Accretional remanence of magnetized dust in the solar nebula

Anticipating the results from the Rosetta magnetometer experiment, we present a theoretical study concerning the possible origin of a cometary magnetic field. Assuming the existence of a permanently magnetized iron dust fraction in the primordial solar nebula, we use a numerical model to investigate the outcome of a dust aggregation process involving both magnetic and nonmagnetic preplanetary grains. The growing dust aggregates of low fractal dimension and sizes on the order of 1 mu m conserve magnetization to a large extent and could thus serve as building material for larger permanently magnetized celestial objects. A special focus is put on deriving numerical parameters for magnetic dust aggregates that can be used in subsequent numerical studies. On the basis of our results, we outline possible future lines of study involving the optical and mechanical properties of magnetized dust, (C) 2000 Academic Press.