ACDS V10.0 - Detailed Description of VIII/42

ACDS V10.0 - Mon Feb 03 15:55:03 CET 2025

| # Detailed Description of VIII/42 : Texas Survey of radio sources at 365MHz (Douglas+ 1996) |

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.

    VIII/42             Texas Survey of radio sources at 365MHz   (Douglas+ 1996)
    ================================================================================
    The Texas survey of radio sources covering -35.5° < {delta} < 71.5°
    at 365MHz
         Douglas J.N., Bash F.N., Bozyan F.A., Torrence G.W., Wolfe C.
        <Astron. J. 111, 1945 (1996)>
        =1996AJ....111.1945D
    ================================================================================
    ADC_Keywords: Radio sources

    Abstract:
        We present the Texas Survey of discrete radio sources between -35.5deg
        and 71.5deg declination (B1950), which was carried out at 365MHz with
        the Texas Interferometer during 1974-1983. The Survey lists accurate
        positions with internal errors of about an arcsecond, flux densities
        which for strong point sources have internal errors of about 1% and
        total errors of about 5%, simple structure models and indications of
        spectrum and variability for 66841 sources. Results of comparisons
        with other data are presented, and show that the Survey is 90%
        complete at 0.4Jy and 80% complete at 0.25Jy, is nearly free from
        spurious sources, and has a lobeshift incidence which is reasonably
        described by quality flags associated with each source.

    Introduction:
        The University of Texas Radio Astronomy Observatory (UTRAO) has
        carried out, with the Texas Interferometer, a 365MHz survey of the sky
        from -35.5 to +71.5° declination, which was intended to be
        complete to a flux density level of 0.25Jy, to provide positions with
        an accuracy of about 1arcsec in both coordinates, to give accurate
        flux densities and indication of source variability, and to give rough
        structure models for each source.
        The observations began in 1974 and were completed in 1983. A
        preliminary version of one declination strip was published
        (Douglas et al., 1980), and a number of intermediate versions of the
        survey have been privately circulated for various purposes pending
        completion of the final analysis and adjustment of the data.

    File Summary:

           FileName      Lrecl  Records   Explanations

    ×                   80        .   This file
    × ReadMe            80        .   This file
    × txs.dat          133    66841   The Texas Survey
    × simpler.dat      133    15758   The sources in the simpler model.

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

       Bytes Format  Units   Label      Explanations

           1  A1     ---     Strip     *[A-J] Main strip
           2  A1     ---     Aflg       [*] * means simpler model(s) exist
       3- 11  A9     ---     TXS       *Source name
          13  I1     ---     XPVRflg    [1,3]? # of subbeams outside the PVR
          14  A1     ---     Mflg       [+CWN] goodness of model fit
          15  A1     ---     Eflg       [+CWX] influence of environment
          16  A1     ---     Lflg       [+CW]  lobeshift probability
          17  I1     ---     LVflg      [1,2]?  # of low-visibility subbeams
      20- 21  I2     h       RAh        Right Ascension 1950
      23- 24  I2     min     RAm        Right Ascension 1950
      26- 31  F6.3   s       RAs        Right Ascension 1950
      33- 37  F5.3   s       e_RAs      ]0,4[  Right Ascension error
          41  A1     ---     DE-        Declination sign
      42- 43  I2     deg     DEd        Declination 1950
      45- 46  I2     arcmin  DEm        Declination 1950
      48- 52  F5.2   arcsec  DEs        Declination 1950
      54- 58  F5.2   arcsec  e_DEs      ]0,30[ Declination error
          60  A1     ---     n_S365     [X] X if flux <0.15 Jy
      62- 67  F6.3   Jy      S365       ]0,80[ 365 MHz flux density
      69- 73  F5.3   Jy      e_S365     ]0,40[ Internal rms flux error
          75  A1     ---     SNflg     *[ YZ] signal-to-noise flag
      77- 80  F4.1   ---     Spec       ? spectral index
      82- 83  F2.1   ---     e_Spec     ? [0,1[  error in spectral index
      86- 89  F4.1   ---     Chi2      *? chi-squared flux residual, 2 dof
          90  A1     ---     u_Chi2     [X] X means value of Chi2 is suspect
          91  A1     ---     Vstar     *[*] * means source may be variable
      94- 96  I3     arcsec  Sep        ?  component separation in double model
          97  A1     ---     ---        [ (] field separator
      98- 99  I2     arcsec  e_Sep      ? error in Sep
         100  A1     ---     ---        [)] field separator
     102-103  A2     ---     Struct    *[PAD ] Structure model type
     104-105  I2     %       q         *? Asymetry q parameter for AD model
         106  A1     ---     ---        [(] field separator
     107-108  I2     %       e_q        ? 100xerror in asymmetry parameter q
         109  A1     ---     ---        [)] field separator
     111-114  I4     deg     Xi         [-180,180]? position angle of double
         115  A1     ---     ---        [(] field separator
     116-117  I2     deg     e_Xi       ? error in position angle
         118  A1     ---     ---        [)] field separator
         120  A1     ---     RAOflg    *[*] RA overlap zone flag
         121  A1     ---     DEOflg    *[*] DE overlap zone flag
         122  A1     ---     ---        [(] field separator
     123-124  I2     ---     KA2        ? second most likely RA lobe
         125  A1     ---     ---        [,] field separator
     126-127  I2     ---     KD2        ? second most likely Dec lobe
         128  A1     ---     ---        [)] field separator
         129  A1     ---     RAOZ      *[ABCDE] RA overlap zone
         130  A1     ---     DEOZ      *[ABCDEFGHIJK] Dec overlap zone
     131-133  A3     ---     strp      *Observation strip source line taken from

    Note on Strip:
        The catalog was originally decomposed in 10 tables table3a to table3j
        corresponding to the 10 declination strips:
            -----------------------
               Strip      Range of
                         Decl. name
            -----------------------
            A   -26     [-357,-187]
            B   -12     [-186,-064]
            C   -01     [-063,+039]
            D   +09     [+040,+135]
            E   +18     [+136,+226]
            F   +27     [+227,+316]
            G   +36     [+317,+406]
            H   +45     [+407,+499]
            I   +55     [+500,+598]
            J   +65     [+599,+715]
            -----------------------
    Note on TXS:
        The TXS source name is constructed from the hours and minutes of right
        ascension, the sign of declination, and truncated tenths of degrees of
        declination: hhmmsddd. Because of a final position system adjustment,
        the source name may not agree with the position in the table, but
        should be used regardless.
    Note on SNflg: the Signal-to-Noise flag is set to:
        X  when       S/N < 4
        Y  when  4 <= S/N < 5
        Z  when  5 <= S/N < 7
        blank when    S/N >=7
    Note on Chi2 and Vstar: values of Chi2 are statistically
        > 5.99   for 5% of non-variable sources
        > 9.21   for 1% of non-variable sources    (Vstar set to '*')
        >13.82   for 0.1% of non-variable sources
    Note on Struct and q:
        'P ' = Point model
        'D ' = Double model
        'AD' = Asymmetric Double model ;
               the 'q' asymmetry parameter is then set.
    Note on RAOflg and RAOZ:
        * means this is one of two versions of this catalog line, because
        the source was in an RA overlap zone; the RA zone is then given
        in the RAOZ column.
    Note on DEOflg and DEOZ:
        * means this is one of two versions of this catalog line, because
        the source was observed separately in two observation declination
        strips; the DE zone is then given in the  DEOZ column.
    Note on strp: observation strip and segment from which the catalog
        line was obtained. For example, in TXS 0000+178, strp=181 means
        that the catalog line came from the +18° observation strip,
        RA segment 1. Some sources came from Version 6 of the Texas
        Survey ('TS6' in strp field) or Version 7 ('TS7' in strp field)

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

       Bytes Format Units   Label     Explanations

           1  A1    ---     Strip     [A-J] Main strip, as in txs.dat file.
       3- 11  A9    ---     TXS      *Source name
          13  I1    ---     XPVRflg   [1,3]? # of subbeams outside the PVR
          14  A1    ---     Mflg      [+CWN] goodness of model fit
          15  A1    ---     Eflg      [+CWX] influence of environment
          16  A1    ---     Lflg      [+CW]  lobeshift probability
          17  I1    ---     LVflg     [1,2]?  # of low-visibility subbeams
      20- 21  I2    h       RAh       Right Ascension 1950
      23- 24  I2    min     RAm       Right Ascension 1950
      26- 31  F6.3  s       RAs       Right Ascension 1950
      33- 37  F5.3  s       e_RAs     ]0,4[  Right Ascension error
          41  A1    ---     DE-       Declination sign
      42- 43  I2    deg     DEd       Declination 1950
      45- 46  I2    arcmin  DEm       Declination 1950
      48- 52  F5.2  arcsec  DEs       Declination 1950
      54- 58  F5.2  arcsec  e_DEs     ]0,30[ Declination error
          60  A1    ---     n_S365    [X] X if flux <0.15 Jy
      62- 67  F6.3  Jy      S365      ]0,80[ 365 MHz flux density
      69- 73  F5.3  Jy      e_S365    ]0,40[ Internal rms flux error
          75  A1    ---     SNflg     [XYZ] signal-to-noise flag
      77- 80  F4.1  ---     Spec      ? spectral index
      82- 83  F2.1  ---     e_Spec    ? [0,1[  error in spectral index
      94- 96  I3    arcsec  Sep       ?  component separation in double model
         102  A1    ---     Struct   *[PD] structure model type
     111-114  I4    deg     Xi        [-180,180]? position angle of double
         129  A1    ---     RAOZ      [ABCDE] RA overlap zone
         130  A1    ---     DEOZ      [ABCDEFGHIJK] Dec overlap zone
     131-133  A3    ---     strp      Observation strip source line taken from

    Note on TXS:
      The name is that of the corresponding Survey source line in file txs.dat
    Note on Struct:
      Point model is 'P'; Double model is 'D';
      there are no AD models in the "Simpler models".

    History:
        AAS CD-ROM series, Volume 6, 1996.
      * At CDS, October 1996:
        The original 'table3*' tables were merged into the "txs.dat" file,
        and 'table4*' tables into the "simpler.dat" file, but the table
        number was inserted in byte one.

    References:
        Douglas J.N., Bash F.N., Torrence G.W., & Wolfe C., 1980,
            Publ. Dept. Astron. Univ. Texas, No 17, October 1980.
    ================================================================================
    (End)                                     Francois Ochsenbein [CDS]  23-Oct-1996