{"paper":{"title":"Inferring the mass of the circumgalactic medium using X-ray resonant scattering","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"astro-ph.GA","authors_text":"Chris Byrohl, Dylan Nelson, Maxim Markevitch, Nhut Truong","submitted_at":"2026-03-26T16:19:27Z","abstract_excerpt":"The circumgalactic medium (CGM) regulates galaxy growth and retains the imprint of feedback from supernovae and supermassive black holes. However, the bulk of the hot CGM produces little X-ray emission and is challenging to study with X-ray telescopes. We propose a novel method for evaluating the CGM mass using resonant scattering of the helium-like oxygen (\\ovii) resonant line at $E=574$ eV. In a spherically symmetric and static CGM halo with a sharp central X-ray peak, the number of \\ovii\\ ions within an outer radial shell can be calculated from the ratio of the two directly observable quant"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2603.25600","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2603.25600/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}