(Credit: NASA/CXC/Stanford/ESA/STScI/M.Postman & CLASH team/J.Hlavacek-Larrondo et al/)
One of the most powerful black holes in the observable universe has been revealed by NASA's Chandra X-Ray Observatory.
A supermassive black hole in the middle of a cluster of galaxies, responsible for preventing trillions of stars from forming, has been photographed by NASA's Chandra X-Ray Observatory and other telescopes, revealing the enormous structures it has created in the hot gas around it.
The galaxy cluster RX J1532.9+3021, approximately 3.9 billion light years from Earth, contains a large elliptical galaxy wherein a cloud of hot gas can be seen. X-ray data obtained from Chandra indicates that it has a mass about a quadrillion times that of the sun.
However, it shouldn't look like that. The hot gas should cool towards the centre of the cluster, where the formation is at its densest. When the gas cools, the pressure is supposed to drop, which causes the gas to sink towards the galaxy, forming stars as it goes. Because of the higher-than-usual density of gas in the centre of RX J1532, the cooling was expected to be especially dramatic — like the Phoenix Cluster, for example, where astronomers have observed large numbers of stars forming. Yet, not only has the RX J1532 cluster remained hot, it shows no evidence of forming stars.
These new images reveal the answer. The two large cavities that can be seen on either side of the gas indicate the polar jets that shoot out from the poles of a black hole — and these cavities align with images of jets taken by the NSF's Karl G Jansky Very Large Array. The supersonic jets have blasted into the gas, creating pockets.
The gas is kept from cooling by shock fronts from these expanding cavities and the release of sound waves reverberating through the gas. The cavities are among the largest ever seen, about 100,000 light years across — about the same size as the Milky Way galaxy.
The fact that Chandra has detected no X-ray emission from matter falling towards the black hole remains a puzzle. There are two possible answers: first, it could be that the black hole is not supermassive, but ultramassive — that is, with a mass 10 billion times greater than that of the sun. An ultramassive black hole can produce powerful jets without consuming larger amounts of matter.
The second explanation is that the black hole is smaller — only about a billion suns (which is still pretty massive) — but is spinning very fast. A fast-spinning black hole can generate more powerful jets than a slowly spinning black hole consuming the same amount of matter.
A paper analysing the phenomenon, "Probing the extreme realm of AGN feedback in the massive galaxy cluster, RX J1532.9+3021", was published in The Astrophysical Journal and can be read online.