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Galaxy Photometry

3.1
Observe a region in Coma in all three bands several times in one night, and repeat over several nights, to test repeatability, completeness and reliability for extended sources. J and H is especially important.

Seven 6 scans of Coma observed in 3 bands on each of 3 nights require 7 3 3 442 secs = 7.7 hrs.

3.2
Observe a region of Virgo to investigate treatment of large galaxies and of low surface brightness galaxies.

Seven scans in 3 bands require 2.6 hrs.

3.3
Observe a cluster at the limit of sensitivity, eg. part of the Corona Borealis supercluster, specifically the A2065 and A2061 clusters. These very dense/rich clusters are located at V (z ). Their R-band magnitudes range from 14.5 to 17, so they will be faint for us (K > 12.5) but doable.

13 6 scans in 3 bands = 4.8 hrs.

3.4
Observe a galaxy field (preferably a cluster) with high foreground star contamination, either at low galactic latitude or behind an open star cluster, to test star-galaxy separation and confusion. Repeat at different foreground star density levels. This may be difficult to do in practice in April since the plane is up only at the very end of the night and it may be hard to find a conveniently juxtaposed galaxy field and star cluster.

7 scans 3 bands 442 seconds = 2.6 hrs.

3.5
Observe a galaxy field with a non-uniform backgound, such as on the edge of a nebula, to test how well the processor does in regions of varying background.

7 scans 3 bands 442 seconds = 2.6 hrs.

3.6
Observe a set of irregular and peculiar galaxies to characterize how the processor handles them.

3 scans on each of 5 fields in 3 bands requires 5.5 hrs.



next up previous
Next: Nebulae Up: 2MASS Technical Memorandum Previous: Point Source Photometry



Gaylin Laughlin
Tue Feb 14 09:11:22 PST 1995