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I. Introduction

2. Executive Summary of WISE All-Sky Release Data Products


WISE All-Sky Data Release Contents
Primary ProductsNumber of Entries
a. Image Atlas18,240 image sets
b. Source Catalog563,921,584 objects
Ancillary ProductsNumber of Entries
c.i. Source Reject Table283,887,651 detections
c.ii. Single-Exposure Images1,491,686 image sets
c.iii. Single-Exposure Source Database9,479,433,101 detections
c.iv. Moving Object Tracklets2,004,918 detections of 158,425 asteroids and comets
c.v. Known Solar System Object Possible Association List7,298,315 entries corresponding to 385,402 asteroids, comets, planets and planetary satellites
c.vi. Full-Depth Ecliptic Polar Atlas Images41 image sets

a. Image Atlas

The WISE All-Sky Image Atlas is comprised of 18,240 4095x4095 pix at 1.375"/pix FITS format image sets. Each image set consists of:

The general properties and descriptions of the Atlas Image sets are presented in II.3. Access instructions for the WISE All-Sky Atlas Images are given in I.3. The algorithms used to produce the Atlas Image products are described in IV.4.f.

Users are strongly encouraged to read the Cautionary Notes for the Atlas Images, and to view the gallery of anomalies and features known to exist in the Images.

See also the Full-depth Ecliptic Polar Atlas Images.

b. Source Catalog

The WISE All-Sky Release Source Catalog contains astrometry and photometry for 563,921,584 objects detected on the Atlas Intensity Images. Positions, magnitudes, astrometric and photometric uncertainties, flags indicating the reliability and quality of the source characterizations, and associations with the 2MASS Point and Extended Source Catalog sources are presented for each source.

The general properties and column descriptions of the Source Catalog are presented in II.2. Instructions for accessing the Catalog are given in I.3. A detailed description of the data reduction algorithms used to generate the the Source Catalog can be found in IV.4 and V.1. Users are strongly encouraged to read the Cautionary Notes to make optimal use of the Catalog in their research.

c. Ancillary Products

i. Reject Table

The WISE All-Sky Reject Table contains measurements of 283,887,651 detections made on the Atlas Images that were not included in the All-Sky Catalog because they did not satisfy the Catalog source selection criteria. These "source" extractions were rejected from the Catalog for a number of reasons including: low flux signal-to-noise ratios, they are believed to be spurious detections of image artifacts, or they are duplicate entries of source detections that are included in the Catalog.

The Reject Table format is the same as that for the Source Catalog and is described in II.2.a. Directions for accessing the Reject Table are given in I.3. The data processing steps and algorithms used to produce the source extractions in the Reject Table are the same as used to generate the All-Sky Release Source Catalog, described in IV.4.

The Reject Table is not a well-vetted list of reliable mid-infrared source detections like the Source Catalog. The majority of entries in the Reject Table are likely spurious detections of low SNR noise events or image artifacts. However, the Reject Table also contains some low SNR extractions of real sources, as well as reliable, higher SNR extractions that may have been omitted from the Source Catalog because of over-aggressive artifact flagging in regions such as the ecliptic poles and high density fields in the Galactic plane. Used with caution, the Reject Table can be a useful database that augments the Source Catalog when looking for sources that appear on the Atlas Images but are not found in the Catalog.

Users are strongly encouraged to read the Cautionary Notes before using the Reject Table.

ii. Single-Exposure Images

The WISE All-Sky Release Single-Exposure images consist of 1,491,686 photometrically and astrometrically calibrated 1016x1016 pix at 2.75"/pix FITS image sets for each individual WISE exposure taken between 7 January and 6 August 2010. Each image set consists of:

The Single-Exposure Images were produced during data processing for the main WISE mission, as input for the WISE Moving Object Pipeline, and for the generation and quality assessment of the Atlas Image and Source Catalog.

The properties and descriptions of the Single-Exposure Image sets are presented in II.4.b. Directions for accessing the Single-Exposure Image products are given in I.3. The processing method and algorithms used to produce the Single-Exposure images are described in IV.4.a.

Individual exposure images are made available even if they were of insufficient quality to be used in the construction of the coadded Image Atlas. Users are strongly encouraged to read the Cautionary Notes for the Single-Exposure Images, and to view the gallery of anomalies known to exist in the Images.

iii. Single-Exposure Source Database

The WISE Single-exposure Source Database is a compendium of position and flux information for 9,479,433,101 "sources" detected on the individual WISE 7.7s (W1 and W2) and 8.8s (W3 and W4) Single-exposure images. Because WISE scanned the same region of the sky multiple times, the Single-exposure Database contains multiple, independent measurements of objects on the sky. Positions, magnitudes in the four WISE bands, astrometric and photometric uncertainties, flags indicating measurement quality, the time of observations and associations with the 2MASS Point Source Catalog are presented for entries in the Database.

The Single-Exposure Source Database was produced during data processing for the main WISE mission, as input for as input for the WISE Moving Object Pipeline, and for the generation and quality assessment of the Atlas Image and Source Catalog.

The general properties and detailed column descriptions of the Single-Exposure Source Database are presented in II.4.c. Access instructions for the Single-Exposure Source Database are given in I.3. A detailed description of the source detection and photometry algorithms used to generate the Single-exposure Database can be found in IV.4.

Entries in the Single-exposure Database include detections of real astrophysical objects, as well as spurious extractions of low SNR noise excursions, transient events such as cosmic ray strikes and noisy pixels, and artifacts and scattered light from bright sources including the moon. Many unreliable detections are flagged in the Single-exposure Database, but they have not been filtered out as they were for the Source Catalog. Therefore, the Database must be used with caution. Users are strongly encouraged to read the Cautionary Notes before using the Database.

iv. Moving Object Tracklets

As part of the NEOWISE program, Moving Object Tracklets of small bodies, i.e. asteroids, comets, and planetary satellites, were reported to the IAU Minor Planet Center (MPC) within 10 days of detection by the WISE spacecraft. These tracklets, comprised of both previously known and WISE-discovered solar system objects, were vetted by the MPC so that the remaining list is a highly reliable collection of solar system object detections. As of January 18, 2012, 2,004,918 vetted individual WISE detections of 158,425 small bodies are available from the MPC. These numbers change as WISE detections are linked with new observations.

Moving Object Tracklets were detected and reported to the MPC by the WISE Moving Object Pipeline System (WMOPS) that is described in IV.5. The tracklet products and the means for their retrieval are described in II.4.e.

v. Known Solar System Object Possible Association List

The Known Solar System Object Possible Association List contains 7,298,315 entries that correspond to 385,402 asteroids, comets, planets or planetary satellites, with orbits known at the time of WISE second-pass data processing, that were predicted to be within the field-of-view at the time of individual WISE exposures. The positions of individual objects were observed multiple times, so most have multiple entries in the list. When the predicted position of a solar system object is in proximity to a source detection in the WISE Single-exposures, the WISE source position and brightness information are also provided.

The purpose of the Known Solar System Object Possible Association List is to advise users if a Single-exposure Source Database entry may be confused with or contaminated by a foreground solar system object. The List is not a vetted list of solar system object identifications. For a reliable, well-vetted list of WISE solar system object detections, please use the Moving Object Tracklets. Users are strongly encouraged to read the Cautionary Notes to understand the limitations of the Known Solar System Object Possible Association List.

The column descriptions for the Known Solar System Object Association table are given in II.4.j, and a description of the processing algorithms used to predict the positions of known solar system objects is given in IV.4.e. Directions for accessing the Known Solar System Possible Association table are given in I.3.

vi. Full-Depth Ecliptic Polar Atlas Images

The Full-depth Ecliptic Polar Atlas Images consist of 41 special Atlas Image sets that were generated for Tiles near the Ecliptic poles whose frameset-coverage was artificially attenuated to approximately 160 frameset depth during the second-pass Multiframe processing. The Full-depth Atlas Images were constructed using all framesets covering those regions, over ~3000 directly at the Ecliptic Poles, so they probe deeper than the All-Sky Atlas versions, particularly in W3 and W4. The depth in W1 and W2 is not significantly greater in W1 and W2 because the confusion limit is reached even with the attenuated coverage.

There is no corresponding extracted source database or Catalog from the Full-depth Polar Atlas Images.

The Full-Depth Polar Atlas Image set were constructed the same way as the All-Sky Atlas Images, as described in IV.4.f, except that many more framesets were coadded. Access to the Full-depth Atlas Image Intensity images, Depth-of-Coverage and Uncertainty maps is available in II.3.h.

Please read the Cautionary Notes for the All-Sky Release Atlas Images.


Last update: 2012 March 15


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