Artist’s impression of the bright core region of a quasar, an active galaxy. The supermassive black hole in the centre is surrounded by a bright disk of gas and dust. The dust component further out can obscure the view of the interior and shines predominantly in the mid-infrared range, light that can be analyzed by the James Webb Space Telescope. A bundled, high-energy particle beam protrudes into space from the immediate vicinity of the black hole perpendicular to the disc. Credit: © T.
But black hole growth cannot be arbitrarily fast. Matter falling onto a black hole forms a swirling, hot, bright “accretion disk.” When this happens around a supermassive black hole, the result is an active galactic nucleus. The brightest such objects, known as quasars, are among the brightest astronomical objects in the whole cosmos. But that brightness limits how much matter can fall onto the black hole: Light exerts a pressure, which can keep additional matter from falling in.
Instruments like MIRI are built by international consortia, with scientists, engineers, and technicians working closely together. Naturally, a consortium is very interested in testing whether their instrument performs as well as planned. In return for building the instrument, consortia typically are given a certain amount of observation time.
The shorter-wavelength part of the spectrum, dominated by the emissions from the accretion disk itself, shows that for us as distant observers, the quasar’s light is not dimmed by more-than-usual dust. Arguments that maybe we are merely overestimating early black hole masses because of additional dust are not the solution either.