VIEW  ReliableGalaxies

High reliability sub-selection of galaxies from Source.

This view of table Source defines a reliable selection of extended
objects (ie. galaxies) from Source. Reliable in this context means that
each galaxy must appear on the UKJ, UKR and UKI plates; must be
classed as non-stellar on UKJ & UKR; must not be deblended on UKJ or
UKR; and must have good quality UKJ, UKR & UKI (ie. quality < 128). A
magnitude cut of Bj < 20.0 provides a reliability of better than
approximately 90%.

The use of this, or any other, SSA view depends on the particular
science application. If your science application needs a highly reliable
selection of galaxies, then use this view. But be aware that this
selection is not in any sense complete, particularly at faint magnitudes.
Note also that because the SSA has general poor completeness of
extragalactic objects at low Galactic latitudes and severe contamination
by blended stars which are indistinguishable from extended sources, this
view is currently limited to |b| > 35.0 and Galactic Centre distance
d > 45.0 (to avoid the crowded Bulge region).


SELECT *
FROM Source
WHERE objidB > 0 AND objidR2 > 0 AND objidI > 0 AND
      classB = 1 AND classR2 = 1 AND
      blendB = 0 AND blendR2 = 0 AND
      qualB < 128 AND qualR2 < 128 AND qualI < 128 AND
      gcormagB < 20.0 AND
      d > 45.0 AND (b > +35.0 OR b < -35.0)