{"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/lyman-a-feedback-prevails-at-cosmic-dawn","title":"Lyman-$α$ feedback prevails at Cosmic Dawn: Implications for the first galaxies, stars, and star clusters","arxiv_id":"2409.19288","date":"2024-09-28","proceeding":null,"authors":["Olof Nebrin","Aaron Smith","Kevin Lorinc","Johan Hörnquist","Åsa Larson","Garrelt Mellema","Sambit K. Giri"],"abstract":"Radiation pressure from Lyman-$\\alpha$ (Ly$\\alpha$) scattering is a potentially dominant form of early stellar feedback, capable of injecting up to $\\sim 100 \\, \\times$ more momentum into the interstellar medium (ISM) than UV continuum radiation pressure and stellar winds. Ly$\\alpha$ feedback is particularly strong in dust-poor environments and is thus especially important during the formation of the first stars and galaxies. As upcoming galaxy formation simulations incorporate Ly$\\alpha$ feedback, it is crucial to consider processes that can limit it to avoid placing $\\Lambda$CDM in apparent tension with recent \\textit{JWST} observations indicating efficient star formation at Cosmic Dawn. We study Ly$\\alpha$ feedback using a novel analytical Ly$\\alpha$ radiative transfer solution that includes the effects of continuum absorption, gas velocity gradients, Ly$\\alpha$ destruction (e.g. by $2p \\rightarrow 2s$ transitions), ISM turbulence, and atomic recoil. We verify our solution for uniform clouds using extensive Monte Carlo radiative transfer (MCRT) tests, and resolve a previous discrepancy between analytical and MCRT predictions. We then study the sensitivity of Ly$\\alpha$ feedback to the aforementioned effects. While these can dampen Ly$\\alpha$ feedback by a factor $\\lesssim \\textrm{few} \\times 10$, we find it remains $\\gtrsim 5 - 100 \\, \\times$ stronger than direct radiation pressure and therefore cannot be neglected. We provide an accurate fit for the Ly$\\alpha$ force multiplier $M_{\\rm F}$, suitable for implementation in subgrid models for galaxy formation simulations. Our findings highlight the critical role of Ly$\\alpha$ feedback in regulating star formation at Cosmic Dawn, and underscore the necessity of incorporating it into simulations to accurately model early galaxy evolution.","url_abs":"https://arxiv.org/abs/2409.19288v2","url_pdf":"https://arxiv.org/pdf/2409.19288v2.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":"lyman-a-feedback-prevails-at-cosmic-dawn","repo_url":"https://github.com/olofnebrin/Lyman-alpha-feedback","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":0,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}