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Description
The DIRBE Project Data Sets cover the whole sky and provide photometric data
in 10 bands ranging in wavelength from 1.25 to 240 microns. SkyView has supported
three maps: an early averaged map including including zodiacal and
Galactic components (COBE DIRBE (OLD)), a more recent cleaner version of
that data (COBE DIRBE/AAM) and a map with the zodaical light subtracted out
(COBE DIRBE/ZSMA). The early data is no longer supported. Please contact us if you
want access to these data.
<P>
Detailed descriptions of the DIRBE, the data processing, and the data products
are given in an Explanatory Supplement. A Small Source Spectral Energy Distribution
Browser can be used to assess the visibility of an unresolved or small extended source
in the DIRBE data and see its spectral energy distribution. As noted in section
5.6.6 of the Explanatory Supplement, the DIRBE Time-ordered Data are required to
derive definitive point source fluxes.
<p>
These maps provide an estimate of the infrared intensity at each pixel and
wavelength band based on an interpolation of the observations made at
various times at solar elongations close to 90&#176;;.
<P>
These COBE DIRBE maps are a combination original ten band passes with the following wavelengths:
<UL>
<LI>Band 1 - 1.25 &#181;;m
<LI>Band 2 - 2.2 &#181;;m
<LI>Band 3 - 3.5 &#181;;m
<LI>Band 4 - 4.9 &#181;;m
<LI>Band 5 - 12 &#181;;m
<LI>Band 6 - 25 &#181;;m
<li>Band 7 - 60 &#181;;m
<li>Band 8 - 100 &#181;;m
<li>Band 9 - 140 &#181;;m
<li>Band 10 - 240 &#181;;m
</ul>
<p>
The default two dimensional array uses Band 8 (100 &#181;;m).
<P>
The COBE DIRBE/Annual Average Maps (AAM) is the cumulative weighted
average of the photometry. This average is calculated using the
weighted number of observations from each Weekly Averaged Map
( WtNumObs from the Weekly Averaged Map) as the weight, such that
annual_average =sum( weekly_average * weekly_weight )/ sum( weekly_weight )
<p>
COBE DIRBE/Zodi-Subtracted Mission Average (ZSMA) Skymap represents
the extra-Solar system sky brightness. It is the average
residual map that results after the modelled interplanetary dust (IPD) signal
is subtracted from each of the DIRBE Weekly Skymaps from the cryogenic mission.
Individual weekly residual maps can be reconstructed from the data supplied in
the DIRBE Sky and Zodi Atlas (DSZA). Provenance: COBE Team. This is a service of NASA HEASARC.
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