ACDS V10.0 - Detailed Description of II/125

ACDS V10.0 - Wed Jan 15 18:48:20 CET 2025

| # Detailed Description of II/125 : IRAS catalogue of Point Sources, Version 2.0 (IPAC 1986) |

Note : this is the description file of the original catalog. This HTML page corresponds well to the original description, but some minor changes in the format may have been introduced in the FITS output files in order to allow for arithmetic operations on quantities such as coordinates and times. h:m:s and d:m:s units are normally converted into degrees, and YYYY-MM-DD into julian days.
Similarly, some slight changes may have been introduced in the units; the value given in the HTML files supersedes the value indicated in the ReadMe file for this catalogue.

    II/125      IRAS catalogue of Point Sources, Version 2.0 (IPAC 1986)
    ================================================================================
    IRAS Catalog of Point Sources, Version 2.0
         Joint IRAS Science W.G.
        <IPAC (1986)>
        =1988IRASP.C......0J
    ================================================================================
    ADC_Keywords: Photometry, infrared ; Infrared sources ; Surveys

    Mission_Name: IRAS

    Description:
        This is a catalog of some 250,000 well-confirmed infrared point
        sources observed by the Infrared Astronomical Satellite, i.e., sources
        with angular extents less than approximately 0.5, 0.5, 1.0, and 2.0
        arcmin in the in-scan direction at 12, 25, 60, and 100 microns,
        respectively. Positions, flux densities, uncertainties, associations
        with known astronomical objects and various cautionary flags are given
        for each object. While two other complementary data sets - the Working
        Survey Data Base and a file of rejected sources - give information
        about point-like sources, the information available in the Point
        Source Catalog should satisfy almost all users. Away from confused
        regions of the sky, the survey is complete to about 0.4, 0.5, 0.6, and
        1.0 Jy at 12, 25, 60, and 100 microns. Typical position uncertainties
        are about 2 to 6 arcseconds in-scan and about 8 to 16 arcseconds
        cross-scan. The processing steps applied to detect and confirm point
        sources, and the positional and photometric error analyses are
        described in the IRAS Catalogs and Atlases Explanatory Supplement; the
        catalog format is described in Chapter X. The sources appear in order
        of increasing (1950.0) right ascension.

        The included script "tofits.sh" should generate the FITS version of the
        tables on Unix platforms.

    References:
      IRAS Catalogs and Atlases Explanatory Supplement, 1988, ed. Beichman C.,
         Neugebauer G., Habing H.J., Clegg P.E., and Chester T.J.
         (Washington, DC: GPO), NASA RP-1190, vol 1

    See also:
        II/126 : IRAS Serendipitous Survey Catalog
        II/156 : IRAS Faint Source Catalog, |b| > 10, Version 2.0
        II/274 : IRAS Point Source Reject Catalog
        VII/91 : IRAS Asteroid and Comet Survey (1986)
        II/190 : IRAS Minor Planet Survey data base (Tedesco, 1992)
       III/197 : IRAS Low Resolution Spectra (LRS) (1987)
       III/170 : IRAS Point Source Identifications (MacConnell, 1993)
        VII/73 : IRAS Small Scale Structure Catalog
       VII/113 : Catalogued Galaxies and QSOs observed in IRAS Survey,
                      Version 2 (IPAC 1989)
        II/174 : IRAS 2Jy Redshift Survey Data File
      J/A+AS/100/473 : IRAS pointed observations data (Assendorp+, 1993)
      J/AJ/109/2318  : Extragalactic IRAS Sources (Condon+ 1995)
      J/A+AS/99/31   : Identification of C stars in IRAS (Guglielmo+ 1993)
      J/A+AS/113/51  : Catalogue of associations IRAS and S stars (Chen+, 1995)
      J/ApJ/411/188  : Classification of bright IRAS variables (Allen+ 1993)
      J/A+AS/80/149  : CO observations of IRAS Sources (Wouterloot+ 1989)
      J/A+AS/98/589  : H2O, OH, CH3OH and CO obs. of IRAS Sources (Wouterloot+ 1993)
      J/A+AS/93/121  : CO emission from a sample of IRAS sources (Nyman+ 1992)
      J/A+AS/90/327  : 1612MHz OH survey of IRAS point sources
                                                    (te Lintel Hekkert+ 1991)
        II/184 : Catalog of Infrared observations, 3rd Edition (Gezari+ 1993)

    File Summary:

           FileName      Lrecl  Records   Explanations

    ×                   80        .   This file
    × ReadMe            80        .   This file
    × psc.txt           79     1091   CD-ROM Documentation
    × SIMPLE.fih        81       44   FITS header
    × main.dat         157   245889   IRAS Point Sources
    × main.fih          80      294   associated FITS header
    × assoc.dat         58   142228   Associations
    × assoc.fih         80       66   associated FITS header
    × meaning.txt       80      235   Details of association catalogues
    × tofits.sh         80       74   Unix shell to generate FITS (1)

    (1) This small script should run on any Unix platform. To generate the FITS
        version of the tables, execute
        tofits main > main.fits       (for the main table)
        tofits assoc  > assoc.fits    (for the association file)

    Byte-by-byte Description of file:  main.dat

       Bytes Format  Units   Label    Explanations

       1- 11  A11    ---     IRAS     IRAS source name
      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- 18  I3     ds      RAds     Seconds RA, equinox 1950.0, epoch 1983.5
          19  A1     ---     DE-      Sign Dec, equinox 1950.0, epoch 1983.5
      20- 21  I2     deg     DEd      Degrees Dec, equinox 1950.0, epoch 1983.5
      22- 23  I2     arcmin  DEm      Minutes Dec, equinox 1950.0, epoch 1983.5
      24- 25  I2     arcsec  DEs      Seconds Dec, equinox 1950.0, epoch 1983.5
      26- 28  I3     arcsec  Major    Uncertainty ellipse major axis
      29- 31  I3     arcsec  Minor    Uncertainty ellipse minor axis
      32- 34  I3     deg     PosAng   Uncertainty ellipse position angle (1)
      35- 36  I2     ---     NHcon    Number of times observed
      37- 45  E9.3   Jy      Fnu_12   Average non-color corrected flux density,
                                        12um (5)
      46- 54  E9.3   Jy      Fnu_25   Average non-color corrected flux density,
                                        25um (5)
      55- 63  E9.3   Jy      Fnu_60   Average non-color corrected flux density,
                                        60um (5)
      64- 72  E9.3   Jy      Fnu_100  Average non-color corrected flux density,
                                        100um (5)
          73  I1     ---    qFnu12  [1,3] Flux density quality, 12um (3)
          74  I1     ---    qFnu25  [1,3] Flux density quality, 25um (3)
          75  I1     ---    qFnu60  [1,3] Flux density quality, 60um (3)
          76  I1     ---   qFnu100  [1,3] Flux density quality, 100um (3)
      77- 78  I2     ---     NLRS     Number of significant LRS spectra (4)
      79- 80  A2     ---     LRSChar  Characterization of averaged LRS spectrum (4)
      81- 83  I3     %      eFnu12  Percent relative flux den. uncertainty, 12um
      84- 86  I3     %      eFnu25  Percent relative flux den. uncertainty, 25um
      87- 89  I3     %      eFnu60  Percent relative flux den. uncertainty, 60um
      90- 92  I3     %     eFnu100  Percent relative flux den. uncertainty, 100um
      93- 97  I5     ---     TSNR_12  10x minimum signal-to-noise ratio, 12um
      98-102  I5     ---     TSNR_25  10x minimum signal-to-noise ratio, 25um
     103-107  I5     ---     TSNR_60  10x minimum signal-to-noise ratio, 60um
     108-112  I5     ---    TSNR_100  10x minimum signal-to-noise ratio, 100um
         113  A1     ---     CC_12    Point source correlation coeff., 12um (8)
         114  A1     ---     CC_25    Point source correlation coeff., 25um (8)
         115  A1     ---     CC_60    Point source correlation coeff., 60um (8)
         116  A1     ---     CC_100   Point source correlation coeff., 100um (8)
     117-118  I2     %       Var      Percent likelihood of variability
         119  A1     ---     Disc     Discrepant fluxes flag, 1 per band,
                                        hex encoded (6)
         120  A1     ---     Confuse  Confusion flags, 1 per band, hex encoded (6)
         121  I1     ---     PNearH   Number of nearby hours-confirmed point sources
         122  I1     ---     PNearW   Number of nearby weeks-confirmed point sources
         123  I1     ---     SES1_12  Nearby seconds-confirmed small ext., 12um (7)
         124  I1     ---     SES1_25  Nearby seconds-confirmed small ext., 25um (7)
         125  I1     ---     SES1_60  Nearby seconds-confirmed small ext., 60um (7)
         126  I1     ---    SES1_100  Nearby seconds-confirmed small ext., 100um (7)
         127  I1     ---     SES2_12  Nearby weeks-confirmed small ext., 12um (7)
         128  I1     ---     SES2_25  Nearby weeks-confirmed small ext., 25um (7)
         129  I1     ---     SES2_60  Nearby weeks-confirmed small ext., 60um (7)
         130  I1     ---    SES2_100  Nearby weeks-confirmed small ext., 100um (7)
         131  A1     ---     HSDFlag  High source density bin flag, hex encoded (6)
         132  I1     ---     Cirr1    Number of nearby 100 micron only WSDB sources
         133  I1     ---     Cirr2    100 micron sky brightness ratio to flux den.
                                        (2)
     134-136  I3     MJy/sr  Cirr3    Total 100 micron sky surface brightness
     137-138  I2     ---     NID      Number of positional associations
         139  I1     ---     IDType   [1,4] Type of association (9)
     140-141  I2     ---     MHcon    ? Possible number of HCONs
     142-145  I4     10-3    FCor_12  ? Flux correction factor applied (5)
     146-149  I4     10-3    FCor_25  ? Flux correction factor applied (5)
     150-153  I4     10-3    FCor_60  ? Flux correction factor applied (5)
     154-157  I4     10-3   FCor_100  ? Flux correction factor applied (5)

    Note (1): Measured in degrees east of north between the major axis of
         the ellipse and the local equatorial meridian.
    Note (2): The spatially filtered 100 micron sky brightness to flux
         density ratio of point source (see Explanatory Supplement)
    Note (3): 3=high quality, 2=moderate quality, 1=upper limit

    Note (4): Low Resolution Spectra, see Cat. III/197

    Note (5): The flux densities listed in the catalog are average values
         computed for the effective wavelengths of the IRAS bands and an
         assumed input energy distribution F({nu}){prop.to}1/{nu} (i.e. a
         spectral index of -1). See details in the Explanatory Supplement
         or at the IRAS archive site at
         http://lambda.gsfc.nasa.gov/product/iras/colorcorr.cfm
    Note (6): The hexadecimal encoding is the representation of a 4-bit
         number with values set to 1=12um, 2=25um, 4=60um, 8=100um. For
         instance, the value A=10=8+2 has flags set for 25 and 100um.
    Note (7): Values of SES1 greater than 1 should caution the user that
         significant extended structure may exist in the region and that
         the source in question may be a point-source like piece of a
         complex field. SES2 values greater than 0 means that the point
         source flux measurement should be treated with caution as the
         source in question may, in fact, be extended; the flux quoted
         in the catalog of small extended sources (Cat. VII/73) may
         provide a better value for the source.
    Note (8): from section V.C.4 of the Explanation:
        the point source correlation coefficient can have values in the range
        87-100%, coded as alphabetic characters with A=100, B=99 .. N=87
    Note (9): Type of association with:
          1 = extragalactic catalog ;
          2 = stellar catalog ;
          3 = other catalogs ;
          4 = multiple types of catalogs.

    Byte-by-byte Description of file:  assoc.dat

       Bytes Format  Units   Label    Explanations

       1- 11  A11    ---     IRAS     IRAS source name
      12- 17  I6     ---     RecNo    Main data table record number for IRAS source
      19- 20  I2     ---     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
      51- 54  I4     ---     Field2   Object data field 2, catalog dependent
      55- 58  I4     ---     Field3   Object data field 3, catalog dependent

    Note (1): See Table X.B.4 in  the "IRAS Catalogs and Atlases Explanatory
        Supplement" also included in the "meaning.txt" file.

    Historical Notes:
        The catalogue is also available on the CD-ROM
        "Selected Astronomical Catalogues", Volume 1, 1992,
        Astronomical Data Center, NASA, directory photom/iraspsc
      * 10-Jun-2004: in file "assoc.dat", record#133500, a control-character
        (in Field 2 representing a spectral type) was replaced.
    ================================================================================
    (End)                                                        [CDS]   29-Jan-1994