Unraveling the Innermost Jet Structure of OJ 287 with the First GMVA + ALMA Observations

dc.contributorAalto Universityen
dc.contributor.authorZhao, Guang Yaoen_US
dc.contributor.authorGómez, José L.en_US
dc.contributor.authorFuentes, Antonioen_US
dc.contributor.authorKrichbaum, Thomas P.en_US
dc.contributor.authorTraianou, Efthaliaen_US
dc.contributor.authorLico, Roccoen_US
dc.contributor.authorCho, Iljeen_US
dc.contributor.authorRos, Eduardoen_US
dc.contributor.authorKomossa, S.en_US
dc.contributor.authorAkiyama, Kazunorien_US
dc.contributor.authorAsada, Keiichien_US
dc.contributor.authorBlackburn, Lindyen_US
dc.contributor.authorBritzen, Silkeen_US
dc.contributor.authorBruni, Gabrieleen_US
dc.contributor.authorCrew, Geoffrey B.en_US
dc.contributor.authorDahale, Rohanen_US
dc.contributor.authorDey, Lankeswaren_US
dc.contributor.authorGold, Romanen_US
dc.contributor.authorGopakumar, Achamveeduen_US
dc.contributor.authorIssaoun, Saraen_US
dc.contributor.authorJanssen, Michaelen_US
dc.contributor.authorJorstad, Svetlanaen_US
dc.contributor.authorKim, Jae Youngen_US
dc.contributor.authorKoay, Jun Yien_US
dc.contributor.authorKovalev, Yuri Y.en_US
dc.contributor.authorKoyama, Shokoen_US
dc.contributor.authorLobanov, Andrei P.en_US
dc.contributor.authorLoinard, Laurenten_US
dc.contributor.authorLu, Ru Senen_US
dc.contributor.authorMarkoff, Seraen_US
dc.contributor.authorMarscher, Alan P.en_US
dc.contributor.authorMartí-Vidal, Ivánen_US
dc.contributor.authorMizuno, Yosukeen_US
dc.contributor.authorPark, Jonghoen_US
dc.contributor.authorSavolainen, Tuomasen_US
dc.contributor.authorToscano, Teresaen_US
dc.contributor.departmentDepartment of Electronics and Nanoengineeringen
dc.contributor.departmentMetsähovi Radio Observatoryen
dc.contributor.groupauthorAnne Lähteenmäki Groupen
dc.contributor.organizationCSIC - Institute of Astrophysics of Andalusiaen_US
dc.contributor.organizationMax Planck Institute for Radio Astronomyen_US
dc.contributor.organizationMassachusetts Institute of Technology MITen_US
dc.contributor.organizationAcademia Sinica Institute of Astronomy and Astrophysicsen_US
dc.contributor.organizationHarvard Universityen_US
dc.contributor.organizationNational Institute for Astrophysics (INAF)en_US
dc.contributor.organizationTata Institute of Fundamental Researchen_US
dc.contributor.organizationUniversity of Southern Denmarken_US
dc.contributor.organizationBoston Universityen_US
dc.contributor.organizationNiigata Universityen_US
dc.contributor.organizationChinese Academy of Sciencesen_US
dc.contributor.organizationUniversity of Amsterdamen_US
dc.contributor.organizationUniversidad de Valenciaen_US
dc.descriptionFunding Information: The work at the IAA-CSIC is supported in part by the Spanish Ministerio de Economía y Competitividad (grants AYA2016-80889-P and PID2019-108995GB-C21), the Consejería de Economía, Conocimiento, Empresas y Universidad of the Junta de Andalucía (grant P18-FR-1769), the Consejo Superior de Investigaciones Científicas (grant 2019AEP112), and the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). This publication acknowledges the project M2FINDERS, which is funded by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 101018682). L.L. acknowledges the support of the DGAPA/PAPIIT grants IN112417 and IN112820, the CONACyT-AEM grant 275201, and the CONACyT-CF grant 263356. T.S. was supported by the Academy of Finland projects 274477, 284495, 312496, and 315721. Y.K. was supported in the framework of the State project “Science” by the Ministry of Science and Higher Education of the Russian Federation, under the contract 075-15-2020-778. J.Y.K acknowledges support from the National Research Foundation of Korea (grant no. 2022R1C1C1005255). R.-S. L is supported by the Max Planck Partner Group of the MPG and the CAS, the Key Program of the National Natural Science Foundation of China (grant No. 11933007), the Key Research Program of Frontier Sciences, CAS (grant No. ZDBS-LY-SLH011), and the Shanghai Pilot Program for Basic Research – Chinese Academy of Science, Shanghai Branch (JCYJ-SHFY-2022-013). Publisher Copyright: © 2022. The Author(s). Published by the American Astronomical Society.
dc.description.abstractWe present the first very long baseline interferometric (VLBI) observations of the blazar OJ 287 carried out jointly with the Global Millimeter VLBI Array (GMVA) and the phased Atacama Large Millimeter/submillimeter Array (ALMA) at 3.5 mm on 2017 April 2. The participation of phased ALMA has not only improved the GMVA north-south resolution by a factor of ∼3, but has also enabled fringe detections with signal-to-noise ratios up to 300 at baselines longer than 2 Gλ. The high sensitivity has motivated us to image the data with newly developed regularized maximum likelihood imaging methods, revealing the innermost jet structure with unprecedentedly high angular resolution. Our images reveal a compact and twisted jet extending along the northwest direction, with two bends within the inner 200 μas, resembling a precessing jet in projection. The component at the southeastern end shows a compact morphology and high brightness temperature, and is identified as the VLBI core. An extended jet feature that lies at ∼200 μas northwest of the core shows a conical shape, in both total and linearly polarized intensity, and a bimodal distribution of the linear polarization electric vector position angle. We discuss the nature of this feature by comparing our observations with models and simulations of oblique and recollimation shocks with various magnetic field configurations. Our high-fidelity images also enabled us to search for possible jet features from the secondary supermassive black hole (SMBH) and test the SMBH binary hypothesis proposed for this source.en
dc.description.versionPeer revieweden
dc.identifier.citationZhao, G Y, Gómez, J L, Fuentes, A, Krichbaum, T P, Traianou, E, Lico, R, Cho, I, Ros, E, Komossa, S, Akiyama, K, Asada, K, Blackburn, L, Britzen, S, Bruni, G, Crew, G B, Dahale, R, Dey, L, Gold, R, Gopakumar, A, Issaoun, S, Janssen, M, Jorstad, S, Kim, J Y, Koay, J Y, Kovalev, Y Y, Koyama, S, Lobanov, A P, Loinard, L, Lu, R S, Markoff, S, Marscher, A P, Martí-Vidal, I, Mizuno, Y, Park, J, Savolainen, T & Toscano, T 2022, ' Unraveling the Innermost Jet Structure of OJ 287 with the First GMVA + ALMA Observations ', The Astrophysical Journal, vol. 932, no. 1, 72 . https://doi.org/10.3847/1538-4357/ac6b9cen
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dc.publisherIOP Publishing Ltd.
dc.relation.ispartofseriesThe Astrophysical Journalen
dc.relation.ispartofseriesVolume 932, issue 1en
dc.subject.keywordHigh Energy Astrophysical Phenomena (astro-ph.HE)en_US
dc.subject.keywordAstrophysics of Galaxies (astro-ph.GA)en_US
dc.subject.keywordFOS: Physical sciencesen_US
dc.titleUnraveling the Innermost Jet Structure of OJ 287 with the First GMVA + ALMA Observationsen
dc.typeA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessäfi