ACDS V10.0 - Detailed Description of J/PASP/111/438

ACDS V10.0 - Mon Jan 20 12:31:30 CET 2025

| # Detailed Description of J/PASP/111/438 : Updated Zwicky catalog (UZC) (Falco+, 1999) |

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.

    J/PASP/111/438      Updated Zwicky catalog (UZC)             (Falco+, 1999)
    ================================================================================
    The updated Zwicky catalog (UZC).
        Falco E.E., Kurtz M.J., Geller M.J., Huchra J.P., Peters J., Berlind P.,
        Mink D.J., Tokarz S.P., Elwell B.
       <Publ. Astron. Soc. Pac. 111, 438 (1999)>
       =1999PASP..111..438F
    ================================================================================
    ADC_Keywords: Galaxy catalogs ; Redshifts ; Surveys

    Abstract:
        The Zwicky Catalog of galaxies (ZC), with mZw<=15.5, has been the
        basis for the Center for Astrophysics (CfA) redshift surveys. To date,
        analyses of the ZC and redshift surveys based on it have relied on
        heterogeneous sets of galaxy coordinates and redshifts. Here we
        correct some of the inadequacies of previous catalogs by providing (1)
        coordinates with ~<2" errors for all of the 19,369 catalog galaxies,
        (2) homogeneously estimated redshifts for the majority (98%) of the
        data taken at the CfA (14,632 spectra), and (3) an estimate of the
        remaining "blunder" rate for both the CfA redshifts and for those
        compiled from the literature. For the reanalyzed CfA data we include a
        calibrated, uniformly determined error and an indication of the
        presence of emission lines in each spectrum. We provide redshifts for
        7257 galaxies in the CfA2 redshift survey not previously published;
        for another 5625 CfA redshifts we list the remeasured or uniformly
        rereduced value. Among our new measurements, 1807 are members of UZC
        "multiplets" associated with the original Zwicky catalog position in
        the coordinate range where the catalog is 98% complete.

    File Summary:

           FileName      Lrecl  Records   Explanations

    ×                   80        .   This file
    × ReadMe            80        .   This file
    × catalog.dat       72    19367   UZC catalog (table 1)
    × refs.dat         123      325   Velocity sources for the UZC (table 2)

    See also:
        VII/190 : Zwicky Galaxy Catalog (Zwicky+ 1968)
        VII/193 : The CfA Redshift Catalogue, Version June 1995 (Huchra+ 1995)

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

       Bytes Format Units   Label    Explanations

       1-  2  I2    h       RAh      Right ascension (J2000)
       3-  4  I2    min     RAm      Right ascension (J2000)
       5-  8  F4.1  s       RAs      Right ascension (J2000)
           9  A1    ---     DE-      Declination sign (J2000)
      10- 11  I2    deg     DEd      Declination (J2000)
      12- 13  I2    arcmin  DEm      Declination (J2000)
      14- 15  I2    arcsec  DEs      Declination (J2000)
      17- 20  F4.1  mag     Bmag     B magnitude (Zwicky magnitude)
      22- 26  I5    km/s    cz       ? Heliocentric redshift
      28- 30  I3    km/s    e_cz     ? rms uncertainty on cz
          32  A1    ---     T        [ABE] Spectral characteristics (1)
          34  I1    ---     U        [0/4] UZC class 0-4 (2)
          36  I1    ---     N        Number of UZC neighboring galaxies, within 3'
      38- 49  A12   ---     Zname    Zwicky label based on 1950 positions
          51  A1    ---     f_cz     [FMTXZ] Origin of the redshift measurement (3)
      53- 56  I4    ---     r_cz     ? Reference code detailed in file refs.dat
                                       (blank for CfA unpublished data)
      58- 68  A11   ---     Name     Other name
          70  A1    ---     UZC      [*] UZC multiplicity, * if multiple
          72  A1    ---     mul      [PTG] NED multiplicity: Pair, Triple, Group

    Note (1): the symbol means:
        A: absorption
        E: emission
        B: both emission and absorption
    Note (2): the UZC class is defined as:

       0: a "hit", where the GSC and Zwicky objects are separated in position
          by less than 180", are comparable in brightness as determined
          visually, and there is no other object within the field that could
          be a Zwicky galaxy.

       1: a "hit" with positional difference less than 180", again with a GSC
          brightness in the vicinity of the Zwicky value. However, the field is
          centered on a GSC "star" rather than on a "nonstar", but there is only
          one possible Zwicky galaxy nearby, within the field. Thus, index 1
          merely indicated that the nearest GSC object to the Zwicky coordinates
          is a star rather than the appropriate galaxy.

       2: a near "hit" with positional difference less than 180". However,
          there is confusion because there are at least two galaxies with an
          estimated spread in magnitudes |{Delta}m| within the expected range,
          either of which could be a Zwicky galaxy.

       3: A near "hit" with positional difference less than 180", but with
          |{Delta}m| outside the expected range, raising suspicions about the
          match of the GSC object to the Zwicky galaxy.

       4: No "hit" at all for a positional difference less than 180", i.e.,
          there is no match for a Zwicky galaxy.
    Note (3): Code for the origin of the redshift measurement taken at the CfA:
       Z for Z-machine,
       M for the MMT (4.5m Multiple Mirror Telescope)
       F for FAST spectra taken from our own and from other projects
       X flags a low-S/N spectrum for Z-machine (FAST) measurements and
         indicates a low S/N match with a spectrum at cz<100km/s.

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

       Bytes Format Units   Label     Explanations

       1-  4  I4    ---     Ref       Reference number
       6- 24  A19   ---     BibCode   BibCode
      27- 54  A28   ---     Aut       Author names
      56-123  A68   ---     Rem       Remarks

    History: Copied at http://cfa-www.harvard.edu/~falco/UZC
      * 30-Jul-2002: slightly modified version copied from
        http://cfa-www.harvard.edu/~falco/UZC (5 duplicates removed)
        and added the references from Huchra's Zcat (VII/193)
    ================================================================================
    (End)      Francois Ochsenbein, James Marcout, Patricia Bauer [CDS]  27-May-1999