This image contains the most distant black hole ever detected in X-rays, a result that may explain how some of the first supermassive black holes in the universe formed. As we report in our press release, this discovery was made using X-rays from NASA’s Chandra X-ray Observatory (purple) and infrared data from NASA’s James Webb Space Telescope (red, green, blue).
The extremely distant black hole is located in the galaxy UHZ1 in the direction of the galaxy cluster Abell 2744. The galaxy cluster is about 3.5 billion light-years from Earth. Webb data, however, reveal that UHZ1 is much farther away than Abell 2744. At some 13.2 billion light-years away, UHZ1 is seen when the universe was only 3% of its current age.
By using over two weeks of observations from Chandra, researchers were able to detect X-ray emission from UHZ1 — a telltale signature of a growing supermassive black hole in the center of the galaxy. The X-ray signal is extremely faint and Chandra was only able to detect it — even with this long observation — because of the phenomenon known as gravitational lensing that enhanced the signal by a factor of four.
The purple parts of the image show X-rays from large amounts of hot gas in Abell 2744. The infrared image shows hundreds of galaxies in the cluster, along with a few foreground stars. The insets zoom into a small area centered on UHZ1. The small object in the Webb image is the distant galaxy UHZ1 and the center of the Chandra image shows X-rays from material close to the supermassive black hole in the middle of UHZ1. The large size of the X-ray source compared to the infrared view of the galaxy is because it represents the smallest size that Chandra can resolve. The X-rays actually come from a region that is much smaller than the galaxy.
Different smoothing was applied to the full-field Chandra image and to the Chandra image in the close-up. Smoothing across many pixels was performed for the large image, to highlight the faint cluster emission, at the expense of not showing faint X-ray point sources like UHZ1. Much less smoothing was applied to the close-up so faint X-ray sources are visible. The image is oriented so that north points 42.5 degrees to the right of vertical.
This discovery is important for understanding how some supermassive black holes — those that contain up to billions of solar masses and reside in the centers of galaxies — can reach colossal masses soon after the big bang. Do they form directly from the collapse of massive clouds of gas, creating black holes weighing between about ten thousand and a hundred thousand suns? Or do they come from explosions of the first stars that create black holes weighing only between about ten and a hundred suns?