This post is part of a series about quick questions and answers about the Virgo experiment and the science of gravitational waves. Do you have a quick question? Tell us and we will reply!
What are the sources of gravitational waves?
No source on Earth is capable of producing gravitational waves large enough to be detected by Virgo, but many violent phenomena in the Universe could generate detectable signals. For instance, models predict that transient gravitational wave signals could be emitted during the merger of two compact celestial objects, such as neutron stars and/or black holes, or during a supernova explosion.This is the case of GW150914, the first detected gravitational wave event, that was produced by the merger of two massive black holes 410 Mpc away from us.
GW150914, the first ever detected gravitaional wave, came from two black holes that merged over a billion light years from Earth. This picture is extracted from a computer simulation showing what this would look like up close.
The black holes are near us, in front of a sky filled with stars and gas and dust. The black regions are the shadows of the two black holes: no light would reach us from these areas. Light from each star or bit of gas or dust travels to our eyes along paths (light rays) that are greatly bent by the holes\’ gravity and by their warped spacetime.
Credit: SXS Lensing (License: CC-BY-SA 4.0)
Furthermore, continuous, periodic gravitational waves are expected from spinning asymmetric neutron stars. There is also an expected stochastic background of gravitational waves, emitted in the early stages of the Universe. There may also be a plethora of new, yet unknown, classes of astrophysical objects emitting gravitational waves.
