The direct detection of gravitational waves will be a transformative event in 21st century astronomy. Construction of the Advanced Laser Interferometer Gravitational wave Observatory (aLIGO) and Virgo are well underway; aLIGO is expected to be complete in 2014. After a commissioning period to reach design sensitivity, the first detection of gravitational waves is virtually assured. Despite a great deal of progress in the field, many open problems remain in the field of binary neutron stars (BNS), binary black holes (BBHs) and neutron star–black hole (NSBH) binaries. These coalescing compact objects are of fundamental interest to physicists and astronomers. Gravitational waves from binary black holes will allow us to test general relativity in the strong-field regime. Binaries containing neutron stars will probe the equation of state of nuclear matter. Observed coalescence rates will shed light on the processes driving stellar evolution. The combined observation of gravitational and electromagnetic waves from a source will open a new window on physics and astronomy.
All of these goals require a detailed understanding of both the gravitational waveforms emitted and their electromagnetic counterparts. A combined observing campaign uniting electromagnetic and gravitational-wave astronomers with astrophysicists, source modelers, and nuclear physicists will be essential to realize the promise of the gravitational-wave sky. To this end, the KITP conference “Rattle and Shine” will address the following points:
1. Detection. The waveforms for binary neutron star mergers are well understood, but systems with significant spin (NSBH and BBH) remain an unsolved problem. How do we best combine the efforts of the source modeling and gravitational-wave astronomy communities to search for these systems? Similarly, the wide range of potential electromagnetic outcomes (from gamma-rays to radio waves) remains largely unexplored. What are the predictions for the disk and remnant object when BNS or NSBH systems merge? What electromagnetic counterparts will be produced? What is the best strategy for coordinating joint gravitational-wave and electromagnetic searches and detections?
2. Measurement. With the detection of gravitational waves and electromagnetic counterparts, how do we measure the astrophysical quantities (mass, spin, luminosity distance, etc.) of compact binary coalescence? How accurately (and quickly) do we need to be able to locate compact binary sources to be able to do interesting astronomy and astrophysics? How accurately can we predict nucleosynthetic yields from BNS mergers and use these mergers to probe nuclear physics? Could we distinguish a BNS merger from a NSBH merger based only on SGRB observations, and thus provide an independent mass constraint for GW observations? What is the emission of an off-axis BNS or NSBH merger?
3. Interpretation. Having detected and measured the parameters of coalescing compact binaries, what can be learned about the distribution and evolution of the sources? About the nature of general relativity? About the processes driving the emission of gravitational waves? About cosmological parameters? The program will lay the foundation for joint gravitational wave and electromagnetic observatories to be used as laboratories for fundamental physics and astronomy.
The conference will bring together several different communities, and so we will ask the invited speakers to give a survey of the state of the field for a broad audience, as well as talks on the latest developments and directions for future research. We intend to have plenty of time for discussion following the talks and the session chairs welcome input from participants for talking points during the discussion. If you would like to raise any issues, please contact the chair of the session. The conference program is designed to allow for lots of interaction between the speakers and the participants.