Introduction

Several fields are selected to test final Catalog Generation algorithms, implementation and analysis.

Field Descriptions

• South1
  
  Large contiguous block of 118 southern tiles covering three bands of declination. All scans observed once with quality 10.
  
  
• Equator1
  
  Contiguous block of 41 tiles covering two declination bands, sampling data from both Mt. Hopkins and CTIO. In the Galactic Plane at l=196, so densities are moderate (~25,000 deg^-2). All scans observed once with quality 10.
  
  
• Equator2
  
  Contiguous block of 46 tiles covering two declination bands, sampling very high source density region in the Galactic Plane at l~+2^o. All scans observed once with quality 10.



• Polar1
  
  311 Tiles circling the north celestial pole. Eighteen Tiles have multiple scans of comparable "best" quality. The method used for selecting the 18 multiply-observed Tiles for the Catalog Generation Database is described here.




• 0/0
  
  Field centered on 0^h meridian and celestial equator to test coordinate calculations.

Details and Statistics

	South1	Equator1	Equator2	Polar1	0/0
Number of Scans:	118	41	46	311
Number of WDB Point Sources:	1205906	957267	3303690	3788450
Number of CatGen Point Sources:	250732	546030	2912796	848192
Number of WDB Extended Sources:	4498	1810	121	10217
Number of CatGen Extended Sources:	4135	1467	94	8589
List of Scans in Field	X	X	X	X
Map of Ks<13m Sources in Galactic Coords (red - R1-saturated in >1 bands; blue - R1-saturated in 3-bands)	X	X	X	X

Test Field FPG Status

	South1	Equator1	Equator2	Polar1	0/0
Drawn from Working DB (available in GATOR and rmt_grit)	X	X	X	X
Multiple Source Processing Complete (use_src, dup_src, spos and sdet values set)	X	X	X	X
DB_MAPCOR Processing Complete (prg_flg and cc_flg updated)	X	X	X	X
Extended Source Processing Complete (cc_flg and vc values set)	X	X	X	X
Proximity Analysis Complete (prox and pxpa values set)
"Catalog" field set	X	X	X	X

Analysis Results

• General



• Duplicate Source Processing
• Duplicate Source Analysis in V3 Processing (S. Wheelock - 1/28/02)
• Nearest Neighbor Analysis and Duplicate Source Processing (R. Stiening - 3/27/02)




I have attached a plot that shows the distribution in nearest neighbor of
sources in the test fields (only sources with use_src=1 were used) where
the nearest neighbor was in a different scan.  The dup resolution
algorithm should have killed all neighbors in a different scan closer than
2" and indeed it has without exception.  I think I understand why the
distribution turns over at larger separations but do others agree?

• Non-duplicate Sources vs. SNR (R. Stiening - 3/31/02)




I have attached two figure that may be useful a discussion of how sources
with use_src=0 and dup_src=0 (i.e. sources that are identified as not
having a matching source in an overlap region where that is geometrically
possible) should be treated in the catalog selection process.

Sherry has indicated that there is a bug in the dup resolution software
and the plots are made with data processed with the bug.  However, I don't
think the bug affects many sources.

I propose that sources not be rejected from the faint source list because
use_src=0 and dup-src=0 and that similar sources in the catalog region of
snr either be accepted as well or be placed in the faint source list.

Rae

Ghost-Kill Fraction vs. SNR (3/31/02)
Ghost-Kill Fraction vs. SNR - expanded scale (3/31/02)



A bug in the duplicate source resolution code was found that was inadvertantly dropping some non-duplicate sources that should be kept for the catalog. That bug was fixed and the duplicate resolution rerun. The following plots show the ghost kill-fractions after the bug fix. Rae reports: "It seems that the fix recovered a few more sources in the catalog region than in the faint source region."

Ghost-Kill Fraction vs. SNR (4/3/02)
Ghost-Kill Fraction vs. SNR - expanded scale (4/3/02)



• Distance to nearest neighbors in use_src=dup_src=0 sources (R. Stiening - 4/9/02)



• The nature of use_src=0 dup_src=0 sources with high SNR (M. Skrutskie - 4/16/02)



• Artifact Flagging
• DB_MAPCOR artifact flagging in the Test Fields (R. Tam and T. Evans - 5/10/02)



• Point Source Count and Color Maps (J. Carpenter - 1/20/02)



• Astrometry
• Analysis of Overlap Positions in Catalog Test Fields (H. McCallon - 4/11/02)



• Extended Sources
• Extended Source Visual Classifications - (T. Jarrett - 1/20/02)



• South1



• Point Source Colors (M. Skrutskie 12/18/01)



Attached is a whirlgif which now shows
the (very nice) color-color/mag diagrams for the first cut query.  I'm blinking
between the entire selected set against a kludge in which I prevent the query 
from selecting the snr>5 in any one band faint sources.  You can see they fill 
in rather nicely.

• Non-3-band Sources (M. Skrutskie 12/19/01)





• Polar1



• Duplicate-resolved Extended Source Distribution at the NCP (R. Stiening - 4/1/02)




I was curious about the bright spot in John Carpenter's plots near the
north equatorial pole.  Since the galaxy distribution is independent of
the star distribution I was curious about whether or not the galaxies
would show a bright spot as well.

NCP Dup-Resolved Galaxy Gatalog



• (M. Skrutskie - 4/1/02)  John notes that the bright spot is NGC 188.  
  I've attached the coadd image.  Since his is a star counts rather 
  than a flux map the cluster really stands out.

J-Band Atlas Image in the vicinity of NGC188

Last Updated: 13 May 2002
R. Cutri - IPAC