Spin Parity of Spiral Galaxies I -- Corroborative Evidence for Trailing
  Spirals
  Whether the spiral structure of galaxies is trailing or leading has been a
subject of debate. We present a new spin parity catalog of 146 spiral galaxies
that lists the following three pieces of information: whether the spiral
structure observed on the sky is S-wise or Z-wise; which side of the minor axis
of the galaxy is darker and redder, based on examination of Pan-STARRS and/or
ESO/DSS2 red image archives, and which side of the major axis of the galaxy is
approaching to us based on the published literature. This paper confirms that
all of the spiral galaxies in the catalog show a consistent relationship among
these three parameters, without any confirmed counterexamples, that supports
the generally accepted interpretation that all the spiral galaxies are trailing
and that the darker/redder side of the galactic disk is closer to us. Although
the results of this paper may not be surprising, they provide a rationale for
analyzing the S/Z winding distribution of spiral galaxies, using the large and
uniform image data bases available now and in the near future, to study the
spin vorticity distribution of galaxies in order to constrain the formation
scenarios of galaxies and the large-scale structure of the Universe.
