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arXiv · 2208.01662

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·Event Horizon Telescope Collaboration
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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 $\mu$as 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-parsec scales. We combine the multi-frequency 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 degrees 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.

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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, Event Horizon Telescope Collaboration. 2022-08-02. Resolving the inner parsec of the blazar J1924-2914 with the Event Horizon Telescope. https://doi.org/10.3847/1538-4357%2Fac7a40

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