Founding countries
Countries which have joined the Virgo experiment later
|
|
Formation | 1993 |
---|---|
Type | International scientific collaboration |
Purpose | Gravitation wave detection |
Headquarters | EGO |
Location | |
Coordinates | 43°37′53″N 10°30′16″E / 43.6313°N 10.5045°ECoordinates: 43°37′53″N 10°30′16″E / 43.6313°N 10.5045°E |
Region
|
Italy |
Fields | Basic research |
Membership
|
CNRS (France), INFN (Italy), NIKHEF (Netherlands), POGRAW (Poland) and RMKI (Hungary) |
Spokesperson
|
Fulvio Ricci |
Affiliations | LVC (LIGO Scientific Collaboration and Virgo Collaboration) |
Budget
|
About ten million euros per year |
Staff
|
More than 320 people contribute to the Virgo experiment |
Slogan | Listening to the cosmic whisper |
Website | www |
The Virgo interferometer is a large interferometer designed to detect gravitational waves predicted by the general theory of relativity. Virgo is a Michelson interferometer that is isolated from external disturbances: its mirrors and instrumentation are suspended and its laser beam operates in a vacuum. The instrument's two arms are three kilometres long and located near Pisa, Italy.
Virgo is part of a scientific collaboration of laboratories from five countries: France and Italy (the two countries behind the project), the Netherlands, Poland and Hungary. Other interferometers similar to Virgo have the same goal of detecting gravitational waves, including the two LIGO interferometers in the United States (at the Hanford Site and in Livingston, Louisiana). Since 2007, Virgo and LIGO have agreed to share and jointly analyze the data recorded by their detectors and to jointly publish their results. Because the interferometric detectors are not directional (they survey the whole sky) and they are looking for signals which are weak and infrequent, simultaneous detection of a gravitational wave in multiple instruments is necessary to confirm the signal and determine its origin.
The interferometer is named for the Virgo Cluster of about 1,500 galaxies in the Virgo constellation, about 50 million light-years from Earth. As no terrestrial source of gravitational wave is powerful enough to produce a detectable signal, Virgo must observe the Universe. The more powerful the detector, the further it can see gravitational waves, which then increases the number of potential sources. This is relevant as the violent phenomena Virgo is potentially sensitive to (coalescence of a compact binary system, neutron stars or black holes; supernova explosion; etc.) are rare: the more galaxies Virgo is surveying, the larger the probability of a detection.