{"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-density-of-the-milky-way-s-corona-at-z","title":"The density of the Milky Way's corona at $z\\approx 1.6$ through ram pressure stripping of the Draco dSph galaxy","arxiv_id":"2401.08563","date":"2024-01-16","proceeding":null,"authors":["Asger Grønnow","Filippo Fraternali","Federico Marinacci","Gabriele Pezzulli","Eline Tolstoy","Amina Helmi","Anthony G. A. Brown"],"abstract":"Satellite galaxies within the Milky Way's (MW) virial radius $R_{\\mathrm{vir}}$ are typically devoid of cold gas due to ram pressure stripping by the MW's corona. The density of this corona is poorly constrained today and essentially unconstrained in the past, but can be estimated using ram pressure stripping. In this paper, we probe the MW corona at $z\\approx 1.6$ using the Draco dwarf spheroidal galaxy. We assume that i) Draco's orbit is determined by its interaction with the MW, whose dark matter halo we evolve in time following cosmologically-motivated prescriptions, ii) Draco's star formation was quenched by ram pressure stripping and iii) the MW's corona is approximately smooth, spherical and in hydrostatic equilibrium. We used GAIA proper motions to set the initial conditions and Draco's star formation history to estimate its past gas content. We found indications that Draco was stripped of its gas during the first pericentric passage. Using 3D hydrodynamical simulations at a resolution that enables us to resolve individual supernovae and assuming no tidal stripping, which we estimate to be a minor effect, we find a density of the MW corona $\\geq 8\\times 10^{-4}$ cm$^{-3}$ at a radius $\\approx 0.72R_{\\mathrm{vir}}$. This provides evidence that the MW's corona was already in place at $z\\approx 1.6$ and with a higher density than today. If isothermal, this corona would have contained all the baryons expected by the cosmological baryon fraction. Extrapolating to today shows good agreement with literature constraints if feedback has removed $\\lesssim 30$% of baryons accreted onto the halo.","url_abs":"https://arxiv.org/abs/2401.08563v2","url_pdf":"https://arxiv.org/pdf/2401.08563v2.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-density-of-the-milky-way-s-corona-at-z","repo_url":"https://github.com/agronnow/ram_pressure_stripping","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":0,"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}