But its announcement was delayed due to the time required to understand two other discoveries: a LIGO - Virgo three - detector observation of gravitational waves from another binary
black hole merger on August 14, and the first - ever detection of a binary neutron star merger in light and gravitational waves on August 17.
Not exact matches
Being able to study things like
black hole mergers through gravity will shed light
on some of the «darkest yet most energetic events in our universe,» said Albert Lazzarini, deputy director of the LIGO Laboratory, in an American Physical Society press release.
Merritt calculated the effect of such a
merger on the spin of the combined
black hole.
LIGO scientist David Reitze takes us
on a 1.3 billion year journey that begins with the violent
merger of two
black holes in the distant universe.
Such
mergers could give themselves away by their effect
on the shapes of the
black holes» parent galaxies, and in infrared and ultraviolet afterglows.
Frustratingly for the Virgo team, the steel wires are expected to have the most impact
on sensitivity to gravitational waves with lower frequencies than neutron star
mergers, such as those from the
mergers of
black holes.
But only some of the most massive astrophysical events, such
mergers of
black holes and neutron stars, can produce gravitational waves strong enough to be detected
on earth.
When Eleonora Troja got the LIGO notification
on 17 August that new gravitational waves had been detected, she dismissed it at first, assuming it was just another
black -
hole merger, she recalls.
«If we assume this is the case, that LIGO caught a
merger of
black holes formed in the early universe, we can look at the consequences this has
on our understanding of how the cosmos ultimately evolved.»
Supermassive
black holes like the one in galaxy M87 probably grow not only by feeding
on infalling gas and stars but also by
mergers of smaller
black holes.
He was also working
on other LIGO papers at the time, including one about an earlier detection of a
black -
hole merger which now needed to be published before it could be eclipsed by the neutron - star
merger announcement.
LIGO researchers spotted a second
black hole merger before ending the observation run
on 12 January.
According to Loeb, the
black hole that Condon's group think they have identified probably had its galaxy shredded, because it held
on to a few stars — if it had been in a
black hole merger or a three - body scuffle, it would have lost everything.
The LIGO press release mentions an estimation of
black hole merger rates — «about one every 10 years in a volume a trillion times the size of the Milky Way Galaxy» — based
on how many signals it's detected so far.
Findings from this and two previous discoveries of
black hole mergers are providing the WSU scientists and colleagues at the Laser Interferometer Gravitational - Wave Observatory (LIGO) an unprecedented glimpse into the early universe and shedding new light
on how binary
black holes form.
On Sept. 14th, 2015, physicists directly observed gravitational waves created by the
merger of 2
black holes.
The very first detection of gravitational waves
on 14 September 2015: Signals received by the LIGO instruments at Hanford, Washington (left) and Livingston, Louisiana (right) and comparisons of these signals to the signals expected due to a
black hole merger event.
This event, detected by the two NSF - supported LIGO detectors at 02:01:16 UTC
on June 8, 2017 (or 10:01:16 pm
on June 7 in US Eastern Daylight time), was actually the second binary
black hole merger observed during LIGO's second observation run since being upgraded in a program called Advanced LIGO.
If the signal LIGO had detected had been, say, neutron stars colliding and not
black holes, we would have had no complaints, but there's probably a very good chance you could see neutron star
mergers with other, conventional observational tools relying
on light.
Indian scientists made direct contributions — ranging from designing algorithms used to analyse signals registered by detectors to ascertain those from a gravitational wave to working out parameters like estimating energy and power radiated during
merger, orbital eccentricity and estimating the mass and spin of the final
black hole and so
on.