Indian-origin Scientist Finds Black Hole Cluster

Introduction

Billions of kilometers beyond the constellation of Virgo, a zoo of monster blackholes has been discovered by a Cambridge team led by Manda Banerji, an Indian-origin scientist. Radiation, hitherto not quite taken into account, is reaching the earth as a result of earlier unidentified black holes in what astronomers call the "early universe".

The discovery has shaken up the scientific world because never has such a collection of monster blackholes remained hidden for so long. The research estimates that there are at least 400 blackholes in the cluster which is 11 billion light years away. Fiercely swirling giant clouds of thick dust had surrounded the blackhole zoo till Banerji's team penetrated it with a cutting edge infrared telescope.
"These results could have a significant impact on studies of supermassive black holes," said Banerji, lead author of the paper which has been published in the journal Monthly Notices of the Royal Astronomical Society. "Although these black holes have been studied for some time, the new results indicate that some of the most massive ones may have so far been hidden from our view," Banerji added.
The zoo contains a monster black hole that has more than 10 billion times the mass of the Sun and 10,000 times the mass of the supermassive black hole in our own Milky Way, making it one of the most massive black holes ever seen.
"Most black holes of this kind are seen through the matter they drag in. As the neighbouring material spirals in towards the black holes, it heats up. Astronomers are able to see this radiation and observe these systems," Banerji explained.
The significance of this discovery lies in the fact that that now scientists will have to take a second look at many dust obscured corners of the Universe searching for hidden blackholes.
The newly discovered monster blackhole has been dubbed ULASJ1234+0907 by the scientists. It is one of the reddest objects in the sky. The red colour comes from the surrounding dust which preferentially absorbs bluer light and allows only light in the red region to escape.
Supermassive black holes are now known to reside at the centres of all galaxies. Scientists think that they grow through violent collisions with other galaxies, which trigger the formation of stars and provides food for the black holes to devour. These violent collisions also produce dust within the galaxies. The dust is ultimately sucked in by the immense force of the blackhole's gravitational attraction.
Relatively nearer than the blackhole discovered by Banerji is the previously studied Markarian 231, located 600 million light years from Earth. Rings of gas and dust can be seen around it as well as "tidal tails" left over from a recent impact with another galaxy.
Banerji is currently working on how galaxies and quasars evolve, using visible light as well as infra-red and submillimeter wavelengths of light. She completed her PhD on Galaxies in the Distant Universe in 2009 at University College London under Prof Ofer Lahav.
Prof Richard McMahon, co-author of the study, told the Royal Astronomy Society: "These results are particularly exciting because they show that our new infrared surveys are finding super massive black holes that are invisible in optical surveys."

Source

The Economic Times , October 10, 2012