| Sub-selection of reliable, BUT INCOMPLETE, stellar objects from Source. |
| This view of table Source defines a reliable, but incomplete, selection of point sources. The select statement of the view requires the source to be present on at least three out of four plates (Nplates > 2) along with a "good" astrometric fit (ie. chi-squared value < 3.0) and on each plate the following conditions are placed on available morphological parameters: ellipticity < 0.25 (ie. image elongation is less than 33%); blend = 0 (ie. image has not been deblended); -3.0 < profile statistic < 3.0 (ie. the areal profile set of the source is close to an idealised PSF set in terms of a 3sigma limit on the N(0,1) profile statistic); quality flag < 128 (ie. any sign of a possibly bad image rejects that image from the view); and limits to exclude the most crowded areas near the Galactic plane and bulge. The use of this, or any other, SSA view depends on the particular science application. If your science application needs a reliable selection of stellar objects but does NOT require high completeness levels, then use this view. Completeness of ReliableStars will be poor in low Galactic latitude regions in particular; note that the Galactic plane region -10 < b < +10 and Galactic bulge region within 20 degrees of the Galactic Centre are not included in this view. If high levels of completeness are required, then use the CompleteStars view. |
select *
from Source
where chi2 < 3.0 and
Nplates > 2 and
ellipB < 0.25 and blendB < 1 and qualB < 128 and
((prfstatB > -3.0 and prfstatB < +3.0) or prfstatB < -0.9e9) and
ellipR1 < 0.25 and blendR1 < 1 and qualR1 < 128 and
((prfstatR1 > -3.0 and prfstatR1 < +3.0) or prfstatR1 < -0.9e9) and
ellipR2 < 0.25 and blendR2 < 1 and qualR2 < 128 and
((prfstatR2 > -3.0 and prfstatR2 < +3.0) or prfstatR2 < -0.9e9) and
ellipI < 0.25 and blendI < 1 and qualI < 128 and
((prfstatI > -3.0 and prfstatI < +3.0) or prfstatI < -0.9e9) and
(b > +10.0 or b < -10.0) and d > +20.0