Goal of this talk is (1) to introduce an emerging new field of gravitational wave astronomy, (2) to consider comparable mass binary black hole system as a prime source for the gravitational waves, and (3) to discuss results of recent binary black hole merger simulations.

Gravitational physics is about to enter completely new and exciting era with highly anticipated direct observation of gravitational waves by the worldwide network of gravitational wave detectors such as LIGO, VIRGO, GEO600 and LISA. Observation of gravitational waves will not only allow us to study strong and dynamic regimes of gravity directly for the first time but also will revolutionize astronomy by providing crucial information about the astrophysical sources that are unavailable in any other ways.

To interpret gravitational wave signals from the merger phase of binary black hole systems, we need theoretical understanding of physics involved based on numerical relativity. I will introduce numerical relativity as an important tool for gravitational wave astronomy and discuss recent results in binary black hole merger simulations and their implications for gravitational wave astrophysics.