As countless science and general news outlets have reported today, the image of Sagittarius A*, the supermassive black hole at the center of our galaxy, is a fabulous scientific achievement. But one aspect that hasn't gotten quite as much attention is the central role played by simulations and synthetic data in the discovery.

If you haven't read about this awesome science news yet, the Event Horizon Telescope's own post is a great place to get the gist. Based on years of observations from around the globe, a huge team at over a hundred institutions managed to assemble an image of the black hole around which our galaxy rotates, despite its relative closeness and the interference from light-years worth of dust, nebulae and other vagaries of the void.

But this wasn't just a matter of pointing the telescope in the right direction at the right time. Black holes can't be observed directly using something like the Hubble or even the still-warming-up Webb. Instead, all kinds of other direct and indirect measurements of the object must be made — how radiation and gravity bend around it and so on.

This means data from dozens of sources must be assembled and reconciled, itself an enormous task and a big part of why observations made in 2017 are only now being published as a final image, which you can see below. But because this project really has no precedent (even the famous M87* image, though superficially similar, used different processes) it was necessary to essentially test multiple possibilities for how the same observations might have been made.

For instance, if it's "dark" in the middle, is it because there's something in the way (and there is — about half the galaxy) or because the hole itself has a hole (and it seems to)? The lack of direct observational data makes it hard to say. (Note that the images here don't simply show an image based on visible light, but the inferred shape based on countless readings of radiation and other measures.)