{"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/astrophysical-constraints-from-the-saras3-non","title":"Astrophysical Constraints from the SARAS3 non-detection of the Cosmic Dawn Sky-Averaged 21-cm Signal","arxiv_id":"2212.00464","date":"2022-12-01","proceeding":null,"authors":["H. T. J. Bevins","A. Fialkov","E. de Lera Acedo","W. J. Handley","S. Singh","R. Subrahmanyan","R. Barkana"],"abstract":"Observations of the redshifted 21-cm line of atomic hydrogen have resulted in several upper limits on the 21-cm power spectrum and a tentative detection of the sky-averaged signal at $z\\sim17$. Made with the EDGES Low-Band antenna, this claim was recently disputed by the SARAS3 experiment, which reported a non-detection and is the only available upper limit strong enough to constrain cosmic dawn astrophysics. We use these data to constrain a population of radio-luminous galaxies $\\sim 200$ million years after the Big Bang ($z\\approx 20$). We find, using Bayesian data analysis, that the data disfavours (at 68% confidence) radio-luminous galaxies in dark matter halos with masses of $4.4\\times10^{5}$ M$_\\odot \\lesssim M \\lesssim 1.1\\times10^{7}$M$_\\odot$ (where $M_\\odot$ is the mass of the Sun) at $z = 20$ and galaxies in which $>5$% of the gas is converted into stars. The data disfavour galaxies with radio luminosity per star formation rate of $L_\\mathrm{r}/\\mathrm{SFR} \\gtrsim 1.549 \\times 10^{25}$ W Hz$^{-1}$M$_\\odot^{-1}$ yr at 150 MHz, a thousand times brighter than today, and, separately, a synchrotron radio background in excess of the CMB by $\\gtrsim 6%$ at 1.42 GHz.","url_abs":"https://arxiv.org/abs/2212.00464v1","url_pdf":"https://arxiv.org/pdf/2212.00464v1.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":"astrophysical-constraints-from-the-saras3-non","repo_url":"https://github.com/htjb/margarine","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":0,"framework":"tf","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}