Neutron stars (NS), which are extremely compact stellar remnants, and black holes (BHs), the densest objects in the universe, are fantastic astrophysical laboratories for probing fundamental aspects of the laws of physics, from quantum mechanics to general relativity. A wealth of information comes from observing them in the final moments of their lives, when they are members of a binary system that merge due to the emission of gravitational waves (GWs). If a NS is member of the binary, then this merger may also produce light, or electromagnetic emission (EM), which greatly increases the astrophysical information that can be extracted. This was shown in the many observations of the merger event GW170817/GRB170817A, the results of which impacted knowledge in a variety of research areas, from high-energy astrophysics, to nuclear physics, to cosmology. A research group at the State University of New York at Stony Brook will undertake theoretical work aimed at maximizing the research gain from future observations. The variety of topics (and techniques) that this research plan encompasses makes it ideal for the involvement of students at all levels, including undergraduates. The principal investigator (PI) is especially interested in involving female undergraduate student in this research, with the goal of empowering and giving confidence to young women in their abilities to do science, and hence encouraging them to pursue careers as scientists.
This project will explore several facets of binary formation and evolution, and of the GW-EM connection, while probing issues of fundamental physics. In particular: (a) It will develop a general framework for the interpretation of the radiation from NS-NS and NS-BH sources triggered by the LIGO and Virgo GW detectors. The goal is to connect the properties of binary compact merger ejecta with the EM emission of their jet-cocoon systems, the time delay from the GW signal, and the type of compact object remnant left behind. Along with mass measurements from GWs, this information aids in constraining the equation of state of NS matter. (b) It will extend and refine the predictions of dynamical formation of compact object binaries in star clusters. Among the outcomes will be an exploration of the mass distribution of NS-BH binaries produced via this channel, and a comparison to those formed from field binaries. (c) It will couple results from the first two studies to compute the broadband EM radiation expected for the main formation channels of NS-NS and NS-BH binaries, as well as BH-BH in dense environments, extracting potentially discriminating features and aiding searches for EM counterparts to GW triggers. As part of this project, the PI plans to partner with the WISE (Women In Science and Engineering) program at Stony Brook. This will involve (a) supervision of undergraduate research projects during the academic year; (b) giving guest lectures in a course specifically designed by WISE to discuss opportunities in STEM fields; (c) being a high-school mentor in the WISE after school program. This project advances the goals of the NSF Windows on the Universe Big Idea.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
