Cosmic Background Explorer DIRBE Zodi-Subtracted Mission Average

Short name[s] used to specify survey: COBEZSMA, COBE DIRBE/ZSMA

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.

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.

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°.

These COBE DIRBE maps are a combination original ten band passes with the following wavelengths:

The default two dimensional array uses Band 8 (100 µm).

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 )

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
Copyright Public Domain
Regime Infrared
NSurvey 2 (10 bands)
Frequency 1.25-240 THz
Frequency Bands
10 1.2491 THz 1.0016 THz 1.4966 THz
9 2.1414 THz 1.8394 THz 2.1717 THz
8 2.9979 THz 2.5159 THz 3.4799 THz
7 4.9965 THz 3.8365 THz 6.1565 THz
6 11.992 THz 9.9270 THz 14.057 THz
5 24.983 THz 18.333 THz 31.633 THz
4 61.182 THz 57.087 THz 65.277 THz
3 85.655 THz 74.655 THz 96.655 THz
2 136.70 THz 1.2550 THz 147.90 THz
1 239.83 THz 210.08 THz 269.58 THz
Coverage All-sky
Scale 0.32 deg/pix
Units MJy/sr
Resolution ca. .75 deg
Coordinates Ecliptic
Projection CobeCube (CSC)
Equinox 2000
Epoch 1989-1990
Reference COBE Diffuse Infrared Background Experiment (DIRBE) Explanatory Supplement ed. M.G. Hauser, T. Kelsall, D. Leisawitz, and J. Weiland COBE Ref. Pub. No. 97-A (Greenbelt, MD: NASA/GSFC) available in electronic form (in a slightly more up-to-date version) from the COBE Web page. Specific DIRBE information is available including an instrument description (PostScript).