So if we see black
hole merger events before stars existed, then we'll know that those black holes are not of stellar origin.»
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.
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.
Two common models for gamma - ray emission from FRBs exist: one invoking magnetic flare
events from magnetars — highly magnetized neutron stars that are the dense remnants of collapsed stars — and another invoking the catastrophic
merger of two neutron stars, colliding to form a black
hole.
For the first time, scientists worldwide and at Penn State University have detected both gravitational waves and light shooting toward our planet from one massively powerful
event in space — the birth of a new black
hole created by the
merger of two neutron stars.
The other aspect is that space - time is incredibly stiff: that's why you need a cataclysmic
event like the
merger of two black
holes to produce a distortion that we can measure.
A year ago, LIGO confirmed a prediction made by Albert Einstein a century earlier: that violent cosmic
events, like the
merger of two black
holes, would wrench the fabric of spacetime and emit ripples.
LIGO's detection of this
event, plus another, fainter signal that also looks like a black
hole merger, means we can conclude that black
hole binaries this size can and do form in nature.
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.
Such
events are the most energetic known; the power of the gravitational waves that they emit can briefly rival that of all the stars in the observable Universe combined.Black -
hole mergers are also among the cleanest gravitational - wave signals to interpret.
The researchers are lucky to have caught this unique
event because not every black -
hole merger produces imbalanced gravitational waves that propel a black
hole in the opposite direction.
Gravitational waves are ripples in space - time caused by
events like the
merger of two black
holes.
A discovery would confirm one of general relativity's most extraordinary predictions and provide an unprecedented glimpse of cataclysmic
events such as black
hole mergers.
Such
events could include the
mergers of lighter binary black
holes, of binary neutron stars or of a black
hole with a neutron star.
More - stringent tests will be possible if and when LIGO detects black -
hole mergers that are larger than this one, or that occur closer to Earth than the
Event's estimated distance of 1.3 billion light years, and thus give «louder» waves that stay above the noise for longer.
Mészáros notes that the gravitational waves looked like they came from objects smaller in mass than black
holes, which pointed to neutron stars, and that the electromagnetic emissions separately correlated to the
event provide two ways to show proof - positive that this is a neutron star
merger.
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.
Unlike the first four gravitational wave
events that involved
mergers of black
holes, the fifth
event involved the
merger of neutron stars.
Title:
Merger of Multiple Accreting Black
Holes Concordant with Gravitational Wave
Events Author: Hiromichi Tagawa & Masayuki Umemura First Author's Institution: Eötvös University, Hungary; National Astronomical Observatory of Japan Status: Accepted to ApJ
When an energetic
event occurs (like a black
hole merger or neutron star collision), spacetime becomes violently disturbed and energy is carried away from the
event in the form of gravitational waves — like ripples traveling across the water's surface after dropping a pebble in a pond.
This latest detection originated from a
merger creating a black
hole of 49 solar masses (another «heavy» black
hole like the first one), but the
merger happened over twice as far away than previous
events.
The 2015
events were caused by
mergers creating black
holes 62 and 21 solar masses in galaxies 1.3 and 1.4 billion light - years away, respectively.
Otherwise unknowable details of some of the universe's most violent
events — from neutron star and binary black
hole mergers, to supernova explosions and even the Big Bang itself — should be revealed by the tell - tale gravitational waves they produce.