Prague Relativistic Astrophysics

Tapas K. Das

The massive black hole at our Galactic centre possesses largest apparent angular size of the event horizon. This allows the astronomers to introduce a novel VLBI technique using which one can observationally resolve the length scale comparable to the size of the event horizon of our Galactic centre black hole, and to directly image the event horizon in radio wave. On the theoretical front, a consistent modeling of the general relativistic black hole accretion in Kerr metric is necessary to predict how that image would look like in reality, and how the spin of the black hole can observationally be estimated. With an accurate measurement of the black hole mass already made, such observational signature of black hole spin as well as the direct imaging of the event horizon can have profound impact on our attempt to understand the strong gravity black hole space time at the close vicinity of the event horizon.