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| Paper: |
Errors in Rotation Curves and Kinematic Distances |
| Volume: |
438, The Dynamic Interstellar Medium: A Celebration of the Canadian Galactic Plane Survey |
| Page: |
31 |
| Authors: |
Gómez, G. C. |
| Abstract: |
We have explored the consequences of ignoring non-circular motions
in galactic orbits by performing synthetic observations of a
simulated disk galaxy. We have obtained a synthetic rotation curve
and estimated the errors in measured kinematic distances. The measured rotation curve had been found to have features similar to
the one measured for the Milky Way Galaxy, and differs from the real rotation, i.e., the one obtained from the background potential
imposed in the simulation. When the measured rotation is used
to estimate distances, the error is < 0.5 kpc for most of the disk
and larger at the locations of the spiral arms, therefore
selectively affecting objects related to the spiral structure. The
distance errors were actually larger when we used the real rotation
curve. If we use kinematic distances under
the assumption of circular orbits in order to reconstruct the
structure of the model galaxy from the synthetic l-v map, we obtain
a quite distorted picture of the galaxy.
If we, instead, assume a non-circular velocity model and
use it to determine distances, most of density structure in the
numerical model is recovered. |
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