  Galaxies uncovered in the Zone of Avoidance (ZOA) with deep optical searches
are compared to the distribution of objects in the 2MASS Extended Source
Catalog (2MASX). While the galaxy density of optical surveys is strongly
correlated to the dust content, and become ineffective in uncovering the galaxy
distribution at A_B > 3.0 mag, this effect is much less severe in the NIR.
Galaxies can be identified in 2MASS at optical extinction layers of over 10mag.
However, star density has been found to be the dominant limiting factor in the
NIR in the wider Galactic Bulge region (see Fig. 4) where optical surveys still
do quite well.
  Systematic positional offsets have also been found between objects in the
2MASX and the optical ZOA as well as other galaxy catalogs. These seem to have
their origin in the astrometric reference frame used by these surveys as well
as different fitting algorithms when determining positions (details are given
in the Appendix). The astrometric offsets between 2MASX and more recent galaxy
catalogs (or on the Digitized Sky Survey remeasured positions) are of the order
of 1 - 1.5 arcsec, comparable to the relative dispersion in positions between
these surveys. Still, it is advisable to take this effect into account when
combining galaxies from different catalogs for observational purposes.
