Aug 19 2014 : The Times of India (Delhi)
Indian-origin student finds, measures black hole
Subodh.Varma@timesgroup.com
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An Indian-origin graduate stu dent has discovered and mea sured one of the most elusive and mysterious objects in the Universe -a middling-sized black hole.University of Maryland astronomy graduate student Dheeraj Pasham and two colleagues made the measurements of the rare black hole which they found hiding in the well-known galaxy M82, some 12 million light years away from earth. Their findings were published online on August 17 in the journal `Nature'. The reason why this discovery and the measurement are considered significant is that these intermediate-mass black holes are hard to measure, even their exist ence is sometimes disputed. Little is known about how they form, a Maryland varsity statement said. Some astronomers question whether they behave like other black holes.
The universe has countless black holes and just our galaxy, the Milky Way, may have up to 100 million of them, it is thought. Nearly all black holes fall into one of two classes: big, and colossal. The `big' ones have from about 10 times to 100 times the mass of our sun.
They are the remnants of dying stars. The supermassive black holes have more than a million times the mass of the sun. These giants inhabit the centres of most galaxies. But scattered across the universe are a few apparent black holes of the more mysterious type.
Ranging from a hundred times to a few hundred thousand times the sun's mass, these intermediate-mass black holes are mysterious because they are difficult to pinpoint. “Objects in this range are the least expected of all black holes,“ Richard Mushotzky , an UMD astronomy professor and a coauthor said. “Astronomers have been asking -do these objects exist or do they not exist? What are their properties? Until now we have not had the data to answer these questions.“ While the intermediate-mass black hole that the team studied is not the first one measured, it is the first one so precisely measured, Mushotzky says, “establishing it as a compelling example of this class of black holes.“
Pasham, who will begin a post-doctoral research position at Nasa Goddard in late August, has identified six potential intermediate-mass black holes that Nasa's to-be launched X-ray telescope NICER might explore.
For the full report, log on to http://www.timesofindia.com
The universe has countless black holes and just our galaxy, the Milky Way, may have up to 100 million of them, it is thought. Nearly all black holes fall into one of two classes: big, and colossal. The `big' ones have from about 10 times to 100 times the mass of our sun.
They are the remnants of dying stars. The supermassive black holes have more than a million times the mass of the sun. These giants inhabit the centres of most galaxies. But scattered across the universe are a few apparent black holes of the more mysterious type.
Ranging from a hundred times to a few hundred thousand times the sun's mass, these intermediate-mass black holes are mysterious because they are difficult to pinpoint. “Objects in this range are the least expected of all black holes,“ Richard Mushotzky , an UMD astronomy professor and a coauthor said. “Astronomers have been asking -do these objects exist or do they not exist? What are their properties? Until now we have not had the data to answer these questions.“ While the intermediate-mass black hole that the team studied is not the first one measured, it is the first one so precisely measured, Mushotzky says, “establishing it as a compelling example of this class of black holes.“
Pasham, who will begin a post-doctoral research position at Nasa Goddard in late August, has identified six potential intermediate-mass black holes that Nasa's to-be launched X-ray telescope NICER might explore.
For the full report, log on to http://www.timesofindia.com
