Millimeter-VLBI observations of low-luminosity active galactic nuclei with source-frequency phase-referencing
| Autor: | Noriyuki Kawaguchi, Dong-Rong Jiang, Xuezheng Wang, Wu Jiang, Ivan Marti-Vidal, Zhi-Qiang Shen |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
Event Horizon Telescope Physics Astrofísica Active galactic nucleus Event horizon FOS: Physical sciences Astronomy and Astrophysics Astrophysics Astrophysics - Astrophysics of Galaxies Luminosity Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) Brightness temperature Very-long-baseline interferometry Magnitude (astronomy) Astronomia Millimeter Astrophysics - High Energy Astrophysical Phenomena |
| Zdroj: | Jiang, Wu Shen, Zhiqiang Martí Vidal, Iván Wang, Xuezheng Jiang, Dongrong Kawaguchi, Noriyuki 2021 Millimeter-VLBI Observations of Low-luminosity Active Galactic Nuclei with Source-frequency Phase Referencing Astrophysical Journal Letters 922 1 L16 RODERIC. Repositorio Institucional de la Universitat de Valéncia instname |
| Popis: | We report millimeter-VLBI results of low-luminosity active galactic nuclei (M 84 and M 87) up to 88 GHz with source-frequency phase-referencing observations. We detected the weak VLBI core and obtained the first image of M 84 at 88 GHz. The derived brightness temperature of M 84 core was about 7.2$\times$10$^9$ K, which could serve as a lower limit as the core down to 30 Schwarzschild radii was still un-resolved in our 88 GHz observations. We successfully determined the core-shifts of M 87 at 22-44 GHz and 44-88 GHz through source-frequency phase-referencing technique. The jet apex of M 87 could be deduced at about 46 $\mu$as upstream of the 43 GHz core from core-shift measurements. The estimated magnetic field strength of the 88 GHz core of M 87 is 4.8$\pm$2.4 G, which is at the same magnitude of 1-30 G near the event horizon probed by the Event Horizon Telescope. Comment: Accept for publication in ApJL |
| Databáze: | OpenAIRE |
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