Large-scale N-body simulations of galaxy collisions, including hydrodynamics and star formation (Wallin, Borne).

Instrumentation design and development (Satyapal).

Computing on space-based platforms (Wood).

Multiwavelength studies of the galactic center (Sambruna).

Observational X-ray, UV, and infrared astronomy; multifrequency data analysis (Sambruna, Kafatos, Wallin).

Studies of planetary atmospheres (Summers).

Extragalactic astronomy and cosmology (Sambruna, Satyapal, Kafatos).

Studies of the solar system and interplanetary dust (Weingartner).

Theoretical studies of photon-photon pair production in compact gamma-ray sources and associated observational constraints (Becker, Kafatos).

Shock waves in astrophysics, including supernova shocks and standing shocks in pulsar accretion columns and black hole accretion disks (Becker).

Transonic accretion onto black holes and neutron stars (Becker, Titarchuk, Kafatos).

Relativistic beams, apparent superluminal motions in blazars, and the production of inverse-Compton X-rays and gamma-rays (Becker, Beall, Guillory).

Space weather, the Sun, and the near-Earth environment (Poland, Withbroe, Zhang).

Acceleration of relativistic particles; first- and second-order Fermi mechanisms; particle distribution functions; radiative losses (Becker, Beall, Guillory).

Thermal Comptonization in astrophysical plasmas; X-ray and gamma-ray emission; variability; self-consistent cooling (Becker, Titarchuk).

Stability and structure of cosmic-ray modified shock waves (Becker).

Effects of general relativity on the propagation of particles and radiation near rotating black holes (Becker, Titarchuk, Kafatos).