{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/the-cosmic-evolution-of-civ-absorbers-at-1-4","title":"The Cosmic Evolution of CIV Absorbers at $1.4<z<4.5$: Insights from $100,000$ Systems in DESI Quasars","arxiv_id":"2504.20299","date":"2025-04-28","proceeding":null,"authors":["Abhijeet Anand","J. Aguilar","S. Ahlen","D. Bianchi","A. Brodzeller","D. Brooks","R. Canning","T. Claybaugh","A. Cuceu","A. de la Macorra","P. Doel","S. Ferraro","A. Font-Ribera","J. E. Forero-Romero","E. Gaztañaga","S. Gontcho A Gontcho","G. Gutierrez","J. Guy","H. K. Herrera-Alcantar","M. Ishak","S. Juneau","R. Kehoe","A. Kremin","M. Landriau","L. Le Guillou","M. E. Levi","M. Manera","A. Meisner","R. Miquel","J. Moustakas","A. Muñoz-Gutiérrez","L. Napolitano","I. Pérez-Ràfols","G. Rossi","E. Sanchez","D. Schlegel","M. Schubnell","D. Sprayberry","G. Tarlé","M. J. Temple","B. A. Weaver","R. Zhou"],"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 $\\mathrm{EW}_{\\mathrm{CIV}} \\geq 0.4$ 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 $\\Omega_{\\rm CIV}$, we estimate a lower limit on intergalactic medium metallicity $\\log(Z_{\\rm IGM}/Z_{\\odot}) \\gtrsim -3.25$ 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.","url_abs":"https://arxiv.org/abs/2504.20299v1","url_pdf":"https://arxiv.org/pdf/2504.20299v1.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"the-cosmic-evolution-of-civ-absorbers-at-1-4","repo_url":"https://github.com/abhi0395/qsoabsfind","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}