{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"609cc0f4a3399cf30ddf862977f05aab57ba57b1b2d46f9b6364bff3e966edf1","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b","f554f82512bcb0a40282b5662df35665d7dad98d88a6683e2eaa04b0dafce056"],"salt":"47adaf60498c01f72db6b79001b999762c922e368a92f3da7f92c68e1a14438c","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"astro.circumgalactic-medium.hot-halo-extent","kind":"well-posed","literature_status":"partially-resolved","n":"2","parents":[],"plain":"Galaxies like ours should be wrapped in gas at a million degrees, which glows faintly in X-rays. Its density profile and how far out it reaches are only beginning to be measured.","posed_since":"","precise":"Determine the electron density profile $n_{e}(r)$ and temperature of X-ray emitting gas ($T \\sim 10^{6}\\,\\mathrm{K}$) around galaxies with $M_{*} \\sim 3 \\times 10^{10}\\text{ to }10^{11}\\,M_{\\mathrm{sun}}$ out to the virial radius (about 250 kpc), including the slope (for example a beta-model with $\\beta \\sim 0.5$) and the total hot gas mass.","problem_ref":"f554f82512bcb0a40282b5662df35665d7dad98d88a6683e2eaa04b0dafce056","references":"","settled_by":"Stacked deep X-ray surface brightness profiles with resolved temperature and metallicity, combined with thermal Sunyaev-Zeldovich profiles for the same galaxies.","status_note":"eROSITA All-Sky Survey stacking detected extended hot gas around Milky Way-mass galaxies (Zhang et al., A&A, 2024), with the total mass and its dependence on contamination by satellites and point sources debated.","title":"How far do hot X-ray halos extend around Milky Way-mass galaxies?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"57194b8e28fdb7c94ddeac47d8837daccc7673ea83d95b92ba11cdf2b97bebf2","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"30a54d15355d13580c940034fcdbd9afa903f3e4d0155612fcd9e5d4c33d1c1a","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"y0DP4CaPixz_ynIp-Y5DYUwIzHI_NhTOBNlZ14lhn6dXoWJPtjyzRb3yC7-nSeH0sFgrC3TTQNdfLJipo5HlAg"},"schema":"pubphys.envelope/1"},"record_hash":"57194b8e28fdb7c94ddeac47d8837daccc7673ea83d95b92ba11cdf2b97bebf2","leaf_index":2308}