# "SgrA*"

## First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way

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 …

## First Sagittarius A* Event Horizon Telescope Results. II. EHT and Multiwavelength Observations, Data Processing, and Calibration

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 …

## First Sagittarius A* Event Horizon Telescope Results. III. Imaging of the Galactic Center Supermassive Black Hole

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 …

## First Sagittarius A* Event Horizon Telescope Results. IV. Variability, Morphology, and Black Hole Mass

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 …

## First Sagittarius A* Event Horizon Telescope Results. V. Testing Astrophysical Models of the Galactic Center Black Hole

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 …

## First Sagittarius A* Event Horizon Telescope Results. VI. Testing the Black Hole Metric

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 …