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VII/155     Third Reference Cat. of Bright Galaxies (RC3) (de Vaucouleurs+ 1991)
================================================================================
Third Reference Catalogue of Bright Galaxies (RC3)
     de Vaucouleurs G., de Vaucouleurs A., Corwin Jr. H.G., Buta R.J.,
     Paturel G., Fouque P.
    <Springer-Verlag: New York, (1991)>
================================================================================
ADC_Keywords: Galaxy catalogs 

Description:
     The University of Texas has revised its third edition of its
     catalogue of bright galaxies. This not only contains many more
     entries than the second edition (23,022) but substantially more
     information for each entry.

Introduction:
     The original Harvard Survey of the External Galaxies brighter
     than the 13th magnitude, by H. Shapley and A. Ames (1932),
     included just 1,249 objects (of which five were not galaxies),
     with estimated photographic magnitudes and diameters from
     heterogeneous sources.

     The first Reference Catalogue of Bright Galaxies (RC1) (G. and
     A. de Vaucouleurs 1964), prepared between 1949 and 1963, included
     2,599 objects (six are not galaxies), over twice the number in
     the original Shapley-Ames catalogue. In addition to diameters,
     magnitudes, colors, and redshifts in relatively homogeneous
     systems, it gave revised classifications and detailed literature
     references from 1913 to 1963. (NGC 8 is a double star; NGC 4361
     is a planetary nebula; NGC 5396 is nonexistent, probably = NGC
     5375; IC 1308 is a H II region in NGC 6822; IC 3917 is
     nonexistent, probably a plate defect (M. Wolf 1905); and A2144 =
     Palomar 12 is a globular cluster.)

     The Second Reference Catalogue (RC2) (G. and A. de Vaucouleurs,
     and H. G. Corwin 1976), prepared between 1971 and 1975, included
     4,364 objects (two are not galaxies), for which it gave improved
     isophotal diameters and axis ratios in the D25 system, newly
     determined total magnitudes and colors in the UBV system,
     continuum and 21-cm radio magnitudes, HI index, and redshifts, as
     well as references to published photographs and a bibliography
     for the years 1964 to 1975. Both the First and Second Reference
     Catalogues are limited to galaxies with useful literature
     references and are incomplete beyond the Shapley-Ames limit.
     (A0733+02 = DDO 45 is a planetary nebula; A2143-21 = Palomar 12
     is a globular cluster.)

     The present, much enlarged Third Reference Catalogue of Bright
     Galaxies (RC3) attempts to be reasonably complete for galaxies
     having apparent diameters larger than 1 arcmin at the D25
     isophotal level and total B-band magnitudes BT brighter than
     about 15.5, with a redshift not in excess of 15,000 km/s. Objects
     of special interest, such as compact galaxies smaller than 1
     arcmin or fainter than magnitude 15.5, and those already in RC2,
     are also included. The number of RC3 objects meeting these
     conditions is 11,897. Additional objects meeting only the
     diameter or the magnitude condition, and objects of interest
     smaller than 1.00, fainter than 15.5, or with redshifts > 15,000
     km/s, bring the total to 23,022. (PGC 41636 and P65386 have been
     deleted since the catalogue was printed. The first is a globular
     cluster, Palomar 15, and the second is a duplicate entry for NGC
     6967.) These were extracted from the database of 73,197 galaxies
     maintained by G. Paturel at Lyons Observatory (Paturel et al.
     1989a,b). Data published prior to mid-1990 are included in the
     main RC3 table and appendices.

     As might be expected in a compilation of this size, a number of
     errors have been detected since this catalog was archived. These
     have been corrected by H. G. Corwin who submitted the current,
     corrected version. Any problems relating to the catalogue itself
     should be addressed to him:
           Dr. Harold G. Corwin, Jr.
           IPAC, M/S 100-22
           California Institute of Technology
           Pasadena, CA 91125

     Details of the reduction procedures, and Notes, References, and
     Appendices are in Volume 1 of the printed version of RC3,
     available from Springer-Verlag New York. Volumes 2 and 3
     (included in this distribution) are also be available from
     Springer-Verlag should you wish to have a printed and bound
     version of the complete catalogue. The user of this catalogue is
     referred to this source volume for notes, references to data on
     individual galaxies, and the important information contained in
     the appendices as well as a discussion of how the entries were
     derived.

     We ask that you acknowledge RC3 and its authors in any
     publication that results from your use of the Catalogue. You may
     also freely distribute unaltered electromagnetic copies of RC3 to
     friends and colleagues as long as a copy of this documentation -
     including this notice - accompanies the Catalogue. The printed
     version of RC3 is protected by copyright, and may not be
     reproduced in any manner without the written permission of the
     copyright holder, Springer-Verlag New York, Inc.

File Summary:
--------------------------------------------------------------------------------
 FileName       Lrecl       Records      Explanations
--------------------------------------------------------------------------------
ReadMe             80             .      This file
rc3.dat           363         23011      The revised RC3 catalog
--------------------------------------------------------------------------------

See also:
   VII/112 : RC2 Catalogue
   VII/119 : PGC Catalogue (Paturel et al., =1989A&AS...80..299P)
   J/AJ/108/2128 : RC3 corrections & additions

Byte-by-byte Description of file: rc3.dat
--------------------------------------------------------------------------------
   Bytes  Format   Units       Label      Explanations
--------------------------------------------------------------------------------
   1-  2   I2      h           RAh       *Right Ascension 2000 (hours)
   3-  4   I2      min         RAm       *Right Ascension 2000 (minutes)
   5-  8   F4.1    s           RAs       *Right Ascension 2000 (sec. or min.)
      10   A1      ---         DE-        [-+] Sign of declination
  11- 12   I2      deg         DEd       *Declination 2000 (degrees)
  13- 14   I2      arcmin      DEm       *Declination 2000 (minutes)
  15- 16   I2      arcsec      DEs       *? Declination 2000 (seconds)
  18- 19   I2      h           RAh1950    Right Ascension 1950 (hours)
  20- 21   I2      min         RAm1950    Right Ascension 1950 (minutes)
  22- 25   F4.1    s           RAs1950   *Right Ascension 1950 (sec. or min.)
      27   A1      ---         DE-1950    [-+] Sign of declination 1950
  28- 29   I2      deg         DEd1950    Declination 1950 (degrees)
  30- 31   I2      arcmin      DEm1950    Declination 1950 (minutes)
  32- 33   I2      arcsec      DEs1950   *? Declination 1950 (seconds)
  35- 40   F6.2    deg         GLON      *Galactic longitude
  42- 47   F6.2    deg         GLAT      *Galactic latitude
  49- 54   F6.2    deg         SGLON      Supergalactic longitude on RC2 sys.
  56- 61   F6.2    deg         SGLAT      Supergalactic latitude on RC2 sys.
  63- 74   A12     ---         name      *Name
  75- 89   A15     ---         altname   *Alternate name
  91-104   A14     ---         desig      Other designation
 106-116   A11     ---         PGC       *PGC number
 118-124   A7      ---         type      *Type
 126-130   A5      ---         typesr    *Source of revised type
 132-135   F4.1    ---         T         *? T (Hubble stage)
 137-139   F3.1    ---         e_T        ? Mean error of T
 141-144   F4.1    ---         lumcl      ? Luminosity class(Section 3.3.d,p18)
 146-148   F3.1    ---         e_lumcl    ? Mean error on luminosity class
     150   I1      ---         o_lumcl    ? Num. of luminosity class estimates
 152-155   F4.2    0.1arcmin   d25       *? Log D25
     156   A1      ---         u_d25      [?]? indicates Log D25 very uncer.
 158-160   F3.2    0.1arcmin   e_d25     *? Mean error on log D25
 162-165   F4.2    ---         R25       *? Log R25 (isophotal diameter ratio)
     166   A1      ---         u_R25      [?]? indicates Log R25 very uncertain
 168-170   F3.2    ---         e_R25     *? Mean error on log R25
 172-175   F4.2    0.1arcmin   Do        *? Log Do
 177-180   F4.2    0.1arcmin   Ae        *? Log Ae (effective aperture)
 182-184   F3.2    0.1arcmin   e_Ae       ? Mean error on log Ae
 186-188   I3      deg         PA        *? Position angle of the major axis
 190-194   F5.2    mag         BT        *? BT (total B magnitude)
     195   A1      ---         BT_code   *? BT code
 197-199   F3.2    mag         e_BT       ? Mean error on BT
 201-205   F5.2    mag         Bmag      *? mB (photographic magnitude)
 207-209   F3.2    mag         e_Bmag    *? Mean error on Bmag
 211-215   F5.2    mag         BoT       *? BoT
 217-221   F5.2    mag/arcmin2 m'25      *? m'25
 223-226   F4.2    mag/arcmin2 e_m'25     ? Mean error m'25
 228-232   F5.2    mag/arcmin2 m'e       *? m'e
 234-236   F3.2    mag/arcmin2 e_m'e      ? Mean error m'e
 238-242   F5.2    mag         mFIR      *? mFIR
 244-248   F5.2    mag         m21       *? m21
 250-251   F2.1    mag         e_m21      ? Mean error on m21
 253-256   F4.2    mag         B-VT      *? (B-V)T (total (B-V))
 258-260   F3.2    mag         e_B-VT     ? Mean error on (B-V)T
 262-265   F4.2    mag         B-Ve      *? (B-V)e (mean B-V within Ae)
 267-269   F3.2    mag         e_B-Ve     ? Mean error on (B-V)e
 271-274   F4.2    mag         B-VoT     *? (B-V)oT
 276-280   F5.2    mag         U-BT      *? (U-B)T (total (U-B))
 282-284   F3.2    mag         e_U-BT     ? Mean error on (U-B)T
 286-289   F4.2    mag         U-Be      *? (U-B)e
 291-293   F3.2    mag         e_U-Be     ? Mean error on (U-B)e
 295-298   F4.2    mag         U-BoT     *? (U-B)To
 300-304   F5.2    mag         HI        *? HI (neutral hydrogen index)
 306-309   F4.2    mag         Ai        *? Ai (internal B extinction)
 311-313   F3.2    mag         A21       *? A21 (HI self absorption)
 315-318   F4.2    mag         Ag        *? Ag (galactic extinction in B)
 320-322   I3      km/s        W20       *? W20
 324-325   I2      km/s        e_W20      ? Mean error on W20
 327-329   I3      km/s        W50       *? W50
 331-332   I2      km/s        e_W50      ? Mean error of W50
 334-338   I5      km/s        V21       *? V21 (heliocentric radial velocity)
 340-341   I2      km/s        e_V21      ? Mean error on V21
 343-347   I5      km/s        cz        *? Vopt= cz
 349-351   I3      km/s        e_cz       ? Mean error on Vopt
 353-357   I5      km/s        VGSR      *? VGSR
 359-363   I5      km/s        V3K       *? V3K
--------------------------------------------------------------------------------
Note on RAh, RAm, RAs, DEd, DEm, DEs, RAs1950 and DEs1950:
   The right ascensions and declinations for the equinox 2000.0, are
   precessed from the 1950.0 position using the 1976 IAU constants
   (see, e.g., the Supplement to The Astronomical Almanac for 1984).
   These are given to 0.1 second of time and 1 arcsec when available,
   and to 0.1 minute of time and 1 arcmin otherwise (Section 3.1.a,
   page 11).
   The right ascensions originally given with an accuracy of 0.1min
   have been converted to seconds; such converted RAs and RAs1950
   values have no decimal, and the corresponding DEs and DEs1950
   are blank.
Note on GLON and GLAT:
   The galactic coordinates given to 0.01, are calculated following
   the IAU 1958 prescription (Blaauw et al. 1960) with the North
   Galactic Pole at alpha = 12h49m , delta = +27 24 (1950), and the
   origin at alpha = 17h 42.4m, delta = -28 55 (1950).
Note on name:
   Names (e.g., LMC, SMC) or NGC and IC designations.
Note on altname:
   UGC (Nilson 1973), ESO (Lauberts 1982), MCG (Vorontsov-Velyaminov
   et al. 1962-1974), UGCA (Nilson 1974), and CGCG (Zwicky et al.
   1961-1968) designations, given in that order of preference. MCG
   designations not listed here are given in UGC and ESO.
Note on PGC:
   PGC (Paturel et al. 1989a,b) designation. For cross identifications
   of various catalogues with the PGC, see Appendix 10, page 561.
Note on type:
   Mean revised morphological type in the RC2 system, coded as in RC2
   (Section 3.3.a, page 13).
Note on typesr:
   "V" indicates a classification by de Vaucouleurs; "4" indicates a
   ring galaxy classified by Buta on 4-meter plates.
Note on T:
   Mean numerical index of stage along the Hubble sequence in RC2
   system (coded as explained in Section 3.3.c, page 16).
Note on d25:
   Mean decimal logarithm of the apparent major isophotal diameter
   measured at or reduced to surface brightness level muB = 25.0 B/mag2,
   as explained in Section 3.4.a, page 21. The unit of D is 0.1
   arcmin to avoid negative entries.
Note on e_d25:
   A "?" indicates a large, uncertain error.
Note on R25:
   Mean decimal logarithm of the ratio of the major isophotal
   diameter, D25, to the minor isophotal diameter, d25, measured at or
   reduced to the surface brightness level muB = 25.0 B/mag2, and its
   mean error as explained in Section 3.4.b, page 26.
Note on e_R25:
   A "?" indicates a large, uncertain error.
Note on Ae:
   Decimal logarithm of the apparent diameter (in 0.1 arcmin) of the
   "effective aperture," the circle centered on the nucleus within
   which one-half of the total B-band flux is emitted, derived as
   explained in Section 3.4.c, page 28.
Note on Do:
   Decimal logarithm of the isophotal major diameter corrected to
   "face-on" (i = 0), and corrected for galactic extinction to Ag = 0,
   but not for redshift, as explained in Section 3.4.d, page 29.
Note on PA:
   Position angle, measured in degrees from north through east (all
   <180), taken when available from UGC, ESO, and ESGC (and in a few
   cases from H I data) (Section 3.5.a, page 30).
Note on Ag:
   Galactic extinction in B-band magnitudes, calculated following
   Burstein and Heiles (1978a,b, 1982, 1984) as explained in Section
   3.5.b, page 30.
Note on Ai:
   Internal extinction in B-band magnitudes (for correction to
   face-on), calculated from log R and T as explained in Section
   3.5.c, page 31.
Note on A21:
   A21 = H I line self-absorption in magnitudes (for correction to
   face-on), calculated from log R and T greater or equal to 1 as
   explained in Section 3.5.d, page 32.
Note on BT:
   BT = total (asymptotic) magnitude in the B system derived by
   extrapolation from photoelectric aperture- magnitude data, BAT, and
   from surface photometry with photoelectric zero point, BSTas
   explained in Section 3.6.a, page 32.
Note on BT_code:
     "M" = BT is the weighted mean of BAT and BST,
     "S" = only surface photometry used
     "V" = BT is a V-band magnitude rather than a B-band magnitude
     "v" = the nucleus of the galaxy is variable.
     "*" indicates that deriving BAT would have required an
         extrapolation in excess of 0.75 mag.
Note on Bmag and e_Bmag:
   Photographic magnitude and its mean error from Ames (1930), Shapley
   and Ames (1932), CGCG, Buta and Corwin (1986), and/or Lauberts and
   Valentijn (1989) reduced to the BT system as explained in Section
   3.6.b, page 37.
Note on mFIR:
   Calculated from mFIR = -20.0 - 2.5 logFIR, where FIR is the far
   infrared continuum flux measured at 60 and 100 microns as listed in
   the IRAS Point Source Catalog (1987) <II/125>. For galaxies larger
    than 80 in RC2 and for the Virgo cluster area, resolved by the IRAS
    beam, integrated fluxes are taken from Rice et al.(1988) or Helou et
    al.(1988). See Section 3.6.c, page 43, for details.
Note on BoT:
   Total "face-on" magnitude corrected for galactic and internal
   extinction, and for redshift as explained in Section 3.6.d, page
   44.
Note on B-VT and U-BT:
   Total (asymptotic) color index in the Johnson B-V and U-B system,
   respectively, derived by extrapolation from photoelectric
   color-aperture data, and/or from surface photometry with a
   photoelectric zero point as explained in Section 3.7.a, page 45.
Note on B-VoT and U-BoT:
   Total B-V and U-B color indices, respectively, corrected for
   galactic and internal extinction, and for redshift, as explained in
   Section 3.7.b, page 47.
Note on B-Ve and U-Be:
   Mean B-V and U-B color indices, respectively, within the effective
   aperture Ae, derived by interpolation from photoelectric
   color-aperture data as explained in Section 3.7.a, page 45.
Note on m'e:
   Mean B-band surface brightness in magnitudes per square arcmin
   (B-m/sm) within the effective aperture Ae, and its mean error,
   calculated by the relation m'e= BT + 0.75 + 5 logAe- 5.26. This m'e
   is statistically related to the effective mean surface brightness,
   mu'e (RC2, p. 31; Olson and de Vaucouleurs 1981), with which it
   coincides when log R = 0 (i = 0) (Section 3.8.a, page 49).
Note on m'25:
   The mean surface brightness in magnitudes per square arcmin
   (B-m/sm) within the muB = 25.0 B-m/ss elliptical isophote of major
   axis log D25 and axis ratio log R25, defined as in RC2 (Equation
   21) by:
         m'25= BT +  delta(m25) + 5 logD25- 2.5 logR25- 5.26,
   where delta(m25) = 2.5 log LT/L25 = B25 - BT and is the magnitude
   increment contributed by the outer regions of a galaxy fainter than
   muB = 25.0B-m/ss and, its mean error. For details, see Section
   3.8.b, page 50.
Note on m21:
   21-cm emission line magnitude defined by m21 = 21.6 - 2.5 log SH ,
   where SH is the measured neutral hydrogen flux density in units of
   10-24W/m2. For details, see Section 3.9.a, page 51.
Note on W20 and W50:
   Neutral hydrogen line full width (in km/s) measured at the 20%
   level (I20/Imax) and the 50% level (I50/Imax), respectively, as
   explained in Section 3.9.b, page 51.
Note on HI:
   Corrected neutral hydrogen index, which is the difference
   mo21-BoT between the corrected (face-on) 21-cm emission line
   magnitude and the similarly corrected magnitude in the BT system.
   Details are given in Section 3.9.c, page 52. Since m21 and BT are
   listed separately in columns 6 and 9, record 1, there is no need to
   print the uncorrected index.
Note on V21:
   The mean heliocentric radial velocity derived from neutral hydrogen
   observations, as explained in Section 3.10.a, page 52.
Note on cz:
   The mean heliocentric radial velocity, derived from optical
   observations, as explained in Section 3.10.b, page 53.
Note on VGSR:
   The weighted mean of the neutral hydrogen and optical velocities,
   corrected to the "Galactic standard of rest", as explained in
   Section 3.10.c, page 54.
Note on V3K:
   The weighted mean velocity corrected to the reference frame defined
   by the 3K microwave background radiation, as explained in Section
   3.10.d, page 55.

NOTE: The references with many of the descriptions are to the page
      numbers in Volume 1 of the printed catalogue.

Construction of the current version of the RC3:
   The RC3 was received electronically from Dr. Harold Corwin. It was
   transferred to a Dec-alpha work station for examination and then to
   a Cray computer for processing and archiving. Dr. Corwin also
   provided the introduction to the catalogue in LaTeX for the
   original version of the Third Reference Catalog. This introduction
   has been modified for the present document.

   Several changes were made in the catalogue. The printed version
   contained plus/minus signs. Since the eighth bit, which
   distinguishes special characters, tends to be dropped when the file
   is transferred electronically, these have all been removed; the
   meaning is obvious. The original version of the catalog contained
   four records for each galaxy. Those values in the same columns were
   often related. The catalog has been reformatted into a single
   record per galaxy and the order of the data has been changed to
   keep related information contiguous. Extra blank columns which
   resulted from the original structure have been removed, keeping a
   single blank between adjacent columns.

Acknowlegements:
   We sincerely thank Dr. Harold Corwin for sending us the RC3 and the
   LaTeX version of the introduction. We also thank him for extensive
   advise during the production of the original document and for a
   careful reading of this final product. We thank Dr. Francois Ochsenbein
   for help in formatting this document.

Historical Notes:
  * 16-Feb-1995: Documentation done by Nancy G. Roman [SSDOO/ADC]
  * 28-Oct-1995: the values of RA (1950 and 2000) originally reported with
    a 0.1 min were converted to seconds at CDS
    (see notes above on RAs and RAs1950)
================================================================================
(End)   Nancy G. Roman [SSDOO/ADC], Francois Ochsenbein [CDS]        16-Feb-1995

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