<h1 class="ql-align-center">Merging of three supermassive black holes&nbsp;</h1> <h2>﻿Context:</h2> <ul><li>Indian astrophysicists spot rare merger of three jumbo black holes&nbsp;</li></ul> <h2>About:</h2> <ul><li>Scientists were investigating the Active Galactic Nuclei&nbsp;(AGN) in the two enormous barred spiral galaxies NGC7733 and NGC7734 when they noticed anomalous emissions from the latter's centre and a strange movement of a big luminous clump within it, which moved at a different speed than NGC7733.</li></ul> <ul><li class="ql-indent-1">The astronomers termed the third galaxy NGC7733N since it was a distinct galaxy.</li></ul> <ul><li class="ql-indent-1">This is only the third time such an event has been observed</li></ul> <ul><li>All three merging black holes were part of galaxies in the Toucan constellation.</li></ul> <ul><li>They are quite far away given that the earth’s nearest galactic neighbour the Andromeda galaxy&nbsp;is 2.5 million light-years away.</li></ul> <ul><li>There are supermassive black holes, which are several million solar masses in size, at the centres of galaxies, and these are known as Active Galactic Nuclei </li></ul> <ul><li>The study 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</li></ul> <h2>Active Galactic Nuclei (AGN):</h2> <ul><li>AGN are&nbsp;supermassive black holes&nbsp;that are several million solar masses in size and are found in the centres of galaxies.</li></ul> <ul><li>A large black hole sits in the core of most galaxies, surrounded by a vast quantity of gas, dust, and star debris. When the gravitational energy of these elements is turned into light as they are drawn towards the black hole, an AGN is produced.</li></ul> <ul><li>They typically have a glow surrounding them because they "accrete" matter, which may be seen via light spectroscopy.</li></ul>