The disk is made of gas and dust, slowly being consumed as it spirals down into the black hole’s center. As it falls in, the material spews out a tremendous amount of energy, forming what is known as a quasi-stellar radio source, or quasar.
Among the brightest objects in the sky, quasars are short-lived phenomena that only existed during the earliest eras of the universe. They are known to be huge — most are around 60 billion miles across — yet they lie billions of light years from Earth, making them nothing but insignificant pinpricks in even the most powerful telescopes.
Hubble was able to image the distant disk, which is approximately 18.5 billion light-years away, because a huge galaxy happens to sit between Earth and the quasar. The mass of the enormous galaxy bent light from the quasar and directed it toward our telescopes, acting like a gigantic gravitational lens.
The technique allowed the Hubble telescope to see with unprecedented detail. Because of this, researchers were able to measure the disk’s size — between 60 and 180 billion miles across — and determine the temperature of different parts of the disk. They found that gas and dust from the imaged quasar became bluer and therefore hotter as it fell toward the central black hole.
Image: NASA, ESA, J.A. Muñoz (University of Valencia)