A team of international scientists, including researchers from The
Australian National University (ANU), have unveiled the largest number of
gravitational waves ever detected.
The discoveries will help solve some of the most complex mysteries of the
Universe, including the building blocks of matter and the workings of space
and time.
The global team’s study, published on November 8, 2021, on ArXiv, made 35
new detections of gravitational waves caused by pairs of black holes merging
or neutron stars and black holes smashing together, using the LIGO and Virgo
observatories between November 2019 and March 2020.
This brings the total number of detections to 90 after three observing runs
between 2015 and 2020.
The new detections are from massive cosmic events, most of them billions of
light years away, which hurl ripples through space-time. They include 32
black hole pairs merging, and likely three collisions between neutron stars
and black holes.
ANU is one of the key players in the international team making the
observations and developing the sophisticated technology to hunt down
elusive gravitational waves across the vast expanse of the Universe.
Distinguished Professor Susan Scott, from the ANU Centre for Gravitational
Astrophysics, said the latest discoveries represented “a tsunami” and were a
“major leap forward in our quest to unlock the secrets of the Universe’s
evolution.”
“These discoveries represent a tenfold increase in the number of
gravitational waves detected by LIGO and Virgo since they started
observing,” Distinguished Professor Scott said.
“We’ve detected 35 events. That’s massive! In contrast, we made three
detections in our first observing run, which lasted four months in 2015-16.
“This really is a new era for gravitational wave detections and the growing
population of discoveries is revealing so much information about the life
and death of stars throughout the Universe.
“Looking at the masses and spins of the black holes in these binary systems
indicates how these systems got together in the first place.
“It also raises some really fascinating questions. For example, did the
system originally form with two stars that went through their life cycles
together and eventually became black holes? Or were the two black holes
thrust together in a very dense dynamical environment such as at the center
of a galaxy?”
Distinguished Professor Scott, who is also a Chief Investigator of the ARC
Centre of Excellence for Gravitational Wave Discovery (OzGrav), said the
continual improvement of gravitational wave detector sensitivity was helping
drive an increase in detections.
“This new technology is allowing us to observe more gravitational waves than
ever before,” she said.
“We are also probing the two black hole mass gap regions and providing more
tests of Einstein’s theory of general relativity.
“The other really exciting thing about the constant improvement of the
sensitivity of the gravitational wave detectors is that this will then bring
into play a whole new range of sources of gravitational waves, some of which
will be unexpected.”
Reference:
GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo During the
Second Part of the Third Observing Run, arXiv:2111.03606v1 [gr-qc],
arxiv.org/abs/2111.03606
Tags:
Space & Astrophysics