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Дата изменения: Wed Mar 18 12:25:11 2015 Дата индексирования: Sun Apr 10 00:45:42 2016 Кодировка: Поисковые слова: titan |
The all sky surveys done by the Palomar Observatory Schmidt, the European
Southern Observatory Schmidt, and the United Kingdom Schmidt, the InfraRed
Astronomical Satellite, and the Two Micron All Sky Survey have proven
to be extremely useful tools for astronomy with value that lasts for
decades. The Wide-field Infrared Survey Explorer (WISE) is mapping the
whole sky following its launch on 2009 December 14. WISE began surveying
the sky on 2010 January 14 and completed its first full coverage of the
sky on July 17. The survey will continue to cover the sky a second time
until the cryogen is exhausted (anticipated in 2010 November). WISE is
achieving 5sigma point source sensitivities better than 0.08, 0.11,
1, and 6 mJy in unconfused regions on the ecliptic in bands centered at
wavelengths of 3.4, 4.6, 12, and 22 mum. Sensitivity improves toward the
ecliptic poles due to denser coverage and lower zodiacal background. The
angular resolution is 6.1'', 6.4'', 6.5'', and 12.0'' at 3.4,4.6, 12, and 22
mum, and the astrometric precision for high signal-to-noise
sources is better than 0.15''.
J2000 positions and uncertainties reconstructed using the 2MASS
Point Source Catalog as astrometric reference. Astrometric accuracy
is approximately ~200 mas RMS on each axis with respect to the 2MASS
reference frame for sources brighter than SNR=40.
Photometry and uncertainties in the four WISE bands. Photometry
is performed using point source profile-fitting and multi-aperture
photometry. WISE 5sigma photometric sensitivity is estimated to be
0.068, 0.098, 0.86 and 5.4 mJy (16.6, 15.6, 11.3, 8.0 Vega mag) at
3.4, 4.6, 12 and 22 mum in unconfused regions on the ecliptic plane.
Sensitivity is better at higher ecliptic latitudes where coverage
is deeper and the zodiacal background is lower, and poorer when
limited by confusion in high source density or complex background regions.
Saturation affects photometry for sources brighter than approximately
8.1, 6.7, 3.8 and -0.4 mag at 3.4, 4.6, 12 and 22 mum, respectively.
Measurement quality flags, image artifact contamination flags, extended
source and variability flags, and association information cross-reference
WISE sources with the 2MASS Point and Extended Source Catalogs.
If desired, use the MD5 checksums to verify the download.
Next, decompress all 50 files using bzip2 or gunzip (depending on
format). The files can then be loaded into a database, the details of
which depend on the user's software.
Users may also choose to download only those Catalog parts corresponding to
desired dec ranges.
Catalog format and column description are available at
site
If you use IRSA in your research, please include the following acknowledgement in your paper:
"This research has made use of the NASA/ IPAC Infrared Science
Archive, which is operated by the Jet Propulsion Laboratory,
California Institute of Technology, under contract with the
National Aeronautics and Space Administration."
Please include the following standard acknowledgment in any published
material that makes use of data products from the primary WISE mission,
such as the Source Catalog:
"This publication makes use of data products from the Wide-field
Infrared Survey Explorer, which is a joint project of the
University of California, Los Angeles, and the Jet Propulsion
Laboratory/California Institute of Technology, funded by the
National Aeronautics and Space Administration."
README
The Wide-field Infrared Survey Explorer (WISE):
Mission Description and Initial On-orbit Performance
WISE All-Sky Release Catalog
Documentation
The WISE All-Sky Release Source Catalog is available in compressed
(gzip or bzip2) ascii form. Catalog records are lines in a simple
bar-delimited format. Users should be aware that the Catalog table
is extremely large. You will need approximately 280 GB of disk space
to download all of the gzipped files, or 225 GB to download all of
the bzip2-ed files, and an additional 805 GB to uncompress the files.
Concatenating the files results in a Catalog with 563,921,584 records.
Each Catalog part contains records corresponding to a specified declination
range. If a user desires only the sources within a specified dec range, that
user may choose to download only those Catalog parts corresponding to that
range. The dec range covered by each file can be found
here
Source Catalog
The WISE Source Catalog contains the attributes for 563,921,584 point-like
and resolved objects detected on the Atlas Intensity images. Catalog
sources are required to have a measured SNR>5 in at least one band, and
to meet other criteria to insure a high degree of reliability. Attributes
included for each entry in the Source Catalog include:
Retrieval Instructions:
Use the wget scripts provided for either
( gzip or
( bzip2 format ,
or access via the Web at
site
Documentation and Acknowledgements
For complete documentation of the WISE All-Sky Release Source Catalog
and the All-Sky Data Release, please see the
Explanatory Supplement
Contact
For assistance with this product, please contact IRSA user support
accessible from the IRSA web site at
IRSA