A Seyfert galaxy as a hidden counterpart to a neutrino-associated blazar

A Seyfert galaxy as a hidden counterpart to a neutrino-associated blazar | 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 Article A Seyfert galaxy as a hidden counterpart to a neutrino-associated blazar Emma Kun This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8481401/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract The origin and production mechanisms of high-energy astrophysical neutrinos remain open questions in multimessenger astronomy. Previous studies have hinted at a possible linear correlation between the hard X-ray and high-energy neutrino emission in active galactic nuclei. New NuSTAR observations, first presented here, reveal that blazar PKS 1424+240, located within a prominent IceCube neutrino hotspot, is far fainter in hard X-rays than expected from this trend. Motivated by this apparent ambiguity, we identify the nearby Seyfert galaxy NGC 5610, also coincident with the hotspot, whose unabsorbed hard X-ray flux exceeds that of PKS 1424+240 by about an order of magnitude. When the local IceCube neutrino flux is apportioned between the two AGN in proportion to their hard X-ray emission, both align with the previously suggested X-ray-neutrino correlation. This suggests that certain IceCube hotspots may be unresolved blends of multiple AGN, and supports a multimessenger scenario in which high-energy neutrinos and hard X-rays originate from the same hadronic interactions, with the X-ray emission produced through cascade reprocessing. Physical sciences/Astronomy and planetary science/Astronomy and astrophysics/High-energy astrophysics Physical sciences/Astronomy and planetary science/Astronomy and astrophysics/Particle astrophysics Physical sciences/Astronomy and planetary science/Astronomy and astrophysics/Galaxies and clusters High energy astrophysics hard X-rays high-energy neutrinos Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Under Review 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. 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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-8481401","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":578834660,"identity":"68360c5a-9ac2-4dc5-b667-c131b309ebf6","order_by":0,"name":"Emma Kun","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAyklEQVRIiWNgGAWjYBACCRiDH4g/NpCkRbKBgXEmaVoMDhCrRXJG7gGGjznb5I2PH3/YOIPBJl/egYAWaYm8BMaZ224bbjuTY9i4gSHNcuMBAlrkJHIMmHm33WbcdoOH/eEDhsMGhoRcB9byd9tt+80z2B82EqVFGqSFcdvtxA0SDCCHHTaQJ6CDQbLnjcHB3m23k2eA/DLDIM3AgJAWieM5hg9+brtt298ODLGeChsDeUIOA4EDCKYBOIJIBUTZMgpGwSgYBSMKAAD00ENwR7IrJgAAAABJRU5ErkJggg==","orcid":"","institution":"Ruhr University Bochum","correspondingAuthor":true,"prefix":"","firstName":"Emma","middleName":"","lastName":"Kun","suffix":""}],"badges":[],"createdAt":"2025-12-30 12:45:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8481401/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8481401/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102996005,"identity":"aa84b50a-ecff-4a6c-85b5-c8729d1369df","added_by":"auto","created_at":"2026-02-19 12:15:21","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1448101,"visible":true,"origin":"","legend":"Article File","description":"","filename":"snarticle.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8481401/v1_covered_6b99df90-4add-4e7b-a1bf-37cfc88d30e8.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"A Seyfert galaxy as a hidden counterpart to a neutrino-associated blazar","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"High energy astrophysics, hard X-rays, high-energy neutrinos","lastPublishedDoi":"10.21203/rs.3.rs-8481401/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8481401/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"The origin and production mechanisms of high-energy astrophysical neutrinos remain open questions in multimessenger astronomy. 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