ABOUT LAMBDA

The COBE Far Infrared Absolute Spectrophotometer (FIRAS)

THIRD-PARTY FIRAS PRODUCTS IN HEALPIX FORMAT
Product
Download Page
Description No. of
Files/Size
Destriped Sky Spectra
There are two HEALPix format Spectral Sky Maps: firas_hpx_destriped_sky_spectra_lowf.fits, and firas_hpx_destriped_sky_spectra_high.fits. Together these cover the full FIRAS frequency range at 13.6041 Gz resolution. More...
2 files
C-Vector
C-Vectors are used in the FIRAS destriping process, as discussed in the FIRAS Explanatory Supplement (especially sections 6.2 and 7.1 ). The values (in MJy/sr) represent the variance (random noise) derived from multiple observations within the same pixel. More...
2 files
Stripes
There are 4 files containing orthogonal stripe information and 4 files containing physical stripe information. For the physical stripes, spectra and covariance values are given, while stripe gammas and betas are given for the orthogonal stripe. More...
8 files
Stripe Templates
These files contain the stripe templates used for destriping the LOWF, HI2, HI3, and HI4 data in production of the HEALPix format data products. The stripe templates are referred to as destriper model functions in the FIRAs Explanatory Supplement. More...
4 files
Uncombined Sky Spec
This file contains destriped calibrated spectra for individual sky coadds More...
2 files
Uncombined Cal Spec
This file contains destriped calibrated spectra for calibration coadds. More...
2 files
FIRAS PROJECT DATA SETS
Product
Download Page
Description No. of
Files/Size
Destriped Sky Spectra
Calibrated, destriped, combined spectra covering 95.1% of the sky. More...
6 files .03 - 28 MB each
C-Vector
C-Vectors are a description of the uncertainties of the data discussed in Explanatory Supplement. More...
6 files 12 KB each
A-Vector
A-Vectors are a description of the Auto Correlation function discussed in Explanatory Supplement. More...
6 files 12 KB each
Covariance Matrix
The Covariance Matrices express all frequency-to-frequency variances in the calibrated spectra. More...
6 files
Chi-Squared
The Chi-Squared files are used in the FIRAS temperature scale calibration. More...
6 files
Calibration Model Solution
Calibration model parameters are given in the 10 Calibration Model Solution files. More...
10 files 45 KB each
Calibration Errors
Errors associated with the calibration model are given in the 16 Calibration Error Terms files. More...
16 files
Model Errors
Four Model Selection Errors files give estimates of the possible systematic errors caused by the choice of destriper model functions at low spectral resolution. More...
4 files 20 KB each
Gradient Kernel
The FIRAS team compared observations grouped into the same sky pixel. More...
3 files
Stripes
There are 6 files containing orthogonal stripe information and 5 files containing physical stripe information. More...
11 files
Uncombined, Undestriped Sky Spectra
Calibrated sky spectra for each individual spectral channel and each scan mode. More...
14 files
Differential Sky Spectra
Differential sky spectra for each individual spectral channel and each scan mode. More...
14 files
Uncombined, Undestriped Calibration Spectra
The time-ordered calibrated calibration spectra for each individual spectral channel and each scan mode. More...
14 files
Differential Calibration Spectra
The time-ordered differential calibration spectra for each individual spectral channel and each scan mode. More...
14 files
Coadded Sky Interferograms
Pixel-ordered coadded sky interferograms for each individual spectral channel and scan mode. More...
14 files
Coadded Calibration Interferograms
Time-ordered coadded calibration interferograms for each individual spectral channel and scan mode. More...
14 files
Time-Ordered Data
Calibrated time-ordered interferograms, engineering, and housekeeping data; 4.8 GBytes total. More...
3542 files
FIRAS ANALYZED SCIENCE DATA SETS
Product
Download Page
Description No. of
Files/Size
CMB Monopole Spectrum
Spectrum of the CMB monopole with uncertainties. More...
1 file 2 KB
CIB Monopole Spectrum
Spectrum of the cosmic infrared background. More...
1 file 12 KB
CMB Temperature Map
CMB temperature map, uncertainties and parameters of dipole fit. More...
1 file .2 MB each
Dust Spectrum Maps
Spectral sky maps from which the CMB, interplanetary dust and IS line emission have been subtracted: More...
2 files 4.5 MB each
Interstellar Dust Maps
"Maps" of Tdust and t1800 GHz are included in the high-frequency Line Emission Maps file. More...
1 file 940 KB
Line Emission Maps
Intensities and the associated uncertainty in 19 spectral lines. More...
5 files .8 MB each
Line Profiles
Synthetic spectral line profiles are provided for each of the channel and scan modes or merged modes. More...
10 files
Zodiacal Light Model
The Zodiacal Light model used by FIRAS was derived from DIRBE data. More...
2 files
FIRAS ANCILLARY DATA PRODUCTS
Product
Download Page
Description No. of
Files/Size
Beam Profile
Instantaeous FIRAS beam profile, derived from Moon observations. More...
1 file 4 KB
Actual Values of Commanded Instrument Gains
To be used for making a reference file containing the commanded C gain values for the four bolometer preamps. More...
1 file 2 KB
Baseline Basis Vectors
This file providesthe RDL format for Legendre polynomial basis vectors for baseline subtraction. More...
1 file 1 KB
Coaddition Consistency Check Thresholds
This reference contains a full set of coaddition Consistency Check Thresholds. More...
1 file 5 KB
Digital Transient Response Functions
This file provides the RDL format for the digital transient response function file structure. More...
1 file 1 KB
Glitch Profiles
This file provides the RDL format for the glitch profile record structure. More...
1 file 2 KB
Glitch Rate Correction Parameters
This file contains the glitchrate correction slopes and intercepts for the FIRAS data. More...
1 file 2 KB
GRT Low/High Current Transition Temperatures
This reference file contains GRT low/high current transition temperatures. More...
1 file 2 KB
GRT Weights for Coadded IFGs
This reference file sets relative weights of GRTs for instrument components. More...
1 file 2 KB
GRT Weights for Raw IFGs
This reference file sets weights to one as RAW weights only do combinations of the XCAL and structure and do not combine sides. More...
1 file 2 KB
Minimum Number of IFGs
Contains minimum number of IFGs needed to form a coadd group. More...
1 file 1 KB
MTM Sampling Rate
This file contains the MTM sampling rates for both I&T and on-orbit data. More...
1 file 1 KB
MTM Scan Times
This reference file, for FPP to use, contains data for the FULL sweep flyback time. More...
1 file 3 KB
Vibration Correction Frequency Offset Indices
This file contains the frequency offsets for which FCF corrects voltage spectra for MTM vibrations. More...
1 file 3 KB

A service of the HEASARC and of the Astrophysics Science Division at NASA/GSFC
Goddard Space Flight Center, National Aeronautics and Space Administration
HEASARC Director: Dr. Alan P. Smale
LAMBDA Director: Dr. Thomas M. Essinger-Hileman
NASA Official: Dr. Thomas M. Essinger-Hileman
Web Curator: Mr. Michael R. Greason