{"paper":{"title":"EPISODE II: Variability in the CO and H$_2$O rovibrational absorption lines in a periodically variable protostar EC 53","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"Chul-Hwan Kim, Doug Johnstone, Giseon Baek, Gregory J. Herczeg, Ho-Gyu Lee, Jaeyeong Kim, Jeong-Eun Lee, Joel D. Green, Jun Takahashi, Jun Toshikawa, Klaus M. Pontoppidan, Logan Francis, Motohide Tamura, Seokho Lee, Takahiro Nagayama, Takayoshi Kusune, Tomohito Ohshima, Tomoki Saito, Yao-Lun Yang, Yoichi Itoh, Young-Jun Kim, Yuri Aikawa","submitted_at":"2026-06-04T18:25:10Z","abstract_excerpt":"We present two-epoch JWST NIRSpec and MIRI observations of the young protostar EC 53 (V371 Ser), a periodically variable source with well-characterized quiescent and burst phases. The spectra in both epochs show absorption in the CO overtone ($\\sim$2.3 $\\mu$m) and fundamental ($\\sim$4.6 $\\mu$m) bands and the H$_2$O stretching ($\\sim$2.7 $\\mu$m) and bending ($\\sim$6.0 $\\mu$m) modes. We also obtained high-resolution ($R\\approx45{,}000$) IGRINS spectra during the burst to constrain the CO overtone line profiles. LTE slab modeling yields gas temperatures of $\\sim$1800 K (CO overtone) and $\\sim$120"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.06628","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/2606.06628/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"}