{"paper":{"title":"Eruptive mass loss less than a year before the explosion of superluminous supernovae: I. The cases of SN 2020xga and SN 2022xgc","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"A. Gal-Yam, A. Gangopadhyay, A. Gkini, A. Sahu, A. Singh, C. Fransson, C. Fremling, C. Inserra, C. M. B. Omand, C. McCully, C. Pellegrino, C. P. Guti\\'errez, D. A. Howell, D. A. Perley, D. Hiramatsu, D. R. Young, E. P. Gonzalez, F. J. Masci, F. Poidevin, F. Ragosta, G. Pignata, I. P\\'erez-Fournon, J. L. Wise, J. P. Anderson, J. Sollerman, K. Matilainen, K. R. Hinds, L. Galbany, L. Lacroix, L. Yan, M. Bronikowski, M. Fraser, M. Gromadzki, M. Kopsacheili, M. Nicholl, N. Sarin, P. J. Pessi, R. Dekany, R. K\\\"onyves-T\\'oth, R. Lunnan, S. Geier, S. J. Brennan, S. L. Groom, S. Schulze, S. Srivastav, T. E. M\\\"uller-Bravo, T. Moore, T. Petrushevska, T.-W. Chen, Y. Hu","submitted_at":"2024-09-25T19:15:34Z","abstract_excerpt":"We present photometric and spectroscopic observations of SN 2020xga and SN 2022xgc, two hydrogen-poor superluminous supernovae (SLSNe-I) at $z = 0.4296$ and $z = 0.3103$, respectively, which show an additional set of broad Mg II absorption lines, blueshifted by a few thousands kilometer second$^{-1}$ with respect to the host galaxy absorption system. Previous work interpreted this as due to resonance line scattering of the SLSN continuum by rapidly expanding circumstellar material (CSM) expelled shortly before the explosion. The peak rest-frame $g$-band magnitude of SN 2020xga is $-22.30 \\pm 0"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2409.17296","kind":"arxiv","version":2},"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/2409.17296/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"}