Resolving the Inner Parsec of the Blazar J1924-2914 with the Event Horizon Telescope

Sara Issaoun; Maciek Wielgus; Svetlana Jorstad; Thomas P. Krichbaum; Lindy Blackburn; Michael Janssen; Chi-kwan Chan; Dominic W. Pesce; Jose L. Gomez; Kazunori Akiyama; Monika Moscibrodzka; Ivan Marti-Vidal; Andrew Chael; Rocco Lico; Jun Liu; Venkatessh Ramakrishnan; Mikhail Lisakov; Antonio Fuentes; Guang-Yao Zhao; Kotaro Moriyama; Avery E. Broderick; Paul Tiede; Nicholas R. MacDonald; Yosuke Mizuno; Efthalia Traianou; Laurent Loinard; Jordy Davelaar; Mark Gurwell; Ru-Sen Lu; Antxon Alberdi; Walter Alef; Juan Carlos Algaba; Richard Anantua; Keiichi Asada; Rebecca Azulay; Uwe Bach; Anne-Kathrin Baczko; David Ball; Mislac Balokovic; John Barrett; Michi Baubock; Bradford A. Benson; Dan Bintley; Raymond Blundell; Wilfred Boland; Katherine L. Bouman; Geoffrey C. Bower; Dong-Jin Kim; Tuomas Savolainen; Jan Wagner; Event Horizon Telescope Collaboration

doi:10.3847/1538-4357/ac7a40

Resolving the Inner Parsec of the Blazar J1924-2914 with the Event Horizon Telescope

Sara Issaoun^*, Maciek Wielgus, Svetlana Jorstad, Thomas P. Krichbaum, Lindy Blackburn, Michael Janssen, Chi-kwan Chan, Dominic W. Pesce, Jose L. Gomez, Kazunori Akiyama, Monika Moscibrodzka, Ivan Marti-Vidal, Andrew Chael, Rocco Lico, Jun Liu, Venkatessh Ramakrishnan, Mikhail Lisakov, Antonio Fuentes, Guang-Yao Zhao, Kotaro MoriyamaAvery E. Broderick, Paul Tiede, Nicholas R. MacDonald, Yosuke Mizuno, Efthalia Traianou, Laurent Loinard, Jordy Davelaar, Mark Gurwell, Ru-Sen Lu, Antxon Alberdi, Walter Alef, Juan Carlos Algaba, Richard Anantua, Keiichi Asada, Rebecca Azulay, Uwe Bach, Anne-Kathrin Baczko, David Ball, Mislac Balokovic, John Barrett, Michi Baubock, Bradford A. Benson, Dan Bintley, Raymond Blundell, Wilfred Boland, Katherine L. Bouman, Geoffrey C. Bower, Dong-Jin Kim, Tuomas Savolainen, Jan Wagner, Event Horizon Telescope Collaboration

^*Corresponding author for this work

Research output: Contribution to journal › Article › Scientific › peer-review

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Abstract

The blazar J1924–2914 is a primary Event Horizon Telescope (EHT) calibrator for the Galactic center’s black hole Sagittarius A ^*. Here we present the first total and linearly polarized intensity images of this source obtained with the unprecedented 20 µas resolution of the EHT. J1924–2914 is a very compact flat-spectrum radio source with strong optical variability and polarization. In April 2017 the source was observed quasi-simultaneously with the EHT (April 5–11), the Global Millimeter VLBI Array (April 3), and the Very Long Baseline Array (April 28), giving a novel view of the source at four observing frequencies, 230, 86, 8.7, and 2.3 GHz. These observations probe jet properties from the subparsec to 100 pc scales. We combine the multifrequency images of J1924–2914 to study the source morphology. We find that the jet exhibits a characteristic bending, with a gradual clockwise rotation of the jet projected position angle of about 90° between 2.3 and 230 GHz. Linearly polarized intensity images of J1924–2914 with the extremely fine resolution of the EHT provide evidence for ordered toroidal magnetic fields in the blazar compact core.

Original language	English
Article number	145
Number of pages	21
Journal	The Astrophysical Journal
Volume	934
Issue number	2
DOIs	https://doi.org/10.3847/1538-4357/ac7a40
Publication status	Published - 1 Aug 2022
MoE publication type	A1 Journal article-refereed

Keywords

SAGITTARIUS A-ASTERISK
MAGNETIC-FIELD STRUCTURE
RELATIVISTIC JETS
BLACK-HOLES
RESULTS. I.
AGN JETS
POLARIZATION
VLBI
M87
SHADOW

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Resolving the Inner Parsec of the Blazar J1924–2914 with the Event Horizon TelescopeFinal published version, 4.92 MBLicence: CC BY

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Issaoun, S., Wielgus, M., Jorstad, S., Krichbaum, T. P., Blackburn, L., Janssen, M., Chan, C., Pesce, D. W., Gomez, J. L., Akiyama, K., Moscibrodzka, M., Marti-Vidal, I., Chael, A., Lico, R., Liu, J., Ramakrishnan, V., Lisakov, M., Fuentes, A., Zhao, G.-Y., ... Event Horizon Telescope Collaboration (2022). Resolving the Inner Parsec of the Blazar J1924-2914 with the Event Horizon Telescope. The Astrophysical Journal, 934(2), Article 145. https://doi.org/10.3847/1538-4357/ac7a40

@article{fac73d2981b2409e8569b6e2edb547ed,

title = "Resolving the Inner Parsec of the Blazar J1924-2914 with the Event Horizon Telescope",

abstract = "The blazar J1924–2914 is a primary Event Horizon Telescope (EHT) calibrator for the Galactic center{\textquoteright}s black hole Sagittarius A *. Here we present the first total and linearly polarized intensity images of this source obtained with the unprecedented 20 µas resolution of the EHT. J1924–2914 is a very compact flat-spectrum radio source with strong optical variability and polarization. In April 2017 the source was observed quasi-simultaneously with the EHT (April 5–11), the Global Millimeter VLBI Array (April 3), and the Very Long Baseline Array (April 28), giving a novel view of the source at four observing frequencies, 230, 86, 8.7, and 2.3 GHz. These observations probe jet properties from the subparsec to 100 pc scales. We combine the multifrequency images of J1924–2914 to study the source morphology. We find that the jet exhibits a characteristic bending, with a gradual clockwise rotation of the jet projected position angle of about 90° between 2.3 and 230 GHz. Linearly polarized intensity images of J1924–2914 with the extremely fine resolution of the EHT provide evidence for ordered toroidal magnetic fields in the blazar compact core.",

keywords = "SAGITTARIUS A-ASTERISK, MAGNETIC-FIELD STRUCTURE, RELATIVISTIC JETS, BLACK-HOLES, RESULTS. I., AGN JETS, POLARIZATION, VLBI, M87, SHADOW",

author = "Sara Issaoun and Maciek Wielgus and Svetlana Jorstad and Krichbaum, {Thomas P.} and Lindy Blackburn and Michael Janssen and Chi-kwan Chan and Pesce, {Dominic W.} and Gomez, {Jose L.} and Kazunori Akiyama and Monika Moscibrodzka and Ivan Marti-Vidal and Andrew Chael and Rocco Lico and Jun Liu and Venkatessh Ramakrishnan and Mikhail Lisakov and Antonio Fuentes and Guang-Yao Zhao and Kotaro Moriyama and Broderick, {Avery E.} and Paul Tiede and MacDonald, {Nicholas R.} and Yosuke Mizuno and Efthalia Traianou and Laurent Loinard and Jordy Davelaar and Mark Gurwell and Ru-Sen Lu and Antxon Alberdi and Walter Alef and Algaba, {Juan Carlos} and Richard Anantua and Keiichi Asada and Rebecca Azulay and Uwe Bach and Anne-Kathrin Baczko and David Ball and Mislac Balokovic and John Barrett and Michi Baubock and Benson, {Bradford A.} and Dan Bintley and Raymond Blundell and Wilfred Boland and Bouman, {Katherine L.} and Bower, {Geoffrey C.} and Dong-Jin Kim and Tuomas Savolainen and Jan Wagner and {Event Horizon Telescope Collaboration}",

year = "2022",

month = aug,

day = "1",

doi = "10.3847/1538-4357/ac7a40",

language = "English",

volume = "934",

journal = "The Astrophysical Journal",

issn = "0004-637X",

publisher = "Institute of Physics Publishing ",

number = "2",

}

Issaoun, S, Wielgus, M, Jorstad, S, Krichbaum, TP, Blackburn, L, Janssen, M, Chan, C, Pesce, DW, Gomez, JL, Akiyama, K, Moscibrodzka, M, Marti-Vidal, I, Chael, A, Lico, R, Liu, J, Ramakrishnan, V, Lisakov, M, Fuentes, A, Zhao, G-Y, Moriyama, K, Broderick, AE, Tiede, P, MacDonald, NR, Mizuno, Y, Traianou, E, Loinard, L, Davelaar, J, Gurwell, M, Lu, R-S, Alberdi, A, Alef, W, Algaba, JC, Anantua, R, Asada, K, Azulay, R, Bach, U, Baczko, A-K, Ball, D, Balokovic, M, Barrett, J, Baubock, M, Benson, BA, Bintley, D, Blundell, R, Boland, W, Bouman, KL, Bower, GC, Kim, D-J, Savolainen, T, Wagner, J & Event Horizon Telescope Collaboration 2022, 'Resolving the Inner Parsec of the Blazar J1924-2914 with the Event Horizon Telescope', The Astrophysical Journal, vol. 934, no. 2, 145. https://doi.org/10.3847/1538-4357/ac7a40

TY - JOUR

T1 - Resolving the Inner Parsec of the Blazar J1924-2914 with the Event Horizon Telescope

AU - Issaoun, Sara

AU - Wielgus, Maciek

AU - Jorstad, Svetlana

AU - Krichbaum, Thomas P.

AU - Blackburn, Lindy

AU - Janssen, Michael

AU - Chan, Chi-kwan

AU - Pesce, Dominic W.

AU - Gomez, Jose L.

AU - Akiyama, Kazunori

AU - Moscibrodzka, Monika

AU - Marti-Vidal, Ivan

AU - Chael, Andrew

AU - Lico, Rocco

AU - Liu, Jun

AU - Ramakrishnan, Venkatessh

AU - Lisakov, Mikhail

AU - Fuentes, Antonio

AU - Zhao, Guang-Yao

AU - Moriyama, Kotaro

AU - Broderick, Avery E.

AU - Tiede, Paul

AU - MacDonald, Nicholas R.

AU - Mizuno, Yosuke

AU - Traianou, Efthalia

AU - Loinard, Laurent

AU - Davelaar, Jordy

AU - Gurwell, Mark

AU - Lu, Ru-Sen

AU - Alberdi, Antxon

AU - Alef, Walter

AU - Algaba, Juan Carlos

AU - Anantua, Richard

AU - Asada, Keiichi

AU - Azulay, Rebecca

AU - Bach, Uwe

AU - Baczko, Anne-Kathrin

AU - Ball, David

AU - Balokovic, Mislac

AU - Barrett, John

AU - Baubock, Michi

AU - Benson, Bradford A.

AU - Bintley, Dan

AU - Blundell, Raymond

AU - Boland, Wilfred

AU - Bouman, Katherine L.

AU - Bower, Geoffrey C.

AU - Kim, Dong-Jin

AU - Savolainen, Tuomas

AU - Wagner, Jan

AU - Event Horizon Telescope Collaboration

PY - 2022/8/1

Y1 - 2022/8/1

N2 - The blazar J1924–2914 is a primary Event Horizon Telescope (EHT) calibrator for the Galactic center’s black hole Sagittarius A *. Here we present the first total and linearly polarized intensity images of this source obtained with the unprecedented 20 µas resolution of the EHT. J1924–2914 is a very compact flat-spectrum radio source with strong optical variability and polarization. In April 2017 the source was observed quasi-simultaneously with the EHT (April 5–11), the Global Millimeter VLBI Array (April 3), and the Very Long Baseline Array (April 28), giving a novel view of the source at four observing frequencies, 230, 86, 8.7, and 2.3 GHz. These observations probe jet properties from the subparsec to 100 pc scales. We combine the multifrequency images of J1924–2914 to study the source morphology. We find that the jet exhibits a characteristic bending, with a gradual clockwise rotation of the jet projected position angle of about 90° between 2.3 and 230 GHz. Linearly polarized intensity images of J1924–2914 with the extremely fine resolution of the EHT provide evidence for ordered toroidal magnetic fields in the blazar compact core.

AB - The blazar J1924–2914 is a primary Event Horizon Telescope (EHT) calibrator for the Galactic center’s black hole Sagittarius A *. Here we present the first total and linearly polarized intensity images of this source obtained with the unprecedented 20 µas resolution of the EHT. J1924–2914 is a very compact flat-spectrum radio source with strong optical variability and polarization. In April 2017 the source was observed quasi-simultaneously with the EHT (April 5–11), the Global Millimeter VLBI Array (April 3), and the Very Long Baseline Array (April 28), giving a novel view of the source at four observing frequencies, 230, 86, 8.7, and 2.3 GHz. These observations probe jet properties from the subparsec to 100 pc scales. We combine the multifrequency images of J1924–2914 to study the source morphology. We find that the jet exhibits a characteristic bending, with a gradual clockwise rotation of the jet projected position angle of about 90° between 2.3 and 230 GHz. Linearly polarized intensity images of J1924–2914 with the extremely fine resolution of the EHT provide evidence for ordered toroidal magnetic fields in the blazar compact core.

KW - SAGITTARIUS A-ASTERISK

KW - MAGNETIC-FIELD STRUCTURE

KW - RELATIVISTIC JETS

KW - BLACK-HOLES

KW - RESULTS. I.

KW - AGN JETS

KW - POLARIZATION

KW - VLBI

KW - M87

KW - SHADOW

UR - http://www.scopus.com/inward/record.url?scp=85138963476&partnerID=8YFLogxK

U2 - 10.3847/1538-4357/ac7a40

DO - 10.3847/1538-4357/ac7a40

M3 - Article

SN - 0004-637X

VL - 934

JO - The Astrophysical Journal

JF - The Astrophysical Journal

IS - 2

M1 - 145

ER -

Resolving the Inner Parsec of the Blazar J1924-2914 with the Event Horizon Telescope

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Keywords

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NT-VGOS: From quasars to geodesy: how astronomy can enable a new era in ultra-precise geodetic measurements

Physics of Black Hole-Powered Jets

Physics of Black Hole-Powered Jets

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Resolving the Inner Parsec of the Blazar J1924-2914 with the Event Horizon Telescope

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NT-VGOS: From quasars to geodesy: how astronomy can enable a new era in ultra-precise geodetic measurements

Physics of Black Hole-Powered Jets

Physics of Black Hole-Powered Jets

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Metsähovi Radio Observatory

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