SunstarTV Bureau: Cosmos acquiring many galaxies together and creating mystery in all the hours and Nano-seconds. Similarly, the Indian researchers have discovered three supermassive black holes from three galaxies merging together to form a triple active galactic nucleus (AGN).
Reportedly, that has a much higher than normal luminosity.
The discovery describes that small merging groups are ideal laboratories to detect multiple accreting supermassive black holes and increases the possibility of detecting such occurrences.
Supermassive black holes are difficult to detect because they do not emit any light, but 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.
A team of researchers from the Indian Institute of Astrophysics consisting of Jyoti Yadav, Mousumi Das, and Sudhanshu Barway along with Francoise Combes of College de France, Chaire Galaxies et Cosmologie, Paris, while studying a known interacting galaxy pair, NGC7733, and NGC7734, detected unusual emissions from the centre of NGC7734 and a large, bright clump along the northern arm of NGC7733.
The study, published as a letter in a journal Astronomy and Astrophysics, used data from the Ultraviolet Imaging Telescope (UVIT) onboard the first Indian space observatory ASTROSAT, the European integral field optical telescope called MUSE mounted on the Very Large Telescope (VLT) in Chile and infrared images from the optical telescope (IRSF) in South Africa.
The UV and H-alpha images also supported the presence of the third galaxy by revealing star formation along with the tidal tails, which could have formed from the merger of NGC7733N with the larger galaxy. Each of the galaxies hosts an active supermassive black hole in their nucleus and hence forms a very rare triple AGN system.
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.
During such galaxy interactions, the respective supermassive black holes can get near each other. The dual black holes start consuming gas from their surroundings and become dual AGN.
The IIA team explains that if two galaxies collide, their black hole will also come closer by transferring the kinetic energy to the surrounding gas.
The distance between the black holes decreases with time until the separation is around a parsec (3.26 light-years).
