National Radio Astronomy Observatory

The Astropy Project: Building an Open-science Project and Status of the v2.0 Core Package^*

Abstract The Astropy Project supports and fosters the development of open-source and openly developed Python packages that provide commonly needed functionality to the astronomi...

First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole

Abstract When surrounded by a transparent emission region, black holes are expected to reveal a dark shadow caused by gravitational light bending and photon capture at the event...

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

Abstract We present the first Event Horizon Telescope (EHT) observations of Sagittarius A* (Sgr A*), the Galactic center source associated with a supermassive black hole. These ...

First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole

Abstract We present measurements of the properties of the central radio source in M87 using Event Horizon Telescope data obtained during the 2017 campaign. We develop and fit ge...

Relativistic Shapiro delay measurements of an extremely massive millisecond pulsar