The black lines in each plot are the density contours.
The core is spinning along its short axis which is usually the case.
The velocity dispersion rises towards center but dips in the center. This
is because of the presence of two separate populations of particles there.
A hot (high dispersion) component from the particles which were originally
there and a cold component from the particles which were originally in
the satellite. The graph marked h3 is the third Gauss-Hermite term. It
is showing that the velocity distributions are skewed towards slower moving
particles. This is in part a projection effect. The final graph is the
fourth Gauss-Hermite term. A positive (negative) term indicates that the
wings of the distribution are lower (higher) than expected from a pure
Gaussian. In this simulation the wings are significantly higher in the
rotation plane.
Primary Particles Only |
Secondary Particles Only |
The two separate populations of particles are visible
when the velocity profiles are viewed separately above. The h4 map of the
secondary particles is not accurate do to the presence of too few
particles at outside of the core. The secondary particles only dominate
in the very center of the remnant galaxy where the rotation velocity is
zero. Most of the rotation is therefore due to the
rotation of the primary particles. Detectability
of the second population might therefore be hard.
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