Astronomers have now taken up more gravity wave measures than they can count on their fingers. Scientists with LIGO and…
Astronomers have now taken up more gravity wave measures than they can count on their fingers.
Scientists with LIGO and Virgo gravity wave observatories report four new sets of these ripples in space. These additions give the total bill to 11, the researchers said in a study published on December 3 at arXiv.org, which marked great progress since the first gravitational wave detection 2015 [ SN: 3/5/16, p. 6 ).
All but one of the 11 sets of waves were stirred in violent collisions of two black holes. The remaining discovery, reported in October 2017, came from the crushing of two star bodies called neutron stars ( SN: 11/11/17, p. 6 ).
The observations begin to reveal how often such waves jiggle the cosmos and the characteristics of the shadowy cosmic figures that release the ripples. For example, the data hint that black holes have been merged more often earlier in the history of the universe, researchers report in a second study published on December 3 at arXiv.org. The team also concluded that mergers involve black holes larger than about 50 times the mass of the sun.
“There are real strong evidence that these [big] black holes are missing,” said LIGO member Daniel Holz, an astrophysician at the University of Chicago. Some theoretical physicists had predicted such a lack of bulky black holes based on the physics of star explosions producing cosmic gaps.
Record-hard black holes produced one of the new sets of spacetime shivers. The combination mass of the colliding behemoths was the largest yet spotted, with a black hole weighing about 50 times the mass of the sun and the other at 34 times the mass of the sun. These ripples also came further than any previous discovery: about 9 billion light years from the earth, give or take a few billion. “It says in every possible way,” says physicist Emanuele Berti of Johns Hopkins University, who was not involved in research. “It’s superintensive.”
LIGO’s two detectors, located in Hanford, Wash., and Livingston, La ., And Virgo, near Pisa in Italy, is shuttered for upgrades until next spring. Improvements in equipment can triple the number of gravity wave observations, “says Holz. “We will get a whole lot more.”