14.4.1 allwise_original_valid

AllWISE source catalogue
Reference paper:
Wright et al. 2010, AJ, 140, 1868
Mainzer et al. 2011, ApJ, 731, 53
Original catalogue:
http://wise2.ipac.caltech.edu/docs/release/allwise
http://wise2.ipac.caltech.edu/docs/release/allwise/expsup/index.html


Columns description:

allwise_oid : Unique Numeric Identifier (long)

Incremental unique numeric identifier (increasing with declination). This is the only field which was not in the original allWISE catalogue, but was added for cross-match purposes.

designation : source Id in original catalog (string)

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.

ra : RA, ICRS (double, Angle[deg])

J2000 right ascension with respect to the 2MASS PSC reference frame from the non-moving source extraction.
The sky coverage depth for sources in the AllWISE Catalog is approximately twice as large in W1 and W2 as it is in W3 and W4. AllWISE combined W1 and W2 Single-exposure images from the WISE 4-Band Cryo, 3-Band Cryo and NEOWISE Post-Cryo survey phases, and W3 and W4 images from the 4-Band Cryo phase only. The additional epoch of W1 and W2 coverage accenuates the weight of those two bands in determining source properties such as position and motion.

dec : DEC, ICRS (double, Angle[deg])

J2000 declination with respect to the 2MASS PSC reference frame from the non-moving source extraction.
The sky coverage depth for sources in the AllWISE Catalog is approximately twice as large in W1 and W2 as it is in W3 and W4. AllWISE combined W1 and W2 Single-exposure images from the WISE 4-Band Cryo, 3-Band Cryo and NEOWISE Post-Cryo survey phases, and W3 and W4 images from the 4-Band Cryo phase only. The additional epoch of W1 and W2 coverage accenuates the weight of those two bands in determining source properties such as position and motion.

ra_error : Error in RAcosDEC (double, Angle[arcsec])

One-sigma uncertainty in right ascension coordinate from the non-moving source extraction.

dec_error : Error in DEC (double, Angle[arcsec])

One-sigma uncertainty in declination coordinate from the non-moving source extraction.

radec_co_error : Co-sigma between position errors (double, Angle[arcsec])

The co-sigma (radec_co_error) of the equatorial position uncertainties (ra_error and dec_error). Unit arcsec.
The covariance between the position errors, Cαδ can be derived from the co-sigma by the formula:
Cαδ=radec_co_error*|radec_co_error|.

w1mpro : W1 profile-fitting magnitude (double, Magnitude[mag])

W1 magnitude measured with profile-fitting photometry, or the magnitude of the 95% confidence brightness upper limit if the W1 flux measurement has SNR<2. This column is null if the source is nominally detected in W1, but no useful brightness estimate could be made. The corresponding error column is null if the W1 profile-fit magnitude is a 95% confidence upper limit.
CAUTION: WISE profile-fit (w?mpro) measurements are optimized for point sources and will systematically underestimate the true flux of resolved objects. If a source entry has ext_flag>0, you may wish to examine the elliptical aperture photometry which are measured using areas that are scaled from 2MASS XSC morphologies.

w1mpro_error : Error on W1 profile-fitting magnitude (double, Magnitude[mag])

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.

w2mpro : W2 profile-fitting magnitude (double, Magnitude[mag])

W2 magnitude measured with profile-fitting photometry, or the magnitude of the 95% confidence brightness upper limit if the W2 flux measurement has SNR<2. This column is null if the source is nominally detected in W2, but no useful brightness estimate could be made. The corresponding error column is null if the W2 profile-fit magnitude is a 95% confidence upper limit.
CAUTION: WISE profile-fit (w?mpro) measurements are optimized for point sources and will systematically underestimate the true flux of resolved objects. If a source entry has ext_flag>0, you may wish to examine the elliptical aperture photometry which are measured using areas that are scaled from 2MASS XSC morphologies.

w2mpro_error : Error on W2 profile-fitting magnitude (double, Magnitude[mag])

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.

w3mpro : W3 profile-fitting magnitude (double, Magnitude[mag])

W3 magnitude measured with profile-fitting photometry, or the magnitude of the 95% confidence brightness upper limit if the W3 flux measurement has SNR<2. This column is null if the source is nominally detected in W3, but no useful brightness estimate could be made. The corresponding error column is null if the W3 profile-fit magnitude is a 95% confidence upper limit.
CAUTION: WISE profile-fit (w?mpro) measurements are optimized for point sources and will systematically underestimate the true flux of resolved objects. If a source entry has ext_flag>0, you may wish to examine the elliptical aperture photometry which are measured using areas that are scaled from 2MASS XSC morphologies.

w3mpro_error : Error on W3 profile-fitting magnitude (double, Magnitude[mag])

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.

w4mpro : W4 profile-fitting magnitude (double, Magnitude[mag])

W4 magnitude measured with profile-fitting photometry, or the magnitude of the 95% confidence brightness upper limit if the W4 flux measurement has SNR<2. This column is null if the source is nominally detected in W4, but no useful brightness estimate could be made. The corresponding error column is null if the W1 profile-fit magnitude is a 95% confidence upper limit.
CAUTION: WISE profile-fit (w?mpro) measurements are optimized for point sources and will systematically underestimate the true flux of resolved objects. If a source entry has ext_flag>0, you may wish to examine the elliptical aperture photometry which are measured using areas that are scaled from 2MASS XSC morphologies.

w4mpro_error : Error on W4 profile-fitting magnitude (double, Magnitude[mag])

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.

cc_flags : Contamination and confusion flag (string)

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.
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.
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.

ext_flag : Extended source flag (short)

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_flag 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 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 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 arcsec of a 2MASS XSC source.

  • 5 - The profile-fit photometry goodness-of-fit is >3.0 in one or more bands, and the source position falls within 5 arcsec of a 2MASS XSC source.

CAUTION: WISE profile-fit (w?mpro) measurements are optimized for point sources and will systematically underestimate the true flux of resolved objects. If a source entry has ext_flag>0, you may wish to examine the elliptical aperture photometry which are measured using areas that are scaled from 2MASS XSC morphologies.

var_flag : Variability flag (string)

Variability flag.
The variability flag is a four-character string, one character per band, in which the value for each band is related to the probability that the source flux measured on the individual WISE exposures was not constant with time.
The probability is computed for a band only when there are at least 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.
VarFlag 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_flag>0), and sources whose measurements are contaminated by image artifacts in a band (cc_flags[band] !=0).

ph_qual : Photometric quality flag (string)

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 >10.

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

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

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

  • X - A profile-fit measurement was not possible at this location 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.

w1mjd_mean : Average mJD of W1 observation (double, Time[Julian Date (day)])

The average modified Julian Date (mJD) of the W1 single-exposures covering the source.

w2mjd_mean : Average mJD of W2 observation (double, Time[Julian Date (day)])

The average modified Julian Date (mJD) of the W2 single-exposures covering the source.

w3mjd_mean : Average mJD of W3 observation (double, Time[Julian Date (day)])

The average modified Julian Date (mJD) of the W3 single-exposures covering the source.

w4mjd_mean : Average mJD of W4 observation (double, Time[Julian Date (day)])

The average modified Julian Date (mJD) of the W4 single-exposures covering the source.

w1gmag : W1 elliptical aperture magnitude (double, Magnitude[mag])

W1 magnitude of source measured in the elliptical aperture.
WISE profile-fit (w?mpro) measurements are optimized for point sources and will systematically underestimate the true flux of resolved objects. If a source entry has ext_flag>0, you may wish to examine the elliptical aperture photometry which are measured using areas that are scaled from 2MASS XSC morphologies.

w1gmag_error : Error on W1 elliptical aperture magnitude (double, Magnitude[mag])

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.

w2gmag : W2 elliptical aperture magnitude (double, Magnitude[mag])

W2 magnitude of source measured in the elliptical aperture.
WISE profile-fit (w?mpro) measurements are optimized for point sources and will systematically underestimate the true flux of resolved objects. If a source entry has ext_flag>0, you may wish to examine the elliptical aperture photometry which are measured using areas that are scaled from 2MASS XSC morphologies.

w2gmag_error : Error on W2 elliptical aperture magnitude (double, Magnitude[mag])

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.

w3gmag : W3 elliptical aperture magnitude (double, Magnitude[mag])

W3 magnitude of source measured in the elliptical aperture.
WISE profile-fit (w?mpro) measurements are optimized for point sources and will systematically underestimate the true flux of resolved objects. If a source entry has ext_flag>0, you may wish to examine the elliptical aperture photometry which are measured using areas that are scaled from 2MASS XSC morphologies.

w3gmag_error : Error on W3 elliptical aperture magnitude (double, Magnitude[mag])

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.

w4gmag : W4 elliptical aperture magnitude (double, Magnitude[mag])

W4 magnitude of source measured in the elliptical aperture.
WISE profile-fit (w?mpro) measurements are optimized for point sources and will systematically underestimate the true flux of resolved objects. If a source entry has ext_flag>0, you may wish to examine the elliptical aperture photometry which are measured using areas that are scaled from 2MASS XSC morphologies.

w4gmag_error : Error on W4 elliptical aperture magnitude (double, Magnitude[mag])

Uncertainty in the W4 magnitude of source measured in elliptical aperture.

CAUTION: A w4gError 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.

tmass_key : 2MASS PSC association (long)

2MASS PSC association.
Unique identifier of the closest source in the 2MASS Point Source Catalog (PSC) that falls within 3 arcsec 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 arcsec of the WISE source position.