An Intertwined Short and Long GRB with 4-minute Separation

An Intertwined Short and Long GRB with 4-minute Separation | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Physical Sciences - Article An Intertwined Short and Long GRB with 4-minute Separation Liang Li, Yu Wang, Bing Zhang, Ye Li, Shu-Rui Zhang, Jochen Greiner, and 16 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6071922/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Gamma-ray bursts (GRBs), among the most energetic events in the universe, are traditionally classified into long-duration GRBs, lasting over two seconds, and short-duration GRBs, lasting less than two seconds 1 . Long GRBs are typically associated with the collapse of massive stars (Type II), while short GRBs arise from the merger of compact binary objects (Type I) 2–5 . Due to their different origins, they exhibit distinct statistical properties in observations, which serve as valuable criteria for GRB classification 4, 6–11 . In this study, we report a peculiar gamma-ray burst, GRB 160425A, which consists of a short-sharp duration burst (G1) followed by a long-broad duration burst (G2) separated by only four minutes. In particular, multiple observational indicators, including duration, pulse shape 12 , minimum variability 13, 14 , spectral index 15 , spectral lag 6, 16–18 , hardness ratio 19, 20 , EHD11 and ϵ 7 parameters, as well as the Amati and Norris correlations 6, 21 , all consistently categorize G1 as a Type-I merger-origin GRB and G2 as a Type-II collapsar-origin GRB. This coexistence of merger and collapsar signatures in a single event challenges existing progenitor models, necessitating a re-evaluation of GRB classification and progenitor scenarios. Physical sciences/Astronomy and planetary science/Astronomy and astrophysics/High-energy astrophysics Physical sciences/Astronomy and planetary science/Astronomy and astrophysics/Time-domain astronomy Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6071922","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Physical Sciences - Article","associatedPublications":[],"authors":[{"id":422216138,"identity":"cf2e8e74-cd47-4e11-8003-7f4a8fe4dc76","order_by":0,"name":"Liang Li","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAxklEQVRIiWNgGAWjYBACPmbmhgNAWo5BAsRlI0ILGzMjWIsxCVoYGBtAdGID8VrYGRsP/NxRm75duseA4UPZYQb+2Q2EHXaw98zx3J1zzhgwzjh3mEHizgHCWg7wth3L3XAjx4CZt+0wg4FEAhG2/G07lm4A0vKXWC2HedtqEsBaGInWItt2wHDDnWMFB3vOpfNI3CCghZ//8OGPb9vq5A1uN2988KPMWo5/BgEtUHAYTB4AYh6i1ANBHbEKR8EoGAWjYCQCAGyiQ7ip0EUGAAAAAElFTkSuQmCC","orcid":"","institution":"Ningbo University","correspondingAuthor":true,"prefix":"","firstName":"Liang","middleName":"","lastName":"Li","suffix":""},{"id":422216139,"identity":"21ad5e08-d6a7-49d2-b65c-9a96f103e1e5","order_by":1,"name":"Yu Wang","email":"","orcid":"","institution":"ICRA","correspondingAuthor":false,"prefix":"","firstName":"Yu","middleName":"","lastName":"Wang","suffix":""},{"id":422216140,"identity":"ecf7f7f4-1d04-455e-9fad-70e527f57874","order_by":2,"name":"Bing Zhang","email":"","orcid":"","institution":"Nevada Center for Astrophysics, University of Nevada","correspondingAuthor":false,"prefix":"","firstName":"Bing","middleName":"","lastName":"Zhang","suffix":""},{"id":422216141,"identity":"660808e2-1404-4bea-b842-4bb8b2af0774","order_by":3,"name":"Ye Li","email":"","orcid":"","institution":"Purple Mountain Observatory","correspondingAuthor":false,"prefix":"","firstName":"Ye","middleName":"","lastName":"Li","suffix":""},{"id":422216142,"identity":"270965d8-593c-41e9-92cd-6597c85a0542","order_by":4,"name":"Shu-Rui Zhang","email":"","orcid":"https://orcid.org/0000-0003-0368-384X","institution":"University of Science and Technology of China","correspondingAuthor":false,"prefix":"","firstName":"Shu-Rui","middleName":"","lastName":"Zhang","suffix":""},{"id":422216143,"identity":"26a2c94e-495c-4312-8770-e48e243c5f5d","order_by":5,"name":"Jochen Greiner","email":"","orcid":"https://orcid.org/0000-0002-9875-426X","institution":"Max-Planck-Institut fuer Extraterrestrische Physik","correspondingAuthor":false,"prefix":"","firstName":"Jochen","middleName":"","lastName":"Greiner","suffix":""},{"id":422216144,"identity":"c94485cc-9e03-4794-a926-7b76bce7682d","order_by":6,"name":"Zhi-Ping Jin","email":"","orcid":"https://orcid.org/0000-0003-4977-9724","institution":"Purple Mountain Observatory, Chinese Academy of Sciences","correspondingAuthor":false,"prefix":"","firstName":"Zhi-Ping","middleName":"","lastName":"Jin","suffix":""},{"id":422216145,"identity":"c9b7ce44-3aa4-43c7-a82b-a16ea6b26243","order_by":7,"name":"Jin-Jun Geng","email":"","orcid":"","institution":"Purple Mountain Observatory","correspondingAuthor":false,"prefix":"","firstName":"Jin-Jun","middleName":"","lastName":"Geng","suffix":""},{"id":422216146,"identity":"fe04cb6e-2eec-4dd3-9e08-9f603c1369c2","order_by":8,"name":"H.-J. 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Long GRBs are typically associated with the collapse of massive stars (Type II), while short GRBs arise from the merger of compact binary objects (Type I) \u003csup\u003e2–5\u003c/sup\u003e. Due to their different origins, they exhibit distinct statistical properties in observations, which serve as valuable criteria for GRB classification\u003csup\u003e4, 6–11\u003c/sup\u003e. In this study, we report a peculiar gamma-ray burst, GRB 160425A, which consists of a short-sharp duration burst (G1) followed by a long-broad duration burst (G2) separated by only four minutes. In particular, multiple observational indicators, including duration, pulse shape \u003csup\u003e12\u003c/sup\u003e, minimum variability\u003csup\u003e13, 14\u003c/sup\u003e , spectral index \u003csup\u003e15\u003c/sup\u003e, spectral lag\u003csup\u003e6, 16–18\u003c/sup\u003e, hardness ratio\u003csup\u003e 19, 20\u003c/sup\u003e, EHD11 and ϵ 7 parameters, as well as the Amati and Norris correlations\u003csup\u003e 6, 21\u003c/sup\u003e, all consistently categorize G1 as a Type-I merger-origin GRB and G2 as a Type-II collapsar-origin GRB. This coexistence of merger and collapsar signatures in a single event challenges existing progenitor models, necessitating a re-evaluation of GRB classification and progenitor scenarios.\u003c/p\u003e","manuscriptTitle":"An Intertwined Short and Long GRB with 4-minute Separation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-03-03 05:56:49","doi":"10.21203/rs.3.rs-6071922/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"153d8b8f-6b88-4441-8735-4fe96e88666d","owner":[],"postedDate":"March 3rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":45005506,"name":"Physical sciences/Astronomy and planetary science/Astronomy and astrophysics/High-energy astrophysics"},{"id":45005507,"name":"Physical sciences/Astronomy and planetary science/Astronomy and astrophysics/Time-domain astronomy"}],"tags":[],"updatedAt":"2025-04-23T16:15:17+00:00","versionOfRecord":[],"versionCreatedAt":"2025-03-03 05:56:49","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6071922","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6071922","identity":"rs-6071922","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}