ZCAT - CfA Redshift Catalog (2000 Version)
The data presented here have primarily been assembled for the purpose of studying the large scale structure of the universe, and, as such, are nearly complete in redshift information, but are not necessarily complete in such categories as diameter, magnitude, and cross-references to other catalogues.
If you have any further questions (and are in dire need of answers), address them to John Huchra <firstname.lastname@example.org>
The name of the object, usually given as a combination of its RA and Dec coordinates.
The Right Ascension of the object. In the original table this was given in 1950 equator to a precision of 0.1 seconds of time.
The Declination of the object. In the original table this was given in 1950 equator to a precision of 1 arcseconds.
The Galactic longitude of the object.
The Galactic latitude of the object.
The magnitude of the galaxy, preferentially on the B(0)-Zwicky system (Huchra 1976, AJ, 81, 952). Magnitudes are taken preferentially from the 1st Reference Catalogue of de Vaucouleurs - B(0), Harvard Corrected, and then from the Zwicky Catalog. B(0) magnitudes are given a source designation (the parameter ref_bmag) of "0", Harvard Corrected magnitudes are given one of "2", and Zwicky catalog magnitudes are given one of "1." Magnitudes from other sources (see the help for ref_bmag for a complete listing) are used only when necessary and available. This choice of system maximizes the number of galaxy magnitudes available and will allow for easy conversion to other systems given diameter and morphological type information (for example, the BT system).
The redshift of the object (only given for the large redshift subset taken from the zbig.dat table).
The radial velocity in km/sec. The velocities quoted are heliocentric, and redshifts (z's) have been converted to velocities with the conversion v equals (z * c), where c equals 299,792.5 km/sec.
Objects listed in the catalog which have no velocity and no listed velocity source (in the northern hemisphere) will be observed as part of the CfA survey extension.
In general, the errors listed for velocities are the errors quoted by the original source, i.e., random errors are quoted and systematic ones are neglected. The only exceptions are where multiple measurements have significantly improved the velocity precision. A small number of the velocities are listed with the notation "poor velocity." Those are weak cross-correlation velocities or velocities from single emission lines that need to be treated with some caution, although they are likely to be nearly correct.
The reference code for the B magnitude value according to the following rubric:
0 = Blank B(0) 1ST Reference Catalogue 1 = Zwicky Catalogue 2 = Corrected Shapley-Ames 3 = Tully and Fisher 4 = J. Graham 5 = Markarian, other Russian estimates 6 = BT - 2ND Reference Catalogue 7 = MCG (Vorontsov-Velyaminov)) 8 = CCD Blue 9 = Observers eye estimates (blue) A = Corrected Blue magnitudes from the RC3 B = Photoelectric or Photographic blue C = Eye estimates from the Case Low dispersion survey D = Dartmouth Red instrumental E = PDS magnitudes calibrated to Kron-Cousins red G = STScI Guide Star Catalogue (V or J) H = Zwicky Mag for multiple systems split by JPH I = CCD I J = Photographic J, IIIa-J L = SSRS2 Magnitude from L. DaCosta (approx BT) P = PGC magnitude S = Gunn red magnitude R = Photographic of Photoelectric R, IIIa-F, O-98 or 103aE T = Dressler's eye estimate (visual) V = Photographic or Photoelectric V W = CCD V
Note that, to avoid mixing upper and lower cases, the HEASARC has changed some of these codes from the original CDS table: values of 'd' were changed to 'E', 'r' to 'S', and 'v' to 'T'.
Identification code for the source of the data listed for velocities. The key to the source listing for Basic Radial Velocity Sources (using just the first two characters of this code) is given below. Velocities with negative source designations are still in the private domain and should not be used without consent from the appropriate owner. The full list of references corresponding to all 4 characters of this code is available at: ftp://cdsarc.u-strasbg.fr/pub/cats/VII/193/zsource.tex (or zsource.dat).
Basic Radial Velocity Sources 00 = Blank 2ND REF CAT, de Vaucouleurs et al. 01 = Sandage and Tammann (CDS/ADC Cat. VII/51) 02 = Tully and Fisher (Nearby Galaxy Catalog, CDS/ADC Cat. VII/145) 03 = Huchra-KPNO, (including Markarian list) 04 = Rubin, Ford, Kinmann 05 = Other Russian ( Byurakan, Alam-Alta, SAO) 06 = Arecibo 21 cm - Salpeter et al., Giovanelli and Haynes 07 = Martin 08 = German 21cm (Bonn) 09 = NRAO, VLA 21cm 10 = CTIO 11 = KPNO 12 = ESO 13 = HCO - M. Davis 14 = E. Turner 15 = Steward Observatory - Tifft, Gregory 16 = Rood, Chincarini, Kinter, Dickel 17 = AAT + Mt. Stromlo 18 = SAO - 6-meter Karachentsev, Kopylov 19 = Texas - McDonald Observatory 20 = Mt. Wilson - HMS, Rudnicki, Zwicky 21 = Lick 22 = French 21sm -- Nancay 23 = British Optical -- I.N.T., Herschel Telescope 24 = Palomar - Hale Telescope, Mayer telescope 25 = Australian 21cm - Parkes 26 = Dutch 21cm 27 = Mt. Hopkins - CfA Redshift Survey, MMT 28 = British 21cm (Jodrell Bank, etc.) 29 = Argentina - Sersic 30 = Thuan, Seitzer, Knapp (21-cm dwarf surveys) 31 = South Africa - SAAO -- Fairall 32 = Arecibo - Sullivan, Bothun, Schommer 33 = H.J. Rood - NSSDC Catalog 34 = Ohio + Penn State 35 = Other Optical (eg.Calar Alto, Wise, Tartu) % LaPalma 36 = Las Campanas (100", 40"),Other Southern 37 = Palumbo, et al. (Catalogue of Redshifts) 38 = ESO-21cm Catalog 39 = Brazil - Southern Survey, L. daCosta 40 = MIT-Dartmouth-Michigan Surveys (McGraw Hill) 41 = Hawaii - CFHT, etc. 42 = Dartmouth - Century Survey 43 = Davis and Strauss IRAS Sources (Published) 44 = Hewitt and Burbidge QSO Catalog 45 = Keck 46 = Redshiftless entries (discoveries, companions...) 47 = QDOT survey references 48 = Master file data 49 = Bothun, Moulf, published velocities; priv. comm. -9 = SAAO, Menzies; Fairall, Vettolani and DaCosta -8 = Dartmouth, not yet published -7 = CFA, not yet published (Kirshner) -6 = Brazil (L. daCosta) not yet published -5 = Davis and Strauss (IRAS Sources) -4 = Bothun, Mould not yet published (Palomar, Arecibo) -3 = CFA, not yet published (Forman and Jones) -2 = CFA, not yet published MMT Observations (JPH) -1 = CFA, not yet published Tillnghast Observations (JPH)
Morphological types are de Vaucouleurs' T types from the RC2, Uppsala Catalog, and the Revised Shapley-Ames Catalog. Some additional types have been defined for peculiar and untyped objects, and for objects that are in catalogs of extragalactic objects but are really galactic in nature. Such objects were retained to prevent their inclusion in future lists of galaxies; however, users should filter out objects of morph_type greater than 20 before using this catalog as a simple catalog of galaxies in order to avoid getting HII regions in M101, stars, plate flaws, and assorted galactic items. Types for southern galaxies come from both the ESO catalog and the Vorontsov-Velyaminov Catalogues. The morphological type has been used to create the HEASARC Browse class parameter. The rubric for these types is:
-9 = QSO/AGN, usually at high redshift -7 = Unclassified Elliptical -6 = Compact Elliptical -5 = E, and dwarf E -4 = E/SO -3 = L-, SO- -2 = L, SO -1 = L+, SO+ 0 = SO/a, SO-a 1 = Sa 2 = Sab 3 = Sb 4 = Sbc 5 = Sc 6 = Scd 7 = Sd 8 = Sdm 9 = Sm, Magellanic Spiral 10 = Im, Irr I, Magellanic Irregular, Dwarf Irregular 11 = Compact Irregular, Extragalactic HII Region 15 = Peculiar, Unclassifiable 16 = Irr II 20 = S..., Sc-Irr, Unclassified Spiral 24 = Open Star Cluster 25 = Plate Flaw, Star, etc. misclassified as galaxy! 26 = T Tauri star (from IRAS Surveys) 27 = Globular Cluster 30 = Planetary Nebula 31 = Dark Cloud (no object visible on POSS) 32 = HII region in external galaxy 33 = Reflection Nebulosity 40 = Indiv. Comp. of Multiple Nucleus Galaxy
The bar type: possible values are 'B' (barred), 'A' (unbarred), and 'X' (for AB or mixed type). The bar type information is also included in the HEASARC Browse class parameter.
The luminosity class (L) for spiral and irregular galaxies according to the following rubric:
1 I 6 III-IV 2 I-II 7 IV 3 II 8 IV-V 4 II-III 9 V 5 III
A parameter giving additional information about peculiarities in the structure, coded as follows:
P = Peculiar S = S-shaped R = Outer ring I = Inner ring M = Mixed (Inner ring/S-shaped) T = Pseudo outer ring D = Double or Multiple Q = SpindleNote that, to avoid mixing upper and lower cases, the HEASARC has changed some of these codes from the original CDS table: values of 'r' were changed to 'I', 's' to 'S', 't' to 'M', and '/' to 'Q'.
The major diameter of the galaxy, in arc minutes, from the blue Palomar Sky Survey or the ESO quick blue survey a la Nilson, ESO, VV, or the RC2.
The minor diameter of the galaxy, in arc minutes, from the blue Palomar Sky Survey or the ESO quick blue survey a la Nilson, ESO, VV, or the RC2.
The B_T magnitude, when available. These are generally about 0.4 magnitudes brighter than magnitudes on the B(0) - Zw system.
The identification number from either the UGC (CDS Cat. VII/26) or the ESO/Upp (CDS Cat. VII/34) catalogs.
Distance in Mpc from velocity-independent distance measures. These numbers are somewhat(!) uncertain, so that the catalog is not complete and may be out of date at any time, according to the catalog authors.
The RFN parameter contains the file number of the spectrum obtained by Huchra et al. for that galaxy. If this parameter is blank, then the galaxy has not yet been measured by Huchra et al.
Most often, the `comments` field contains other names and/or other catalog designations for the object, but it may also contain some general comments, such as "poor velocity," when applicable.
The Browse classification flag for the object. It includes the morphological type and bar type as applicable.