Manchester Particle Physics Seminars, Colloquia and Meetings

Giles Hammond: Listening to the Universe with the aLIGO Detectors

Friday, 20 October 2017 from to (Europe/London)
at Schuster ( 54-6-6.40 - Niels Bohr Common Room )
The field of gravitational-wave astronomy has been launched by aLIGO’s recent detections of multiple binary black hole coalescences. The aLIGO (advanced Laser Interferometer Gravitational-wave Observatory) detectors comprises two instruments located in Hanford, WA and Livinsgton LA. These detectors are 4km long Fabry-Perot Michelson interferometers and the most sensitive length measuring devices in the world. They are able to sense a change equivalent to 1/1000th the diameter of a proton over their 4km baseline. The interferometers utilise a 1064nm Nd-YAG laser to illuminate the cavity mirrors. The mirrors are operated as free test masses, requiring multiple stage pendulum suspensions and inertial seismic isolation to ensure that seismic noise does not limit the detector sensitivity. The final stage of the suspension is fabricated entirely from fused silica to ensure that thermal noise does not limit their sensitivity. The UK has made major contributions to the aLIGO via development of the test mass mirror suspensions.
In this talk I will describe the technology development necessary to realise the LIGO detectors, and also describe the gravitational wave signals that have been observed in the 1st/2nd observing runs. I will provide some insight into the astrophysics which can be gained from these “dark systems”, only observable by listening to the Universe. Finally I will provide a future view of the field, both on ground and in space.