Astronomical Data Center

ADCADC/CDS Standard Document for Catalog:
/catalogs/2/2156A/

The following is the "ReadMe" document that describes this ADC catalog. You can access the files described here in three ways:

1. Use the ADC Data Viewer Suite to visualize the data. [preview
2. Get the data files via anonymous FTP. (See Note.) [ftp


II/156A     IRAS Faint Source Catalog, |b| > 10, Version 2.0 (Moshir+ 1989)
================================================================================
IRAS Faint Source Catalog, |b| > 10 Degrees, Version 2.0
    Moshir M., Copan G., Conrow T., McCallon H., Hacking P., Gregorich D.,
    Rohrbach G., Melnyk M., Rice W., Fullmer L., Chester T.J.
    <Infrared Processing and Analysis Center (1989)>
    =1989ifss.book.....M
================================================================================
ADC_Keywords: Infrared sources ; Photometry, infrared ; Surveys

Description:
    The Faint Source Survey (FSS) is the definitive Infrared Astronomical
    Satellite data set for faint point sources. The FSS was produced by
    point-source filtering the individual detector data streams and then
    coadding those data streams using a trimmed-average algorithm. The
    resulting images, or plates, give the best estimate from the IRAS
    survey data of the point source flux density at every surveyed point
    of the sky. The Faint Source Catalog (FSC) is a compilation of the
    sources extracted from the FSS plates that have met reasonable
    reliability requirements. Averaged over the whole catalog, the FSC is
    at least 98.5% reliable at 12 and 25 microns, and ~94% at 60 microns.
    For comparison, the IRAS Point Source Catalog (PSC) is >99.997%
    reliable, but the sensitivity of the FSC exceeds that of the PSC by
    about a factor of 2.5. The FSC contains data for 173,044 point sources
    in unconfused regions with flux densities typically above 0.2 Jy at
    12, 25, and 60 microns, and above 1.0 Jy at 100 microns. The FSS
    plates are somewhat more sensitive but less reliable than the FSC;
    typically, only sources with SNR > 5 - 6 in the plates are contained
    in the FSC. Sources with SNR > 3 but which do not meet the reliability
    requirements of the FSC are catalogued in the Faint Source Reject File
    (FSR). The data products, the processing methods used to produce them,
    results of an analysis of these products, and cautionary notes are
    given in the Explanatory Supplement to the IRAS Faint Source Survey
    (see references in fsc.doc).

File Summary:
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 FileName        Lrecl       Records    Explanations
--------------------------------------------------------------------------------
ReadMe              80             .    This file
fsc.doc             84           897    CD-ROM Documentation
main.dat           227        173044    IRAS Faint Sources
assoc.dat           64        235935    Associations
meaning.txt         80           304    Details of association catalogues
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See also:
  II/125  : IRAS Point Source Catalog
  II/126  : IRAS Serendipitous Survey Catalog
  II/174  : IRAS 2Jy Redshift Survey Data File
  II/190  : IRAS Minor Planet Survey Data Base
  VII/73  : IRAS Small Scale Structure Catalog
  VII/91  : IRAS Asteroid and Comet Survey
  VII/109 : IRAS Observations of Large Optical Galaxies
  VII/113 : Catalogued Galaxies + QSOs observed in IRAS Survey

Byte-by-byte Description of file: main.dat
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   Bytes Format  Units   Label       Explanations
--------------------------------------------------------------------------------
   1- 12  A12    ---     Name        Source name
  13- 14  I2     h       RAh         Hours RA, equinox 1950.0, epoch 1983.5
  15- 16  I2     min     RAm         Minutes RA, equinox 1950.0, epoch 1983.5
  17- 19  I3     0.1s    RAds        Deci-seconds RA
      20  A1     ---     DE-         Sign of DEC, equinox 1950.0, epoch 1983.5
  21- 22  I2     deg     DEd         Degrees Dec, equinox 1950.0, epoch 1983.5
  23- 24  I2     arcmin  DEm         Minutes Dec, equinox 1950.0, epoch 1983.5
  25- 26  I2     arcsec  DEs         Seconds Dec, equinox 1950.0, epoch 1983.5
  27- 29  I3     arcsec  UncMajor    Uncertainty ellipse major axis
  30- 32  I3     arcsec  UncMinor    Uncertainty ellipse minor axis
  33- 35  I3     deg     PosAng      Uncertainty ellipse position angle
  36- 38  I3     ---     Nobs_12     ? Number of times observed at 12um
  39- 41  I3     ---     Nobs_25     ? Number of times observed at 25um
  42- 44  I3     ---     Nobs_60     ? Number of times observed at 60um
  45- 47  I3     ---     Nobs_100    ? Number of times observed at 100um
  48- 56  E9.3   Jy      Fnu_12      Non-color corrected flux density at 12um
  57- 65  E9.3   Jy      Fnu_25      Non-color corrected flux density at 25um
  66- 74  E9.3   Jy      Fnu_60      Non-color corrected flux density at 60um
  75- 83  E9.3   Jy      Fnu_100     Non-color corrected flux density at 100um
      84  I1     ---     FQual_12    Flux density quality at 12um
      85  I1     ---     FQual_25    Flux density quality at 25um
      86  I1     ---     FQual_60    Flux density quality at 60um
      87  I1     ---     FQual_100   Flux density quality at 100um
  88- 90  I3     ---     Relunc_12   Percent relative flux density uncertainty
                                       at 12um
  91- 93  I3     ---     Relunc_25   Percent relative flux density uncertainty
                                       at 25um
  94- 96  I3     ---     Relunc_60   Percent relative flux density uncertainty
                                       at 60um
  97- 99  I3     ---     Relunc_100  Percent relative flux density uncertainty
                                       at 100um
 100-101  I2     ---     MinRel      Percent minimum source reliability
 102-108  E7.1   ---     SNR_12      ? SNR at 12um
 109-115  E7.1   ---     SNR_25      ? SNR at 25um
 116-122  E7.1   ---     SNR_60      ? SNR at 60um
 123-129  E7.1   ---     SNR_100     ? SNR at 100um
 130-136  E7.1   ---     LocSNR_12   ? Local SNR at 12um
 137-143  E7.1   ---     LocSNR_25   ? Local SNR at 25um
 144-150  E7.1   ---     LocSNR_60   ? Local SNR at 60um
 151-157  E7.1   ---     LocSNR_100  ? Local SNR at 100um
 158-160  I3     ---     Area_12     ? Number of pixels above threshold at 12um
 161-163  I3     ---     Area_25     ? Number of pixels above threshold at 25um
 164-166  I3     ---     Area_60     ? Number of pixels above threshold at 60um
 167-169  I3     ---     Area_100    ? Number of pixels above threshold at 
                                       100um
 170-171  I2     ---     CatNbr      Number of nearby catalog sources
 172-173  I2     ---     ExtNbr_12   Number of nearby extractions at 12 um
 174-175  I2     ---     ExtNbr_25   Number of nearby extractions at 25 um
 176-177  I2     ---     ExtNbr_60   Number of nearby extractions at 60 um
 178-179  I2     ---     ExtNbr_100  Number of nearby extractions at 100 um
 180-181  I2     ---     Cirrus      Number of nearby 100 um-only extractions
 182-183  I2     ---     Confuse     Confusion flag, 1 per band, hex-encoded
 184-188  F5.2   ---     NoisCor_12  ? Noise correction factor at 12um
 189-193  F5.2   ---     NoisCor_25  ? Noise correction factor at 25um
 194-198  F5.2   ---     NoisCor_60  ? Noise correction factor at 60um
 199-203  F5.2   ---     NoisCor_100 ? Noise correction factor at 100um
 204-205  I2     ---     NID         ? Number of positional associations
 206-207  I2     ---     IDType      ? Type of object
 208-212  F5.3   ---     NoisRat_12  ? Ratio of 85% to 68% of flux distribution
                                      at 12um
 213-217  F5.3   ---     NoisRat_25  ? Ratio of 85% to 68% of flux distribution
                                      at 25um
 218-222  F5.3   ---     NoisRat_60  ? Ratio of 85% to 68% of flux distribution
                                      at 60um
 223-227  F5.3   ---     NoisRat_100 ? Ratio of 85% to 68% of flux distribution
                                      at 100um
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Byte-by-byte Description of file: assoc.dat
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   Bytes Format  Units   Label    Explanations
--------------------------------------------------------------------------------
   1- 12  A12    ---     Name     IRAS source name
  13- 18  I6     ---     RecNo    Main data table record number for IRAS source
  19- 20  I2     ---     CatNo    Catalog number (1)
  21- 35  A15    ---     Source   Source identification
  36- 40  A5     ---     Type     Source type or spectral class
  41- 43  I3     arcsec  Radius   Radius vector from IRAS source to association
  44- 46  I3     deg     Pos      Position angle from IRAS source to 
                                    association
  47- 49  I3     arcsec  DstMajor Distance from IRAS source to association
  50- 52  I3     arcsec  DstMinor Distance from IRAS source to association
  53- 56  I4     ---     Field1   Object data field 1, catalog dependent
  57- 60  I4     ---     Field2   Object data field 2, catalog dependent
  61- 64  I4     ---     Field3   Object data field 3, catalog dependent
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Note (1): Detailed explanations are presented in the file meaning.txt.

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(End)                                                                24-Feb-1993

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