Gravitational Waves

Thu Feb 11, 2016 4:26 pm

Gravitational Waves
and LIGO

https://www.youtube.com/watch?v=zyo4DFr4D4I

Announcement of LIGO press conference Feb 11 @ 10:30am EST

Thu Feb 11, 2016 7:16 pm

The Thursday update event
Announcement of LIGO press conference Feb 11 @ 10:30am EST

Gravitational Waves Detected
100 Years After Einstein's Prediction.

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10^(−21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410[+160−180] Mpc corresponding to a redshift z=0.09[+0.03−0.04]. In the source frame, the initial black hole masses are 36[+5−4]M⊙ and 29[+4−4]M⊙, and the final black hole mass is 62[+4−4]M⊙, with 3.0[+0.5−0.5]M⊙c^2 radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.