We present the first Event Horizon Telescope (EHT) observations of Sagittarius A$^\ast$ (Sgr A$^\ast$), the Galactic center source associated with a supermassive black hole. These observations were conducted in 2017 using a global interferometric …
We present Event Horizon Telescope (EHT) $1.3 \mathrm{mm}$ measurements of the radio source located at the position of the supermassive black hole Sagittarius A$^\ast$ (Sgr A$^\ast$), collected during the 2017 April $5–11$ campaign. The observations …
We present the first event-horizon-scale images and spatiotemporal analysis of Sgr A$^\ast$ taken with the Event Horizon Telescope in $2017$ April at a wavelength of $1.3 \mathrm{mm}$. Imaging of Sgr A$^\ast$ has been conducted through surveys over a …
In this paper we quantify the temporal variability and image morphology of the horizon-scale emission from Sgr A$^\ast$, as observed by the EHT in $2017$ April at a wavelength of $1.3 \mathrm{mm}$. We find that the Sgr A$^\ast$ data exhibit …
In this paper we provide a first physical interpretation for the Event Horizon Telescope's (EHT) $2017$ observations of Sgr A$^\ast$. Our main approach is to compare resolved EHT data at $230$GHz and unresolved non-EHT observations from radio to …
Astrophysical black holes are expected to be described by the Kerr metric. This is the only stationary, vacuum, axisymmetric metric, without electromagnetic charge, that satisfies Einstein's equations and does not have pathologies outside of the …