Third Detector up and running:

[beecee]

http://www.virgo-gw.eu/docs/AdV_joins_O2_en.pdf

VIRGO joins LIGO for the “Observation Run 2” (O2) data-taking period

Today, Tuesday August 1st 2017, 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. “The last months have been spent on commissioning VIRGO, and this went very well. We are eager to start our first science run, joining LIGO at this exciting time for our field” says Jo van den Brand of Nikhef and VU University Amsterdam, the spokesperson of the VIRGO collaboration.

Although the VIRGO sensitivity is, for the time being, at a lower level of those of the LIGO interferometers, it is adequate for confirming a potential detection with LIGO and would allow locating sources of gravitational waves in the sky with greater accuracy. The current VIRGO sensitivity significantly exceeds the previous VIRGO record sensitivity, achieved in 2011 before dismantling the detector to start its upgrade. VIRGO is now a brand new instrument comprising several new components, which have been made work together in less than one year, during the so-called commissioning phase. “It took many years of intense and innovative work to realize the ambitious objectives of the VIRGO upgrade. I wish to recognize the dedication of the members of the VIRGO Collaboration, of the EGO staff and of the participating labs” says Federico Ferrini, the director of the European Gravitational Observatory (EGO).

Edited August 11, 2017 by beecee

[beecee]

https://www.preposterousuniverse.com/blog/

A Response to “On the time lags of the LIGO signals” (Guest Post)

Posted on June 18, 2017 by Sean Carroll

This is a special guest post by Ian Harry, postdoctoral physicist at the Max Planck Institute for Gravitational Physics, Potsdam-Golm. You may have seen stories about a paper that recently appeared, which called into question whether the LIGO gravitational-wave observatory had actually detected signals from inspiralling black holes, as they had claimed. Ian’s post is an informal response to these claims, on behalf of the LIGO Scientific Collaboration. He argues that there are data-analysis issues that render the new paper, by James Creswell et al., incorrect. Happily, there are sufficient online tools that this is a question that interested parties can investigate for themselves. Here’s Ian:

 

more at link......

Edited August 11, 2017 by beecee