{"paper":{"title":"EP250827b/SN 2025wkm: An X-ray Flash-Supernova Powered by a Central Engine and Circumstellar Interaction","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"A magnetar central engine powers an X-ray flash supernova through wind breakout in circumstellar material","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"Abdusamatjan Iskandar, Alberto J. Castro-Tirado, Aleksandra Bochenek, Ali Esamdin, Amar Aryan, Annabelle E. Niblett, Anna Y. Q. Ho, Anthony L. Piro, Antonella Palmese, Ben Rusholme, Binbin Zhang, Brendan O'Connor, Cassie Sevilla, Chen Zhang, Chichuan Jin, Christopher L. Fryer, Constantin Tabor, Curtis McCully, D. Andrew Howell, Daniel A. Perley, Daniel Gruen, Dong Xu, Dongyue Li, Emilio Fern\\'andez-Garc\\'ia, Eric Burns, Eric C. Bellm, Estefania Padilla Gonzalez, Frank J. Masci, Genevieve Schroeder, Giacomo Terreran, Gokul P. Srinivasaragavan, Grace Daja, Gursimran Bhullar, Han-Long Peng, Heyang Liu, Huaqing Chen, Hui Sun, Ignacio P\\'erez-Garc\\'ia, Jennifer Faba-Moreno, Jesper Sollerman, Jialian Liu, Ji-an Jiang, Jie An, Jingwei Hu, Joahan Castaneda Jaims, Johan P.U. Fynbo, Joseph Farah, Josiah Purdum, Jule Augustin, Julius Gassert, Kangrui Ni, Kanthanakorn Noysena, Kathryn Wynn, Krittapas Chanchaiworawit, Letian Wang, Linbo He, Lin Yan, Malte Busmann, Mansi Kasliwal, Maria D. Caballero-Garc\\'ia, Maria Edvige Ravasio, Maria Gritsevich, Matthew Graham, M. Coleman Miller, Megan Newsome, Moira Andrews, Niharika Sravan, Nikhil Sarin, Ning Jiang, Ore Gottlieb, Pablo Vega, Qinyu Wu, Robert Stein, Roger Smith, Rub\\'en S\\'anchez-Ram\\'irez, Runduo Liang, Samaporn Tinyanont, Sam Rose, S. Bradley Cenko, Sergiy Guziy, Shaoyu Fu, Shashi B. Pandey, Shengyu Yan, Shreya Anand, Shuaijiao Jiang, Siyu Wu, Tao An, Tinggu Wang, Tom\\'as Ahumada, Weimin Yuan, Wenxiong Li, Xander J. Hall, Xiaofeng Wang, Xiaoxiong Zuo, Xing Liu, Xuefeng Wu, You-Dong Hu, Yuan Liu, Yujia Song, Yu-Jing Qin, Yunfei Xu, Zhixing Ling, Zipei Zhu","submitted_at":"2025-12-11T02:44:47Z","abstract_excerpt":"We present the discovery of EP250827b/SN 2025wkm, an X-ray Flash (XRF) discovered by the Einstein Probe (EP), accompanied by a broad-line Type Ic supernova (SN Ic-BL) at $z = 0.1194$. EP250827b possesses a prompt X-ray luminosity of $\\sim 10^{45} \\, \\rm{erg \\, s^{-1}}$, lasts over 1000 seconds, and has a peak energy $E_{\\rm{p}} < 1.5$ keV at 90\\% confidence. SN 2025wkm possesses a double-peaked optical light curve (LC), though its bolometric luminosity plateaus after its initial peak for $\\sim 20$ days, consistent with a central engine injecting additional energy into the explosion. Its spectr"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"The collapse gives rise to a long-lived magnetar, potentially surrounded by an accretion disk. Magnetically-driven winds from the magnetar and the disk mix together and break out with a velocity ∼0.35c and interact with an extended circumstellar medium with radius ∼10^13 cm, generating X-ray breakout emission through non-thermal free-free processes.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The X-ray emission arises specifically from non-thermal free-free processes in the magnetar/disk wind breakout through the CSM at the quoted radius and velocity; this is invoked to simultaneously explain the soft X-ray spectrum, duration, and optical plateau without independent verification of the wind properties or CSM structure.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"EP250827b/SN 2025wkm is an X-ray flash supernova at z=0.1194 powered by a long-lived magnetar and disk winds interacting with extended circumstellar medium, without an on-axis relativistic jet.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"A magnetar central engine powers an X-ray flash supernova through wind breakout in circumstellar material","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"1449e2c09318e1dc9a683477dbfb9a7a9a246dc0e681fba483e57ce125f3fec6"},"source":{"id":"2512.10239","kind":"arxiv","version":3},"verdict":{"id":"d3499f97-fe64-4b21-85ed-9bd5e2d75937","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-16T23:57:16.051147Z","strongest_claim":"The collapse gives rise to a long-lived magnetar, potentially surrounded by an accretion disk. Magnetically-driven winds from the magnetar and the disk mix together and break out with a velocity ∼0.35c and interact with an extended circumstellar medium with radius ∼10^13 cm, generating X-ray breakout emission through non-thermal free-free processes.","one_line_summary":"EP250827b/SN 2025wkm is an X-ray flash supernova at z=0.1194 powered by a long-lived magnetar and disk winds interacting with extended circumstellar medium, without an on-axis relativistic jet.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The X-ray emission arises specifically from non-thermal free-free processes in the magnetar/disk wind breakout through the CSM at the quoted radius and velocity; this is invoked to simultaneously explain the soft X-ray spectrum, duration, and optical plateau without independent verification of the wind properties or CSM structure.","pith_extraction_headline":"A magnetar central engine powers an X-ray flash supernova through wind breakout in circumstellar material"},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2512.10239/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":2,"snapshot_sha256":"4ed34c05dc53928cf81e24e725f910e9723bddf5afb7f8a12e19429e7af7c1d6"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}