The Laser Interferometric Gravitational Wave Observatory (LIGO for short) is a large research instrument that listens to gravitational waves from deep in the universe with the help of a laser interferometer.
On December 3, 2018, Advanced LIGO discovered the largest black hole merger event to date, 9 billion light years away from the Earth.[1]
On June 15, 2016, the Scientific Cooperation Organization of the Laser Interferometer Gravitational Wave Observatory (LIGO) and the Virgo Scientific Cooperation Organization officially announced at the 228th meeting of the American Astronomical Society held in San Diego that another gravitational wave event GW151226 was confirmed in the data of the high-tech LIGO detector: 3:38:53 on December 26, 2015, World Coordinated Time,Scientists observed gravitational waves for the second time.[2]
On October 16, 2017, scientists from many countries around the world held a press conference at the same time, announcing that for the first time, human beings directly detected gravitational waves from the merger of two neutron stars, and simultaneously "saw" the electromagnetic signals sent by this spectacular cosmic event.[3]
On December 3, 2018, according to the Physicist Organization Network, an international team of scientists found the largest black hole merger event and gravitational waves generated by three other black hole mergers by analyzing the observation data obtained by the Advanced LIGO.The largest black holes have merged into a new black hole about 80 times the size of the sun, which is also the farthest black hole merger from the Earth so far.[1]
At 5:10:39 p.m. on August 14, 2019, three giant detectors in the United States and Italy detected a strange event. Analysis shows that this is obviously a gravitational wave pulse generated by a pair of black holes and neutron stars moving together about 900 million light years away.The report pointed out that the new discovery was jointly made by the Laser Interferometer Gravitational Wave Observatory (LIGO) in the United States and the Virgo Observatory in Italy.[4]
Composition
Announce
edit
LIGO consists of two interferometers, each of which has two 4km long arms and forms an L-shape. They are located in Livingston, the south coast of the United States, and Hanford, the northwest coast of the United States, 3000 km away.Each arm is composed of 1.2 m diameter vacuum steel pipe.
In optics, it uses high power continuous stable laser to process extremely fine low absorption mirror, FP cavity and power cycle cavity.
In mechanical aspect, it uses passive damping and active damping isolation technology as well as vacuum technology.In terms of information technology, for example, its computing load in the autumn of 2015 is equivalent to one thousand years of computing on a four core computer.Only the main technical features used by LIGO are listed above.
In addition, LIGO's research team is constantly trying to upgrade the instrument.
