The jet and resolved features of the central supermassive black hole of M 87 observed with EHT

Abstract

We report our independent image reconstruction of the M 87 from the public data of the Event Horizon Telescope Collaborators (EHTC). Our result is different from the image published by the EHTC. Our analysis shows that (a) the structure at 230 GHz is consistent with those of lower frequency VLBI observations, (b) the jet structure is evident at 230 GHz extending from the core to a few mas, though the intensity rapidly decreases along the axis, and (c) the unresolved core is resolved into bright three features presumably showing an initial jet with a wide opening angle of about 70 deg. The ring-like structures of the EHTC can be created not only from the public data, but also from the simulated data of a point image. Also, the rings are very sensitive to the FOV size. The u-v coverage of EHT lack about 40 micro-asec fringe spacings. Combining with a very narrow FOV, it created the 40 micro-asec ring structure. We conclude that the absence of the jet and the presence of the ring in the EHTC result are both artifacts owing to the narrow FOV setting and the u-v data sampling bias effect of the EHT array. Because the EHTC's simulations only take into account the reproduction of the input image models, and not those of the input noise models, their optimal parameters can enhance the effects of sampling bias and produce artifacts such as the 40 micro-asec ring structure, rather than reproducing the correct image.

68 pages, 34 figures, ApJ accepted 5th May 2022

References in corpus (19)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
• First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
• First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
• First M87 Event Horizon Telescope Results. II. Array and Instrumentation
• First M87 Event Horizon Telescope Results. III. Data Processing and Calibration
• Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre
• Relativistic images of Schwarzschild black hole lensing
• Kinematics of the jet in M87 on scales of 100 -- 1000 Schwarzschild radii
• The Inner Jet of the Radio Galaxy M87
• Superluminal Radio Features in the M87 Jet and the Site of Flaring TeV Gamma-ray Emission
• 230 GHz VLBI observations of M87: event-horizon-scale structure at the enhanced very-high-energy $\gamma$-ray state in 2012
• Intrinsic Brightness Temperatures of AGN Jets
• Variable structures in M87* from space, time and frequency resolved interferometry
• Pilot KaVA monitoring on the M87 jet: confirming the inner jet structure and superluminal motions at sub-pc scales
• Determination of the intrinsic velocity field in the M87 jet
• Time Variations in the Flux Density of Sgr A* at 230 GHz Detected with ALMA
• Observations of the Structure and Dynamics of the Inner M87 Jet
• Hybrid mapping of the Black Hole Shadow in M87

Cited by in corpus (4)

• An independent hybrid imaging of Sgr A* from the data in EHT 2017 observations
• Shadows of naked singularity in Brans-Dicke gravity
• Determining parameters of a spherical black hole with a thin accretion disk by observing its shadow
• Interferometric Image Reconstruction using Closure Invariants and Machine Learning