By Afrin Fatima
Hubble Space Telescope has witnessed not just one but two prodigious black holes at the heart of the distant spiral galaxy NGC 7674. These holes are 400 million light-years away from earth and the astronomers say that they are supermassive black holes. Researchers say that they are separated by a distance of 1 light-year and together nestle about 40 million times the mass of sun.
If it holds up, then it would be just the second known system of double supermassive black holes. The other, announced in 2006, is in a galaxy known as 0402+379, whose two giant black holes are separated by about 24 light-years and boast a combined 15 billion solar masses. The observations are made by the Very Large Array, a network of radio telescopes in New Mexico. The researchers found two distinct source of radio-wave emission at the centre of galaxy.
“These two massive holes have the property to coalescence gas giving way to the presence of the two black holes,” study lead author Preeti Kharb, of the National Centre for Radio Astrophysics at the Tata Institute of Fundamental Research in India, said in a statement.
The two newfound black holes probably ingratiated when their former host galaxies merged to form the current NGC 7674. This supposition is propped up by the twisted, Z-like shape of the galaxy’s radio emission — a large-scale structure thought to be produced by a galaxy collision, study team members said.
Co-author David Merritt, of the Rochester Institute of Technology in New York, said in the same statement that detection of a binary supermassive black hole in this galaxy also confirms a theoretical prediction that such binaries should be present in so-called Z-shaped radio sources.