Using NASA’s Chandra X-ray Observatory, ESA’s XMM-Newton and three radio telescopes (the Giant Metrewave Radio Telescope, the Low Frequency Array, and the Karl G. Jansky Very Large Array), astronomers have observed the huge galaxy cluster merger Abell 2256.
Galaxy clusters contain thousands of galaxies of all ages, shapes and sizes.
Typically, these structures have a mass of about one million billion times the mass of the Sun.
At one point in time they were believed to be the largest structures in the Universe — until they were usurped in the 1980s by the discovery of superclusters.
However, clusters do have one thing to cling on to; superclusters are not held together by gravity, so galaxy clusters still retain the title of the biggest structures in the Universe bound by gravity.
Collisions and mergers are the primary ways galaxy clusters grow, and can cause them to act as giant particle accelerators.
“Galaxy clusters contain enormous reservoirs of superheated gas, with temperatures of several million degrees Fahrenheit,” said University of Bologna astronomer Kamlesh Rajpurohit and colleagues.
“Only X-ray telescopes like Chandra and XMM can see this hot gas.”
The radio emission in Abell 2256, which is located 780 million light-years away in the constellation of Ursa Minor, arises from an even more complex set of sources.
“The first are the galaxies themselves, in which the radio signal is generated by particles blasting away in jets from supermassive black holes at their centers,” the astronomers said.
“These jets are either shooting into space in straight and narrow lines (those labeled ‘C’ and ‘I’ in the image) or slowed down as the jets interact with gas they are running into, creating complex shapes and filaments (‘A,’ ‘B,’ and ‘F’).”
“Source F contains three sources, all created by a black hole in a galaxy aligning with the left-most source of this trio.”
“Radio waves are also coming from huge filamentary…
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