{"id":"https://openalex.org/W7213406522","doi":"https://doi.org/10.48550/arxiv.2609.16384","title":"NOCTURNE. II. Extreme radio variability in the heart of early-stage active galactic nuclei","display_name":"NOCTURNE. II. Extreme radio variability in the heart of early-stage active galactic nuclei","publication_year":2026,"publication_date":"2026-09-14","ids":{"openalex":"https://openalex.org/W7213406522","doi":"https://doi.org/10.48550/arxiv.2609.16384"},"language":"en","primary_location":{"id":"pmh:oai:arXiv.org:2609.16384","doi":null,"is_oa":true,"landing_page_url":"https://arxiv.org/abs/2609.16384","pdf_url":"https://arxiv.org/pdf/2609.16384","source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"text"},"volume":null,"type":"preprint","is_traditional":true,"indexed_in":["arxiv","datacite"],"open_access":{"is_oa":true,"oa_status":"green","oa_url":"https://arxiv.org/pdf/2609.16384","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5054878430","display_name":"E. J\u00e4rvel\u00e4","orcid":"https://orcid.org/0000-0001-9194-7168","observed_orcids":["https://orcid.org/0000-0001-9194-7168"]},"institutions":[{"id":"https://openalex.org/I12315562","display_name":"Texas Tech University","ror":"https://ror.org/0405mnx93","country_code":"US","type":"education","lineage":["https://openalex.org/I12315562"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"J\u00e4rvel\u00e4, Emilia","raw_affiliation_strings":["Department of Physics and Astronomy , Texas Tech University , Box 41051 , Lubbock , 79409-1051 , TX , USA"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Physics and Astronomy , Texas Tech University , Box 41051 , Lubbock , 79409-1051 , TX , USA","institution_ids":["https://openalex.org/I12315562"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5000627504","display_name":"Patrizia Romano","orcid":"https://orcid.org/0000-0003-0258-7469","observed_orcids":["https://orcid.org/0000-0003-0258-7469"]},"institutions":[{"id":"https://openalex.org/I2802155305","display_name":"Brera Astronomical Observatory","ror":"https://ror.org/02kx1hs47","country_code":"IT","type":"archive","lineage":["https://openalex.org/I2802155305","https://openalex.org/I875825670"]},{"id":"https://openalex.org/I875825670","display_name":"National Institute for Astrophysics","ror":"https://ror.org/02gh4kt33","country_code":"IT","type":"government","lineage":["https://openalex.org/I875825670"]}],"countries":["IT"],"is_corresponding":false,"raw_author_name":"Romano, Patrizia","raw_affiliation_strings":["INAF -Osservatorio Astronomico di Brera , Via Emilio Bianchi 46 , I-23807 Merate (LC) , Italy"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"INAF -Osservatorio Astronomico di Brera , Via Emilio Bianchi 46 , I-23807 Merate (LC) , Italy","institution_ids":["https://openalex.org/I2802155305","https://openalex.org/I875825670"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5084784260","display_name":"Anne L\u00e4hteenm\u00e4ki","orcid":"https://orcid.org/0000-0002-0393-0647","observed_orcids":["https://orcid.org/0000-0002-0393-0647"]},"institutions":[{"id":"https://openalex.org/I9927081","display_name":"Aalto University","ror":"https://ror.org/020hwjq30","country_code":"FI","type":"education","lineage":["https://openalex.org/I9927081"]}],"countries":["FI"],"is_corresponding":false,"raw_author_name":"L\u00e4hteenm\u00e4ki, Anne","raw_affiliation_strings":["Aalto University Department of Electronics and Nanoengineering , P.O. Box 15500 , FI-00076 AALTO , Finland","Aalto University Mets\u00e4hovi Radio Observatory , Mets\u00e4hovintie 114 , FI-02540 Kylm\u00e4l\u00e4 , Finland"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Aalto University Department of Electronics and Nanoengineering , P.O. Box 15500 , FI-00076 AALTO , Finland","institution_ids":["https://openalex.org/I9927081"]},{"raw_affiliation_string":"Aalto University Mets\u00e4hovi Radio Observatory , Mets\u00e4hovintie 114 , FI-02540 Kylm\u00e4l\u00e4 , Finland","institution_ids":["https://openalex.org/I9927081"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5083148154","display_name":"Marco Berton","orcid":"https://orcid.org/0000-0002-1058-9109","observed_orcids":["https://orcid.org/0000-0002-1058-9109"]},"institutions":[{"id":"https://openalex.org/I4210129531","display_name":"European Southern Observatory","ror":"https://ror.org/0377t1328","country_code":"CL","type":"facility","lineage":["https://openalex.org/I4210129531"]}],"countries":["CL"],"is_corresponding":false,"raw_author_name":"Berton, Marco","raw_affiliation_strings":["European Southern Observatory (ESO) , Alonso de C\u00f3rdova 3107 , Casilla 19 , Santiago 19001 , Chile"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"European Southern Observatory (ESO) , Alonso de C\u00f3rdova 3107 , Casilla 19 , Santiago 19001 , Chile","institution_ids":["https://openalex.org/I4210129531"]}]}],"institutions":[],"countries_distinct_count":4,"institutions_distinct_count":5,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":null,"has_fulltext":true,"cited_by_count":0,"citation_normalized_percentile":null,"cited_by_percentile_year":null,"biblio":{"volume":null,"issue":null,"first_page":null,"last_page":null},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10744","display_name":"Astrophysical Phenomena and Observations","score":0.9726999998092651,"subfield":{"id":"https://openalex.org/subfields/3103","display_name":"Astronomy and Astrophysics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T10744","display_name":"Astrophysical Phenomena and Observations","score":0.9726999998092651,"subfield":{"id":"https://openalex.org/subfields/3103","display_name":"Astronomy and Astrophysics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10026","display_name":"Galaxies: Formation, Evolution, Phenomena","score":0.009100000374019146,"subfield":{"id":"https://openalex.org/subfields/3103","display_name":"Astronomy and Astrophysics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10818","display_name":"Astrophysics and Cosmic Phenomena","score":0.008899999782443047,"subfield":{"id":"https://openalex.org/subfields/3106","display_name":"Nuclear and High Energy Physics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/active-galactic-nuclei","display_name":"active galactic nuclei","score":0.8529999852180481},{"id":"https://openalex.org/keywords/narrow-line-seyfert-1-galaxies","display_name":"narrow-line Seyfert 1 galaxies","score":0.9350000023841858},{"id":"https://openalex.org/keywords/supermassive-black-holes","display_name":"supermassive black holes","score":0.7929999828338623},{"id":"https://openalex.org/keywords/relativistic-jets","display_name":"relativistic jets","score":0.8270000219345093},{"id":"https://openalex.org/keywords/coherent-emission","display_name":"coherent emission","score":0.5809999704360962},{"id":"https://openalex.org/keywords/doppler-factor","display_name":"Doppler factor","score":0.7519999742507935},{"id":"https://openalex.org/keywords/brightness-temperature","display_name":"brightness temperature","score":0.6449999809265137}],"concepts":[{"id":"https://openalex.org/C43481613","wikidata":"https://www.wikidata.org/wiki/Q46587","display_name":"Active galactic nucleus","level":3,"score":0.8852999806404114},{"id":"https://openalex.org/C121332964","wikidata":"https://www.wikidata.org/wiki/Q413","display_name":"Physics","level":0,"score":0.8519999980926514},{"id":"https://openalex.org/C4032939","wikidata":"https://www.wikidata.org/wiki/Q1434381","display_name":"Jansky","level":4,"score":0.8034999966621399},{"id":"https://openalex.org/C44870925","wikidata":"https://www.wikidata.org/wiki/Q37547","display_name":"Astrophysics","level":1,"score":0.7314000129699707},{"id":"https://openalex.org/C173120059","wikidata":"https://www.wikidata.org/wiki/Q40392","display_name":"Supermassive black hole","level":3,"score":0.6446999907493591},{"id":"https://openalex.org/C125245961","wikidata":"https://www.wikidata.org/wiki/Q221656","display_name":"Brightness","level":2,"score":0.5932999849319458},{"id":"https://openalex.org/C142757262","wikidata":"https://www.wikidata.org/wiki/Q76436","display_name":"Doppler effect","level":2,"score":0.5670999884605408},{"id":"https://openalex.org/C180205008","wikidata":"https://www.wikidata.org/wiki/Q159190","display_name":"Amplitude","level":2,"score":0.5407000184059143},{"id":"https://openalex.org/C1276947","wikidata":"https://www.wikidata.org/wiki/Q333","display_name":"Astronomy","level":1,"score":0.4952000081539154},{"id":"https://openalex.org/C100752510","wikidata":"https://www.wikidata.org/wiki/Q221221","display_name":"Blazar","level":3,"score":0.44269999861717224},{"id":"https://openalex.org/C50341732","wikidata":"https://www.wikidata.org/wiki/Q880302","display_name":"Black hole (networking)","level":5,"score":0.40939998626708984},{"id":"https://openalex.org/C135041427","wikidata":"https://www.wikidata.org/wiki/Q83373","display_name":"Quasar","level":3,"score":0.3181999921798706},{"id":"https://openalex.org/C59375849","wikidata":"https://www.wikidata.org/wiki/Q5013513","display_name":"COSMIC cancer database","level":2,"score":0.2863999903202057},{"id":"https://openalex.org/C145472833","wikidata":"https://www.wikidata.org/wiki/Q284657","display_name":"Astrophysical jet","level":4,"score":0.28439998626708984},{"id":"https://openalex.org/C32602459","wikidata":"https://www.wikidata.org/wiki/Q4913879","display_name":"Binary black hole","level":3,"score":0.26660001277923584},{"id":"https://openalex.org/C79896159","wikidata":"https://www.wikidata.org/wiki/Q1148351","display_name":"Very-long-baseline interferometry","level":2,"score":0.2637999951839447},{"id":"https://openalex.org/C146024833","wikidata":"https://www.wikidata.org/wiki/Q1385457","display_name":"Extreme ultraviolet","level":3,"score":0.2556000053882599},{"id":"https://openalex.org/C73329638","wikidata":"https://www.wikidata.org/wiki/Q527","display_name":"Sky","level":2,"score":0.25040000677108765}],"mesh":[],"locations_count":2,"locations":[{"id":"pmh:oai:arXiv.org:2609.16384","doi":null,"is_oa":true,"landing_page_url":"https://arxiv.org/abs/2609.16384","pdf_url":"https://arxiv.org/pdf/2609.16384","source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"text"},{"id":"doi:10.48550/arxiv.2609.16384","doi":"https://doi.org/10.48550/arxiv.2609.16384","is_oa":true,"landing_page_url":"https://doi.org/10.48550/arxiv.2609.16384","pdf_url":null,"source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":null,"is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"Preprint"}],"best_oa_location":{"id":"pmh:oai:arXiv.org:2609.16384","doi":null,"is_oa":true,"landing_page_url":"https://arxiv.org/abs/2609.16384","pdf_url":"https://arxiv.org/pdf/2609.16384","source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"text"},"sustainable_development_goals":[],"study_designs":[],"awards":[],"funders":[],"has_content":{"grobid_xml":true,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W7213406522.pdf","grobid_xml":"https://content.openalex.org/works/W7213406522.grobid-xml"},"referenced_works_count":25,"referenced_works":["https://openalex.org/W1558717895","https://openalex.org/W1559252181","https://openalex.org/W1912512737","https://openalex.org/W1983879464","https://openalex.org/W2037338049","https://openalex.org/W2037687557","https://openalex.org/W2081096924","https://openalex.org/W2170310650","https://openalex.org/W2604243687","https://openalex.org/W2732802991","https://openalex.org/W2784019939","https://openalex.org/W2800922733","https://openalex.org/W2804337859","https://openalex.org/W2851955548","https://openalex.org/W2917234208","https://openalex.org/W2975474592","https://openalex.org/W3009405053","https://openalex.org/W3047081199","https://openalex.org/W3201477391","https://openalex.org/W3204668591","https://openalex.org/W4213440398","https://openalex.org/W4297999461","https://openalex.org/W4306974326","https://openalex.org/W4353045963","https://openalex.org/W4400639884"],"related_works":["https://openalex.org/W7131867850","https://openalex.org/W4400639884","https://openalex.org/W3023209732","https://openalex.org/W7133302630","https://openalex.org/W7131814149","https://openalex.org/W3013282198","https://openalex.org/W94989489","https://openalex.org/W3119090872","https://openalex.org/W2185663256","https://openalex.org/W2995970363"],"abstract_inverted_index":{"We":[0],"report":[1],"the":[2,22,87,112],"discovery":[3],"of":[4,17,24,52,57,61,96,100,131,158],"extreme":[5],"37":[6,44,106],"GHz":[7],"radio":[8],"variability":[9,51,136,140],"in":[10,75],"early-stage":[11],"active":[12],"galactic":[13],"nuclei":[14],"(AGN).":[15],"Most":[16],"these":[18,46,76,101,124],"sources":[19],"belong":[20],"to":[21,54,86,135,147,170],"class":[23],"narrow-line":[25],"Seyfert":[26],"1":[27],"(NLS1)":[28],"galaxies,":[29],"which":[30,103],"harbour":[31],"fast-growing,":[32],"low-mass":[33],"supermassive":[34],"black":[35,88],"holes":[36],"that":[37,79,143],"accrete":[38],"at":[39,105],"high":[40],"Eddington":[41],"ratios.":[42],"At":[43],"GHz,":[45,107],"extraordinary":[47],"AGN":[48,97],"exhibit":[49],"amplitude":[50],"three":[53],"four":[55],"orders":[56],"magnitude":[58],"over":[59],"timescales":[60],"a":[62,93,155],"few":[63],"days.":[64],"Notably,":[65],"despite":[66],"several":[67],"attempts,":[68],"we":[69,126],"have":[70],"not":[71],"detected":[72],"relativistic":[73],"jets":[74],"sources,":[77,102],"suggesting":[78],"this":[80],"phenomenon":[81],"may":[82,91],"occur":[83],"very":[84],"close":[85],"hole":[89],"and":[90,119,139],"represent":[92],"new":[94],"form":[95],"variability.":[98],"One":[99],"flared":[104],"was":[108],"followed":[109],"up":[110],"with":[111],"Karl":[113],"G.":[114],"Jansky":[115],"Very":[116],"Large":[117],"Array":[118],"Swift":[120],"XRT/UVOT.":[121],"Based":[122],"on":[123],"observations,":[125],"estimated":[127],"an":[128,150,162],"e-folding":[129],"timescale":[130],"mere":[132],"hours,":[133],"leading":[134],"brightness":[137],"temperatures":[138],"Doppler":[141],"factors":[142],"are":[144],"extremely":[145],"difficult":[146],"explain":[148],"by":[149],"incoherent":[151],"emitter.":[152],"This":[153],"suggests":[154],"possible":[156],"detection":[157],"coherent":[159],"emission":[160],"from":[161],"AGN,":[163],"although":[164],"more":[165],"observations":[166],"will":[167],"be":[168],"needed":[169],"distinguish":[171],"between":[172],"alternative":[173],"scenarios.":[174]},"counts_by_year":[],"updated_date":"2026-11-07T11:25:07.637180","created_date":"2026-09-17T00:00:00"}
