Chanda J. Jog
Department of Physics, Indian Institute of Science, Bangalore
560012, India
Abstract. We have analyzed the near-IR Ks-band data from the 2MASS
archival database for a large sample of twenty-seven galaxies that show
signs
of interaction but have a single nucleus. Surprisingly, half of these
advanced
mergers of galaxies show luminosity profiles which have an outer
exponential
fall-off with radius, as in a spiral galaxy (Chitre and Jog 2002). The
kinematical
data for two of these, Arp 224 and Arp 214, available from the HYPERCAT
database were used and these show kinematics similar to elliptical
galaxies with
the random motion dominating the rotation (Jog and Chitre 2002). The
origin
of the mixed properties shown by these mergers is a puzzle. To
understand
these systems, we have recently studied the dynamics of mergers via
N-body
simulations for unequal-mass mergers covering a new range of galaxy mass
ratios 4:1-10:1 (Bournaud, Combes, and Jog 2004). We show that such
mergers
naturally result in remnants that have the mixed properties as we have
observed
from the 2MASS data analysis. The transition between elliptical and
disk-like
remnants is found to occur over a narrow range of galaxy mass ratios
3:1-4.5:1
(Bournaud, Jog and Combes 2005).
Keywords: Galaxies: kinematics and dynamics - Galaxies : interactions - Galaxies: evolution - Galaxies: photometry - Galaxies: structure.