{"paper":{"title":"High-ionization coronal lines trace quasar-like activity in recently quenched galaxies at high redshift","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.HE"],"primary_cat":"astro-ph.GA","authors_text":"A. L. Faisst, A. Pensabene, A. W. S. Man, C. K. Jespersen, C. Lagos, D. Ceverino, F. Fontanot, F. Valentino, G. Brammer, G. De Lucia, G. Magdis, G. Scarpe, J. Antwi-Danso, J. R. Weaver, K. E. Whitaker, K. Ito, L. Xie, M. Farcy, M. Hamadouche, M. Hirschmann, M. Kubo, M. Onodera, M. Tanaka, O. Ilbert, P. Araya-Araya, P.-F. Wu, P. Zhu, R. Shimakawa, S. Fujimoto, S. Gillman, S. Toft, T. Kakimoto, V. Kokorev, W. M. Baker","submitted_at":"2026-05-28T18:00:04Z","abstract_excerpt":"We report the detection of the high-ionization line [NeV]$\\lambda$3427 in the JWST/NIRSpec archival spectra of 6 massive quenched galaxies at $z \\sim 1.5-4.5$, identified from a parent sample of 87 systems. With an ionization potential of approximately 97 eV, [NeV] can only be produced by strong nuclear activity in these massive systems, providing a clean and unambiguous tracer of highly accreting supermassive black holes uncontaminated by residual star formation. For 4 of the 6 [NeV]-detected systems, we detect broad H$\\alpha$ emission ($\\mathrm{FWHM} \\gtrsim 4000$ km s$^{-1}$), yielding blac"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2605.30424","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2605.30424/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"}