First direct detection of gravitational waves nearing success

The LIGO Scientific Collaboration (LSC) is dedicating their second-generation gravitational-wave detectors (aLIGO) in a ceremony at the Hanford detector site on May 19.

The efforts of researchers at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, AEI) in Hannover and Potsdam, Germany, will open a new window to the otherwise invisible "dark" side of the universe and mark the beginning of gravitational-wave astronomy.

Gravitational waves are ripples in space-time that are emitted by cataclysmic cosmic events such as exploding stars, merging black holes and/or neutron stars, and rapidly rotating compact stellar remnants.

These waves were predicted in 1916 by Albert Einstein as a consequence of his general theory of relativity, but have never been observed directly. At their design sensitivity, the aLIGO instruments should detect multiple gravitational-wave events each year.

Researchers at the AEI together with the Laser Zentrum Hannover developed and installed the high-power laser systems used in the aLIGO detectors.

AEI director Karsten Danzmann said that with their UK colleagues they designed and operate the gravitational-wave detector GEO600, adding that they use it as a think tank and test bed for advanced detector techniques.

He added that many of these new methods are now in use at the aLIGO detectors, such as signal recycling and monolithic mirror suspensions.

Alessandra Buonanno, director at the AEI in Potsdam, added that the wave form models used for the upcoming search include the full coalescence process (inspiral, merger and ringdown) and for the first time they contain effects of the black holes' spins, which will improve the sensitivity and thereby their chances of detection.