AllWISE Source Catalog and Reject Table
发布时间：
2015-09-16 10:07
修改时间：
2020-03-01 16:16
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1. General Properties

1.a. Format and Column Descriptions

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

The AllWISE Source Catalog and Reject Table have the same format with the exception of one column (use_src). The Catalog contains source extractions that meet the uniqueness and/or reliability criteria described in V.4, and the Reject Table contains the source extractions that do not meet those criteria.

The columns in each table are: 

  • Column Name: The parameter name in the Catalog/Reject 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/Reject Table, expressed in "C"-readable notation. This is useful when parsing the aligned tabular output from the IRSA/Gatorcatalog query service. 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 or Reject Table. A "yes" value does not necessarily mean that there are null values, only that they are allowed by the IRSA/WISE database server. A "no" means there will always be a value in this column in the Catalog/Reject Table. 

  • 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 AllWISE Source Catalog sources has the form "WISEA  Jhhmmss.ss+ddmmss.s," where "WISEA" indicates the source is from the AllWISE Source Catalog, and "J"indicates the position is J2000. The "WISEA" acronym is not listed explicitly in the designation column.

The acronym for entries in the AllWISE Reject Table is "WISEAR".

CAUTION: Source designations should not be used as an astrometric reference. They are not a substitute for the source position information in the raand dec columns.

  
ra %11.7f deg no J2000 right ascension with respect to the 2MASS PSC reference frame from the non-moving source extraction.  
dec %11.7f deg no J2000 declination with respect to the 2MASS PSC reference frame from the non-moving source extraction.  
sigra %8.4f arcsec yes One-sigma uncertainty in right ascension coordinate from the non-moving source extraction.  
sigdec %8.4f arcsec yes One-sigma uncertainty in declination coordinate from the non-moving source extraction.  
sigradec %9.4f arcsec yes The co-sigma of the equatorial position uncertainties, sigra, sigdec (σα, σδ). The covariance between the position errors, Vαδ, can be derived from the quoted co-sigma, σαδ, by the formula Vαδ = σαδ×|σαδ|. This maintains the sign information for the covariance since σαδ 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 %11.7f deg no Galactic longitude, computed from the non-moving source fit equatorial position. CAUTION: This coordinate should not be used as an astrometric reference.
glat %11.7f deg no Galactic latitude computed from the non-moving source fit equatorial position. CAUTION: This coordinate should not be used as an astrometric reference.
elon %11.7f deg no Ecliptic longitude computed from the non-moving source fit equatorial position. CAUTION: This coordinate should not be used as an astrometric reference.
elat %11.7f deg no Ecliptic latitude computed from the non-moving source fit equatorial position. CAUTION: This coordinate should not be used as an astrometric reference.
wx %8.3f pix ex The x-pixel coordinate of this source on the Atlas Image.
wy %8.3f pix yes The y-pixel coordinate of this source on the Atlas Image.
cntr %19d ---- no Unique identification number for this object in the AllWISE Catalog/Reject Table. This number is formed from the source_id, which is in turn formed from the coadd_id and source number, src.

The cntr value is formed by making the source_id into an integer, in the format: RRRRsDDDtrevIIIIII, 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)].
  • [trev] = 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, (For AllWISE: "c" = "3").
    • e - Survey Phase ("5" = AllWISE [Full cryogenic + 3-Band Cryo + Post-Cryo]).
    • v - Processing version.

    The translated disambiguation string is always 01351 for AllWISE.

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

For example, a source in the Tile 3041m137_ac51, with a source_id of '3041m137_ac51-012345', has a cntr value of 3041013701351012345.

NOTE: AllWISE Catalog and Reject Table entries are cross-referenced with the Multiepoch Photometry (MEP) Database via the cntr identifier. The Catalog/Reject Table cntr value is referred to as cntr_mf in the MEP Database.

  
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. Thesource_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 AllWISE Tile 3041m137_ac51 has a source_id of 3041m137_ac51-000001.

NOTE: AllWISE Catalog and Reject Table entries are cross-referenced with the Multiepoch Photometry (MEP) Database via the source_ididentifier. The Catalog/Reject Table cntr value is referred to as source_id in the MEP Database.

  
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 ("c" = AllWISE)
    • e - Survey Phase ("5" = AllWISE [Full Cryogenic + 3-Band Cryo + Post-Cryo])
    • v - Processing version.

    The disambiguation string is always ac51 for Tiles in the AllWISE Release products.

For example, the identifier of the AllWISE Atlas Tile with center at (α,δ = 304.13896,-13.63000) is 3041m137_ac51.

  
src %6d ---- no Sequential number of the source extraction in the Atlas Tile from in which this source detected and measured, 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 hasSNR<2. This column is null if the source is nominally detected in W1, but no useful brightness estimate could be made.

NOTE: A special exception to the upper limit conditions described above applies if the W1 value of ph_qual is "Z" (e.g. ph_qual LIKE 'Z%'). In these cases, the value of w1mpro corresponds to the actual flux measurement, w1flux, or is null if w1flux is negative. This occurs for 106,140 sources in the AllWISE Catalog and 54,900 sources in the Reject Table, all of which are confined to a narrow strip of ecliptic longitude. See V.1.b.iiifor more details.

  
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.

Note - In a small number of cases where the W1 value of ph_qual is "Z" (e.g. ph_qual LIKE 'Z%'), the W1 source flux uncertainty was not measurable because of the presence of a large number of saturated pixels from 3-Band Cryo frames covered the source. In these cases, this column isnull, but the w1mpro column will correspond either to the actual source flux, w1flux, rather than the 95% confidence upper limit, or will be null ifw1flux is negative. See V.1.b.iii for more details.

  
w1snr %8.1f ---- 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 hasSNR<2. This column is null if the source is nominally detected in W2, 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 %8.1f ---- 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 hasSNR<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 %8.1f ---- 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 hasSNR<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 %8.1f ---- 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 Combined reduced χ2 in all bands for the profile-fit photometry measurement.  
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 nbis "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 charged particle strikes, or if the source is covered by 3-Band Cryo single-exposures that began to saturate because of rising temperatures (see V.1.b.iii for details).  
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 charged particle strikes.  
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 charged particle strikes.  
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 charged particle strikes.  
satnum %4s ---- yes 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".  
Motion Fit Parameters
ra_pm %11.7f deg yes Right ascension at epoch MJD=55400.0 (2010.5589) from the profile-fitting measurement model that includes motion. This column is null if the fit failed to converge or was not attempted.

NOTE: This will be similar but not identical to the value of ra which is the measured right ascenscion of the source from the non-moving profile-fit.

  
dec_pm %11.7f deg yes Declination at epoch MJD=55400.0 (2010.5589) from the profile-fitting measurement model that includes motion. This column is null if the fit failed to converge or was not attempted.

NOTE: This will be similar but not identical to the value of dec which is the measured declination of the source from the non-moving profile-fit.

  
sigra_pm %8.4f arcsec yes One-sigma uncertainty in right ascension from the profile-fitting measurement model that includes motion. This column is null if the motion-fit failed to converge or was not attempted.  
sigdec_pm %8.4f arcsec yes One-sigma uncertainty in declination from the profile-fitting measurement model that includes motion. This column is null if the motion-fit failed to converge or was not attempted.  
sigradec_pm %9.4f arcsec yes The co-sigma of the equatorial position uncertainties from the profile-fitting measurement model that includes motion, sigra_pm, sigdec_pm (σα_pm, σδ_pm). The covariance between the position errors, Vα_pmδ_pm, can be derived from the quoted co-sigma, σα_pmδ_pm, by the formula Vα_pmδ_pm= σα_pmδ_pm×|σα_pmδ_pm|. This maintains the sign information for the covariance since σα_pmδ_pm 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.

This column is null if the motion-fit failed to converge or was not attempted.

  
pmra %8d mas/year yes The apparent motion in right ascension estimated for this source. This column is null if the motion fit failed to converge or was not attempted.

CAUTION: This is the total motion in right ascension, and not the proper motion. The apparent motion can be significantly affected by parallax for nearby objects. See II.6.b for more information.

  
sigpmra %8d mas/year yes Uncertainty in the RA motion estimation. This column is null if the motion fit failed to converge or was not attempted.  
pmdec %8d mas/year yes The apparent motion in declination estimated for this source. This column is null if the motion fit failed to converge or was not attempted.

CAUTION: This is the total motion in declination, and not the proper motion. The apparent motion can be significantly affected by parallax for nearby objects. See II.6.b for more information.

  
sigpmdec %8d mas/year yes Uncertainty in the Dec motion estimated for this source. This column is null if the motion fit failed to converge or was not attempted.  
w1rchi2_pm %9.3e ---- yes Reduced χ2 of the W1 profile-fit photometry measurement including motion estimation. This column is null if the source is not detected in W1, or if the motion fit failed to converge or was not attempted.  
w2rchi2_pm %9.3e ---- yes Reduced χ2 of the W2 profile-fit photometry measurement including motion estimation. This column is null if the source is not detected in W2 magnitude or if the motion fit failed to converge or was not attempted.  
w3rchi2_pm %9.3e ---- yes Reduced χ2 of the W3 profile-fit photometry measurement including motion estimation. This column is null if the source is not detected in W3 or if the motion fit failed to converge or was not attempted.  
w4rchi2_pm %9.3e ---- yes Reduced χ2 of the W4 profile-fit photometry measurement including motion estimation. This column is null if the source is not detected in W4 or if the motion fit failed to converge or was not attempted.  
rchi2_pm %9.3f ---- yes Combined reduced χ2 in all bands for the profile-fit photometry measurement that includes source motion. This column is null if the motion fit failed to converge or was not attempted.  
pmcode %5s --- yes This is a five character string that encodes information about factors that impact the accuracy of the motion estimation. These include the original blend count, whether a blend-swap took place, and the distance in hundredths of an arcsecond between the non-motion position and the motion mean-observation-epoch position. The format is 

NQDDD

where N is the original blend count, Q is either "Y" or "N" for "yes" or "no" a blend-swap occurred (i.e., the original primary component was not the final primary component), and DDD is the radial distance between the non-motion and motion at mean-observation epoch positions in units of 0.01 arcsec, clipped at 999 (almost 10 arcsec).

For example, a well-behaved source that is not part of a blend and that has similar stationary and motion fit positions would have a pmcode value like "1N008". A source with a questionable motion estimate that is passively deblended (nb=2) and whose stationary-fit and motion position differ by a significant amount would have a pmcode value like "3Y234".

This column is null if a motion solution was not attempted or a valid solution was not found.

  
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. The type of artifact that may contaminate the measurements is denoted by the following codes. Lower-case letters correspond to 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.
  • D,d - Diffraction spike. Source may be a spurious detection of (D) or contaminated by (d) a diffraction spike from a nearby bright star on the same image, or
  • P,p - Persistence. Source may be a spurious detection of (P) or contaminated by (p) a short-term latent image left by a bright source, or
  • H,h - Halo. Source may be a spurious detection of (H) or contaminated by (h) the scattered light halo surrounding a nearby bright source, or
  • O,o (letter "o") - Optical ghost. Source may be a spurious detection of (O) or contaminated by (o) an optical ghost image caused by a nearby bright source, or
  • 0 (number zero) - Source is unaffected by known artifacts.

A source extraction may be affected by more than one type of artifact or condition. In this event, the cc_flags value in each band is set in the following priority order: D,P,H,O,d,p,h,o,0. The full tally of artifacts affecting a source in each band is given in the w?cc_map and w?cc_map_str columns.

A source can appear in the AllWISE Source Catalog even if it is flagged as a spurious artifact detection in a band if there is a reliable detection in another band that is not flagged as a spurious artifact detection (see V.3.b). Entries in the AllWISE Reject Table may be flagged as spurious detections of artifacts in all bands.

CAUTION: Non-zero cc_flags values in any band indicate the the measurement in that band may be contaminated and the photometry should be used with caution.

  
rel %1c ---- yes Small-separation, same-Tile (SSST) detection flag. Non-null values of this flag indicate that this Catalog/Reject Table entry is part of a group of detections with unphysically small separations that were extracted on the same Tile. SSST groups occurred when a faint, often spurious noise detection was shifted towards the position of a brighter nearby source during the chi-squared minimization profile-fit source extraction process. This resulted in two or more extractions on the same Tile that have nearly the same position and similar fluxes. SSST groups were identified and classified using the relflag, and the classifications are used as part of Catalog source selection. The possible values of the rel column are: 
  • null - The extraction is not part of a SSST group, and is eligible for the AllWISE Catalog.
  • s - The extraction is part of an SSST group, and is the original, correct extraction that is eligible for the AllWISE Catalog.
  • c - The extraction is part of an SSST group amd is the original, correct extraction, but is inadvertantly flagged as a spurious artifact. It is eligible for inclusion in the AllWISE Catalog.
  • r - The extraction is part of an SSST group, but is the least reliable extraction in the group. It is not eligible for the Catalog. These are found only in the AllWISE Reject Table.
  
ext_flg %1d ---- yes Extended source flag. This is an integer flag, the value of which indicates whether or not the morphology of a source is consistent with the WISE point spread function in any band, or whether the source is associated with or superimposed on a previously known extended object from the 2MASS Extended Source Catalog (XSC). The values of the ext_flg indicate the following conditions:
  • 0 - The source shape is consistent with a point-source and the source is not associated with or superimposed on a 2MASS XSC source
  • 1 - The profile-fit photometry goodness-of-fit, w?rchi2, is >3.0 in one or more bands.
  • 2 - The source falls within the extrapolated isophotal footprint of a 2MASS XSC source.
  • 3 - The profile-fit photometry goodness-of-fit, w?rchi2, is >3.0 in one or more bands, and The source falls within the extrapolated isophotal footprint of a 2MASS XSC source.
  • 4 - The source position falls within 5" of a 2MASS XSC source.
  • 5 - The profile-fit photometry goodness-of-fit, w?rchi2, is >3.0 in one or more bands, and the source position falls within 5" of a 2MASS XSC source.

CAUTION: 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>0, you may wish to examine the large aperture photometry, or theelliptical 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 calculation uses the standard deviation of the single exposure flux measurements, w?sigp1, as well as the band-to-band flux correlation significance, q12,q23,q34.

The probability is computed for a band only when there are at least six single-exposure measurements available that satisfy minimum quality criteria. A value of "n" in a band indicates insufficient or inadequate data to make a determination of possible variability. Values of "0" through "9" indicate increasing probabilities of variation. Values of "0" through "5" are most likely not variables. Sources with values of "6" and "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.

CAUTION: Estimation of flux variability is unreliable for sources that are extended (ext_flg>0), and sources whose measurements are contaminated by image artifacts in a band (cc_flags[b] != '0').

  
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.
  • C - Source is detected in this band with a flux signal-to-noise ratio 2.
  • 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 in this band. The value of w?mpro and w?sigmpro will be "null" in this band.
  • Z - A profile-fit source flux measurement was made at this location, but the flux uncertainty could not be measured. The value of w?sigmpro will be "null" in this band. The value of w?mpro will be "null" if the measured flux, w?flux, is negative, but will not be "null" if the flux is positive. If a non-null magnitude is present, it corresponds to the true flux, and not the 95% confidence upper limit. This occurs for a small number of sources found in a narrow range of ecliptic longitude which were covered by a large number of saturated pixels from 3-Band Cryo single-exposures, as described in V.1.b.iii.
  
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).  
moon_lev %4s ---- no Scattered moonlight contamination flag. This is a four-character string, one character per band, in which the value is an integer indicates the fraction of single-exposure frames on which the source was measured that were possibly contaminated by scattered moonlight. The value in each band is given by[ceiling(#frmmoon/#frames*10)], with a maximum value of 9, where #frmmoon is the number of affected frames and #frames is the total number of frames on which the source was measured.  
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.

This column is null if there is no frame coverage in this band at the position of this source.

CAUTION: The value of w1m may be lower than expected for sources that were covered by saturated 3-Band Cryo single-exposures. A sign of this is if w1m differs significantly from w1cov. See V.1.b.iii for details.

  
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 7.7s 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.

This column is null if there is no frame coverage in this band at the position of this source.

  
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 8.8s 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.

This column is null if there is no frame coverage in this band at the position of this source.

  
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.

This column is null if there is no frame coverage in this band at the position of this source.

  
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. Third, the values of w1m may be artificially reduced for sources that are covered by saturated 3-Band Cryo single-exposures.

  
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 16.5" 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.

  
w1cc_map %3d ---- yes 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 0 0 0 O H 0 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. Source may be a spurious detection of or contaminated by a diffraction spike a nearby bright star on the same image.
  • P - Persistence. Source may be a spurious detection of or contaminated by a short-term latent (persistence) image left by a bright source.
  • H - Halo. Source may be a spurious detection of or contaminated by the scattered light halo associated with a bright star.
  • 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 on the same image.

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 %9s ---- 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,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 ---- yes 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 0 0 0 O H 0 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. Source may be a spurious detection of or contaminated by a diffraction spike a nearby bright star on the same image.
  • P - Persistence. Source may be a spurious detection of or contaminated by a short-term latent (persistence) image left by a bright source.
  • H - Halo. Source may be a spurious detection of or contaminated by the scattered light halo associated with a bright star.
  • 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 on the same image.

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 %9s ---- 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,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 ---- yes 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 0 0 0 O H 0 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. Source may be a spurious detection of or contaminated by a diffraction spike a nearby bright star on the same image.
  • P - Persistence. Source may be a spurious detection of or contaminated by a short-term latent (persistence) image left by a bright source.
  • H - Halo. Source may be a spurious detection of or contaminated by the scattered light halo associated with a bright star.
  • 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 on the same image.

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 %9s ---- 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,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 correspondingcc_flags entry is "0."

  
w4cc_map %3d ---- yes 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 0 0 0 O H 0 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. Source may be a spurious detection of or contaminated by a diffraction spike a nearby bright star on the same image.
  • P - Persistence. Source may be a spurious detection of or contaminated by a short-term latent (persistence) image left by a bright source.
  • H - Halo. Source may be a spurious detection of or contaminated by the scattered light halo associated with a bright star.
  • 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 on the same image.

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 %9s ---- 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,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."

  
use_src %1d ---- no Duplicate detection resolution flag. This is a one digit integer flag that is present in the AllWISE Reject Table only. The flag has a value of "0" or "1", where:
  • "0" - indicates that extraction is
    • within 50" of a Tile edge boundary where the largest aperture photometry measurements may be corrupted, or
    • positionally associated with one or more other extractions that are measurements of the same objects, and this extraction is not the apparition that is selected for the Catalog.
  • "1" - indicates that extraction is a single, unique detection of an object, or it is a duplicate measurement and is the apparition that is eligible for inclusion in the Source Catalog.

Only extractions that have use_src="1" are eligible for the AllWISE Source Catalog, so this column is not carried explicitly in the Catalog. Entries in the AllWISE Reject Table can have either value.

The process for setting the use_src flag is described in V.4.b.

  
best_use_cntr %19d ---- yes Cntr identification value of the source extraction that was selected as a candidate Catalog source in the duplicate resolution process for the group of associated sources that included this extraction. For the AllWISE Source Catalog, best_use_cntr = cntr. For the AllWISE Reject Table,best_use_cntr may be the cntr value of a corresponding source in the AllWISE Source Catalog.  
ngrp %2d ---- yes Excess number of positionally associated duplicate resolution groups in which this extractions was included. Values of ngrp>0 indicate that the source was associated with more than one possible group.

CAUTION: In the All-Sky Release Catalog and 3-Band Cryo Source Working Database, this column indicated the total number of groups with which a source was associated. In the AllWISE Catalog and Reject Table, ngrp is the total number of groups minus one.

  
Additional Photometric Information
w1flux %11.4e 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 %11.4e 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 %11.4e 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 %11.4e 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 %11.4e 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 %11.4e 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 %11.4e dn yes The "raw" W4 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 %11.4e dn yes Uncertainty in the "raw" W4 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 W4 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 W4 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 W4 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 %2d ---- 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 %2d ---- 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 %2d ---- 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 %2d ---- 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 %2d ---- 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, w1flg.  
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 %2d ---- 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, w2flg.  
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 %2d ---- 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, w3flg.  
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 %2d ---- 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, w4flg.  
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 %2d ---- 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, w1flg.  
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 %2d ---- 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, w2flg.  
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 %2d ---- 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, w3flg.  
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 %2d ---- 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, w4flg.  
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 %2d ---- 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, w1flg.  
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 %2d ---- 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, w2flg.  
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 %2d ---- 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, w3flg.  
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 %2d ---- 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, w4flg.  
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 %2d ---- 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, w1flg.  
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 %2d ---- 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, w2flg.  
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 %2d ---- 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, w3flg.  
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 %2d ---- 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, w4flg.  
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 %2d ---- 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, w1flg.  
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 %2d ---- 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, w2flg.  
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 %2d ---- 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, w3flg.  
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 %2d ---- 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, w4flg.  
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 %2d ---- 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, w1flg.  
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 %2d ---- 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, w2flg.  
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 %2d ---- 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, w3flg.  
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 %2d ---- 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, w4flg.  
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 %2d ---- 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, w1flg.  
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 %2d ---- 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, w2flg.  
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 %2d ---- 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, w3flg.  
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 %2d ---- 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, w4flg.  
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 %2d ---- 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, w1flg.  
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 %2d ---- 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, w2flg.  
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 %2d ---- 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, w3flg.  
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 %2d ---- 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, w4flg.  
w1magp %7.3f mag yes Magnitude computed from the inverse-variance-weighted mean of the profile-fit flux measurements on the w1m individual W1 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. Users 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.

  
w1k %5.3f ---- yes Stetson K variability index (Stetson, P. 1996, PASP, 108, 851) computed using the W1 profile-fit fluxes measured on the individual single-exposure images. This column is null if there are <3 single-exposure measurements available in W1.  
w1ndf %6d ---- yes Number of degrees of freedom in the flux variability chi-square, W1.  
w1mlq %5.2f ---- yes Probability measure that the source is variable in W1 flux. The value is -ln(Q), where Q = 1 - P(χ2). P is the cumulative chi-square distribution probability for the flux sample measured on the individual single-exposure images. The value is clipped at 9.

The Q value is the fraction of all cases to be at least as large as that observed if the null hypothesis is true. The null hypothesis is that the flux is emitted by a non-variable astrophysical object. It may be false because the object is a true variable. It may also be false because the flux measurement is corrupted by artifacts such as cosmic rays, scattered light, etc. The smaller the Q value, the more implausible the null hypothesis, i.e., the more likely it is that the flux is either variable or corrupted or both.

  
w1mjdmin %14.8f ---- yes The earliest modified Julian Date (mJD) of the W1 single-exposures covering the source.  
w1mjdmax %14.8f ---- yes The latest modified Julian Date (mJD) of the W1 single-exposures covering the source.  
w1mjdmean %14.8f ---- yes The average modified Julian Date (mJD) of the W1 single-exposures covering the source.  
w2magp %7.3f mag yes Magnitude computed from the inverse-variance-weighted mean of the profile-fit flux measurements on the w2m individual W2 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. Users 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.

  
w2k %5.3f ---- yes Stetson K variability index (Stetson, P. 1996, PASP, 108, 851) computed using the W2 profile-fit fluxes measured on the individual single-exposure images. This column is null if there are <3 single-exposure measurements available in W2.  
w2ndf %6d ---- yes Number of degrees of freedom in the flux variability chi-square, W2.  
w2mlq %5.2f ---- yes Probability measure that the source is variable in W2 flux. The value is -ln(Q), where Q = 1 - P(χ2). P is the cumulative chi-square distribution probability for the flux sample measured on the individual single-exposure images. The value is clipped at 9.

The Q value is the fraction of all cases to be expected to be at least as large as that observed if the null hypothesis is true. The null hypothesis is that the flux is emitted by a non-variable astrophysical object. It may be false because the object is a true variable. It may also be false because the flux measurement is corrupted by artifacts such as cosmic rays, scattered light, etc. The smaller the Q value, the more implausible the null hypothesis, i.e., the more likely it is that the flux is either variable or corrupted or both.

  
w2mjdmin %14.8f ---- yes The earliest modified Julian Date (mJD) of the W2 single-exposures covering the source.  
w2mjdmax %14.8f ---- yes The latest modified Julian Date (mJD) of the W2 single-exposures covering the source.  
w2mjdmean %14.8f ---- yes The average modified Julian Date (mJD) of the W2 single-exposures covering the source.  
w3magp %7.3f mag yes Magnitude computed from the inverse-variance-weighted mean of the profile-fit flux measurements on the w3m individual W3 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. Users 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.

  
w3k %5.3f ---- yes Stetson K variability index (Stetson, P. 1996, PASP, 108, 851) computed using the W3 profile-fit fluxes measured on the individual single-exposure images. This column is null if there are <3 single-exposure measurements available in W3.  
w3ndf %6d ---- yes Number of degrees of freedom in the flux variability chi-square, W3.  
w3mlq %5.2f ---- yes Probability measure that the source is variable in W3 flux. The value is -ln(Q), where Q = 1 - P(χ2). P is the cumulative chi-square distribution probability for the flux sample measured on the individual single-exposure images. The value is clipped at 9.

The Q value is the fraction of all cases to be expected to be at least as large as that observed if the null hypothesis is true. The null hypothesis is that the flux is emitted by a non-variable astrophysical object. It may be false because the object is a true variable. It may also be false because the flux measurement is corrupted by artifacts such as cosmic rays, scattered light, etc. The smaller the Q value, the more implausible the null hypothesis, i.e., the more likely it is that the flux is either variable or corrupted or both.

  
w3mjdmin %14.8f ---- yes The earliest modified Julian Date (mJD) of the W3 single-exposures covering the source.  
w3mjdmax %14.8f ---- yes The latest modified Julian Date (mJD) of the W3 single-exposures covering the source.  
w3mjdmean %14.8f ---- yes The average modified Julian Date (mJD) of the W3 single-exposures covering the source.  
w4magp %7.3f mag yes Magnitude computed from the inverse-variance-weighted mean of the profile-fit flux measurements on the w4m individual W4 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. Users 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.

  
w4k %5.3f ---- yes Stetson K variability index (Stetson, P. 1996, PASP, 108, 851) computed using the W4 profile-fit fluxes measured on the individual single-exposure images. This column is null if there are <3 single-exposure measurements available in W4.  
w4ndf %6d ---- yes Number of degrees of freedom in the flux variability chi-square, W4.  
w4mlq %5.2f ---- yes Probability measure that the source is variable in W4 flux. The value is -ln(Q), where Q = 1 - P(χ2). P is the cumulative chi-square distribution probability for the flux sample measured on the individual single-exposure images. The value is clipped at 9.

The Q value is the fraction of all cases to be expected to be at least as large as that observed if the null hypothesis is true. The null hypothesis is that the flux is emitted by a non-variable astrophysical object. It may be false because the object is a true variable. It may also be false because the flux measurement is corrupted by artifacts such as cosmic rays, scattered light, etc. The smaller the Q value, the more implausible the null hypothesis, i.e., the more likely it is that the flux is either variable or corrupted or both.

  
w4mjdmin %14.8f ---- yes The earliest modified Julian Date (mJD) of the W4 single-exposures covering the source.  
w4mjdmax %14.8f ---- yes The latest modified Julian Date (mJD) of the W4 single-exposures covering the source.  
w4mjdmean %14.8f ---- yes The average modified Julian Date (mJD) of the W4 single-exposures covering the source.  
rho12 %3d percent yes The correlation coefficient between the W1 and W2 single-exposure flux measurements. The value is a signed 2-digit integer, expressed as a percentage. Negative values indicate anticorrelation.

rho12 is approximately equal to 100 times the J variability index of Stetson (1996 PASP, 108, 851) computed for W1 and W2.

  
rho23 %3d percent yes The correlation coefficient between the W2 and W3 single-exposure flux measurements. The value is a signed 2-digit integer, expressed as a percentage. Negative values indicate anticorrelation.

rho23 is approximately equal to 100 times the J variability index of Stetson (1996 PASP, 108, 851) computed for W2 and W3.

  
rho34 %3d percent yes The correlation coefficient between the W3 and W4 single-exposure flux measurements. The value is a signed 2-digit integer, expressed as a percentage. Negative values indicate anticorrelation.

rho34 is approximately equal to 100 times the J variability index of Stetson (1996 PASP, 108, 851) computed for W3 and W4.

  
q12 %4d ---- yes Correlation significance between W1 and W2. The value is -log10(Q2(rho12)), where Q2 is the two-tailed fraction of all cases expected to show at least this much apparent positive or negative correlation when in fact there is no correlation. The value is clipped at 9.

When the number of measurements is large, the significance of correlation also tends to be large even though the correlations themselves may have a small magnitude. This is a typical manifestation of statistical significance increasing as the sample size increases; eventually the significant effect can be due to small correlated errors in background estimation or even roundoff errors. These effects tend to be small but become significant when there are enough observations of them. High flux correlation significance should be taken seriously only when the magnitude of the correlation is also fairly high.

  
q23 %4d ---- yes Correlation significance between W2 and W3. The value is -log10(Q2(rho23)), where Q2 is the two-tailed fraction of all cases expected to show at least this much apparent positive or negative correlation when in fact there is no correlation. The value is clipped at 9.

When the number of measurements is large, the significance of correlation also tends to be large even though the correlations themselves may have a small magnitude. This is a typical manifestation of statistical significance increasing as the sample size increases; eventually the significant effect can be due to small correlated errors in background estimation or even roundoff errors. These effects tend to be small but become significant when there are enough observations of them. High flux correlation significance should be taken seriously only when the magnitude of the correlation is also fairly high.

  
q34 %4d ---- yes Correlation significance between W3 and W4. The value is -log10(Q2(rho34)), where Q2 is the two-tailed fraction of all cases expected to show at least this much apparent positive or negative correlation when in fact there is no correlation. The value is clipped at 9.

When the number of measurements is large, the significance of correlation also tends to be large even though the correlations themselves may have a small magnitude. This is a typical manifestation of statistical significance increasing as the sample size increases; eventually the significant effect can be due to small correlated errors in background estimation or even roundoff errors. These effects tend to be small but become significant when there are enough observations of them. High flux correlation significance should be taken seriously only when the magnitude of the correlation is also fairly high.

  
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 Ks 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.4.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.

CAUTION: A w1gerr value of 9.999 indicates that the measurement uncertainty is very large, or the uncertainty could not be computed. In either case, the w1gmag measurement should be considered highly suspect.

  
w1gflg %2d ---- 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, w1flg.  
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.

CAUTION: A w2gerr value of 9.999 indicates that the measurement uncertainty is very large, or the uncertainty could not be computed. In either case, the w2gmag measurement should be considered highly suspect.

  
w2gflg %2d ---- 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, w2flg.  
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.

CAUTION: A w3gerr value of 9.999 indicates that the measurement uncertainty is very large, or the uncertainty could not be computed. In either case, the w3gmag measurement should be considered highly suspect.

  
w3gflg %2d ---- 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, w3flg.  
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.

CAUTION: A w4gerr value of 9.999 indicates that the measurement uncertainty is very large, or the uncertainty could not be computed. In either case, the w4gmag measurement should be considered highly suspect.

  
w4gflg %2d ---- 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, w4flg.  
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 non-motion fit 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 zero 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 Ks-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 Ks-band magnitude entry is "null".  
k_msig_2mass %5.3f mag yes 2MASS Ks-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 Ks-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 Level 7 HTM spatial index key  
htm20 %19d ---- no Level 20 HTM spatial index key  


Last Updated: 22 November 2013

 

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