14 de junio – 13:30 horas
Expositor: Jonathan Weintroub, Harvard–Smithsonian Center for Astrophysics
Resumen: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 published in 2019, and of polarization images published just the year. 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.