To make the Point Source Working Database more user friendly during final 2MASS data processing, additional fields derived from the standard source information will be loaded during normal operations. Some of these new fields are akin those found in the Incremental Data Release Point Source Catalogs, including the familiar "Read Flag", "Contamination and Confusion Flag", "Blend Flag" and sexigessimal source Designation. A new flag, the "Blend Type" flag is designed to aid diagnosis of various types of source deblending. Those familiar with the CATFORM program will recognize most of the fields.
The following document is the Subsystem Interface Specification (SIS) of the the ADDCAT program. This program constructs the derived fields and appends them to each row of the standard pipeline point source output list (sNNN.cal file). The DBMAN subsystem will read the ADDCAT output file and load the new columns explicitly into the Working Database.
The definition of each of the new database columns is given in the SIS, as are the logical tests used to derive the flag values using existing working database parameters.
2MAPPS Software Interface Specification ADC01 0.1 010612
Interface Name: ADDCAT/DBMAN
Type of Interface: ASCII Text Source Data File Specification
Written By: ADCAT.V0.1 _____________________ R. Cutri
Read By: DBMAN _____________________ T. Evans
Description: This output file contains all columns in the calibrated
point source record file, with seven additional columns appended that contain a
compact summary of properties for point sources. The additional columns
are the same that were derived and added during the Catalog Reformatting
step in final product generation. The program ADDCAT reads the point source
output file (sNNN.cal). All information is in ASCII format, with header
lines followed by one line per input source.
ADDCAT writes to stdout. The output file name is set by runtime scripts,
but should have the form sNNN.cal.acat. The output file is read by
DBMAN for loading into the point source Working Database.
The header comment lines are exact copies of those contained in the
sNNN.cal files, and are described in the CAL01 interface specification.
The first 85 header column descriptors are identical to those in the sNNN.cal
file, as described in CAL01, with the addition of descriptors of the
seven additional columns. The headers have the following form:
Column header lines (columns 1 through 85) as described in CAL01
...
Column header lines (columns 86 through 92)
|Rd |Bln|CC | Ndet |BlT|A| designation |
| c | c | c | char | c |c| char |
| | | | | | | |
| | | | | | | |
| | | | | | | |
The format of each data line is as follows:
Cols Name Description Units Type Format
_______ _____________ _____________________________________ _____ ______ ______
1-545 - As described in CAL01
547-549 Rd Read Flag, 1 bit per band (JHK) - str 3s
551-553 Bln Blend flag, 1 bit per band (JHK) - str 3s
555-557 CC Confusion and Contamination flag, - str 3s
1 bit per band (JHK)
559-564 Ndet N/M flag, 2bits per band (JHK) - str 6s
566-568 BlT Blend-type, 1 bit per band (JHK) - str 3s
570 A Positionally associated optical - str 1s
catalog source
572-586 designation Sexigessimal source designation - str 15s
Explanation of Data Encoding:
Rd = Read Flag, 1 bit per band (JHK). Indicates the origin of
the magnitude and uncertainty in the ?mag and ?sig fields. Logic
used to set flags is as described above for the default magnitude
Rd_Flg Source of Default Magnitude
0 Non-detection. Default mag is the 97% confidence upper-limit
from band-filling (aperture photometry on atlas image).
(?_prg_flg = 'fil')
1 Non-saturated R1. Default magnitude is R1 aperture mag.
(?_mrg_flg[0] > 0)
2 Non-saturated R2-R1. Default magnitude is from R2-R1 psf-fittin.
(?_mrg_flg[0] = 0 AND ?_pix_flg[2] > 0)
3 Saturated R1. Default magnitude is magnitude estimated
from radial profile-fitting of R1 image.
(?_mrg_flg[0] > 0 AND ?_pix_flg[0] > 0 AND ?_pix_flg[2] = 0)
4 Non-saturated R2-R1. Default magnitude is from R2-R1 aperture
photometry. Occurs when psf-fitting fails to produce a valid
measurement.
(?_mrg_flg[0] = 0 AND ?_mpsf = 99.999)
6 Inconsistent deblend. Default magnitude is the 97% confidence
upper limit from R2-R1 band-filling at the position of an
inconstent deblended source.
(?_prg_flg = 'upl')
9 Although there was a detection at this position, no useful
magnitude was returned by any of the photometry routines
(default mag = 99.999). This occurs if both the psf-fit
and aperture magnitudes are 99.999 for R2, the aperture
magnitude is 99.999 for R1, or if there is a saturated
R2 magnitude with no accompanying R1 magnitude.
Bln = Blend flag, 1 bit per band (JHK). Describes the number of component
profiles fit simultaneously to a detection.
0 = not detected
1 = Single profile fit to source, aprture photometry, or saturated R1
radial profile fit
>1 = Multiple profiles fit simultaneously to source. Value is the
number of profiles fit.
CC = Contamination and confusion flag, 1 bit per band (JHK). Set in
hieiarchical order according to the following table. The
logical condition checked in the source record is also provided.
(Note that array indeces follow C-convention: 0,1,2,3,...)
P = Persistence probability > 0.5 for that band.
G = Source is positionally associated with a filter Glint.
(?_prg_flg[0] = 1)
C = Confusion Artifact. Source is likely a spurious detection of
the confusion halo around a bright star. Occurs when a source
falls within the artifact confusion radius of a brighter source.
(?_prg_flg[2] = 2)
D = Diffraction Spike Artifact. Source is likely a detection of a diffr
action spike from a nearby bright star.
(?_prg_flg[1] = 6)
p = Persistence probability 0.1 < pers_prob <= 0.5 for that band.
c = Photometric Confusion. Source has biased photometry due to
proximity to a bright star that causes an incorrect measurement
of the background.
(?_prg_flg[2] = 1)
d = Real source that is effected by proximity to a diffraction spike
from a nearby star.
(?_prg_flg[1] = 5)
s = Detection is likely a detection of or effected by a "stripe" from
a bright star.
(?_prg_flg[1] = 1)
b = Bandmerge confustion - more than one bandmerge candidate.
(CnfFlg for that band is >1 in either first or second field)
0 = Source is unaffected by artifacts, or is not detected in band.
(?_prg_flg = '000')
Ndet = This flag consists of 6 single-digit numbers, two digits per band in
the order JJHHKK. The 1st digit for each band indicates the number of
frames on which there were >3-sigma aperture mag detections, and the
2nd digit indicates the number of frames in which aperture
measurements were possible. Measurements can be made impossible on
a frame because of the location of cosmic rays, noisy pixels, or
other masking. Valid faint R2 sources can have N=0 because
single-frame aperture photometry may not return a >3-sigma
measurements while photometry from the stack of 6 frames does
yield a measurement. (This flag is AKA the N-out-of-M statistic).
For each band, the two digits are set as follows:
?1 = ?_pix_flg[2]
?2 = ?_pix_flg[3]
if the source is not band-filled or an inconsistent deblend upper
limit (?_prg_flg = 'fil' OR ?_prg_flg = 'upl')
Where the indeces follow C-convention (0,1,2,...)
BlT = Deblend mode flag that denotes type of deblending used for source,
1 bit/band (JHK). The value of each digit is as described below.
The logical condition checked in the source record is also provided.
(Note that array indeces follow C-convention: 0,1,2,3,...)
0 = not deblended, or not detected in that band
(?_bl_flg = 0) OR (?bl_flg = 1 AND ?_acbl_chi != 9.999)
1 = Passive deblend
(?_bl_flg >= 2 AND (?_acbl_chi = 0.0 OR ?_acbl_chi = 9.999)
2 = Active deblend
(?_bl_flg = 2 AND ?_acbl_chi > 0 AND ?_acbl_chi < 9.999)
3 = Mixture of passive and active deblend
(?_bl_flg > 2 AND ?_acbl_chi > 0 AND ?_acbl_chi < 9.999)
9 = Rejected active deblend
(?_bl_flg = 1 AND ?_acbl_chi = 9.999)
(The ?_acbl_chi flags in the working DB are equivalent to the
"Sharp" parameters in the pipeline source list output)
the following matrix gives the value of the BlT in each band
as a function of blend and sharpness (acbl_chi) values:
Bl 0 1 2 >2
Sh ---------------------
0.0 | 0 0 1 1
|
>0 && <9.999 | 0 0* 2 3
|
9.999 | 0 9 1 1
* - denotes condition that should not be possible.
A = Catalog identifier of positionally associated optical source. A
matched source is flagged only if it is within 5" of the 2MASS
position.
0 = no optical source positionally associated with 2MASS source.
T = Tycho 2 catalog source positionally associated with
2MASS source.
U = USNOA_1.0 catalog source positionally associated with 2MASS
source.
designation = Source "name" constructed from J2000 sexigessimal equatorial
coordinates. Construction follows IAU conventions.
The RA portion is truncated to one-tenth second of time
and DEC is truncated to one arcsecond. Name contains one
trailing blank space for the optional inclusion of a
letter designation to discriminate between multiple sources
having the same name.