{"paper":{"title":"A Substantial Mass of Cool, Metal-Enriched Gas Surrounding the Progenitors of Modern-Day Ellipticals","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"2), (2) Max-Planck-Institut fur Astronomie, (3) MIT Kavli Institute for Astrophysics, Joseph F. Hennawi (2), J. Xavier Prochaska (1, Robert A. Simcoe (3) ((1) UCO/Lick Observatory, Space Research), UC Santa Cruz","submitted_at":"2012-11-26T21:10:41Z","abstract_excerpt":"The hosts of luminous z~2 quasars evolve into today's massive elliptical galaxies. Current theories predict that the circum-galactic medium (CGM) of these massive, dark-matter halos (M~10^12.5 Msun) should be dominated by a T~10^7 K virialized plasma. We test this hypothesis with observations of 74 close-projected quasar pairs, using spectra of the background QSO to characterize the CGM of the foreground one. Surprisingly, our measurements reveal a cool (T~10^4 K), massive (M_CGM > 10^10 Msun), and metal-enriched (Z > ~0.1 Zsun) medium extending to at least the expected virial radius (r_vir = "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1211.6131","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"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"}