  We study galaxy mergers with various mass ratios using N-body simulations,
with an emphasis on the unequal-mass mergers in the relatively unexplored range
of mass-ratios 4:1-10:1. Our recent work (Bournaud et al. 2004) shows that the
above range of mass ratio results in hybrid systems with spiral-like luminosity
profiles but with elliptical-like kinematics, as observed in the data analysis
for a sample of mergers by Jog & Chitre (2002). In this paper, we study the
merger-remnants for mass ratios from 1:1 to 10:1 while systematically covering
the parameter space. We obtain the morphological and kinematical properties of
the remnants, and also discuss the robustness and the visibility of disks in
the merger remnants with a random line-of-sight. We show that the mass ratios
1:1-3:1 give rise to elliptical remnants whereas the mass ratios 4.5:1-10:1
produce the hybrid systems with mixed properties. We find that the transition
between disk-like and elliptical remnants occurs between a narrow mass-range of
4.5:1-3:1. The unequal-mass mergers are more likely to occur than the standard
equal-mass mergers studied in the literature so far, and we discuss their
implications for the evolution of galaxies.

Astrophysics