November 8, 2013
Revealing New Information On Strength Of Black Hole Mergers
Lee Rannals for redOrbit.com - Your Universe Online
The Commonwealth Scientific and Industrial Research Organization (CSIRO) in eastern Australia has helped reveal new information about the strength of black hole mergers.
Giant black holes throughout the universe sometimes pair up and merge, sending out gravitational waves that ripple across space and time. Albert Einstein predicted that these waves exist, but scientists have yet to directly detect one.
Astronomers were able to use CSIRO to reveal new information about black hole mergers, including their frequency, distance from Earth and masses. Although this study didn’t directly observe gravitational waves, it is a step closer to a new age of astronomy.
"We expect that many gravitational waves are passing through us all the time, and now we have a better idea of the extent of this background activity," said Sarah Burke-Spolaor, co-author of a new paper published in the journal Science.
During the study, gravitational waves passed through an array of 20 pulsars, which were detected like bobbing buoys used in fishing. The team recorded the radio waves from the pulsars and pieced together the background hum of the waves.
"The gravitational waves cause the space between Earth and pulsars to stretch and squeeze," said Burke-Spolaor.
The researchers said the array will be able to detect a gravitational wave within the next 10 years, if they continue using the current sensitivity.
NASA said that its scientists are developing a similar precision pulsar-timing capability for its Deep Space Network, which is a system of large dish antennas that track and communicate with deep-space spacecraft. These antennas can be used to measure the timing of pulsars’ radio waves. The antennas are distributed around the world, enabling them to see pulsars across the whole sky to help improve sensitivity to gravitational waves.
"Right now, the focus in the pulsar-timing array communities is to develop more sensitive technologies and to establish long-term monitoring programs of a large ensemble of the pulsars," stated Walid Majid, the principal investigator of the Deep Space Network pulsar-timing program at NASA’s Jet Propulsion Laboratory (JPL). "All the strategies for detecting gravitational waves, including LIGO [Laser Interferometer Gravitational-Wave Observatory], are complementary, since each technique is sensitive to detection of gravitational waves at very different frequencies.”
Majid said that the end goal is to detect gravitational waves, which will help usher in the beginning of gravitational wave astronomy. “That is the real exciting part of this whole endeavor,” he said.