RUI: Pulsars, Relativistic Gravitation, and the Interstellar Medium

Carleton College, Northfield MN

Investigators

Abstract

Weisberg, Joel RUI: Pulsars, Relativistic Gravitation, and the Interstellar Medium AST-0098540 In astronomy, we commonly encounter physical conditions quite unfamiliar to us here on Earth. It gives us a chance to test physical theories that apply locally in order to see if they remain valid at extremes. As neutron stars, pulsars represent one such extreme. With their many unusual properties, pulsars can be studied in themselves but they can also be used to probe the interstellar medium and to investigate experimentally the effects of relativistic gravitation. Starting from the background and results of a current grant, the investigation outlined here moves on to new research in each of these three areas. Intrinsic studies of pulsars will include measurements of polarized pulse profiles, investigations of the emission beam geometry, and searches for free and radiative precession. The binary pulsar B1913+16 will be used as a relativistic gravitational laboratory. Gravitational radiation emission and relativistic spin precession will be measured and compared with theory. The interstellar medium investigations will involve Faraday rotation measurements of the galactic magnetic field and several pulsar pulse-phase-resolved spectrometry studies. The spectrometry experiments will include the determination of pulsar distances and interstellar electron densities through neutral hydrogen kinematic distance measurements.