NEW DELHI, Aug. 27 (Xinhua) -- Indian researchers discovered three black holes from three galaxies merging to a triple active galactic nucleus, the federal ministry of science and technology said Friday.
"It's a compact region at the center of a newly discovered galaxy that has a much-higher-than-normal luminosity," the ministry in a statement said. "This rare occurrence in our nearby universe indicates that small merging groups are ideal laboratories to detect multiple accreting supermassive black holes and increases the possibility of detecting such rare occurrences."
According to the ministry, a team of researchers from the Indian Institute of Astrophysics while studying a known interacting galaxy pair, NGC7733, and NGC7734, detected unusual emissions from the center of NGC7734 and a large, bright clump along the northern arm of NGC7733.
"Their investigations showed that the clump is moving with a different velocity compared to the galaxy NGC7733 itself. The scientists meant that this clump was not a part of NGC7733; rather, it was a small separate galaxy behind the arm. They named this galaxy NGC7733N," the statement said.
The researchers used data from the Ultra-Violet Imaging Telescope (UVIT), the European integral field optical telescope called MUSE in Chile and infrared images from the optical telescope (IRSF) in South Africa.
The ministry said supermassive black holes are difficult to detect because they do not emit any light. But they can reveal their presence by interacting with their surroundings.
"When the dust and gas from the surroundings fall onto a supermassive black hole, some of the mass is swallowed by the black hole, but some of it is converted into energy and emitted as electromagnetic radiation that makes the black hole appear very luminous," the ministry said.
"They are called active galactic nuclei (AGN) and release huge amounts of ionized particles and energy into the galaxy and its environment. Both of these ultimately contribute to the growth of the medium around the galaxy and ultimately the evolution of the galaxy itself."
According to the researchers, a major factor impacting galaxy evolution is galaxy interactions, which happen when galaxies move close by each other and exert tremendous gravitational forces on each other. Enditem
