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

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.

Daniel C. M. Palumbo | Michael F. Wondrak | Chih-Wei L. Huang | P. K. Leung | Alexander W. Raymond | K. Souccar | H. Falcke | T. Lauer | K. Bouman | G. Desvignes | S. Ikeda | B. Benson | J. Carlstrom | D. Michalik | A. Nadolski | D. James | P. Koch | L. Rezzolla | K. Menten | R. Neri | P. Ho | L. Blackburn | E. Ros | J. Algaba | Sang-Sung Lee | M. Kino | S. Trippe | Jongho Park | Guangyao Zhao | D. Byun | M. Gurwell | Jae-Young Kim | P. Galison | M. Hecht | C. Gammie | N. Patel | M. Inoue | Aviad Levis | F. Schloerb | E. Fomalont | Jongsoo Kim | R. Narayan | Michael D. Johnson | S. Doeleman | J. Wardle | S. Chatterjee | L. Loinard | F. Roelofs | D. Psaltis | J. Weintroub | A. Rogers | R. Plambeck | R. Tilanus | P. Friberg | J. Moran | K. Young | M. Titus | D. Marrone | T. Krichbaum | A. Roy | V. Fish | K. Akiyama | A. Lobanov | A. Broderick | R. Blundell | M. Honma | T. Oyama | J. SooHoo | F. Tazaki | J. Dexter | A. Chael | K. Asada | C. Brinkerink | G. Crew | R. Gold | J. Zensus | D. Haggard | R. Karuppusamy | Kuo Liu | P. Torne | I. Martí-Vidal | N. Nagar | D. Hughes | Ming-Tang Chen | R. Hesper | I. Myserlis | M. Sasada | D. Pesce | P. Tiede | H. Pu | Dong-Jin Kim | A. Marscher | S. Jorstad | U. Pen | T. Crawford | D. Bintley | D. Ward-Thompson | B. Jannuzi | A. Young | K. Chatterjee | I. Natarajan | A. Alberdi | W. Alef | R. Azulay | A. Baczko | D. Ball | M. Baloković | J. Barrett | W. Boland | M. Bremer | R. Brissenden | S. Britzen | T. Bronzwaer | Chi-kwan Chan | I. Cho | P. Christian | Yuzhu Cui | J. Davelaar | R. Deane | J. Dempsey | R. Eatough | R. Fraga-Encinas | C. Fromm | Roberto García | O. Gentaz | B. Georgiev | K. Hada | S. Issaoun | M. Janssen | B. Jeter | T. Jung | M. Karami | T. Kawashima | G. Keating | M. Kettenis | Junhan Kim | J. Koay | S. Koyama | C. Kuo | M. Lindqvist | E. Liuzzo | W. Lo | C. Lonsdale | N. MacDonald | S. Markoff | S. Matsushita | L. Matthews | L. Medeiros | Y. Mizuno | I. Mizuno | K. Moriyama | M. Mościbrodzka | C. Müller | H. Nagai | G. Narayanan | C. Ni | A. Noutsos | H. Okino | H. Olivares | D. Palumbo | V. Piétu | A. PopStefanija | O. Porth | B. Prather | J. A. Preciado-López | V. Ramakrishnan | M. Rawlings | B. Ripperda | A. Roshanineshat | H. Rottmann | C. Ruszczyk | K. Rygl | S. Sánchez | D. Sánchez-Arguelles | T. Savolainen | K. Schuster | D. Small | B. Sohn | T. Trent | N. Wex | R. Wharton | M. Wielgus | G. Wong | Z. Younsi | Shan-Shan Zhao | U. Bach | J. Farah | A. Gómez-Ruiz | C. Impellizzeri | J. Neilsen | M. Nowak | H. Parsons | Ignacio Ruiz | P. Yamaguchi | H. Ford | A. Cruz-Osorio | H. V. van Langevelde | J. Conway | Michael Kramer | F. Özel | R. Rao | I. V. van Bemmel | D. V. van Rossum | K. Wiik | William T. Freeman | C. Kramer | J. Gómez | M. Bauböck | A. Jiménez-Rosales | D. Yoon | G. Witzel | N. Marchili | H. Boyce | R. Lico | M. Laurentis | A. Nathanail | R. Emami | A. Tetarenko | Vedant Dhruv | Angelo Ricarte | C. Romero-Cañizales | G. Musoke | Z. Li 李 | Richard Anantua | C. Ceccobello | A. Fuentes | E. Traianou | Greg Lindahl | Daeyoung Lee | Alejandro Mus | D. Broguiere | Y. Chen 陈 | Nicholas S. Conroy | M. Gu 顾 | L. Ho 何 | Lei 磊 Huang 黄 | Wu 悟 Jiang 江 | Abhishek V. Joshi | Prashant Kocherlakota | Yutaro Kofuji | M. Lisakov | J. Liu 刘 | R. Lu 路 | J. Mao 毛 | Junghwan Oh | F. M. Pötzl | M. Sánchez-Portal | Kaushik Satapathy | Z. Shen 沈 | J. Vos | Q. Wu 吴 | Y. Yuan 袁 | Shuo Zhang | Sandra Bustamante | N. Bella | G. Paraschos | M. Nakamura | C. Goddi | J. Oh | G. Ortiz-Léon | Lijing Shao | H. Sun 孙 | J. Wagner | F. Yuan 袁 | J. Cordes | M. Wondrak | G. Bower | J. Liu 刘 | Sergio Abraham Dzib Quijano | R. García | M. Kramer | A. Raymond | P. Leung | L. Huang 黄 | J. Gómez | David Ball | Shiro Ikeda | Aleksandar PopStefanija | W. T. Freeman | Olivier Gentaz | Britton Jeter | C. Kuo | Wen-Ping Lo | Kotaro Moriyama | Jorge A. Preciado-López | Hung-Yi Pu | Ramprasad Rao | Arash Roshanineshat | I. van Bemmel | Daniel R. van Rossum | Doosoo Yoon | D. Hughes | Des Small | A. Mus | F. Pötzl | A. Levis | R. Anantua | S. Bustamante | N. S. Conroy | A. Joshi | Y. Kofuji | G. Lindahl | I. Ruiz | K. Satapathy

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