A very exciting LIGO-Virgo Observing run draws to a close on the 25th of August. The Virgo and LIGO Scientific Collaborations have been observing since November 30, 2016 in the second Advanced Detector Observing Run ‘O2’, searching for gravitational-wave signals, first with the two LIGO detectors, then with both LIGO and Virgo instruments operating together since August 1, 2017. Some promising gravitational-wave candidates have been identified in data from both LIGO and Virgo during our preliminary analysis, and we have shared what we currently know with astronomical observing partners.
Gravitational Waves: astrophysics, source modeling, data analysis, construction of the Virgo detector
Today, Tuesday August 1st 2017 at 11 CEST, the VIRGO detector based in Europe has officially joined “Observation Run 2” (O2) and is now taking data alongside the American-based twin LIGO detectors. This major step forward for the VIRGO Collaboration is the outcome of a multi-year upgrade program, whose primary goal was to significantly improve the detector performance in terms of sensitivity. More informations.
The Advanced LIGO detectors registered in the 4th of January 2017 a merger of a black hole binary system of masses approx. 30 and 20 Solar masses and a formation of a remnant black hole of 49 solar masses and spin parameter of about 0.64, at a distance of about 880 Mpc (corresponding to a redshift z = 0.18). It is likely that at least one of the black holes was spinning opposite the direction of the binary orbit.