Galaxy Structure & Dynamics

The Group

The galaxy group at the University of Florida consists of the following members:

Dr. Stephen Gottesman and Dr. James Hunter, Jr., and graduate student Ms. Lauren E. Davis. Drs. Seppo Laine, Robert Hueckstaedt, Doug Ratay, and Veera Boonyasait are recent recipients of the Ph. D. Degree.

Interests

Dr. Gottesman directs the observational study of galaxies. His current interests include observing barred spiral galaxies and dwarf irregular systems using the Very Large Array. Together with Dr. Hunter and Dr. Lance Erickson (Ph.D. '87) he continues the study of dark matter in the halo of spiral galaxies using their satellites as probes for the mass. Gottesman was Laine's mentor in his study of the dynamics and star formation in the barred spiral galaxy NGC 7479. During the recent past Gottesman has collaborated closely with Dr. Mercedes Prieto and Dr. John Beckman of the IAC in Spain. During his research leave at the IAC 1995-1996, Gottesman observed a sample of barred spiral galaxies at the William Herschel 4.2 m and Calar Alto 3.5 m telescopes. Collaborative observations have been made also at the Isaac Newton 2.5 m and Calar Alto 2.2 m telescopes. As part of that collaboration, the dissertation project of Dr. Boonyasait was concerned with the barred spiral galaxy NGC 3359. This project also involves theoreticians at the Academy of Athens, Greece. Dr. Ratay's research was concerned with the properties of barred galaxies that have flocculent spiral structure. Optical and NIR observations have been obtained at the IAC. Studies of the galaxy NGC 1784 have been a major focus of this program. Currently, Ms. Davis, a second-year graduate student, is using the VLA B-array observation of NGC157 to analyze HI structures and dynamics of the galaxy at sub-10" resolution. The data will be combined with the C & D data of Ryder et al. (1998) to form the most comprehensive map of the neutral hydrogen content of NGC157.

Dr. Hunter leads the theoretical studies of gas in barred spiral galaxies. Together with previous graduate student Davies he has studied the stability of galactic disks with counterrotating orbits. With several outside collaborators, including R. Whitaker at Los Alamos, Hunter has continued his investigations of the various interface instabilities in the interstellar medium, the early evolution and fragmentation of disks and the dynamics and masses of barred spiral galaxies. His recent interests have included the study of vortices around the Lagrangian points L4 and L5 in barred potentials, in collaboration with previous Florida graduate Dr. Martin England and Prof. George Contopoulos of the Academy of Athens, Greece.