Gravitational wave astronomy

Gravitational Wave Astronomy is an emerging branch of observational astronomy which aims to use gravitational waves (minute distortions of spacetime predicted by Einstein's theory of general relativity) to collect observational data about objects such as neutron stars and black holes, about events such as supernovae and about the early universe shortly after the big bang. The Laser Interferometer Gravitational-Wave Observatory or LIGO, a joint project between MIT and CalTech is spearheading this new field of research along with equally ambitious projects such as LISA, VIRGO, TAMA 300 and GEO 600.

So far, gravitational waves have only been detected indirectly, and gravitational wave astronomy remains more of a possibility than an actuality. However, a number of gravitational wave detectors are in operation with the aim of making gravitational wave astronomy a reality. This young area of research is still in the developmental stages, however there is consensus within the astrophysics community that this field will evolve to become an established component of 21st century multi-messenger astronomy, and that gravitational wave astronomers, working with ground and spaced-based detectors, will stand shoulder-to-shoulder with gamma-ray, x-ray, optical, infrared and radio astronomers in exploring the cosmos in the years to come.

Detecting gravitational waves promises to complement observations in the electromagnetic spectrum: [Cf. Harvnb|Thorne|1995.] Terrestrial detectors are expected to yield new information about the inspiral phase and mergers of binary stellar mass black holes ,and binaries consisting of one such black hole and a neutron star (a candidate mechanism for some gamma ray bursts). They could also detect signals from core-collapse supernovae, and from periodic sources such as rotating neutron stars with small deformations. If there is truth to speculation about certain kinds of phase transitions or kink bursts from long cosmic strings in the very early universe (at cosmic times around $10^\{-25\}$ seconds), these could also be detectable. [See Harvnb|Cutler|Thorne|2002|loc=sec. 2.] Space-based detectors like LISA should detect objects such as binaries consisting of two White Dwarfs, and AM CVn stars (a White Dwarf accreting matter from its binary partner, a low-mass helium star), and also observe the mergers of supermassive black holes and the inspiral of smaller objects (between one and a thousand solar masses) into such black holes. LISA should also be able to listen to the same kind of sources from the early universe as ground-based detectors, but at even lower frequencies and with greatly increased sensitivity. [See Harvnb|Cutler|Thorne|2002|loc=sec. 3.]

Notes

References

* Citation
last1=Cutler
first1=Curt
last2=Thorne
first2=Kip S.
contribution=An overview of gravitational wave sources
year=2002
title=Proceedings of 16th International Conference on General Relativity and Gravitation (GR16)
editor1-last=Bishop
editor1-first=Nigel
editor2-last=Maharaj
editor2-first=Sunil D.
publisher=World Scientific
isbn=981-238-171-6
year=2002
id=arxiv|gr-qc|0204090
*Citation
author-link=Kip Thorne
last=Thorne
first=Kip S.
year=1995
title=Gravitational radiation
id= arxiv|gr-qc|9506086