Great excitement about the opening of a new era in the observation of the universe has been generated by the first detection of gravitational waves by the LIGO interferometers on September 14, 2015 at 5:51 a.m. Eastern Daylight Time. This image posted on the Cal Tech site will undoubtedly be an icon for the new field of observation.
Image Courtesy Caltech/MIT/LIGO Laboratory
These are plots of the signals received by the two LIGO interferometers at Hanford, Washington and Livingston, Louisiana. The two signals were in excellent agreement but separated in time, reaching Hanford 0.007 seconds after detection in Livingston. Corresponding to a distance difference of about 2000 km at the speed of light, this is consistent with the idea that the exchange particle, the graviton, associated with gravity is massless and therefore the gravity wave travels at the speed of light.
If an analogy with sound waves were used to describe the signals shown above, you might describe it as a "chirp" since the frequency starts out low and increases until its termination. The initial model of the source of this signal is that of two black holes of masses about 29 and 36 solar masses orbiting each other until they coalesce into a single black hole of mass about 62 solar masses. This would correspond to the conversion of about 3 solar masses into energy during this brief event, described on the Caltech site as having a "peak power output about 50 times that of the whole visible universe".
Although the projected distance has large error bars, the most probable distance is about 1.3 x 109 light years.
Cal Tech, image of data
Caltech news release, February 11, 2016
LIGO Educator's Guide
Fundamental force concepts