The video above explains some of what you're asking. And yes, we are studying images of the object's past. This article explains a bit more: http://chandra.harva...u/blog/node/719 ...the first image ever taken of a black hole (more precisely, of its shadow) truly rises up to that standard. By definition, nothing not even light, can escape the gravitational grasp of a black hole. This, however, is only true if you get too close, and the boundary between what can and cannot get away is called the event horizon. While Chandra can’t see the shadow itself, its field of view is much larger than the EHT’s, so Chandra can view the full length of the jet of high-energy particles launched by the intense gravitational and magnetic fields around the black hole. This jet extends more than 1,000 light years from the center of the galaxy. To use an analogy, consider a trumpeter in a concert hall: the EHT data, taken from radio telescopes around the globe, provide a close-up view of the mouthpiece (the origin of the sound, like the “central engine” of M87). The Chandra data, by contrast, reveal the sound waves as they travel down the trumpet and reverberate around the concert hall. (As with many analogies, the scale is not exact.) We need both of these pieces in order to understand the sound completely. (For a music analogy for interferometry and the EHT from the CfA’s Katie Bouman, see
). As for the investigation of the black hole in M87, Chandra has been on the case for quite some time. First off, let’s start with some basics. M87 is an elliptical galaxy in the Virgo galaxy cluster, about 60 million light years away from Earth. For years, scientists have known that a supermassive black hole weighing several billion times the mass of the Sun sits at the center of M87. Surrounding the elliptical galaxy is a reservoir of multimillion-degree gas, which glows brightly in X-ray light. Chandra's studies of this hot gas have given astronomers insight into the behavior and properties of the giant black hole. For example, astronomers have used Chandra data to discover ripples in the hot gas, which provide evidence for repeated outbursts from the black hole roughly every 6 million years or so. (As an aside and extension to the music analogy, these ripples represent sound waves in the hot gas. Since they are uneven, the “note” would likely be unharmonious noise rather than a melodic tone, many octaves below the threshold of human hearing. Not sure if anyone here could answer this, but how to they know any of this? How do they know this black hole weighs any amount much less several billion times the mass of the Sun? How do they know a galaxy is elliptical? How do they know it's surrounded by "multi-million degree gas"? Also, if I did the math correctly, and it's likely I didn't, it would take more than 59,000 years for light from M87 to reach us (please correct me if that's wrong, and I rounded down when making calculations). Secondly, the article says "Surrounding the elliptical galaxy is a reservoir of multimillion-degree gas, which glows brightly in X-ray light". To be able to see that, it would take more than 118,000 years for that light to get there and return and on this point there is no question, X-rays didn't exist 59,000 years ago. What am I missing? Here is the simple answer to your question.