VII/73      IRAS Small Scale Structure Catalog, Ver 1.00 (Helou, Walker 1985)
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IRAS Small Scale Structure Catalog
    Helou G., Walker D.W.
    
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ADC_Keywords: Photometry, infrared ; Nonstellar objects ; Infrared sources

Description:
   Sources resolved by the Infrared Astronomical Satellite in any band
   (12, 25, 60, or 100 microns) but smaller than eight arcmin in angular
   extent are to be found in the Small Scale Structure Catalog, also
   known as the catalog of "small extended sources."  The catalog gives
   the infrared characteristics of 16740 objects including, e.g.,
   galaxies, planetary nebulae and compact H II regions. The catalog
   lists for each entry and in each band separately: a position accurate
   to about one arcminute (rms); a flux density accurate to 50% (rms)
   overall, and better at high signal to noise ratios; a rough indicative
   size if a point source is present at the same location; and a variety
   of warning and processing flags. If a detailed shape description, or a
   more accurate poistion, flux, or size are needed, these must be
   determined from the raw detector output. Incompleteness is a complex
   function of wavelength band, brightness, and location, so the absence
   of an entry in the SSS Catalog does not necessarily imply the lack of
   detectable extended emission.  Many entries, mostly at 60 and 100
   microns, refer only to emission features that are details in larger
   structures known as Galactic cirrus. Complete documentation, including
   a description of the catalog format, is contained in the printed
   version.
  
References:
   IRAS Catalogs: The Small Scale Structure Catalog, 1988, eds. Helou, G.,
      and Walker, D.W. (Washington, DC: GPO), NASA RP-1190, vol 7

File Summary:
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 FileName    Lrecl    Records    Explanations
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ReadMe          80          .    This file
irassss.dat    180      16740    IRAS Small Scale Structure Catalog Sources
assoc.dat       58       5178    Information about positional associations
                                   with sources in other catalogs
meaning.txt     80        235    Details of association catalogues
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Byte-by-byte Description of file: irassss.dat
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   Bytes Format  Units   Label      Explanations
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   1- 10  A10    ---     PSCname    IRAS source name
      11  A1     ---     BMFlg      Number of bands in source and band merging
                                      warning flag
  12- 13  I2     h       RAh        Hours RA, equinox 1950.0, epoch 1983.5
  14- 15  I2     min     RAm        Minutes RA, equinox 1950.0, epoch 1983.5
  16- 19  F4.1   s       RAs        Seconds RA, equinox 1950.0, epoch 1983.5
      20  A1     ---     DE-        Sign 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  A1     ---     NH_12      Number of hours-confirmed sightings, 12um
      28  A1     ---     NH_25      Number of hours-confirmed sightings, 25um
      29  A1     ---     NH_60      Number of hours-confirmed sightings, 60um
      30  A1     ---     NH_100     Number of hours-confirmed sightings, 100um
  31- 38  E8.2   Jy      Fnu_12     Average non-color corrected, spatially integ-
                                      rated flux density, 12um (1)
  39- 46  E8.2   Jy      Fnu_25     Average non-color corrected, spatially integ-
                                      rated flux density, 25um (1)
  47- 54  E8.2   Jy      Fnu_60     Average non-color corrected, spatially integ-
                                      rated flux density, 60um (1)
  55- 62  E8.2   Jy      Fnu_100    Average non-color corrected, spatially integ-
                                      rated flux density, 100um (1)
      63  A1     ---     Xtalk_12   Cross-talk flag, 12um (1)
      64  A1     ---     Xtalk_25   Cross-talk flag, 25um (1)
      65  A1     ---     Xtalk_60   Cross-talk flag, 60um (1)
      66  A1     ---     Xtalk_100  Cross-talk flag, 100um (1)
      67  A1     ---     NearPS_12  Number of near-by weeks-confirmed point
                                      sources, 12um
      68  A1     ---     NearPS_25  Number of near-by weeks-confirmed point
                                      sources, 25um
      69  A1     ---     NearPS_60  Number of near-by weeks-confirmed point
                                      sources, 60um
      70  A1     ---     NearPS_100 Number of near-by weeks-confirmed point
                                      sources, 100um
      71  A1     ---     SES1_12    Number of nearby FISES entries, 12um
      72  A1     ---     SES1_25    Number of nearby FISES entries, 25um
      73  A1     ---     SES1_60    Number of nearby FISES entries, 60um
      74  A1     ---     SES1_100   Number of nearby FISES entries, 100um
  75- 76  I2     ---     Cir        Number of hours-confirmed, 100um-only point
                                      sources
      77  A1     ---     HD         High source density flag, encoded, one bit
                                      per band
      78  A1     ---     DblPS      Possibility this is a double point source
                                      (1 bit per band)
  79- 90  A12    ---     PtSrc      Name of IRAS Point Source counterpart and
                                      conflict flag
  91- 93  I3     darcsec Psiz_12    Size estimate from comparison of FLUX
                                      with PTSRC flux, 12um
  94- 96  I3     darcsec Psiz_25    Size estimate from comparison of FLUX
                                      with PTSRC flux, 25um
  97- 99  I3     darcsec Psiz_60    Size estimate from comparison of FLUX
                                      with PTSRC flux, 60um
 100-102  I3     darcsec Psiz_100   Size estimate from comparison of FLUX
                                      with PTSRC flux, 100um
 103-104  I2     ---     NID        Number of positional associations
 105-108  I4     ---     IDType     Type of objects associated
     109  A1     ---     Fqlt       12um flux quality class (2)
     110  A1     ---     Fcat       12um final selection flags (2)
 111-116  F6.1   s       Dra        Right ascension offset from mean position to
                                      12um (2)
 117-120  I4     arcsec  Ddec       Declination offset from mean position to
                                      12um (2)
 121-123  I3     darcmin Unc        95% confidence diameter for position at
                                      12um (2)
 124-126  I3     ---     NS         Number of individual detections at 12um (2)
     127  A1     ---     Fqlt       25um flux quality class (2)
     128  A1     ---     Fcat       25um final selection flags (2)
 129-134  F6.1   s       Dra        Right ascension offset from mean position to
                                      25um (2)
 135-138  I4     arcsec  Ddec       Declination offset from mean position to
                                      25um (2)
 139-141  I3     darcmin Unc        95% confidence diameter for position at
                                      25um (2)
 142-144  I3     ---     NS         Number of individual detections at 25um (2)
     145  A1     ---     Fqlt       60um flux quality class (2)
     146  A1     ---     Fcat       60um final selection flags (2)
 147-152  F6.1   s       Dra        Right ascension offset from mean position to
                                      60um (2)
 153-156  I4     arcsec  Ddec       Declination offset from mean position to
                                      60um (2)
 157-159  I3     darcmin Unc        95% confidence diameter for position at
                                      60um (2)
 160-162  I3     ---     NS         Number of individual detections at 60um (2)
     163  A1     ---     Fqlt       100um flux quality class (2)
     164  A1     ---     Fcat       100um final selection flags (2)
 165-170  F6.1   s       Dra        Right ascension offset from mean position to
                                      100um (2)
 171-174  I4     arcsec  Ddec       Declination offset from mean position to
                                      100um (2)
 175-177  I3     darcmin Unc        95% confidence diameter for position at
                                      100um (2)
 178-180  I3     ---     NS         Number of individual detections at 100um (2)
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Note (1): This quantity appears with a different format or representation, or is
          omitted in the printed version of the catalog.
     (2): These fields are blank if the source was not detected in the corres-
          ponding IRAS band.
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Byte-by-byte Description of file: assoc.dat
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   Bytes Format  Units   Label    Explanations
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   1- 10  A10    ---     PSCName  IRAS source name
  11- 17  I7     ---     RecNo    Main data table record number for SSS source
  18- 20  I3     ---     CatNum   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 (E of N), IRAS source to object
  47- 50  I4     ---     Field1   Object data field 1, catalog dependent (1)
  51- 54  I4     ---     Field2   Object data field 2, catalog dependent (1)
  55- 58  I4     ---     Field3   Object data field 3, catalog dependent (1)
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Note (1): See Table X.B.4 in the "IRAS Catalogs and Atlases Explanatory
    Supplement" also included in the file "meaning.txt" in this directory.
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(End)                                 Gail L. Schneider [SSDOO/ADC]  25-Sep-1995