. | . |
Are dense star clusters the origin of the gravitational waves discovered by LIGO? by Staff Writers San Francisco CA (SPX) Jun 05, 2017
Astrophysicists everywhere are thrilled about yesterday's news that the LIGO experiment has detected its third set of gravitational waves. Predicted more than a century ago by Albert Einstein, and finally detected by LIGO for the first time in 2015, gravitational waves have opened an entirely new way of observing the universe's most violent events. The origin of each of the trio of gravitational wave events LIGO has recorded to date appears to be the cataclysmic collision of a pair of monstrous black holes. Before LIGO, astronomers had no evidence that these kinds of black holes, with masses dozens of times that of our Sun's, even existed. A major new mystery is just how these enormous black holes form and, for that matter, how two such black holes end up paired in a gravitational "death dance," spiraling inward and eventually crashing together. Three researchers recently participated in a roundtable discussion, hosted by The Kavli Foundation, focused on this very mystery. The researchers are using powerful computer simulations and observations from telescopes to identify the cosmic environments that spawn colliding black holes. Much of the evidence - including new data from LIGO's most recent discovery - points to dense star clusters, called globular clusters, as ground zero. These dazzling, celestial "snow globes" are filled with hundreds of thousands of closely packed stars. Researchers increasingly think that globular clusters have dark "hearts," loaded with dozens to even hundreds of black holes - by far the greatest concentration of these exotic objects found anywhere in the universe. If so, globular clusters would provide an ideal environment for the black hole smash-ups that unleash gravitational waves. "The assumption used to be that globular clusters couldn't retain black holes," says Rainer Spurzem, a professor at the Kavli Institute for Astronomy and Astrophysics (KIAA) at Peking University and the Chinese Academy of Sciences. "But that's not what computer simulations by me and my colleagues, as well as in work by Carl [Rodriguez] and others, are now showing." Rodriguez, a Pappalardo Postdoctoral Fellow and a postdoctoral scholar at the Massachusetts Institute of Technology (MIT), as well as a member of MIT's Kavli Institute for Astrophysics and Space Research, also participated in the roundtable discussion. He notes that in globular clusters, the "extreme density of stars allows for dynamical processes you don't see other places in the universe. Black holes can come close enough to one another that they'll undergo gravitational interactions and form a pair." Once paired, the black holes become a ticking time bomb, counting down to an explosion of gravitational radiation that can be sensed here on Earth, by LIGO, billions of light years from its source. "Rainer and Carl are creating computer simulations based on theoretical models, while my team is gathering observational evidence for the existence of black holes in globular clusters," says Jay Strader, an assistant professor in the department of physics and astronomy at Michigan State University. "At the moment, we're reaching the same conclusions, that globular clusters can keep their black holes. And if that's the case, then globular clusters could be where black holes often collide and create gravitational waves." + Read the full conversation with Spurzem, Rodriguez, and Strader on The Kavli Foundation website here
Innsbruck, Austria (SPX) Jun 05, 2017 A ripe apple falling from a tree has inspired Sir Isaac Newton to formulate a theory that describes the motion of objects subject to a force. Newton's equations of motion tell us that a moving body keeps on moving on a straight line unless any disturbing force may change its path. The impact of Newton's laws is ubiquitous in our everyday experience, ranging from a skydiver falling in the earth's ... read more Related Links The Kavli Foundation The Physics of Time and Space
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |