IAU Symposium Abstract S186-051T

Fundamental plane and merger scenario

Kenji Bekki
Astronomical Institute, Tohoku University, Sendai, 980-77, Japan
< bekki@astroa.astr.tohoku.ac.jp >

We perform a set of numerical simulations of galaxy mergers between disk galaxies considerably abundant in interstellar gas in order to explore physical meaning of the fundamental plane (FP) of elliptical galaxies. We consider that origin of global scaling relation in the FP is closely related to nonhomology both in spacial structure and in kinematics of elliptical galaxies formed by galaxy merging. We therefore investigate dynamical and kinematical properties of merger remnants and found that rapidity of gas consumption by star formation during galaxy merging can determine radial density profile and relative importance of global rotation in kinematics of the remnants. This result indicates that both structural nonhomology and kinematical one observed in elliptical galaxies result from the difference in the rapidity of star formation between the precursor mergers. It is also found that the ratio of total dynamical mass to luminous mass in the remnants, which is also regarded as an another important determinant for the origin of the FP, depends on the rapidity of gas consumption by star formation in galaxy mergers. These numerical results demonstrate that the origin of the FP can be essentially ascribed to the difference in the star formation history between forming elliptical galaxies.