A surviving disk from a galaxy collision at z=0.4
  Spiral galaxies dominate the local galaxy population. Disks are known to be
fragile with respect to collisions. Thus it is worthwhile to probe under which
conditions a disk can possibly survive such interactions. We present a detailed
morpho-kinematics study of a massive galaxy with two nuclei,
J033210.76--274234.6, at z=0.4. The morphological analysis reveals that the
object consists of two bulges and a massive disk, as well as a faint blue ring.
Combining the kinematics with morphology we propose a near-center collision
model to interpret the object. We find that the massive disk is likely to have
survived the collision of galaxies with an initial mass ratio of ~4:1. The
N-body/SPH simulations show that the collision possibly is a single-shot polar
collision with a very small pericentric distance of ~1 kpc and that the remnant
of the main galaxy will be dominated by a disk. The results support the disk
survival hypothesis. The survival of the disk is related to the polar collision
with an extremely small pericentric distance. With the help of N-body/SPH
simulations we find the probability of disk survival is quite large regardless
whether the two galaxies merge or not.
