Research output: Contribution to journal › Article › peer-review
Unraveling the Innermost Jet Structure of OJ 287 with the First GMVA + ALMA Observations. / Zhao, Guang Yao; Gómez, José L.; Fuentes, Antonio; Krichbaum, Thomas P.; Traianou, Efthalia; Lico, Rocco; Cho, Ilje; Ros, Eduardo; Komossa, S.; Akiyama, Kazunori; Asada, Keiichi; Blackburn, Lindy; Britzen, Silke; Bruni, Gabriele; Crew, Geoffrey B.; Dahale, Rohan; Dey, Lankeswar; Gold, Roman; Gopakumar, Achamveedu; Issaoun, Sara; Janssen, Michael; Jorstad, Svetlana; Kim, Jae Young; Koay, Jun Yi; Kovalev, Yuri Y.; Koyama, Shoko; Lobanov, Andrei P.; Loinard, Laurent; Lu, Ru Sen; Markoff, Sera; Marscher, Alan P.; Martí-Vidal, Iván; Mizuno, Yosuke; Park, Jongho; Savolainen, Tuomas; Toscano, Teresa.
In: Astrophysical Journal, Vol. 932, No. 1, 72, 01.06.2022.Research output: Contribution to journal › Article › peer-review
}
TY - JOUR
T1 - Unraveling the Innermost Jet Structure of OJ 287 with the First GMVA + ALMA Observations
AU - Zhao, Guang Yao
AU - Gómez, José L.
AU - Fuentes, Antonio
AU - Krichbaum, Thomas P.
AU - Traianou, Efthalia
AU - Lico, Rocco
AU - Cho, Ilje
AU - Ros, Eduardo
AU - Komossa, S.
AU - Akiyama, Kazunori
AU - Asada, Keiichi
AU - Blackburn, Lindy
AU - Britzen, Silke
AU - Bruni, Gabriele
AU - Crew, Geoffrey B.
AU - Dahale, Rohan
AU - Dey, Lankeswar
AU - Gold, Roman
AU - Gopakumar, Achamveedu
AU - Issaoun, Sara
AU - Janssen, Michael
AU - Jorstad, Svetlana
AU - Kim, Jae Young
AU - Koay, Jun Yi
AU - Kovalev, Yuri Y.
AU - Koyama, Shoko
AU - Lobanov, Andrei P.
AU - Loinard, Laurent
AU - Lu, Ru Sen
AU - Markoff, Sera
AU - Marscher, Alan P.
AU - Martí-Vidal, Iván
AU - Mizuno, Yosuke
AU - Park, Jongho
AU - Savolainen, Tuomas
AU - Toscano, Teresa
N1 - Publisher Copyright: © 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/6/1
Y1 - 2022/6/1
N2 - We 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.
AB - We 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.
UR - http://www.scopus.com/inward/record.url?scp=85133541293&partnerID=8YFLogxK
UR - https://www.mendeley.com/catalogue/1f30c84a-2b9b-3c2d-b577-f6d9461701b2/
U2 - 10.3847/1538-4357/ac6b9c
DO - 10.3847/1538-4357/ac6b9c
M3 - Article
AN - SCOPUS:85133541293
VL - 932
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1
M1 - 72
ER -
ID: 99846912