2MASS PSC Reference Field Characteristics




I. Introduction


We have generated a number of diagnostic plots to characterize the Point Source Catalog behavior over a variety of galactic and equatorial positions. At each position, a circular (in galactic coordinates) Reference Field with one degree radius has been defined, and all PSC entires within the regions have been extracted. These Reference Fields provide a more "microscopic" spot-checking of the catalog to complement the global characterizations of the PSC carried out by Martin Weinberg and John Carpenter.

The first 11 Reference Fields sample northern data, and the second 11 Fields probe the south.

These reference fields are also designed to be used as target regions for other investigations. Please see Mike Egan's comparison of the source counts with SKY model predictions for these fields.

II. Field Selection


The Reference Fields were selected using two criteria:

  1. The field centers were chosen to sample the catalog at regular intervals in both galactic coordinates, to illustrate the effects of source density, and equatorial coordinates to illustrate any possible telescope position dependent effects.


  2. Fields were selected to have contiguous coverage over their two degree diameters. This was verified by using the Fall/Winter Release Survey Previewer which uses the Survey Visualizer interface to allow one to "zoom-in" on the upcoming release fields.


  3. No a priori knowledge of contents of a field were used in field selection.

    The table below lists the definitions of the current set of Reference Fields, along with the total number of point sources in each field.

    
    \ 2MASS Fall/Winter Release Reference Fields
    \ Last update - 7 January 2000
    |N |   RA    |    Dec0   | glon0   | glat0   | radius | nsrcs  |
    |  |   c     |     c     |   d     |   d     |   d    |   i    |
      1 12h50m00s  +15d00m00s  301.28    +77.87     3600.0    3701
      2 10h42m00s  +21d00m00s  217.58    +59.91     3600.0    4406  
      3 09h16m00s  +21d00m00s  207.79    +40.80     3600.0    6193
      4 08h17m00s  +21d00m00s  202.27    +28.80     3600.0    9403
      5 06h56m00s  +27d00m00s  188.97    +12.87     3600.0   27134
      6 06h20m00s  +21d00m00s  190.75     +2.85     3600.0   50724
      7 04h45m00s  +27d00m00s  175.09    -10.47     3600.0   27333
      8 04h35m00s  +15d00m00s  182.10    -21.35     3600.0   11520
      9 02h21m00s  +21d00m00s  149.45    -37.22     3600.0    6209
     10 19h30m00s  +21d00m00s   55.03     +0.91     3600.0  273545
     11 12h55m00s  +32d00m00s  114.12    +85.07     3600.0    2972
     12 18h45m00s  -16d00m00s   17.92     -5.83     3600.0  211253
     13 19h35m00s  -18d00m00s   21.25    -17.51     3600.0   49670
     14 20h25m00s  -24d00m00s   19.73    -30.55     3600.0   19348
     15 21h50m00s  -27d00m00s   22.34    -49.84     3600.0    7636
     16 23h10m00s  -24d00m00s   35.04    -66.95     3600.0    4800
     17 00h50m00s  -27d00m00s   35.16    -87.45     3600.0    3721
     18 02h30m00s  -22d00m00s  205.43    -67.05     3600.0    3686
     19 02h50m00s  -46d00m00s  259.66    -59.92     3600.0    4382
     20 05h10m00s  -30d00m00s  232.35    -33.92     3600.0    8118
     21 06h15m00s  -26d00m00s  233.06    -19.06     3600.0   19941
     22 07h50m00s  -30d00m00s  245.96     -1.90     3600.0   98542
    
    

    III. Diagnostic Plots


    Plots showing the following relationships for the PSC entries in each field have been generated. Whenever single-band information is shown in a plot panel, J-band sources are denoted by blue points, H-band by green points, and Ks by red points.

    IV. The Plots


    Field l b Spatial Dist. dLogN/dM N(<M) vs. Mag    Sigma vs. Mag Chi-Squared vs. Mag Chi-Squared vs. Sigma J-H-Ks color B-J-Ks color JHK Sigma JHK Chi-Squared
    1 301.28 +77.87 x x x x x x x x x x
    2 217.58 +59.91 x x x x x x x x x x
    3 207.79 +40.80 x x x x x x x x x x
    4 202.27 +28.80 x x x x x x x x x x
    5 188.97 +12.87 x x x x x x x x x x
    6 190.75 +2.85 x x x x x x x x x x
    7 175.09 -10.47 x x x x x x x x x x
    8 182.10 -21.35 x x x x x x x x x x
    9 149.45 -37.22 x x x x x x x x x x
    10 55.03 +0.91 x x x x x x x x x x
    11 114.12 +85.07 x x x x x x x x x x
    12 17.92 -5.82 x x x x x x x x x x
    13 21.25 -17.51 x x x x x x x x x x
    14 19.73 -30.55 x x x x x x x x x x
    15 22.34 -49.84 x x x x x x x x x x
    16 35.04 -66.95 x x x x x x x x x x
    17 35.16 -87.45 x x x x x x x x x x
    18 205.43 -67.05 x x x x x x x x x x
    19 259.66 -59.92 x x x x x x x x x x
    20 232.35 -33.92 x x x x x x x x x x
    21 233.06 -19.06 x x x x x x x x x x
    22 245.96 -1.90 x x x x x x x x x x

    R. Cutri - IPAC
    Last Updated - 8 January 2000