This Principle Investigator is carrying out radio pulsar investigations of relativistic gravitation, the interstellar medium, and the pulsar emission process in Australia and in the U.S. The relativistic gravitation projects include timing and profile measurements of the double neutron star pulsar B1913+16 to achieve better precision on the orbital decay rate due to gravitational radiation emission, information on the geometry of the emission beam, and a much improved proper motion which has implications for studies of the evolution and galactic population of these objects. Further precise timing of millisecond pulsars is being done in order to search for timing irregularities ascribable to low-frequency gravitational waves emitted in the early Universe or from binary supermassive black holes. Interstellar medium investigations include galactic magnetic field studies of the overall magnetic field structure in the inner and outer Galaxy. Other pulsar studies will yield additional pulsar kinematical distances essential to calibrating galactic electron density models. These provide estimates of the distance to all pulsars contributing to a variety of general pulsar population issues. Work related to the pulsar radio emission process includes single-pulse and average-pulse polarimetry and analyses. The new data will be combined with earlier work in an effort to advance our knowledge of fundamental emission and magnetospheric propagation phenomena.
Broader impacts. This work promotes the scientific education and training of the Carleton College students by enabling them to do real research rather than just reading about it in textbooks. The Carleton group collaborates with colleagues in Australia, Cornell, Berkeley, and Princeton, exposing them to the latest techniques, procedures, and ideas from some of the finest investigators in the field and at some of the finest observatories in the world. The project director's teaching and public outreach activities are inspired by this work. The project strengthens Carleton's record as one of the principal undergraduate sources of future physicists and astronomers, while also educating the broader public both within and outside Carleton.
