BIOGRAPHY

Jonathan Weintroub is an electrical engineer and scientist at the Harvard-Smithsonian Center for Astrophysics. He leads the digital signal processing group for the Submillimeter Array (SMA), an eight element open-skies radio interferometer located on Maunakea in Hawaii. That group designed and deployed the SMA Wideband Astronomical ROACH2 Machine (SWARM), a 32 GHz bandwidth astronomical correlator and phased array. SWARM transformed the utility of the SMA when it was commissioned as the primary facility instrument in 2017. Dr. Weintroub plays a leadership role in digital instrumentation, timing systems, observation, as well as system engineering for the Event Horizon Telescope (EHT), a global wideband interferometer operating at 1.3 millimeters wavelength.

ABSTRACT

The Event Horizon Telescope (EHT) is an earth-size very long baseline interferometry (VLBI) array, operating at the shortest radio wavelengths of about 1 millimeter, corresponding to radio frequencies 230 GHz and higher. As a result it has an extremely fine angular resolution of the order of 20 microarcseconds. For super massive black holes (SMBH) which are relatively nearby and sufficiently massive, this is the angular scale subtended by the event horizon. Relativistically lensed emission from the black hole’s accretion disk and jet can be directly observed. Retrofitting new wideband technology and atomic clocks to existing radio telescopes led to the first image of the “shadow” of the event horizon of a black hole, which the EHT published on 10 April 2019.   I will give an introduction to the science behind the EHT and describe the significance of the image. The balance of the talk will focus the technology and instrumentation that enabled these observations. I will close by outlining our vision for the next generation EHT or ngEHT.

This talk is given on behalf of the Event Horizon Telescope Collaboration, https://eventhorizontelescope.org/.