丁香园AV

Link to join: 

Meeting ID: 613 8456 3656

Password: 719853

Synopsis

In 2017, the Event Horizon Telescope (EHT) observed the Galactic Center supermassive black hole Sagittarius A* (Sgr A*) using a global interferometric array of 8 telescopes.  The resulting horizon scale images provide a unique opportunity to constrain the astrophysics of the accreting plasma and to test Einstein's general theory of relativity in a strong field regime.  In this talk, I will introduce the EHT project and go over its data processing pathway and imaging methods.  By comparing EHT's images with a large black hole simulation library, we constrain the properties of the accretion flow around Sgr A*.  By comparing the size of the observed photon ring with the predicted size of the shadow, we show that EHT's observations are consistent with the general relativity.