ACDS V10.0 - Detailed Description of II/305

ACDS V10.0 - Sun Jan 19 09:05:24 CET 2025

| # Detailed Description of II/305 : SAGE LMC and SMC IRAC Source Catalog (IPAC 2009) |

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/305           SAGE LMC and SMC IRAC Source Catalog           (IPAC 2009)
    ================================================================================
    Spitzer Survey of the Magellanic Clouds: Surveying the Agents of a
         Galaxy's,Evolution (SAGE and SAGE-SMC)
        <IPAC, Caltech (2009)>
        2012yCat.2305....0G
    ================================================================================
    ADC_Keywords: Infrared sources ; Photometry, infrared ; Magellanic Clouds

    Mission_Name: Spitzer

    Description:
        The SAGE project is a Cycle 2 legacy program on the Spitzer Space
        Telescope, entitled, "Spitzer Survey of the Large Magellanic Cloud:
        Surveying the Agents of a Galaxy's Evolution (SAGE)", with Margaret
        Meixner (STScI) as the PI. The project overview and initial results
        are described in a paper by Meixner et al. (2006AJ....132.2268M).
        The Catalog is a highly reliable list of 6.4 million sources. Faint
        limits for SAGE are 18.1, 17.5, 15.3, and 14.2 for IRAC 3.6, 4.5, 5.8,
        8.0 um, respectively.

        The SAGE-SMC project is a Cycle 4 legacy program on the Spitzer Space
        Telescope, entitled, "SAGE-SMC: Surveying the Agents of Galaxy Evolution
        in the Tidally-Disrupted, Low-Metallicity Small Magellanic Cloud", with
        Karl Gordon (STScI) as the PI. The project overview and initial results
        are described in a paper by Gordon et al. (2011AJ....142..102G).
        The Catalog is a highly reliable list of 2.0 million sources. Faint
        limits for SAGE-SMC are 18.3, 17.7, 15.7, and 14.5 for IRAC 3.6, 4.5,
        5.8, 8.0 um, respectively.

        The archive tables are more complete but less reliable than the catalogs.

        IRAC Single Frame + Mosaic Photometry Catalog: a combination of mosaic
        photometry source list extracted from the combined Epoch 1 and Epoch 2
        12 second frametime mosaics with all-epochs single frame source list,
        bandmerged with 2MASS or 2MASS6X. Detailed documentations are available
        from http://irsa.ipac.caltech.edu/data/SPITZER/SAGE/doc/ as
        SAGEDataProductsDescription_Sep09.pdf and from
        http://irsa.ipac.caltech.edu/data/SPITZER/SAGE-SMC/docs/ as
        sage-smcdeliveryapr11.pdf

    File Summary:

           FileName      Lrecl  Records   Explanations

    ×                   80        .   This file
    × ReadMe            80        .   This file
    × catalog.sam      487      500   Sample of SAGE LMC+SMC catalog
                                  (among 8414394 sources)
    × archive.sam      487      500   Sample of SAGE LMC+SMC archive
                                  (among 9094829 sources)

    See also:
        http://sage.stsci.edu/ : SAGE and SAGE-SMC home page
        http://data.spitzer.caltech.edu/ : Access to Spitzer data

    Byte-by-byte Description of file:  catalog.sam  archive.sam

       Bytes Format Units   Label    Explanations

       1- 19  A19   ---  SSTISAGEMC  SAGE source designation name (G3)
      21- 30  F10.6 deg     RAdeg    Right ascension (J2000)
      32- 41  F10.6 deg     DEdeg    Declination (J2000)
      43- 47  F5.3  arcsec  eeMaj    [0.3] Semi-major axis of the error ellipse
      49- 53  F5.3  arcsec  eeMin    [0.3] Semi-minor axis of the error ellipse
      55- 60  F6.3  deg     eePA     [90] Position angle of the error ellipse
      63- 68  F6.3  mag     Jmag     ? 2MASS-PSC J magnitude (1.25um)
      70- 75  F6.3  mag     Hmag     ? 2MASS-PSC H magnitude (1.65um)
      77- 82  F6.3  mag     Kmag     ? 2MASS-PSC Ks magnitude (2.17um)
      84- 89  F6.3  mag     [3.6]    ? 3.6um IRAC (Band 1) magnitude
      91- 96  F6.3  mag     [4.5]    ? 4.5um IRAC (Band 2) magnitude
      98-103  F6.3  mag     [5.8]    ? 5.8um IRAC (Band 3) magnitude
     105-110  F6.3  mag     [8.0]    ? 8.0um IRAC (Band 4) magnitude
     113-117  F5.3  mag     e_Jmag   ? 1-{sigma} error on Jmag
     119-123  F5.3  mag     e_Hmag   ? 1-{sigma} error on Hmag
     125-129  F5.3  mag     e_Kmag   ? 1-{sigma} error on Ksmag
     131-135  F5.3  mag     e_[3.6]  ? 1-{sigma} error on [3.6]
     137-141  F5.3  mag     e_[4.5]  ? 1-{sigma} error on [4.5]
     143-147  F5.3  mag     e_[5.8]  ? 1-{sigma} error on [5.8]
     149-153  F5.3  mag     e_[8.0]  ? 1-{sigma} error on [8.0]
     155-171  A17   ---     2MASS    ? 2MASS PSC (II/246) or 6X (II/281) designation
     173-182  F10.3 mJy     F(J)     ? 2MASS-PSC J flux (1.25um)
     184-193  F10.3 mJy     e_F(J)   ? 1-{sigma} error on fluxJ
     195-204  F10.3 mJy     F(H)     ? 2MASS-PSC H flux (1.65um)
     206-215  F10.3 mJy     e_F(H)   ? 1-{sigma} error on fluxH
     217-226  F10.3 mJy     F(Ks)    ? 2MASS-PSC Ks flux (2.17um)
     228-237  F10.3 mJy     e_F(Ks)  ? 1-{sigma} error on fluxK
     239-247  F9.3  mJy     F(3.6)   ? 3.6um IRAC (Band 1) flux
     249-256  F8.3  mJy    e_F(3.6)  ? 1-{sigma} error on F(3.6)
     258-266  F9.3  mJy     F(4.5)   ? 4.5um IRAC (Band 2) flux
     268-275  F8.3  mJy    e_F(4.5)  ? 1-{sigma} error on F(4.5)
     277-285  F9.3  mJy     F(5.8)   ? 5.8um IRAC (Band 3) flux
     287-294  F8.3  mJy    e_F(5.8)  ? 1-{sigma} error on F(5.8)
     296-304  F9.3  mJy     F(8.0)   ? 8.0um IRAC (Band 4) flux
     306-313  F8.3  mJy    e_F(8.0)  ? 1-{sigma} error on F(8.0)
     316-321  F6.2  ---     SNJ      ? 2MASS J Band Signal/Noise
     323-328  F6.2  ---     SNH      ? 2MASS H Band Signal/Noise
     330-335  F6.2  ---     SNK      ? 2MASS Ks Band Signal/Noise
     337-343  F7.2  ---     SN3.6    ? 3.6um IRAC (band 1) Signal/Noise
     345-351  F7.2  ---     SN4.5    ? 4.5um IRAC (band 2) Signal/Noise
     353-359  F7.2  ---     SN5.8    ? 5.8um IRAC (band 3) Signal/Noise
     361-367  F7.2  ---     SN8.0    ? 8.0um IRAC (band 4) Signal/Noise
     370-377  I8    ---     q_Jmag   ?=-9 2MASS J Band Source Quality Flag (G1)
     379-386  I8    ---     q_Hmag   ?=-9 2MASS H Band Source Quality Flag (G1)
     388-395  I8    ---     q_Kmag   ?=-9 2MASS Ks Band Source Quality Flag (G1)
     397-405  I9    ---     q_[3.6]  ?=-9 3.6um Source Quality Flag (G1)
     407-415  I9    ---     q_[4.5]  ?=-9 4.5um Source Quality Flag (G1)
     417-425  I9    ---     q_[5.8]  ?=-9 5.8um Source Quality Flag (G1)
     427-435  I9    ---     q_[8.0]  ?=-9 8.0um Source Quality Flag (G1)
     438-439  I2    ---     N3.6     Number of detections for 3.6um
     441-442  I2    ---     N4.5     Number of detections for 4.5um
     444-445  I2    ---     N5.8     Number of detections for 5.8um
     447-448  I2    ---     N8.0     Number of detections for 8.0um
     450-451  I2    ---     n3.6     Number of possible detections for 3.6um
     453-454  I2    ---     n4.5     Number of possible detections for 4.5um
     456-457  I2    ---     n5.8     Number of possible detections for 5.8um
     459-460  I2    ---     n8.0     Number of possible detections for 8.0um
     463-467  I5    ---     mf3.6    ?=-9 Flux calculation method for 3.6um (G2)
     469-473  I5    ---     mf4.5    ?=-9 Flux calculation method for 4.5um (G2)
     475-479  I5    ---     mf5.8    ?=-9 Flux calculation method for 5.8um (G2)
     481-485  I5    ---     mf8.0    ?=-9 Flux calculation method for 8.0um (G2)
         487  I1    ---     C        [0/1]? '0' for sources existing only in
                                           the archive (in "sage_arc" file only)

    Global Notes:

    Note (G1): Source Quality Flag (sqf)
           0  OK - no problems encountered
       -------------------------------------------------------------
         bit  Explanation                                    Survey
       -------------------------------------------------------------
           1  poor pixels in dark current                    SAGE
           2  flat field applied using questionable value    SAGE
           3  latent image                                   SAGE
           3  persistence ("p" in "cc" flag)                2MASS
           4  saturated star correction                      SAGE
           4  photometric confusion ("c" in "cc" flag)      2MASS
           7  muxbleed correction applied                    SAGE
          *8  hot, dead or otherwise unacceptable pixel      SAGE
           9  muxbleed > 3-sigma above the background        SAGE
           9  electronic stripe ("s" in "cc" flag)          2MASS
          10  DAOPHOT tweak positive                         SAGE
          11  DAOPHOT tweak negative                         SAGE
         *13  confusion in in-band merge                     SAGE
         *14  confusion in cross-band merge                  SAGE
         *15  column pulldown correction                     SAGE
         *16  banding correction                             SAGE
          17  stray light                                    SAGE
          19  nonlinear correction not applied               SAGE
         *20  saturated star wing region                     SAGE
          20  diffraction spike ("d" in "cc" flag)          2MASS
          21  pre-lumping in in-band merge                   SAGE
          22  post-lumping in cross-band merge               SAGE
          23  2MASS Quality flag (*)                        2MASS
          24  2MASS Quality flag (*)                        2MASS
          24  in-band merge confusion (mosaic entry)         SAGE
          25  2MASS Quality flag (*)                        2MASS
         *30  edge of frame (within 3 pixels of edge)        SAGE
          31  truth list    (for simulated data)             SAGE
       -------------------------------------------------------------
         *The flags to possibly cull on. (Note that flag 8,20, and 30
           have already been removed from Catalog or nulled.)
       (*) the 2MASS quality is stored here on 3 bits (25,24,23), with
           A (best): all three flags set to 1 (bit pattern 111)
           B (2nd) : bit pattern 110 ...
           E (poor): bit pattern 011
           F (none): bit pattern 010
           U (upper limit):      001
           X (no valid estimate) 000
       -------------------------------------------------------------

          For 2MASS data, the 2MASS PSC flags are mapped into bits 3,4,20,
          and 9 in the source quality flag.

         bit values (2bit-1):
         1=>1; 2=>2; 3=>4; 4=>8; 5=>16; 6=>32; 7=>64; 8=>128; 9=>256;
         10=>512; 11=>1024; 12=>2048; 13=>4096; 14=>8192; 15=>16384;
         16=>32768; 17=>65536; 18=>131072; 19=>262144; 20=>524288;
         21=>1048576; 22=>2097152; 30=>536870912; 31=>1073741824
    Note (G2): Flux calculation method Flag (mf)
         mf indicates by bit whether a given exposure time was present, and
         whether that exposure time was used in the final flux.
       ---------------------
            present  used
       ---------------------
         exp      bit    bit
       ---------------------
         0.6       1      2
         1.2       3      4
         2         5      6
         12        7      8
         30        9     10
         100      11     12
         mosaic   13     14
         addBack  15
       ---------------------
         i.e. if 0.6 and 12 were present, but only 12 was used, then bits
         1 and 5 will be set (fluxes present) and bit 6 will be set (12s used),
         and the mflag will be 1+16+32=49.

         For SAGE HDR mode (High Dynamic Range), the relevant numbers
         work out to be:
               3 = short exp data used, long exp data absent
              67 = short used, long present but unused
             192 = long exp used, short absent
             193 = long exp used, short present but unused
             195 = both long and short present and used
            4099 = 0.6 sec data, mosaic photometry data present
            4163 = 0.6 sec data, 12 sec and mosaic present
            4288 = 12 sec data, mosaic present
            4291 = 12 sec and 0.6 sec data, mosaic present
           12288 = mosaic photometry only, present and used
           12352 = mosaic photometry present and used, 12 sec present
           12353 = mosaic photometry present and used, 0.6 and 12 sec present
          >16384 = an addBack source
    Note (G3): the recommended designations are:
      * SSTISAGEMC for the Catalog sources, followed by the
                   truncated J2000 position (JHHMMSS.ss+DDMMSS.s)
      * SSTISAGEMA for the Archive sources, followed by the
                   truncated J2000 position (JHHMMSS.ss+DDMMSS.s)

    History:
      * 22-Feb-2012: SAGE-catalog only
      * 24-Jan-2013: includes both catalog and archive
      * 03-Jun-2013: addition of epoch catalog and archive
    ================================================================================
    (End)                                   Laurent Cambresy [CDS]       22-Feb-2012