The Black Hole in the Galactic Center

The Event Horizon: Can we see it?

Slide 14 of 16

Clearly, if Sagittarius A* is a black hole the shadow is a unique signature. However, will we ever be able to see this? Most likely yes, and it may not take too long. Below we show images similar to those shown before, now blurred with the scattering the light experiences on its way towards us and blurred with the instrumental resolution we get if we are able to decrease the observing wavelength even further. At the left we see the un-blurred image; the images in the middle are produced for an observing wavelength of 0.6mm; and on the right for an observing wavelength at 1.3mm. Somewhere between 0.6mm and 1.3mm we may be able to see the shadow. First successful observations at 1.3mm, though with very low image quality, have already been made. Hence, we only need to further develop this technique (called mm-VLBI). This may be possible within a few years!

(Figure: The appearance of the shadow of the black hole for Sagittarius A* calculated for the instrumental resolution expected to be available in a few years - from Falcke, Melia, & Agol 2000)

Slide 14 of 16
Contact: Heino Falcke