J/A+A/463/503       Early-type dwarf galaxies in Fornax cluster  (Mieske+, 2007)
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The early-type dwarf galaxy population in the Fornax cluster.
    Mieske S., Hilker M., Infante L., Mendes de Oliveira C.
   <Astron. Astrophys. 463, 503 (2007)>
   =2007A&A...463..503M
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ADC_Keywords: Galaxies, photometry ; Photometry, CCD ; Photometry, surface
Keywords: galaxies: clusters: individual: Fornax cluster - galaxies: dwarf -
          galaxies: fundamental parameters - techniques: photometric -
          galaxies: luminosity function, mass function

Abstract:
    We analyse the photometric properties of the early-type Fornax cluster
    dwarf galaxy population, based on a wide field imaging study of the
    central cluster area in V and I. We used the instrument/telescope
    combination IMACS/Magellan at Las Campanas Observatory.
    We create a fiducial sample of Fornax cluster dwarf ellipticals (dEs)
    in the following three steps: (1) To verify cluster membership, we
    measured I-band surface brightness fluctuation (SBF) distances to
    candidate dEs; (2) We re-assessed morphological classifications for
    candidate dEs too faint for SBF detection; and (3) We searched for new
    candidate dEs in the size-luminosity regime close to the resolution
    limit of previous surveys.

    (1) We confirm cluster membership for 28 candidate dEs in the range
    -16.6<M_V_<-10.1mag by means of SBF distances. We find no SBF
    background galaxy. (2) Of 51 further candidate dEs in the range
    -13.2<M_V_<-8.6mag, 2/3 are confirmed as probable cluster members by
    morphological re-assessment, while 1/3 are re-classified as probable
    background objects. (3) We find 12 new dE candidates in the range
    -12.3<M_V_<-8.8mag. The surface brightness-magnitude relation defined
    by the resulting fiducial dE sample shows that Fornax dEs are about
    40% larger than Local Group dEs. The Fornax dE sample furthermore
    defines a colour-magnitude relation that appears slightly shallower
    than that of Local Group dEs. The early-type dwarf galaxy luminosity
    function in Fornax has a faint end slope alpha=-1.1+/- 0.1.

Description:
    Total V-band magnitude, central V-band surface brightness, and V-I
    colour is presented for a sample of 100 dwarf elliptical galaxy
    candidates in the central Fornax cluster. We also give the cluster
    membership flag assigned to each galaxy, based upon distance
    measurements obtained with the SBF method and on morphological
    assessment. For most of the sources, the photometric parameters are
    derived from imaging with the IMACS instrument at the Magellan
    telescope on Las Campanas Observatory. For some fainter sources the
    photometric parameters were derived from imaging with the WFCCD camera
    at the 2.5m du Pont telescope on Las Campanas Observatory. Those
    sources are specifically indicated in the comments column of the
    table.

File Summary:
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 FileName   Lrecl  Records   Explanations
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ReadMe         80        .   This file
table1.dat    108      100   Photometric parameters for 100 dwarf galaxy
                              candidates in the Fornax cluster
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See also:
    VII/180 : Galaxies in Fornax Cluster and five nearby groups (Ferguson+ 1990)
 J/A+AS/134/59 : The central Fornax Cluster. I. Galaxy photometry (Hilker+ 1999)

Byte-by-byte Description of file: table1.dat
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   Bytes Format Units        Label   Explanations
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   1- 12  A12   ---          Name    Galaxy Name (1)
  14- 16  F3.1  ---          Memb    Membership flag (2)
  19- 23  F5.2  mag          Vmag    Apparent V-band magnitude
  27- 30  F4.2  mag        e_Vmag    Error of V-band magnitude
  34- 38  F5.2 mag/arcsec2   SuBrV   Central surface brightness in V-band
  42- 45  F4.2 mag/arcsec2 e_SuBrV   Error of central surface brightness
  48- 53  F6.3  mag          V-I     V-I colour index
  57- 61  F5.3  mag        e_V-I     Error of V-I colour index
  65- 66  I2    h            RAh     Right Ascension J2000 (hours)
  68- 69  I2    min          RAm     Right Ascension J2000 (minutes)
  71- 75  F5.2  s            RAs     Right Ascension J2000 (seconds)
      79  A1    ---          DE-     Declination J2000 (sign)
  80- 81  I2    deg          DEd     Declination J2000 (degrees)
  83- 84  I2    arcmin       DEm     Declination J2000 (minutes)
  86- 90  F5.2  arcsec       DEs     Declination J2000 (seconds)
  94-108  A15   ---          Notes   Special notes for some galaxies (3)
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Note (1): Three different namings:
     FCC xxx refers to sources already included in the Fornax Cluster
         Catalog (Ferguson et al., 1990, Cat. <VII/180>)
     WFLSBxxxx refers to sources detected in our WFCCD imaging campaign
         (Hilker et al., 2003A&A...397L...9H)
     IMxxxxxxxxxx refers to sources detected only in our IMACS imaging
         campaign
Note (2): Membership flags are as follows:
      1 = Membership confirmed by SBF distance measurement
      2 = Probable member based on morphological assessment
      3 = Probable background based on morphological assessment
      4 = Unclear classification
      Non-integer numbers denote intermediate classifications
Note (3): Explanation of the different symbols:
      * = Photometry is derived from WFCCD images
          (Hilker et al., 2003A&A...397L...9H)
     ** = Candidate was not imaged in the WFCCD data but is listed in
          the FCC as likely members. The FCC number is also given.
    *** = Listed in the FCC as likely background member and as GCF_1-44
          in Hilker et al. (1999, Cat. <J/A+AS/134/59>).
          The FCC number is also given.
      + = Candidate was detected in the IMACS imaging by visual inspection,
          not by SExtractor.
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Acknowledgements:
    Steffen Mieske, smieske(at)eso.org
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(End)     Steffen Mieske [ESO, Germany], Patricia Vannier [CDS]      15-Dec-2006