First Sagittarius A* Event Horizon Telescope Results. IV. Variability, Morphology, and Black Hole Mass [PDF]
Astrophysical Journal Letters, 2022 In this paper we quantify the temporal variability and image morphology of the horizon-scale emission from Sgr A*, as observed by the EHT in 2017 April at a wavelength of 1.3 mm. We find that the Sgr A* data exhibit variability that exceeds what can be
Event Horizon Telescope Collaboration +269 more
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First Sagittarius A* Event Horizon Telescope Results. III. Imaging of the Galactic Center Supermassive Black Hole [PDF]
Astrophysical Journal Letters, 2022 We present the first event-horizon-scale images and spatiotemporal analysis of Sgr A* taken with the Event Horizon Telescope in 2017 April at a wavelength of 1.3 mm.
Event Horizon Telescope Collaboration +270 more
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First Sagittarius A* Event Horizon Telescope Results. II. EHT and Multi-wavelength Observations, Data Processing, and Calibration [PDF]
, 2023 We present Event Horizon Telescope (EHT) 1.3 mm measurements of the radio source located at the position of the supermassive black hole Sagittarius A* (Sgr A*), collected during the 2017 April 5--11 campaign.
The Event Horizon Telescope Collaboration
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Magnetic reconnection plasmoid model for Sagittarius A* flares [PDF]
Astronomy & Astrophysics, 2023 Sagittarius A*, the supermassive black hole at the center of our galaxy, exhibits episodic near-infrared flares. The recent monitoring of three such events by the GRAVITY instrument has shown that some flares are associated with orbital motions in the ...
N. Aimar +6 more
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Shadows of loop quantum black holes: semi-analytical simulations of loop quantum gravity effects on Sagittarius A* and M87* [PDF]
Journal of Cosmology and Astroparticle Physics, 2023 In this study, we delve into the observational implications of rotating Loop Quantum Black Holes (LQBHs) within an astrophysical framework. We employ semi-analytical General Relativistic Radiative Transfer (GRRT) computations to study the emission from ...
Hong-Xuan Jiang +6 more
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New Black Hole Spin Values for Sagittarius A* Obtained with the Outflow Method [PDF]
Monthly notices of the Royal Astronomical Society, 2023 Six archival Chandra observations are matched with eight sets of radio data and studied in the context of the outflow method to measure and study the spin properties of $\rm {Sgr ~A^*}$.
Ruth A. Daly +5 more
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Orbital polarimetric tomography of a flare near the Sagittarius A* supermassive black hole [PDF]
Nature Astronomy, 2023 The interaction between the supermassive black hole at the centre of the Milky Way, Sagittarius A*, and its accretion disk occasionally produces high-energy flares seen in X-ray, infrared and radio.
A. Levis +4 more
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The internal Faraday screen of Sagittarius A* [PDF]
Astronomy & Astrophysics, 2023 We report on 85-101\,GHz light curves of the Galactic Center supermassive black hole, Sagittarius A* ( observed in April 2017 with the Atacama Large Millimeter/submillimeter Array (ALMA).
M. Wielgus +7 more
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Testing black hole mimickers with the Event Horizon Telescope image of Sagittarius A* [PDF]
Monthly notices of the Royal Astronomical Society, 2022 The Event Horizon Telescope (EHT) has recently observed the image and shadow of the supermassive compact object Sagittarius A* (Sgr A*). According to the EHT collaboration, the observed image is consistent with the expected appearance of a Kerr black ...
R. Shaikh
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Probing Lorentz symmetry violation using the first image of Sagittarius A*: Constraints on standard-model extension coefficients [PDF]
Physical Review D, 2022 Thanks to unparalleled near-horizon images of the shadows of Messier 87* (M87*) and Sagittarius A* (Sgr A*) delivered by the Event Horizon Telescope (EHT), two amazing windows opened up to us for the strong-field test of the gravity theories as well as ...
Mohsen Khodadi, Gaetano Lambiase
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