with Gaussian processes
• Evolution of CIV Absorbers I. The Cosmic Incidence
• MusE GAs Flow and Wind (MEGAFLOW) VI. A study of CIV and MgII absorbing gas surrounding [OII] emitting galaxies
• Archetype-Based Redshift Estimation for the Dark Energy Spectroscopic Instrument Survey
• The Faint Host Galaxies of C IV Absorbers at z > 5
• Detecting and Characterizing Mg II absorption in DESI Survey Validation Quasar Spectra
• Cool circumgalactic gas in galaxy clusters: connecting the DESI legacy imaging survey and SDSS DR16 MgII absorbers
• Metal enrichment and evolution in four z > 6.5 quasar sightlines observed with JWST/NIRSpec
• The comoving mass density of MgII from $z\sim 2$ to $5.5$
• The COS-legacy survey of C IV absorbers: properties and origins of the intervening systems
• The C IV forest as a probe of baryon acoustic oscillations
• Absorption-based Circumgalactic Medium Line Emission Estimates

Cited by in corpus (1)

• Mapping the z>=5 SiIV Column Density Distribution onto the Galaxy Stellar Mass Function Using the Cumulative Absorption Cross Section