6533b834fe1ef96bd129e1e5
RESEARCH PRODUCT
Millimeter-VLBI observations of low-luminosity active galactic nuclei with source-frequency phase-referencing
Noriyuki KawaguchiDong-rong JiangXuezheng WangXuezheng WangWu JiangIvan Marti-vidalZhi-qiang Shensubject
High Energy Astrophysical Phenomena (astro-ph.HE)Event Horizon TelescopePhysicsAstrofísicaActive galactic nucleusEvent horizonFOS: Physical sciencesAstronomy and AstrophysicsAstrophysicsAstrophysics - Astrophysics of GalaxiesLuminositySpace and Planetary ScienceAstrophysics of Galaxies (astro-ph.GA)Brightness temperatureVery-long-baseline interferometryMagnitude (astronomy)AstronomiaMillimeterAstrophysics - High Energy Astrophysical Phenomenadescription
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.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2021-01-01 |