ACDS V10.0 - Detailed Description of II/295

ACDS V10.0 - Sun Jan 19 03:42:13 CET 2025

| # Detailed Description of II/295 : Spitzer IRAC survey of the galactic center (Ramirez+, 2008) |

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/295           Spitzer IRAC survey of the galactic center     (Ramirez+, 2008)
    ================================================================================
    Point sources from a Spitzer IRAC survey of the galactic center.
        Ramirez S.V., Arendt R.G., Sellgren K., Stolovy S.R., Cotera A.,
        Smith H.A., Yusef-Zadeh F.
       <Astrophys. J. Suppl. Ser., 175, 147-164 (2008)>
       =2008ApJS..175..147R
    ================================================================================
    ADC_Keywords: Cross identifications ; Surveys ; Photometry, infrared

    Mission_Name: Spitzer

    Keywords: Galaxy: center - stars: late-type

    Abstract:
        We have obtained Spitzer IRAC observations of the central
        2.0°x1.4° (~280x200pc) of the Galaxy at 3.6-8.0um. A
        point-source catalog of 1065565 objects is presented. The catalog
        includes magnitudes for the point sources at 3.6, 4.5, 5.8, and 8.0um,
        as well as JHKs photometry from Two Micron All Sky Survey (2MASS). The
        point-source catalog is confusion limited with average limits of 12.4,
        12.1, 11.7, and 11.2mag for [3.6], [4.5], [5.8], and [8.0],
        respectively. We find that the confusion limits are spatially variable
        because of stellar surface density, background surface brightness
        level, and extinction variations across the survey region. The overall
        distribution of point-source density with Galactic latitude and
        longitude is essentially constant, but structure does appear when
        sources of different magnitude ranges are selected. Bright stars show
        a steep decreasing gradient with Galactic latitude and a slow
        decreasing gradient with Galactic longitude, with a peak at the
        position of the Galactic center. From IRAC color-magnitude and
        color-color diagrams, we conclude that most of the point sources in
        our catalog have IRAC magnitudes and colors characteristic of red
        giant and asymptotic giant branch (AGB) stars.

    File Summary:

           FileName      Lrecl  Records   Explanations

    ×                   80        .   This file
    × ReadMe            80        .   This file
    × table2.dat       106   735020   Galactic Center IRAC 1 (3.6um) source lists
    × table3.dat       106   700923   Galactic Center IRAC 2 (4.5um) source lists
    × table4.dat       106   493207   Galactic Center IRAC 3 (5.8um) source lists
    × table5.dat       106   323512   Galactic Center IRAC 4 (8.0um) source lists
    × table6.dat       108      207   Galactic Center IRAC sub-array photometry
    × table7.dat       340  1065565   Galactic Center 2MASS/IRAC Catalog

    See also:
            II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
            II/293 : GLIMPSE Source Catalog (I+II+3D) (IPAC 2008)
     J/A+AS/97/587 : JHK photometry of Galactic center stars (Ruelas-Mayorga+ 1993)

    Byte-by-byte Description of file:  table[2-5].dat

       Bytes Format Units   Label     Explanations

       1-  7  A7    ---     ---       [GC-IRAC-]
           8  I1    ---     Ch        [1/4] Channel number:
                                            1=3.6um, 2=4.5um, 3=5.8um, 4=8.0um
           9  A1    ---     ---       [-]
      10- 15  I06   ---     ID        Source identification number (1)
          17  I1    ---     ---       Channnel number (repetition of Ch)
      19- 20  I2    h       RAh       Hour of Right Ascension (J2000)
      22- 23  I2    min     RAm       Minute of Right Ascension (J2000)
      25- 29  F5.2  s       RAs       Second of Right Ascension (J2000)
          32  A1    ---     DE-       Sign of the Declination (J2000)
      33- 34  I2    deg     DEd       Degree of Declination (J2000)
      36- 37  I2    arcmin  DEm       Arcminute of Declination (J2000)
      39- 42  F4.1  arcsec  DEs       Arcsecond of Declination (J2000)
      45- 56  F12.8 deg     GLON      Galactic longitude
      58- 68  F11.8 deg     GLAT      Galactic latitude
      70- 79  F10.3 mJy     Flux      Flux density in the channel wavelength
      81- 89  F9.3  mJy     e_Flux    Uncertainty in Flux
      91- 92  I2    ---     N         Number of observations of source
      94-102  F9.1  ---     S/N       Signal-to-noise ratio
     104-106  A3    ---     Meth      Method used to compute the flux (2)

    Note (1): Name in Simbad is  [RAS2008] GC-IRACc-NNNNNN
         where c is the channel number, and N the ID number
    Note (2): Method as follows:
        APC = Aperture Corrected Photometry.
        PRF = Point Response Function Fitting.

    Byte-by-byte Description of file:  table6.dat

       Bytes Format Units   Label     Explanations

       1-  3  I3    ---     ID        Source identification (NNN)
       5-  9  A5    ---     Field     IRAC sub-array field (1)
      11- 12  I2    h       RAh       Hour of Right Ascension (J2000)
      14- 15  I2    min     RAm       Minute of Right Ascension (J2000)
      17- 21  F5.2  s       RAs       Second of Right Ascension (J2000)
          23  A1    ---     DE-       Sign of the Declination (J2000)
      24- 25  I2    deg     DEd       Degree of Declination (J2000)
      27- 28  I2    arcmin  DEm       Arcminute of Declination (J2000)
      30- 33  F4.1  arcsec  DEs       Arcsecond of Declination (J2000)
      35- 46  F12.8 deg     GLON      Galactic longitude
      48- 58  F11.8 deg     GLAT      Galactic latitude
      60- 65  F6.3  mag     3.6mag    ? IRAC 3.6 micron band magnitude
      67- 71  F5.3  mag     e_3.6mag  ? Uncertainty in 3.6mag
      73- 78  F6.3  mag     4.5mag    ? IRAC 4.5 micron band magnitude
      80- 84  F5.3  mag     e_4.5mag  ? Uncertainty in 4.5mag
      86- 90  F5.3  mag     5.8mag    ? IRAC 5.8 micron band magnitude
      92- 96  F5.3  mag     e_5.8mag  ? Uncertainty in 5.8mag
      98-102  F5.3  mag     8.0mag    ? IRAC 8.0 micron band magnitude
     104-108  F5.3  mag     e_8.0mag  ? Uncertainty in 8.0mag

    Note (1): Note as follows:
        sat = individual sub-array pointings.
       sgra = sub-array field centered on SgrA*
      quint = sub-array field centered on the Quintuplet cluster

    Byte-by-byte Description of file:  table7.dat

       Bytes Format Units   Label   Explanations

       1-  5  A5    ---     ---     [SSTGC]
       7- 13  I07   ---     SSTGC   Source identification
      15- 16  I2    h       RAh     Hour of Right Ascension (J2000)
      18- 19  I2    min     RAm     Minute of Right Ascension (J2000)
      21- 25  F5.2  s       RAs     Second of Right Ascension (J2000)
          28  A1    ---     DE-     Sign of the Declination (J2000)
      29- 30  I2    deg     DEd     Degree of Declination (J2000)
      32- 33  I2    arcmin  DEm     Arcminute of Declination (J2000)
      35- 38  F4.1  arcsec  DEs     Arcsecond of Declination (J2000)
      41- 49  F9.5  deg     GLON    Galactic longitude
      51- 58  F8.5  deg     GLAT    Galactic latitude
          60  I1    ---     2+1     [0,1] satisfies the "2+1" criterion flag (1)
          62  I1    ---     loc     [0,3] Note about source location (2)
      64- 80  A17   ---     2MASS   2MASS identification (HHMMSSss+DDMMSSsA)
      82- 87  F6.3  mag     Jmag    ?=-9.999 2MASS J band magnitude
      89- 94  F6.3  mag     e_Jmag  ?=-9.999 Uncertainty in Jmag
      96-103  F8.3  mag     Hmag    ?=-9.999 2MASS H band magnitude
     105-110  F6.3  mag     e_Hmag  ?=-9.999 Uncertainty in Hmag
     112-119  F8.3  mag     Ksmag   ?=-9.999 2MASS KS band magnitude
     121-126  F6.3  mag    e_Ksmag  ?=-9.999 Uncertainty in Ksmag
     128-130  A3    ---     q2M     [ABCDEFUXZ] 2MASS quality flag in J H K (3)
     132-140  A9    ---     ---     [GC IRAC1-]
     141-146  I06   ---     ID1     ? Identification in Channel 1 (3.6um)
     149-154  F6.3  mag     3.6mag  ?=-9.999 Channel 1 magnitude at 3.6um
     156-161  F6.3  mag   e_3.6mag  ?=-9.999 Uncertainty in 3.6mag
     163-170  F8.1  ---     SNR1    ?=-9.9 Channel 1 signal-to-noise
         172  I1    ---     f1      [0,4] Channel 1 flag (4)
     174-175  I2    ---     N1      Channel 1 Coverage (#frames at source position)
     177-180  F4.2  ---     M/N1    Channel 1 M/N ratio (5)
     182-190  A9    ---     ---     [GC IRAC2-]
     191-196  I06   ---     ID2     ? Identification in Channel 2 (4.5um)
     199-204  F6.3  mag     4.5mag  ?=-9.999 Channel 2 magnitude at 4.5um
     206-211  F6.3  mag   e_4.5mag  ?=-9.999 Uncertainty in 4.5mag
     213-221  F9.1  ---     SNR2    ?=-9.9 Channel 2 signal-to-noise
         223  I1    ---     f2      [0,4] Channel 2 flag (4)
     225-226  I2    ---     N2      Channel 2 Coverage (#frames at source position)
     228-231  F4.2  ---     M/N2    Channel 2 M/N ratio (5)
     233-241  A9    ---     ---     [GC IRAC3-]
     242-247  I06   ---     ID3     ? Identification in Channel 3 (5.8um)
     250-255  F6.3  mag     5.8mag  ?=-9.999 Channel 3 magnitude at 5.8um
     257-262  F6.3  mag   e_5.8mag  ?=-9.999 Uncertainty in 5.8mag
     264-271  F8.1  ---     SNR3    ?=-9.9 Channel 3 signal-to-noise
         273  I1    ---     f3      [0,4] Channel 3 flag (4)
     275-276  I2    ---     N3      Channel 3 Coverage (#frames at source position)
     278-281  F4.2  ---     M/N3    Channel 3 M/N ratio (5)
     283-291  A9    ---     ---     [GC IRAC4-]
     292-297  I06   ---     ID4     ? Identification in Channel 4 (8.0um)
     300-305  F6.3  mag     8.0mag  ?=-9.999 Channel 4 magnitude at 8.0um
     307-312  F6.3  mag   e_8.0mag  ?=-9.999 Uncertainty in 8.0mag
     314-321  F8.1  ---     SNR4    ?=-9.9 Channel 4 signal-to-noise
         323  I1    ---     f4      [0,4] Channel 4 flag (4)
     325-326  I2    ---     N4      Channel 4 Coverage (#frames at source position)
     328-331  F4.2  ---     M/N4    Channel 4 M/N ratio (5)
     334-340  A7    ---     ID6     Name from table6 (sub-array photometry) (6)

    Note (1): the value '1' indicates that the source satisfies the GLIMPSE
         "2+1" criterion: M/N>=0.6 in one IRAC band,  M/N>=0.4 in an adjacent
         band where M is the number of detections and N, the number of possible
         observations.
    Note (2): Flag as follows:
        0 = source is located in areas of incomplete coverage.
        2 = source is located within 40 arcmin on the Central Cluster.
        3 = source is located within 42 arcmin of the Quintuplet Cluster.
        1 = none of the above
    Note (3): JHK photometric quality flag from the 2MASS Catalog as follows:
        A = SNR>10
        B = SNR>7
        C = SNR>5
        D = no SNR requirement
        E = poor profile-fit photometry
        F = detection without photometric uncertainty
        U = detection with upper limit on magnitude
        X = detection without brightness estimate
      ZZZ = no 2MASS counterpart
    Note (4): Flag as follows:
        0 = source is not detected at the corresponding IRAC band.
        1 = magnitude comes from PRF fitting algorithm.
        2 = magnitude comes from aperture corrected measurement.
        3 = magnitude is greater than corresponding saturation limit.
        4 = magnitude comes from sub-array photometry.
    Note (5): Ratio between M number of detections over N number of possible
         observations (coverage).
    Note (6): for sources observed in the sub-array photometry, the name is
         * satNNN = source in individual sub-array pointings
         * sgraNNN = source in sub-array field centered on SgrA*
         * qintNNN = source in sub-array field centered on Quintuplet cluster

    History:
        From electronic version of the journal
    ================================================================================
    (End)                 Greg Schwarz [AAS], Emmanuelle Perret [CDS]    10-Jun-2009