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J/A+A/297/61        E+A galaxies in Cl0939+472                  (Belloni+, 1995)
Detectability and incidence of E+A galaxies in the distant cluster
Cl0939+472 (z=0.41)
       BELLONI P., BRUZUAL A.G., THIMM G.J.,ROESER H.-J.
      <Astron. Astrophys. 297, 61 (1995)>
      =1995A&A...297...61B      (SIMBAD/NED Reference)
ADC_Keywords: Clusters, galaxy; Photometry

Keywords: distant clusters - galaxies: evolution - galaxies: photometry


Description:
   We present results of a study of E+A galaxies in the cluster  Cl0939+472
   (z=0.41). We have used a series of narrow-band filters (FWHM~=90-200A)
   covering the range from 3800 to 9200A, and broad band B, R, I filters
   to obtain low resolution spectra for all galaxies brighter than R=22.5mag
   in a 5'x5' cluster field. Two of the narrow-band filters have been chosen
   to measure the 4000A-break index, and 3 filters were centered on the
   Hβ, Hγ and Hδ lines which are indicators of
   recent star formation.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table8            87       35   E+A galaxies in Cl0939+472
table9            44       68   Redshifts and morphological type for all
                                  objects that could be identified in
                                  Dressler A., 1992, STScI Newsletter 9, 2.


Table 7: Discrimination among morphological types for Cl0939+472 members for
         objects with mR=<22.5
   --------------------------------------------------------------------------
   Spectral type   DG92  This work    <B-R>        <B-I>          <D4000>
   --------------------------------------------------------------------------
   Elliptical      22     110       2.40±0.17    3.55±0.26     2.21±0.35
   E+A              6      31       2.03±0.17    3.01±0.32     1.81±0.23
   Spiral & Im      2      24       1.37±0.34    2.11±0.34     1.30±0.22
   --------------------------------------------------------------------------

Byte-by-byte Description of file: table8

   Bytes Format  Units   Label      Explanations

   2-  4  I3     ---     ID         Identification number
   6- 12  F7.2   arcsec  xpos       x position (1)
  14- 20  F7.2   arcsec  ypos       y position (1)
  22- 26  F5.2   mag     Rmag       R magnitude
  28- 32  F5.3   mag     B-R        B-R colour
  36- 39  F4.2   mag     B-I        B-I colour
  44- 47  F4.2   ---     D4000      D4000 index (4000 A-break) (2)
  49- 53  F5.3   ---     zD         []? Redshift for DG
  55- 60  F6.4   ---     z          Redshifth derived from this work
  66- 71  F6.4   ---     e_z        1-sigma error on z
  73- 76  F4.2   Myr     Age        Galaxy age after the beginning of the second
                                     starburst
  81- 87  A7     ---    MType(HST)  Morphology type derived from
                                      Hubble Space Telescope (HST)

Note (1): x and y positions relative to the galaxy 259 in DG

Note (2): D4000 = 1.162xFλ(5770/120)/Fλ(5430/130)
           where Fλ(5770/120) is the filter for which the ratio
           represent the mean wavelength of filter passband/FWHM of filter


Byte-by-byte Description of file: table9

   Bytes Format  Units   Label      Explanations

   2-  4  I3     ---     ID         Identification number
   8- 12  F5.3   ---     zD         []? Redshift derived from DG
  16- 20  F5.3   ---     z          Redshift derived from this work
  22- 26  F5.3   ---     e_z        1-sigma error on z
  28- 32  A5     ---    MType(SED)  Morphology type derived from
                                     spectral energy distribution (SED)
  34- 39  A6     ---    MType(HST)  Morphology type derived from
                                     Hubble Space Telescope (HST)


References:
  DG : Dressler A. & Gunn J., 1992, ApJS 78, 1
(End)                                           Patricia Bauer [CDS] 08-Nov-1994