II. User's Guide to the WISE Preliminary Data Release

2. Source Catalog

a. Format and Column Descriptions

The following table contains brief descriptions of the parameters provided for each source in the WISE Preliminary Data Release Source Catalog. The table is organized according to the broad function and utility of the parameters: positional information, photometric information, and source quality information. For Catalog flag parameters, the meaning of each possible flag value is given, along with some practical information on their usage.

The columns in the following table are:

Column Name: The parameter name in the Catalog table. Click on this to go to the section of the Explanatory Supplement section in which the derivation and/or usage of that parameter is described in greater detail.

Format: The ASCII-equivalent format of the field in the Catalog, expressed in "C"-readable notation. This is useful when parsing the aligned tabular output from IRSA/Gator. Although the data values will conform to these formats, the actual width of the field in the Gator output may be padded with extra blank spaces to accommodate column headers. Note that some fields contain null values that will require special handling when parsing Catalog tables from IRSA/Gator output.

Units: The units of the parameter. A value of "----" in this column means the parameter is dimensionless or non-numeric.

nulls: A "yes" in this column means this parameter can be null in the Catalog. A "no" means there will always be a value in this column in the Catalog.

Description: A brief description of the parameter and its values.

Column Name Format Units nulls Description

Basic Position and Identification Information

designation %20s ---- no Sexagesimal, equatorial position-based source name in the form: hhmmss.ss+ddmmss.s. The full naming convention for WISE Preliminary Release Catalog sources has the form "WISEP Jhhmmss.ss+ddmmss.s," where "WISEP" indicates the source is from the Preliminary Release Source Catalog, and "J" indicates the position is J2000. The "WISEP" acronym is not listed explicitly in the designation column.
CAUTION: Source designations should not be used as an astrometric reference. They are not a substitute for the source position information in the ra and dec columns.

ra %10.6f deg no J2000 right ascension with respect to the 2MASS PSC reference frame

dec %10.6f deg no J2000 declination with respect to the 2MASS PSC reference frame.

CAUTION: Approximately 20% of sources fainter than W1~14.5 mag in the Preliminary Release Source Catalog suffer from a source extraction software error that resulted in their declinations being offset between 0.2 and 1.0 arcsec from the true position. An increasingly smaller fraction exhibit this effect to magnitudes as bright as W1~13.0 mag. The declination uncertainties (sigdec) for all Catalog entries have been inflated by adding 0.5" in quadrature to the pure extraction measurement uncertainty to reflect the realized distribution of declination errors. See I.4.b for further information.

sigra %4.2f arcsec no One-sigma uncertainty in right ascension coordinate.

sigdec %4.2f arcsec no One-sigma uncertainty in declination coordinate.
CAUTION: The declination uncertainty is overestimated for the majority of sources in the Preliminary Release Source Catalog. Sigdec was computed by adding 0.5 arcsec in quadrature to the extraction measurement uncertainty to reflect the impact of the declination bias error known to affect a fraction of source fainter than W1~13.0 mag. The value of 0.5 arcsec was selected so the median absolute deviation (MAD) of the declination difference between 2MASS and WISE positions for the faint half of cross-identified sources have the value 0.6745σ expected for a Gaussian. See I.4.b for further information.

sigradec %3d arcsec no The co-sigma of the equatorial position uncertainties, sig_ra, sig_dec (σ_α, σ_δ). The co-sigma is related to the covariance between the position errors Vαδ by the formula Vαδ = σ_αδ|σ_αδ|. This maintains the sign information for the correlation, since σ_αδ may be negative. It is more natural to carry the co-sigma along with the other uncertainties instead of the covariance because the former is in the same units as the other uncertainties.

glon %7.3f deg no Galactic longitude. CAUTION: This coordinate should not be used as an astrometric reference.

glat %7.3f deg no Galactic latitude. CAUTION: This coordinate should not be used as an astrometric reference.

elon %7.3f deg no Ecliptic longitude. CAUTION: This coordinate should not be used as an astrometric reference.

elat %7.3f deg no Ecliptic latitude. CAUTION: This coordinate should not be used as an astrometric reference.

wx %7.3f pix no The x-pixel coordinate of this source on the Atlas Image.

wy %7.3f pix no The y-pixel coordinate of this source on the Atlas Image.

cntr %19d ---- no Unique identification number for the Catalog source. This number is formed entirely from the source_id, which is in turn formed from the coadd_id and source number src. On average, sources with cntr values close to each other are also close to each other on the sky, except at Tile boundaries. Cntr ordering thus provides a useful mapping of the WISE Catalog on storage media.
The cntr value is formed by making the source_id into an integer, in the format: RRRRsDDDttrevIIIIII, where

RRRR = Tile center RA in deci-degrees, truncated not rounded (e.g. RRRR=int[10*ra]), as in the coadd_id.

s = Tile center Declination sign translated from "p" or "m" into "1" or "0", respectively.

DDD = Tile center Declination in deci-degrees, as in the coadd_id. For positive declinations, the tenths of a degree is truncated not rounded (e.g. DDD=int[10*dec]). For negative declinations, the tenths of a degree is always truncated leftward on the number line (e.g. DDD=ceil[10*abs(dec)].

[ttrev] = Disambiguation string, translated where necessary into digits corresponding to the letters' places in the alphabet.

t - Tile type translated into two digits, zero-filled ("a" = "01").

r - Data Release identifier translated into a single digit, since the possible values are limited to "a" through "i" ("a" = "1").

e - Sky coverage epoch ("1" = first).

v - Processing version.

The translated disambiguation string is always 01111 for Tiles in the WISE Preliminary Data Release.

IIIIII = six-digit, zero-filled, sequential extracted source number, src, within the Tile.

For example, a source in the Tile 3041m137_aa11, with a source_id of '3041m137_aa11-012345', has a cntr value of 3041013701111012345.

source_id %28s ---- no Unique source ID, formed from a combination of the Atlas Tile ID, coadd_id, and sequential extracted source number, src, within the Tile. The source_id string has the form RRRRsDDD_[trev]-IIIIII where:

RRRRsDDD_[trev] = the coadd_id

IIIIII = six-digit, zero-filled, sequential extracted source number, src, within the Tile.

For example, the first source extracted in Tile 3041m137_aa11 has Catalog has a source_id of 3041m137_aa11-000001.

coadd_id %20s ---- no Atlas Tile identifier from which source was extracted. The identifier has the general form: RRRRsDDD_[trev], where

RRRR = Tile center RA in deci-degrees, truncated not rounded (e.g. RRRR=int[10*ra]).

s = Tile center Declination sign ("p"="+", "m"="-")

DDD = Tile center Declination in deci-degrees. For positive declinations, the tenths of a degree is truncated not rounded (e.g. DDD=int[10*dec]). For negative declinations, the tenths of a degree is always truncated leftward on the number line (e.g. DDD=ceil[10*abs(dec)].

[trev] = Disambiguation string.

t - Tile type ("a" = Atlas)

r - Data Release ("a" = Preliminary)

e - Sky coverage epoch ("1" = first)

v - Processing version.

The disambiguation string is always aa11 for Tiles in the WISE Preliminary Data Release.

For example, the identifier of the Atlas Tile with center at (α,δ = 304.13896,-13.63000) is 3041m137_aa11.

src %6d ---- no Sequential number of this source extraction in the Atlas Tile from which this source was extracted, in approximate descending order of W1 source brightness.

Primary Photometric Information

w1mpro %7.3f mag yes W1 magnitude measured with profile-fitting photometry, or the magnitude of the 95% confidence brightness upper limit if the W1 flux measurement has SNR<2. This column is null if the source is nominally detected in W1, but no useful brightness estimate could be made.

w1sigmpro %5.3f mag yes W1 profile-fit photometric measurement uncertainty in mag units. This column is null if the W1 profile-fit magnitude is a 95% confidence upper limit or if the source is not measurable.

w1snr %7.1f ---- yes W1 profile-fit measurement signal-to-noise ratio. This value is the ratio of the flux (w1flux) to flux uncertainty (w1sigflux)in the W1 profile-fit photometry measurement. This column is null if w1flux is negative, or if w1flux or w1sigflux are null.

w1rchi2 %9.3e ---- yes Reduced χ² of the W1 profile-fit photometry measurement. This column is null if the W1 magnitude is a 95% confidence upper limit (i.e. the source is not detected).

w2mpro %7.3f mag yes W2 magnitude measured with profile-fitting photometry, or the magnitude of the 95% confidence brightness upper limit if the W2 flux measurement has SNR<2. This column is null if the source is nominally detected in W1, but no useful brightness estimate could be made.

w2sigmpro %5.3f mag yes W2 profile-fit photometric measurement uncertainty in mag units. This column is null if the W2 profile-fit magnitude is a 95% confidence upper limit or if the source is not measurable.

w2snr %7.1f ---- yes W2 profile-fit measurement signal-to-noise ratio. This value is the ratio of the flux (w2flux to flux uncertainty (w2sigflux)in the W2 profile-fit photometry measurement. This column is null if w2flux is negative, or if w2flux or w2sigflux are null.

w2rchi2 %9.3e ---- yes Reduced χ² of the W2 profile-fit photometry measurement. This column is null if the W2 magnitude is a 95% confidence upper limit (i.e. the source is not detected).

w3mpro %7.3f mag yes W3 magnitude measured with profile-fitting photometry, or the magnitude of the 95% confidence brightness upper limit if the W3 flux measurement has SNR<2. This column is null if the source is nominally detected in W3, but no useful brightness estimate could be made.

w3sigmpro %5.3f mag yes W3 profile-fit photometric measurement uncertainty in mag units. This column is null if the W3 profile-fit magnitude is a 95% confidence upper limit or if the source is not measurable.

w3snr %7.1f ---- yes W3 profile-fit measurement signal-to-noise ratio. This value is the ratio of the flux (w3flux to flux uncertainty (w3sigflux)in the W3 profile-fit photometry measurement. This column is null if w3flux is negative, or if w3flux or w3sigflux are null.

w3rchi2 %9.3e ---- yes Reduced χ² of the W3 profile-fit photometry measurement. This column is null if the W3 magnitude is a 95% confidence upper limit (i.e. the source is not detected).

w4mpro %7.3f mag yes W4 magnitude measured with profile-fitting photometry, or the magnitude of the 95% confidence brightness upper limit if the W4 flux measurement has SNR<2. This column is null if the source is nominally detected in W4, but no useful brightness estimate could be made.

w4sigmpro %5.3f mag yes W4 profile-fit photometric measurement uncertainty in mag units. This column is null if the W4 profile-fit magnitude is a 95% confidence upper limit or if the source is not measurable.

w4snr %7.1f ---- yes W4 profile-fit measurement signal-to-noise ratio. This value is the ratio of the flux (w4flux to flux uncertainty (w4sigflux)in the W4 photometry measurement. This column is null if w4flux is negative, or if w4flux or w4sigflux are null.

w4rchi2 %9.3e ---- yes Reduced χ² of the W4 profile-fit photometry measurement. This column is null if the W4 magnitude is a 95% confidence upper limit (i.e. the source is not detected).

rchi2 %9.3f ---- yes Combine reduced χ² of the profile-fit photometry measurement in all bands.

nb %1d ---- yes Number of PSF components used simultaneously in the profile-fitting for this source. This number includes the source itself, so the minimum value of nb is "1". Nb is greater than "1" when the source is fit concurrently with other nearby detections (passive deblending), or when a single source is split into two components during the fitting process (active deblending).

na %1d ---- yes Active deblending flag. Indicates if a single detection was split into multiple sources in the process of profile-fitting.

0 - the source is not actively deblended.

1 - the source is actively deblended.

w1sat %5.3f ---- yes Saturated pixel fraction, W1. The fraction of all pixels within the profile-fitting area in the stack of single-exposure images used to characterize this source that are flagged as saturated. A value larger than 0.0 indicates one or more pixels of saturation. Saturation begins to occur for point sources brighter than [W1]~8 mag. Saturation may occur in fainter sources because of a charged particle strike.

w2sat %5.3f ---- yes Saturated pixel fraction, W2. The fraction of all pixels within the profile-fitting area in the stack of single-exposure images used to characterize this source that are flagged as saturated. A value larger than 0.0 indicates one or more pixels of saturation. Saturation begins to occur for point sources brighter than [W2]~7 mag. Saturation may occur in fainter sources because of a charged particle strike.

w3sat %5.3f ---- yes Saturated pixel fraction, W3. The fraction of all pixels within the profile-fitting area source in the stack of single-exposure images used to characterize this source that are flagged as saturated. A value larger than 0.0 indicates one or more pixels of saturation. Saturation begins to occur for point sources brighter than [W3]~4 mag. Saturation may occur in fainter sources because of a charged particle strike.

w4sat %5.3f ---- yes Saturated pixel fraction, W4. The fraction of all pixels within the profile-fitting area in the stack of single-exposure images used to characterize this source that are flagged as saturated. A value larger than 0.0 indicates one or more pixels of saturation. Saturation begins to occur for point sources brighter than [W4]~0 mag. Saturation may occur in fainter sources because of a charged particle strike.

satnum %4s ---- no Minimum sample at which saturation occurs in each band. Four character string, one character per band, that indicates the minimum SUTR sample in which any pixel in the profile-fitting area in all of the single-exposure images used to characterize this source was flagged as having reached the saturation level in the on-board WISE payload processing. If no pixels in a given band are flagged as saturated, the value for that band is "0".

Measurement Quality and Source Reliability Information

cc_flags %4s ---- no Contamination and confusion flag. Four character string, one character per band [W1/W2/W3/W4], that indicates that the photometry and/or position measurements of a source may be contaminated or biased due to proximity to an image artifact.
CAUTION: Non-zero cc_flags values in any band are an indicator that the measurements of that source may be contaminated and the photometry should be used with caution, or that the source detection may be unreliable.
The cc_flags value in each band is set in priority order according to the following table, in the event a source is affected by more than one artifact or condition:

D,d - Diffraction spike. Source may be a spurious detection of or contaminated by a diffraction spike from a nearby bright star on the same image, or

P,p - Persistence. Source may be a spurious detection of or contaminated by a latent image left by a bright star, or

H,h - Halo. Source photometry may be a spurious detection of or contaminated by the scattered light halo surrounding a nearby bright source, or

O,o (letter "o") - Optical ghost. Source may be a spurious detection of or contaminated by an optical ghost image caused by a nearby bright source, or

0 (number zero) - Source is unaffected by known artifacts.

Lower-case letters denote instances in which the source detection in a band is believed to be real but the measurement may be contaminated by the artifact. Upper-case letters are instances in which the source detection in a band may be a spurious detection of an artifact. A source can appear in the Preliminary Release Source Catalog if it is flagged as a spurious detection of an artifact in a band only if there is a reliable detection in another band that is not flagged as a spurious artifact detection.
A source extraction may be affected by more than one type of artifact. The full tally of artifacts affecting a source in each band is given in the w?cc_map and w?cc_map_str columns.

ext_flg %1d ---- no Extended source flag. This flag indicates whether or not the morphology of a source is consistent with the WISE point spread function in any band.

0 - The source shape is consistent with a point-source

1 - The source shape is not consistent with a point-source.

A source is flagged as extended if it has a profile-fit photometry measurement reduced χ²>3, or if it is within 5" of the position of an entry in the 2MASS Extended Source Catalog (XSC).
WISE profile-fit (w?mpro) and standard aperture (w?mag) measurements are optimized for point sources and will systematically underestimate the true flux of resolved objects. If a source entry has ext_flg="1", you may wish to examine the large aperture photometry, or the elliptical aperture photometry which are measured using areas that are scaled from 2MASS XSC morphologies.

var_flg %4s ---- yes Variability flag. The variability flag is a four-character string, one character per band, in which the value for each band is related to the probability that the source flux measured on the individual WISE exposures was not constant with time.
The probability is computed for a band only when there are at least 11 individual exposure measurements available. A value of "0" in a band indicates insufficient or inadequate data to make a determination of possible variability. Values of "1" through "9" indicate increasing probabilities of variation. Values of "1" through "4" are most likely not variables. Sources with values of "5" through "7" are likely flux variables, but are the most susceptible to false-positive variability. Var_flg values greater than "7" have the highest probability of being true flux variables in a band.

ph_qual %4s ---- no
Photometric quality flag. Four character flag, one character per band [W1/W2/W3/W4], that provides a shorthand summary of the quality of the profile-fit photometry measurement in each band, as derived from the measurement signal-to-noise ratio.

A - Source is detected in this band with a flux signal-to-noise ratio w?snr>10.

B - Source is detected in this band with a flux signal-to-noise ratio 3<w?snr<10.

C - Source is detected in this band with a flux signal-to-noise ratio 2<w?snr<3.

U - Upper limit on magnitude. Source measurement has w?snr<2. The profile-fit magnitude w?mpro is a 95% confidence upper limit.

X - A profile-fit measurement was not possible at this location possible in this band. The value of w?mpro and w?sigmpro will be "null" in this band.

det_bit %3d ---- no Bit-encoded integer indicating bands in which a source has a w?snr>2 detection. For example, a source detected in W1 only has det_bit=1 (binary 0001). A source detected in W4 only has det_bit=8 (binary 1000). A source detected in all four bands has det_bit=15 (binary 1111).

w1nm %6d ---- yes Integer frame detection count. This column gives the number of individual 7.7s exposures on which this source was detected with SNR>3 in the W1 profile-fit measurement. This number can be zero for sources that are well-detected on the coadded Atlas Image, but too faint for detection on the single exposures.

w1m %6d ---- yes Integer frame coverage. This column gives the number of individual 7.7s W1 exposures on which a profile-fit measurement of this source was possible.
This number can differ between the four bands because band-dependent criteria are used to select individual frames for inclusion in the coadded Atlas Images.

w2nm %6d ---- yes Integer frame detection count. This column gives the number of individual 7.7s exposures on which this source was detected with SNR>3 in the W2 profile-fit measurement. This number can be zero for sources that are well-detected on the coadded Atlas Image, but too faint for detection on the single exposures.

w2m %6d ---- yes Integer frame coverage. This column gives the number of individual 8.8s W2 exposures on which a profile-fit measurement of this source was possible.
This number can differ between the four bands because band-dependent criteria are used to select individual frames for inclusion in the coadded Atlas Images.

w3nm %6d ---- yes Integer frame detection count. This column gives the number of individual 8.8s exposures on which this source was detected with SNR>3 in the W3 profile-fit measurement. This number can be zero for sources that are well-detected on the coadded Atlas Image, but too faint for detection on the single exposures.

w3m %6d ---- yes Integer frame coverage. This column gives the number of individual 7.7s W3 exposures on which a profile-fit measurement of this source was possible.
This number can differ between the four bands because band-dependent criteria are used to select individual frames for inclusion in the coadded Atlas Images.

w4nm %6d ---- yes Integer frame detection count. This column gives the number of individual 8.8s exposures on which this source was detected with SNR>3 in the W4 profile-fit measurement. This number can be zero for sources that are well-detected on the coadded Atlas Image, but too faint for detection on the single exposures.

w4m %6d ---- yes Integer frame coverage. This column gives the number of individual 8.8s W4 exposures on which a profile-fit measurement of this source was possible.
This number can differ between the four bands because band-dependent criteria are used to select individual frames for inclusion in the coadded Atlas Images.

w1cov %7.3f ---- yes Mean pixel coverage in W1. This column gives the mean pixel value from the W1 Atlas Tile Coverage Map within the "standard" aperture, a circular area with a radius of 8.25" centered on the position of this source.
W1cov may differ from the integer frame coverage value given in w1m for two reasons. First, individual pixels in the measurement area may be masked or otherwise unusable, reducing the effective pixel count and thus the mean coverage value. Second, the effective sky area sampled by a pixels in single-exposure image varies across the focal plane because of field distortion. Distortion is corrected when coadding to generate the Atlas Images. Therefore, the effective number of pixels contributing to a pixel in the Atlas Coverage Map may be slightly smaller or larger than expected if there was no distortion.

w2cov %7.3f ---- yes Mean pixel coverage in W2. This column gives the mean pixel value from the W2 Atlas Tile Coverage Map within the "standard" aperture, a circular area with a radius of 8.25" centered on the position of this source.
W2cov may differ from the integer frame coverage value given in w2m for two reasons. First, individual pixels in the measurement area may be masked or otherwise unusable, reducing the effective pixel count and thus the mean coverage value. Second, the effective sky area sampled by a pixels in single-exposure image varies across the focal plane because of field distortion. Distortion is corrected when coadding to generate the Atlas Images. Therefore, the effective number of pixels contributing to a pixel in the Atlas Coverage Map may be slightly smaller or larger than expected if there was no distortion.

w3cov %7.3f ---- yes Mean pixel coverage in W3. This column gives the mean pixel value from the W3 Atlas Tile Coverage Map within the "standard" aperture, a circular area with a radius of 8.25" centered on the position of this source.
W3cov may differ from the integer frame coverage value given in w3m for two reasons. First, individual pixels in the measurement area may be masked or otherwise unusable, reducing the effective pixel count and thus the mean coverage value. Second, the effective sky area sampled by a pixels in single-exposure image varies across the focal plane because of field distortion. Distortion is corrected when coadding to generate the Atlas Images. Therefore, the effective number of pixels contributing to a pixel in the Atlas Coverage Map may be slightly smaller or larger than expected if there was no distortion.

w4cov %7.3f ---- yes Mean pixel coverage in W4. This column gives the mean pixel value from the W4 Atlas Tile Coverage Map within the "standard" aperture, a circular area with a radius of 17.0" centered on the position of this source.
W4cov may differ from the integer frame coverage value given in w4m for two reasons. First, individual pixels in the measurement area may be masked or otherwise unusable, reducing the effective pixel count and thus the mean coverage value. Second, the effective sky area sampled by a pixels in single-exposure image varies across the focal plane because of field distortion. Distortion is corrected when coadding to generate the Atlas Images. Therefore, the effective number of pixels contributing to a pixel in the Atlas Coverage Map may be slightly smaller or larger than expected if there was no distortion.

w1frl %5.3f ---- yes Fraction of pixels affected by latents. This column gives the fraction of all W1 pixels in the stack of individual W1 exposures used to characterize this source that may be affected by the presence of a latent image produced by a bright source. This number is computed by counting the number of pixels in the single exposure Bit Mask images with value "25" that are present within the profile-fitting area, a circular region with radius of 7.25", centered on the position of this source, and dividing by the total number of pixels in the same area that are available for measurement.

w2frl %5.3f ---- yes Fraction of pixels affected by latents. This column gives the fraction of all W2 pixels in the stack of individual W2 exposures used to characterize this source that may be affected by the presence of a latent image produced by a bright source. This number is computed by counting the number of pixels in the single exposure Bit Mask images with value "25" that are present within the profile-fitting area, a circular region with radius of 7.25", centered on the position of this source, and dividing by the total number of pixels in the same area that are available for measurement.

w3frl %5.3f ---- yes Fraction of pixels affected by latents. This column gives the fraction of all W3 pixels in the stack of individual W3 exposures used to characterize this source that may be affected by the presence of a latent image produced by a bright source. This number is computed by counting the number of pixels in the single exposure Bit Mask images with value "25" that are present within the profile-fitting area, a circular region with radius of 7.25", centered on the position of this source, and dividing by the total number of pixels in the same area that are available for measurement.

w4frl %5.3f ---- yes Fraction of pixels affected by latents. This column gives the fraction of all W4 pixels in the stack of individual W4 exposures used to characterize this source that may be affected by the presence of a latent image produced by a bright source. This number is computed by counting the number of pixels in the single exposure Bit Mask images with value '25' that are present within the profile-fitting area, a circular region with radius of 15.0", centered on the position of this source, and dividing by the total number of pixels in the same area that are available for measurement.

w1cc_map %3d ---- no Contamination and confusion map for this source in W1. This column contains the integer equivalent of the 9-bit binary number that specifies if the W1 measurement is believed to be contaminated by or a spurious detection of an image artifact. The elements of the binary array are:

S C E T O H G P D

The leftmost bit, S, differentiates whether the band-detection is believed to be a real detection contaminated by an artifact ("0") or a spurious detection of an artifact ("1"). The remaining bits are set to "1" to denote contamination by different types of artifacts according to the letters:

D - Diffraction spike

P - Persistence or latent image

G - Glint from off-frame source (not used in first-pass processing)

H - Scattered light halo from a bright source

O - Optical ghost

T - Transient event (not used in first-pass processing)

E - Electronic ghost (not used in first-pass processing)

C - Confusion (not used in first-pass processing)

For example, a measurement that is believed to be a spurious detection of a diffraction spike and scattered light halo has a binary bit map value of "100001001" and w1cc_map=265.

w1cc_map_str %12s ---- yes Contamination and confusion string. This column is a character string that denotes all artifacts that may contaminate the W1 measurement of this source, in the priority order D,P,H,O. Lower-case letters denote cases where the source detection in this band is believed to be real but the measurement may be contaminated by the artifact. upper-case letters denote cases where the source detection in this band may be a spurious detection of an artifact.
For example, a real detection that is contaminated by a diffraction spike and a latent (persistent) image has a w1cc_map_str="dp". A spurious detection of a diffraction spike that is also contaminated by a latent image has w1cc_map_str="Dp".
This string is "null" if there are no artifacts that affect the measurement in this band.
The value that appears in first element of the cc_flags string is the left-most character in w1cc_map_str. If w1cc_map_str is "null", then the corresponding cc_flags entry is "0".

w2cc_map %3d ---- no Contamination and confusion map for this source in W2. This column contains the integer equivalent of the 9-bit binary number that specifies if the W2 measurement is believed to be contaminated by or a spurious detection of an image artifact. The elements of the binary array are:

S C E T O H G P D

The leftmost bit, S, differentiates whether the band-detection is believed to be a real detection contaminated by an artifact ("0") or a spurious detection of an artifact ("1"). The remaining bits are set to "1" to denote contamination by different types of artifacts according to the letters:

D - Diffraction spike

P - Persistence or latent image

G - Glint from off-frame source (not used in first-pass processing)

H - Scattered light halo from a bright source

O - Optical ghost

T - Transient event (not used in first-pass processing)

E - Electronic ghost (not used in first-pass processing)

C - Confusion (not used in first-pass processing)

For example, a measurement that is believed to be a spurious detection of a diffraction spike and scattered light halo has a binary bit map value of "100001001" and w2cc_map=265.

w2cc_map_str %12s ---- yes
Contamination and confusion string. This column is a character string that denotes all artifacts that may contaminate the W2 measurement of this source, in the priority order D,P,H,O. Lower-case letters denote cases where the source detection in this band is believed to be real but the measurement may be contaminated by the artifact. Upper-case letters denote cases where the source detection in this band may be a spurious detection of an artifact.

For example, a real detection that is contaminated by a diffraction spike and a latent (persistent) image has a w2cc_map_str="dp". A spurious detection of a diffraction spike that is also contaminated by a latent image has w2cc_map_str="Dp".
This string is "null" if there are no artifacts that affect the measurement in this band.
The value that appears in second element of the cc_flags string is the left-most character in w2cc_map_str. If w2cc_map_str is "null," then the corresponding cc_flags entry is "0."

w3cc_map %3d ---- no Contamination and confusion map for this source in W3. This column contains the integer equivalent of the 9-bit binary number that specifies if the W3 measurement is believed to be contaminated by or a spurious detection of an image artifact. The elements of the binary array are:

S C E T O H G P D

The leftmost bit, S, differentiates whether the band-detection is believed to be a real detection contaminated by an artifact ("0") or a spurious detection of an artifact ("1"). The remaining bits are set to "1" to denote contamination by different types of artifacts according to the letters:

D - Diffraction spike

P - Persistence or latent image

G - Glint from off-frame source (not used in first-pass processing)

H - Scattered light halo from a bright source

O - Optical ghost

T - Transient event (not used in first-pass processing)

E - Electronic ghost (not used in first-pass processing)

C - Confusion (not used in first-pass processing)

For example, a measurement that is believed to be a spurious detection of a diffraction spike and scattered light halo has a binary bit map value of "100001001" and w3cc_map=265.

w3cc_map_str %12s ---- yes Contamination and confusion string. This column is a character string that denotes all artifacts that may contaminate the W3 measurement of this source, in the priority order D,P,H,O. Lower-case letters denote cases where the source detection in this band is believed to be real but the measurement may be contaminated by the artifact. Upper-case letters denote cases where the source detection in this band may be a spurious detection of an artifact.
For example, a real detection that is contaminated by a diffraction spike and a latent (persistent) image has a w3cc_map_str="dp". A spurious detection of a diffraction spike that is also contaminated by a latent image has w3cc_map_str="Dp".
This string is "null" if there are no artifacts that affect the measurement in this band.
The value that appears in first element of the cc_flags string is the third character in w3cc_map_str. If w3cc_map_str is "null", then the corresponding cc_flags entry is "0."

w4cc_map %3d ---- no Contamination and confusion map for this source in W4. This column contains the integer equivalent of the 9-bit binary number that specifies if the W4 measurement is believed to be contaminated by or a spurious detection of an image artifact. The elements of the binary array are:

S C E T O H G P D

The leftmost bit, S, differentiates whether the band-detection is believed to be a real detection contaminated by an artifact ("0") or a spurious detection of an artifact ("1"). The remaining bits are set to "1" to denote contamination by different types of artifacts according to the letters:

D - Diffraction spike

P - Persistence or latent image

G - Glint from off-frame source (not used in first-pass processing)

H - Scattered light halo from a bright source

O - Optical ghost

T - Transient event (not used in first-pass processing)

E - Electronic ghost (not used in first-pass processing)

C - Confusion (not used in first-pass processing)

For example, a measurement that is believed to be a spurious detection of a diffraction spike and scattered light halo has a binary bit map value of "100001001" and w4cc_map=265.

w4cc_map_str %12s ---- yes Contamination and confusion string. This column is a character string that denotes all artifacts that may contaminate the W4 measurement of this source, in the priority order D,P,H,O. Lower-case letters denote cases where the source detection in this band is believed to be real but the measurement may be contaminated by the artifact. Upper-case letters denote cases where the source detection in this band may be a spurious detection of an artifact.
For example, a real detection that is contaminated by a diffraction spike and a latent (persistent) image has a w4cc_map_str="dp". A spurious detection of a diffraction spike that is also contaminated by a latent image has w4cc_map_str="Dp".
This string is "null" if there are no artifacts that affect the measurement in this band.
The value that appears in first element of the cc_flags string is the fourth character in w4cc_map_str. If w4cc_map_str is "null", then the corresponding cc_flags entry is "0."

Additional Photometric Information

w1flux %9.3f dn yes The "raw" W1 source flux measured in profile-fit photometry in units of digital numbers. This value may be negative. This column is null if no useful profile-fit measurement of the source is possible because of masked or otherwise unusable pixels.

w1sigflux %9.3f dn yes Uncertainty in the "raw" W1 source flux measurement in profile-fit photometry in units of digital numbers. This column is null if no useful profile-fit measurement of the source is possible because of masked or otherwise unusable pixels.

w1sky %9.3f dn yes The trimmed average of the W1 sky background value in digital numbers measured in an annulus with an inner radius of 50" and outer radius of 70". Both profile-fit and aperture photometry source brightness measurements are made relative to this sky background value.
For profile-fit photometry, the sky background is measured on the individual single-exposure images that are used for source characterization. For aperture photometry, the sky background is measured on the Atlas Image.

w1sigsk %7.3f dn yes The uncertainty in the W1 sky background value in units of digital numbers measured in an annulus with an inner radius of 50" and outer radius of 70".

w1conf %9.3f dn yes Estimated confusion noise in the W1 sky background annulus, in digital numbers. This number is the difference between the measured noise in the sky background w1sigsk and the noise measured in the same region on the Atlas Uncertainty Maps.

w2flux %9.3f dn yes The "raw" W2 source flux measured in profile-fit photometry in units of digital numbers. This value may be negative. This column is null if no useful profile-fit measurement of the source is possible because of masked or otherwise unusable pixels.

w2sigflux %9.3f dn yes Uncertainty in the "raw" W2 source flux measurement in profile-fit photometry in units of digital numbers. This column is null if no useful profile-fit measurement of the source is possible because of masked or otherwise unusable pixels.

w2sky %9.3f dn yes The trimmed average of the W2 sky background value in digital numbers measured in an annulus with an inner radius of 50" and outer radius of 70". Both profile-fit and aperture photometry source brightness measurements are made relative to this sky background value.
For profile-fit photometry, the sky background is measured on the individual single-exposure images that are used for source characterization. For aperture photometry, the sky background is measured on the Atlas Image.

w2sigsk %7.3f dn yes The uncertainty in the W2 sky background value in units of digital numbers measured in an annulus with an inner radius of 50" and outer radius of 70".

w2conf %9.3f dn yes Estimated confusion noise in the W2 sky background annulus, in digital numbers. This number is the difference between the measured noise in the sky background w2sigsk and the noise measured in the same region on the Atlas Uncertainty Maps.

w3flux %9.3f dn yes The "raw" W3 source flux measured in profile-fit photometry in units of digital numbers. This value may be negative. This column is null if no useful profile-fit measurement of the source is possible because of masked or otherwise unusable pixels.

w3sigflux %9.3f dn yes Uncertainty in the "raw" W3 source flux measurement in profile-fit photometry in units of digital numbers. This column is null if no useful profile-fit measurement of the source is possible because of masked or otherwise unusable pixels.

w3sky %9.3f dn yes The trimmed average of the W3 sky background value in digital numbers measured in an annulus with an inner radius of 50" and outer radius of 70". Both profile-fit and aperture photometry source brightness measurements are made relative to this sky background value.
For profile-fit photometry, the sky background is measured on the individual single-exposure images that are used for source characterization. For aperture photometry, the sky background is measured on the Atlas Image.

w3sigsk %7.3f dn yes The uncertainty in the W3 sky background value in units of digital numbers measured in an annulus with an inner radius of 50" and outer radius of 70".

w3conf %9.3f dn yes Estimated confusion noise in the W3 sky background annulus, in digital numbers. This number is the difference between the measured noise in the sky background w3sigsk and the noise measured in the same region on the Atlas Uncertainty Maps.

w4flux %9.3f dn yes The "raw" W1 source flux measured in profile-fit photometry in units of digital numbers. This value may be negative. This column is null if no useful profile-fit measurement of the source is possible because of masked or otherwise unusable pixels.

w4sigflux %9.3f dn yes Uncertainty in the "raw" W1 source flux measurement in profile-fit photometry in units of digital numbers. This column is null if no useful profile-fit measurement of the source is possible because of masked or otherwise unusable pixels.

w4sky %9.3f dn yes The trimmed average of the W1 sky background value in digital numbers measured in an annulus with an inner radius of 50" and outer radius of 70". Both profile-fit and aperture photometry source brightness measurements are made relative to this sky background value.
For profile-fit photometry, the sky background is measured on the individual single-exposure images that are used for source characterization. For aperture photometry, the sky background is measured on the Atlas Image.

w4sigsk %7.3f dn yes The uncertainty in the W1 sky background value in units of digital numbers measured in an annulus with an inner radius of 50" and outer radius of 70".

w4conf %9.3f dn yes Estimated confusion noise in the W1 sky background annulus, in digital numbers. This number is the difference between the measured noise in the sky background w4sigsk and the noise measured in the same region on the Atlas Uncertainty Maps.

w1mag %7.3f mag yes W1 "standard" aperture magnitude. This is the curve-of-growth corrected source brightness measured in an 8.25" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". The curve-of-growth correction is given in w1mcor.
This column is null if an aperture measurement was not possible in W1.

w1sigm %5.3f mag yes Uncertainty in the W1 "standard" aperture magnitude.
This column is null if the W1 "standard" aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w1flg %3d ---- yes W1 "standard" aperture measurement quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag value is an integer that is the combination of one or more of the following values that signify different conditions:

0 - No contamination

1 - Source confusion - another source falls within the measurement aperture

2 - Presence of bad pixels in the measurement aperture

4 - Non-zero bit flag tripped (other than 2 or 18)

8 - All pixels are flagged as unusable, or the aperture flux is negative. In the former case, the aperture magnitude is "null". In the latter case, the aperture magnitude is a 95% confidence upper limit.

16 - Saturation - there are one or more saturated pixels in the measurement aperture

32 - The magnitude is a 95% confidence upper limit

w1mcor %6.3f mag yes W1 aperture curve-of-growth correction, in magnitudes. This correction is subtracted from the nominal 8.25" aperture photometry brightness, w1mag_2, to give the "standard-aperture" magnitude.

w2mag %7.3f mag yes W2 "standard" aperture magnitude. This is the curve-of-growth corrected source brightness measured in an 8.25" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". The curve-of-growth correction is given in w2mcor.
This column is null if an aperture measurement was not possible in W2.

w2sigm %5.3f mag yes Uncertainty in the W2 "standard" aperture magnitude.
This column is null if the W2 "standard" aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w2flg %3d ---- yes W2 "standard" aperture measurement quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag value is an integer that is the combination of one or more of the following values that signify different conditions:

0 - No contamination

1 - Source confusion - another source falls within the measurement aperture

2 - Presence of bad pixels in the measurement aperture

4 - Non-zero bit flag tripped (other than 2 or 18)

8 - All pixels are flagged as unusable, or the aperture flux is negative. In the former case, the aperture magnitude is "null". In the latter case, the aperture magnitude is a 95% confidence upper limit.

16 - Saturation - there are one or more saturated pixels in the measurement aperture

32 - The magnitude is a 95% confidence upper limit

w2mcor %6.3f mag yes W2 aperture curve-of-growth correction, in magnitudes. This correction is subtracted from the nominal 8.25" aperture photometry brightness, w2mag_2, to give the "standard-aperture" magnitude.

w3mag %7.3f mag yes W3 "standard" aperture magnitude. This is the curve-of-growth corrected source brightness measured in an 8.25" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". The curve-of-growth correction is given in w3mcor.
This column is null if an aperture measurement was not possible in W3.

w3sigm %5.3f mag yes Uncertainty in the W3 "standard" aperture magnitude.
This column is null if the W3 "standard" aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w3flg %3d ---- yes W3 "standard" aperture measurement quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag value is an integer that is the combination of one or more of the following values that signify different conditions:

0 - No contamination

1 - Source confusion - another source falls within the measurement aperture

2 - Presence of bad pixels in the measurement aperture

4 - Non-zero bit flag tripped (other than 2 or 18)

8 - All pixels are flagged as unusable, or the aperture flux is negative. In the former case, the aperture magnitude is "null". In the latter case, the aperture magnitude is a 95% confidence upper limit.

16 - Saturation - there are one or more saturated pixels in the measurement aperture

32 - The magnitude is a 95% confidence upper limit

w3mcor %6.3f mag yes W3 aperture curve-of-growth correction, in magnitudes. This correction is subtracted from the nominal 8.25" aperture photometry brightness, w3mag_2, to give the "standard-aperture" magnitude.

w4mag %7.3f mag yes W4 "standard" aperture magnitude. This is the curve-of-growth corrected source brightness measured in a 16.5" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". The curve-of-growth correction is given in w4mcor.
This column is null if an aperture measurement was not possible in W4.

w4sigm %5.3f mag yes Uncertainty in the W4 "standard" aperture magnitude.
This column is null if the W4 "standard" aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w4flg %3d ---- yes W4 "standard" aperture measurement quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag value is an integer that is the combination of one or more of the following values that signify different conditions:

0 - No contamination

1 - Source confusion - another source falls within the measurement aperture

2 - Presence of bad pixels in the measurement aperture

4 - Non-zero bit flag tripped (other than 2 or 18)

8 - All pixels are flagged as unusable, or the aperture flux is negative. In the former case, the aperture magnitude is "null". In the latter case, the aperture magnitude is a 95% confidence upper limit.

16 - Saturation - there are one or more saturated pixels in the measurement aperture

32 - The magnitude is a 95% confidence upper limit

w4mcor %6.3f mag yes W4 aperture curve-of-growth correction, in magnitudes. This correction is subtracted from the nominal 16.5" aperture photometry brightness, w4mag_2, to give the "standard-aperture" magnitude.

w1mag_1 %7.3f mag yes W1 5.5" radius aperture magnitude. This is the calibrated source brightness measured in a 5.5" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W1.

w1sigm_1 %5.3f mag yes Uncertainty in the W1 5.5" radius aperture magnitude.
This column is null if the the 5.5" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w1flg_1 %3d ---- yes W1 5.5" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w1mflg.

w2mag_1 %7.3f mag yes W2 5.5" radius aperture magnitude. This is the calibrated source brightness measured in a 5.5" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W2.

w2sigm_1 %5.3f mag yes Uncertainty in the W2 5.5" radius aperture magnitude.
This column is null if the the 5.5" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w2flg_1 %3d ---- yes W2 5.5" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w2mflg.

w3mag_1 %7.3f mag yes W3 5.5" radius aperture magnitude. This is the calibrated source brightness measured in a 5.5" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W3.

w3sigm_1 %5.3f mag yes Uncertainty in the W3 5.5" radius aperture magnitude.
This column is null if the the 5.5" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w3flg_1 %3d ---- yes W3 5.5" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w3mflg.

w4mag_1 %7.3f mag yes W4 11.0" radius aperture magnitude. This is the calibrated source brightness measured in a 11.0" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W4.

w4sigm_1 %5.3f mag yes Uncertainty in the W4 11.0" radius aperture magnitude.
This column is null if the the 11.0" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w4flg_1 %3d ---- yes W4 11.0" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w4mflg.

w1mag_2 %7.3f mag yes W1 8.25" radius aperture magnitude. This is the calibrated source brightness measured in a 8.25" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W1.

w1sigm_2 %5.3f mag yes Uncertainty in the W1 8.25" radius aperture magnitude.
This column is null if the the 8.25" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w1flg_2 %3d ---- yes W1 8.25" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w1mflg.

w2mag_2 %7.3f mag yes W2 8.25" radius aperture magnitude. This is the calibrated source brightness measured in a 8.25" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W2.

w2sigm_2 %5.3f mag yes Uncertainty in the W2 8.25" radius aperture magnitude.
This column is null if the the 8.25" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w2flg_2 %3d ---- yes W2 8.25" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w2mflg.

w3mag_2 %7.3f mag yes W3 8.25" radius aperture magnitude. This is the calibrated source brightness measured in a 8.25" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W3.

w3sigm_2 %5.3f mag yes Uncertainty in the W3 8.25" radius aperture magnitude.
This column is null if the the 8.25" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w3flg_2 %3d ---- yes W3 8.25" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w3mflg.

w4mag_2 %7.3f mag yes W4 16.5" radius aperture magnitude. This is the calibrated source brightness measured in a 16.5" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W4.

w4sigm_2 %5.3f mag yes Uncertainty in the W4 16.5" radius aperture magnitude.
This column is null if the the 16.5" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w4flg_2 %3d ---- yes W4 16.5" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w4mflg.

w1mag_3 %7.3f mag yes W1 11.0" radius aperture magnitude. This is the calibrated source brightness measured in a 11.0" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W1.

w1sigm_3 %5.3f mag yes Uncertainty in the W1 11.0" radius aperture magnitude.
This column is null if the the 11.0" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w1flg_3 %3d ---- yes W1 11.0" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w1mflg.

w2mag_3 %7.3f mag yes W2 11.0" radius aperture magnitude. This is the calibrated source brightness measured in a 11.0" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W2.

w2sigm_3 %5.3f mag yes Uncertainty in the W2 11.0" radius aperture magnitude.
This column is null if the the 11.0" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w2flg_3 %3d ---- yes W2 11.0" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w2mflg.

w3mag_3 %7.3f mag yes W3 11.0" radius aperture magnitude. This is the calibrated source brightness measured in a 11.0" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W3.

w3sigm_3 %5.3f mag yes Uncertainty in the W3 11.0" radius aperture magnitude.
This column is null if the the 11.0" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w3flg_3 %3d ---- yes W3 11.0" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w3mflg.

w4mag_3 %7.3f mag yes W4 22.0" radius aperture magnitude. This is the calibrated source brightness measured in a 22.0" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W4.

w4sigm_3 %5.3f mag yes Uncertainty in the W4 22.0" radius aperture magnitude.
This column is null if the the 22.0" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w4flg_3 %3d ---- yes W4 22.0" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w4mflg.

w1mag_4 %7.3f mag yes W1 13.75" radius aperture magnitude. This is the calibrated source brightness measured in a 13.75" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W1.

w1sigm_4 %5.3f mag yes Uncertainty in the W1 13.75" radius aperture magnitude.
This column is null if the the 13.75" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w1flg_4 %3d ---- yes W1 13.75" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w1mflg.

w2mag_4 %7.3f mag yes W2 13.75" radius aperture magnitude. This is the calibrated source brightness measured in a 13.75" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W2.

w2sigm_4 %5.3f mag yes Uncertainty in the W2 13.75" radius aperture magnitude.
This column is null if the the 13.75" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w2flg_4 %3d ---- yes W2 13.75" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w2mflg.

w3mag_4 %7.3f mag yes W3 13.75" radius aperture magnitude. This is the calibrated source brightness measured in a 13.75" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W3.

w3sigm_4 %5.3f mag yes Uncertainty in the W3 13.75" radius aperture magnitude.
This column is null if the the 13.75" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w3flg_4 %3d ---- yes W3 13.75" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w3mflg.

w4mag_4 %7.3f mag yes W4 27.5" radius aperture magnitude. This is the calibrated source brightness measured in a 27.5" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W4.

w4sigm_4 %5.3f mag yes Uncertainty in the W4 27.5" radius aperture magnitude.
This column is null if the the 27.5" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w4flg_4 %3d ---- yes W4 27.5" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w4mflg.

w1mag_5 %7.3f mag yes W1 16.5" radius aperture magnitude. This is the calibrated source brightness measured in a 16.5" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W1.

w1sigm_5 %5.3f mag yes Uncertainty in the W1 16.5" radius aperture magnitude.
This column is null if the the 16.5" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w1flg_5 %3d ---- yes W1 16.5" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w1mflg.

w2mag_5 %7.3f mag yes W2 16.5" radius aperture magnitude. This is the calibrated source brightness measured in a 16.5" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W2.

w2sigm_5 %5.3f mag yes Uncertainty in the W2 16.5" radius aperture magnitude.
This column is null if the the 16.5" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w2flg_5 %3d ---- yes W2 16.5" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w2mflg.

w3mag_5 %7.3f mag yes W3 16.5" radius aperture magnitude. This is the calibrated source brightness measured in a 16.5" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W3.

w3sigm_5 %5.3f mag yes Uncertainty in the W3 16.5" radius aperture magnitude.
This column is null if the the 16.5" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w3flg_5 %3d ---- yes W3 16.5" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w3mflg.

w4mag_5 %7.3f mag yes W4 33.0" radius aperture magnitude. This is the calibrated source brightness measured in a 33.0" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W4.

w4sigm_5 %5.3f mag yes Uncertainty in the W4 33.0" radius aperture magnitude.
This column is null if the the 33.0" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w4flg_5 %3d ---- yes W4 33.0" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w4mflg.

w1mag_6 %7.3f mag yes W1 19.25" radius aperture magnitude. This is the calibrated source brightness measured in a 19.25" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W1.

w1sigm_6 %5.3f mag yes Uncertainty in the W1 19.25" radius aperture magnitude.
This column is null if the the 19.25" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w1flg_6 %3d ---- yes W1 19.25" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w1mflg.

w2mag_6 %7.3f mag yes W2 19.25" radius aperture magnitude. This is the calibrated source brightness measured in a 19.25" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W2.

w2sigm_6 %5.3f mag yes Uncertainty in the W2 19.25" radius aperture magnitude.
This column is null if the the 19.25" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w2flg_6 %3d ---- yes W2 19.25" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w2mflg.

w3mag_6 %7.3f mag yes W3 19.25" radius aperture magnitude. This is the calibrated source brightness measured in a 19.25" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W3.

w3sigm_6 %5.3f mag yes Uncertainty in the W3 19.25" radius aperture magnitude.
This column is null if the the 19.25" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w3flg_6 %3d ---- yes W3 19.25" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w3mflg.

w4mag_6 %7.3f mag yes W4 38.5" radius aperture magnitude. This is the calibrated source brightness measured in a 38.5" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W4.

w4sigm_6 %5.3f mag yes Uncertainty in the W4 38.5" radius aperture magnitude.
This column is null if the the 38.5" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w4flg_6 %3d ---- yes W4 38.5" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w4mflg.

w1mag_7 %7.3f mag yes W1 22.0" radius aperture magnitude. This is the calibrated source brightness measured in a 22.0" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W1.

w1sigm_7 %5.3f mag yes Uncertainty in the W1 22.0" radius aperture magnitude.
This column is null if the the 22.0" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w1flg_7 %3d ---- yes W1 22.0" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w1mflg.

w2mag_7 %7.3f mag yes W2 22.0" radius aperture magnitude. This is the calibrated source brightness measured in a 22.0" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W2.

w2sigm_7 %5.3f mag yes Uncertainty in the W2 22.0" radius aperture magnitude.
This column is null if the the 22.0" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w2flg_7 %3d ---- yes W2 22.0" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w2mflg.

w3mag_7 %7.3f mag yes W3 22.0" radius aperture magnitude. This is the calibrated source brightness measured in a 22.0" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W3.

w3sigm_7 %5.3f mag yes Uncertainty in the W3 22.0" radius aperture magnitude.
This column is null if the the 22.0" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w3flg_7 %3d ---- yes W3 22.0" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w3mflg.

w4mag_7 %7.3f mag yes W4 44.0" radius aperture magnitude. This is the calibrated source brightness measured in a 44.0" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W4.

w4sigm_7 %5.3f mag yes Uncertainty in the W4 44.0" radius aperture magnitude.
This column is null if the the 44.0" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w4flg_7 %3d ---- yes W4 44.0" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w4mflg.

w1mag_8 %7.3f mag yes W1 24.75" radius aperture magnitude. This is the calibrated source brightness measured in a 24.75" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W1.

w1sigm_8 %5.3f mag yes Uncertainty in the W1 24.75" radius aperture magnitude.
This column is null if the the 24.75" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w1flg_8 %3d ---- yes W1 24.75" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w1mflg.

w2mag_8 %7.3f mag yes W2 24.75" radius aperture magnitude. This is the calibrated source brightness measured in a 24.75" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W2.

w2sigm_8 %5.3f mag yes Uncertainty in the W2 24.75" radius aperture magnitude.
This column is null if the the 24.75" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w2flg_8 %3d ---- yes W2 24.75" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w2mflg.

w3mag_8 %7.3f mag yes W3 24.75" radius aperture magnitude. This is the calibrated source brightness measured in a 24.75" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W3.

w3sigm_8 %5.3f mag yes Uncertainty in the W3 24.75" radius aperture magnitude.
This column is null if the the 24.75" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w3flg_8 %3d ---- yes W3 24.75" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w3mflg.

w4mag_8 %7.3f mag yes W4 49.5" radius aperture magnitude. This is the calibrated source brightness measured in a 49.5" radius circular aperture centered on the source position on the Atlas Image. If the source is not detected in the aperture measurement, this is the 95% confidence upper limit to the brightness. The background sky reference level is measured in an annular region with inner radius of 50" and outer radius of 70". No curve-of-growth correction has been applied.
This column is null if an aperture measurement was not possible in W4.

w4sigm_8 %5.3f mag yes Uncertainty in the W4 49.5" radius aperture magnitude.
This column is null if the the 49.5" radius aperture magnitude is an upper limit, or if an aperture measurement was not possible.

w4flg_8 %3d ---- yes W4 49.5" radius aperture magnitude quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the standard aperture photometry quality flag, w4mflg.

w1magp %6.3f mag yes Inverse-variance-weighted mean W1 magnitude computed from profile-fit measurements on the w1m individual frames covering this source. This differs from w1mpro in that it is computed by combining the profile-fit measurements from individual frames, whereas w1mpro is computed by fitting all W1 frames simultaneously and incorporating a robust error model.
This column is "null" if w1m=0, the mean flux is negative or if no individual frame measurements are possible.
CAUTION: This is not a robust measurement of source brightness. It is provided as an internal repeatability diagnostic only. User's should always defer to w1mpro for the optimal flux measurement for point sources.

w1sigp1 %6.3f mag yes Standard deviation of the population of W1 fluxes measured on the w1m individual frames covering this source, in magnitudes. This provides a measure of the characteristic uncertainty of the measurement of this source on individual frames.
This column is "null" if w1m<2 or if no individual frame measurements are possible.

w1sigp2 %6.3f mag yes Standard deviation of the mean of the distribution of W1 fluxes (w1magp) computed from profile-fit measurements on the w1m individual frames covering this source, in magnitudes. This is equivalent to w1sigp1/sqrt(w1m).
This column is "null" if w1m<2 or if no individual frame measurements are possible.

w2magp %6.3f mag yes Inverse-variance-weighted mean W2 magnitude computed from profile-fit measurements on the w2m individual frames covering this source. This differs from w2mpro in that it is computed by combining the profile-fit measurements from individual frames, whereas w2mpro is computed by fitting all W2 frames simultaneously and incorporating a robust error model.
This column is "null" if w2m=0, the mean flux is negative or if no individual frame measurements are possible.
CAUTION: This is not a robust measurement of source brightness. It is provided as an internal repeatability diagnostic only. User's should always defer to w2mpro for the optimal flux measurement for point sources.

w2sigp1 %6.3f mag yes Standard deviation of the population of W2 fluxes measured on the w2m individual frames covering this source, in magnitudes. This provides a measure of the characteristic uncertainty of the measurement of this source on individual frames.
This column is "null" if w2m<2 or if no individual frame measurements are possible.

w2sigp2 %6.3f mag yes Standard deviation of the mean of the distribution of W2 fluxes (w2magp) computed from profile-fit measurements on the w2m individual frames covering this source, in magnitudes. This is equivalent to w2sigp1/sqrt(w2m).
This column is "null" if w2m<2 or if no individual frame measurements are possible.

w3magp %6.3f mag yes Inverse-variance-weighted mean W3 magnitude computed from profile-fit measurements on the w3m individual frames covering this source. This differs from w3mpro in that it is computed by combining the profile-fit measurements from individual frames, whereas w3mpro is computed by fitting all W3 frames simultaneously and incorporating a robust error model.
This column is "null" if w3m=0, the mean flux is negative or if no individual frame measurements are possible.
CAUTION: This is not a robust measurement of source brightness. It is provided as an internal repeatability diagnostic only. User's should always defer to w3mpro for the optimal flux measurement for point sources.

w3sigp1 %6.3f mag yes Standard deviation of the population of W3 fluxes measured on the w3m individual frames covering this source, in magnitudes. This provides a measure of the characteristic uncertainty of the measurement of this source on individual frames.
This column is "null" if w3m<2 or if no individual frame measurements are possible.

w3sigp2 %6.3f mag yes Standard deviation of the mean of the distribution of W3 fluxes (w3magp) computed from profile-fit measurements on the w3m individual frames covering this source, in magnitudes. This is equivalent to w3sigp1/sqrt(w3m).
This column is "null" if w3m<2 or if no individual frame measurements are possible.

w4magp %6.3f mag yes Inverse-variance-weighted mean W4 magnitude computed from profile-fit measurements on the w4m individual frames covering this source. This differs from w4mpro in that it is computed by combining the profile-fit measurements from individual frames, whereas w4mpro is computed by fitting all W4 frames simultaneously and incorporating a robust error model.
This column is "null" if w4m=0, the mean flux is negative or if no individual frame measurements are possible.
CAUTION: This is not a robust measurement of source brightness. It is provided as an internal repeatability diagnostic only. User's should always defer to w4mpro for the optimal flux measurement for point sources.

w4sigp1 %6.3f mag yes Standard deviation of the population of W4 fluxes measured on the w4m individual frames covering this source, in magnitudes. This provides a measure of the characteristic uncertainty of the measurement of this source on individual frames.
This column is "null" if w4m<2 or if no individual frame measurements are possible.

w4sigp2 %6.3f mag yes Standard deviation of the mean of the distribution of W4 fluxes (w4magp) computed from profile-fit measurements on the w4m individual frames covering this source, in magnitudes. This is equivalent to w4sigp1/sqrt(w4m).
This column is "null" if w4m<2 or if no individual frame measurements are possible.

xscprox %8.2f arcsec yes 2MASS Extended Source Catalog (XSC) proximity. This column gives the distance between the WISE source position and the position of a nearby 2MASS XSC source, if the separation is less than 1.1 times the K_s isophotal radius size of the XSC source. This identifies WISE sources that are identically the 2MASS XSC source as well as WISE sources that are fragments of large galaxies. This column is "null" if there is no 2MASS XSC source in proximity to the WISE source.
If xscprox<2" and is not "null", the WISE source is assumed to be the galaxy detected by 2MASS. The WISE source is measured using an elliptical aperture with a size, shape and orientation that is scaled from that of the 2MASS XSC source, as described in IV.5.c.v. The elliptical aperture parameters and photometry are given in the w?rsemi, w?pa, w?ba, w?gmag and w?gerr columns.

w1rsemi %8.2f arcsec yes Semi-major axis of the elliptical aperture used to measure source in W1.

w1ba %4.2f arcsec yes Axis ratio (b/a) of the elliptical aperture used to measure source in W1.

w1pa %7.2f deg yes Position angle (degrees E of N) of the elliptical aperture major axis used to measure source in W1.

w1gmag %7.3f mag yes W1 magnitude of source measured in the elliptical aperture described by w1rsemi, w1ba, and w1pa.

w1gerr %5.3f mag yes Uncertainty in the W1 magnitude of source measured in elliptical aperture.

w1gflg %1d ---- yes W1 elliptical aperture measurement quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the "standard" aperture photometry quality flag, w1mflg.

w2rsemi %8.2f arcsec yes Semi-major axis of the elliptical aperture used to measure source in W2.

w2ba %4.2f arcsec yes Axis ratio (b/a) of the elliptical aperture used to measure source in W2.

w2pa %7.2f deg yes Position angle (degrees E of N) of the elliptical aperture major axis used to measure source in W2.

w2gmag %7.3f mag yes W2 magnitude of source measured in the elliptical aperture described by w2rsemi, w2ba, and w2pa.

w2gerr %5.3f mag yes Uncertainty in the W2 magnitude of source measured in elliptical aperture.

w2gflg %1d ---- yes W2 elliptical aperture measurement quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the "standard" aperture photometry quality flag, w2mflg.

w3rsemi %8.2f arcsec yes Semi-major axis of the elliptical aperture used to measure source in W3.

w3ba %4.2f arcsec yes Axis ratio (b/a) of the elliptical aperture used to measure source in W3.

w3pa %7.2f deg yes Position angle (degrees E of N) of the elliptical aperture major axis used to measure source in W3.

w3gmag %7.3f mag yes W3 magnitude of source measured in the elliptical aperture described by w3rsemi, w3ba, and w3pa.

w3gerr %5.3f mag yes Uncertainty in the W3 magnitude of source measured in elliptical aperture.

w3gflg %1d ---- yes W3 elliptical aperture measurement quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the "standard" aperture photometry quality flag, w3mflg.

w4rsemi %8.2f arcsec yes Semi-major axis of the elliptical aperture used to measure source in W4.

w4ba %4.2f arcsec yes Axis ratio (b/a) of the elliptical aperture used to measure source in W4.

w4pa %7.2f deg yes Position angle (degrees E of N) of the elliptical aperture major axis used to measure source in W4.

w4gmag %7.3f mag yes W4 magnitude of source measured in the elliptical aperture described by w4rsemi, w4ba, and w4pa.

w4gerr %5.3f mag yes Uncertainty in the W4 magnitude of source measured in elliptical aperture.

w4gflg %1d ---- yes W4 elliptical aperture measurement quality flag. This flag indicates if one or more image pixels in the measurement aperture for this band is confused with nearby objects, is contaminated by saturated or otherwise unusable pixels, or is an upper limit. The flag values are as described for the "standard" aperture photometry quality flag, w4mflg.

2MASS PSC Association Information

tmass_key %10d ---- yes 2MASS PSC association. Unique identifier of the closest source in the 2MASS Point Source Catalog (PSC) that falls within 3" of the position of this WISE source. This is equivalent to the pts_key in the 2MASS PSC entry. This column is "null" if there is no 2MASS PSC source within 3" of the WISE source position. The number of 2MASS PSC sources within 3" of the WISE position is given in n_2mass

CAUTION - 2MASS source information included in the WISE source record is an association not an identification. Although the position accuracies of the two Catalogs are good, there is a non-zero probability of chance associations between physically unrelated objects, as well as missed associations between the Catalogs. You should always confirm associations by reviewing the entries from both Catalogs.

r_2mass %7.3f arcsec yes Distance separating the positions of the WISE source and associated 2MASS PSC source within 3". This column is "null" if there is no associated 2MASS PSC source.

pa_2mass %6.1f deg yes Position angle (degrees E of N) of the vector from the WISE source to the associated 2MASS PSC source. This column is "null" if there is no associated 2MASS PSC source.

n_2mass %3d ---- yes The number of 2MASS PSC entries found within a 3" radius of the WISE source position. If more than one 2MASS PSC falls within 3" of the WISE position, the closest 2MASS PSC entry is listed. This column is "null" if there is no associated 2MASS PSC source.

j_m_2mass %7.3f mag yes 2MASS J-band magnitude or magnitude upper limit of the associated 2MASS PSC source. This column is "null" if there is no associated 2MASS PSC source or if the 2MASS PSC J-band magnitude entry is "null".

j_msig_2mass %5.3f mag yes 2MASS J-band corrected photometric uncertainty of the associated 2MASS PSC source. This column is "null" if there is no associated 2MASS PSC source or if the 2MASS PSC J-band uncertainty entry is "null".

h_m_2mass %7.3f mag yes 2MASS H-band magnitude or magnitude upper limit of the associated 2MASS PSC source. This column is "null" if there is no associated 2MASS PSC source or if the 2MASS PSC H-band magnitude entry is "null".

h_msig_2mass %5.3f mag yes 2MASS H-band corrected photometric uncertainty of the associated 2MASS PSC source. This column is "null" if there is no associated 2MASS PSC source or if the 2MASS PSC H-band uncertainty entry is "null".

k_m_2mass %7.3f mag yes 2MASS K_s-band magnitude of the associated 2MASS PSC source. This column is "null" if there is no associated 2MASS PSC source or if the 2MASS PSC K_s-band magnitude entry is "null".

k_msig_2mass %5.3f mag yes 2MASS K_s-band corrected photometric uncertainty of the associated 2MASS PSC source. This column is "null" if there is no associated 2MASS PSC source or if the 2MASS PSC K_s-band uncertainty entry is "null".

Spatial Indexing Information

x %19.16f ---- no Unit sphere position x value

y %19.16f ---- no Unit sphere position y value

z %19.16f ---- no Unit sphere position z value

spt_ind %9d ---- no HTM spatial index key

Last Updated: 2011 October 5

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