Letters of Intent received in 2016

LoI 2018-1903
The New Era of Gravitational Wave Astronomy and Astrophysics - Focus Meeting (GA)

Topics

• Binary stellar-mass black holes: rate, mass distribution and astrophysical implications after the first observational runs of the ground-based gravitational-wave detectors
• Binary systems containing neutron stars, and core-collapse of massive stars: search results and astrophysical interpretation
• Multi-messenger astrophysics: results and interpretation of joint GW/EM/neutrino observing campaigns
• Searches for persistent periodic and stochastic gravitational waves, and astrophysical connections
• Modeling and simulations of astrophysical sources of gravitational waves: emission and population models
• Forum about lessons learned, prospects and challenges of exploiting the first years of multi-messenger observations with gravitational waves

Rationale

The first observational campaign of the Advanced LIGO interferometers marked the dawn of gravitational-wave astronomy with the first detections of gravitational waves from binary stellar-mass black-hole systems. The discovery of gravitational waves showed the first evidence that binary black holes (with masses also larger than 25 Mo) exist and merge within a Hubble time, providing a novel probe of the formation and evolution of compact objects. The sky location of the gravitational-wave signals were rapidly and extensively observed by satellites and ground-based electromagnetic and neutrino observatories, demonstrating the capability to cover large areas of the sky, to analyze huge amount of data, identify candidate counterparts, and to characterize their nature. The rich physics of gravitational-wave sources can now begin to be probed by multi-messenger observations.

The full exploitation of gravitational-wave observations relies on i) increasingly sophisticated GW and EM observations and data analysis; ii) numerical modelling of gravitational-wave sources, including realistic microphysics of matter under extreme conditions and strong gravitational fields; iii) simulation and prediction of gravitational-wave source populations using a deeper understanding of compact object formation and evolution.

We therefore propose an IAU Focus Meeting to bring together experts from the gravitational-wave/electromagnetic/neutrino communities in a common forum to discuss the latest results and identify future directions as multi-messenger observatories continue to evolve. At the time of the proposed Focus Meeting in 2018, the Advanced LIGO and Virgo detectors will have results from two to three observational runs, with full sensitivity expected to be achieved in 2019+. This will provide us with an unprecedented quantity of multi-messenger data, to be accurately analyzed and interpreted. The first multi-messenger campaign including gravitational-wave observations enlisted facilities and astronomer groups on all seven continents showing how this new emerging field provides opportunities for scientists around the world, even in developing countries, to get involved.

Although the guidelines indicate that an IAU Focus Meeting should promote new topics not covered by any sub-structures of the IAU commission, the recent progress in gravitational-wave observations (although covered by Commission D1 Gravitational Wave Astrophysics) makes it vital to deepen collaborations in this area to address each observational and theoretical astrophysical aspect that will arise in this field. For each improvement of the gravitational-wave network and the results achieved, the multi-messenger observations, data analysis and theory should be prepared at the state-of-the-art evolving with new results. An IAU Focus Meeting at the 2018 General Assembly would provide an ideal forum to bring together astronomers and gravitational-wave researchers to compare exciting multi-messenger observations, discuss the astrophysical implications, and on the basis of the lessons learned overcome challenges and define prospects and goals for the emerging field of gravitational-wave astronomy.