{"paper":{"title":"The kangaroo's first hop: the early fast cooling phase of EP250108a/SN 2025kg","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"Agnes P. C. van Hoof, Aishwarya Linesh Thakur, Andrea Saccardi, Andrew J. Levan, Antonio Martin-Carrillo, Ashley A. Chrimes, Ben C. Rayson, Benjamin P. Gompertz, Ben Schneider, Charles D. Kilpatrick, Christopher J. Nixon, Christopher L. Fryer, Daniele Bj{\\o}rn Malesani, Dani\\\"elle L. A. Pieterse, Daniel Mata S\\'anchez, Dieter H. Hartmann, Eric Burns, Francesco Carotenuto, Franz E. Bauer, Giavanna Pugliese, Giorgos Leloudas, Gregory Corcoran, Ilya Mandel, Jan van Roestel, Jennifer A. Chac\\'on, Jesse Palmerio, Jillian C. Rastinejad, Joe S. Bright, Jonathan Quirola-V\\'asquez, Joyce N. D. van Dalen, Laura Cotter, Luca Izzo, Manuel A. P. Torres, Maria E. Ravasio, Massimiliano De Pasquale, Nial R. Tanvir, Nikhil Sarin, Nusrin Habeeb, P\\'all Jakobsson, Paul J. Groot, Paul M. Vreeswijk, Paul T. O'Brien, Peter G. Jonker, Rhaana L. C. Starling, Rob A. J. Eyles-Ferris, Ruben Salvaterra, Sergio Campana, Stefano Covino, Steven Bloemen, Susanna D. Vergani, Tanmoy Laskar, Tayyaba Zafar, Valerio D'Elia, Wen-fai Fong, Yashaswi Julakanti","submitted_at":"2025-04-11T18:00:02Z","abstract_excerpt":"Fast X-ray transients (FXTs) are a rare and poorly understood population of events. Previously difficult to detect in real time, the launch of the Einstein Probe with its wide field X-ray telescope has led to a rapid expansion in the sample and allowed the exploration of these transients across the electromagnetic spectrum. EP250108a is a recently detected example linked to an optical counterpart, SN 2025kg, or 'the kangaroo'. Together with a companion paper (Rastinejad et al. 2025), we present our observing campaign and analysis of this event. In this letter, we focus on the early evolution o"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2504.08886","kind":"arxiv","version":4},"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/2504.08886/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"}