J/ApJ/723/251    Keck/LRIS confirmation of Coma membership    (Chiboucas+, 2010)
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Keck/LRIS spectroscopic confirmation of Coma cluster dwarf galaxy membership
assignments.
    Chiboucas K., Tully R.B., Marzke R.O., Trentham N., Ferguson H.C.,
    Hammer D., Carter D., Khosroshahi H.
   <Astrophys. J., 723, 251-266 (2010)>
   =2010ApJ...723..251C
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ADC_Keywords: Clusters, galaxy ; Galaxies, photometry ; Photometry, HST ;
              Redshifts ; Spectroscopy ; Morphology
Keywords: galaxies: clusters: individual (Coma) - galaxies: dwarf

Abstract:
    Keck/LRIS multi-object spectroscopy has been carried out on 140 of
    some of the lowest and highest surface brightness faint (19<R<22)
    dwarf galaxy candidates in the core region of the Coma Cluster. These
    spectra are used to measure redshifts and establish membership for
    these faint dwarf populations. The primary goal of the low surface
    brightness sample is to test our ability to use morphological and
    surface brightness criteria to distinguish between Coma Cluster
    members and background galaxies using high resolution Hubble Space
    Telescope/Advanced Camera for Surveys images. Candidates were rated as
    expected members, uncertain, or expected background. From 93 spectra,
    51 dwarf galaxy members and 20 background galaxies are identified. Our
    morphological membership estimation success rate is ~100% for objects
    expected to be members and better than ~90% for galaxies expected to
    be in the background. We confirm that low surface brightness is a very
    good indicator of cluster membership. High surface brightness galaxies
    are almost always background with confusion arising only from the
    cases of the rare compact elliptical (cE) galaxies. The more
    problematic cases occur at intermediate surface brightness. Many of
    these galaxies are given uncertain membership ratings, and these were
    found to be members about half of the time. In a sample of 47 high
    surface brightness, ultracompact dwarf candidates, 19 objects have
    redshifts which place them in the Coma Cluster, while another 6 have
    questionable redshift measurements but may also prove to be members.

Description:
    We use the Keck LRIS low resolution imaging spectrometer in
    multi-object spectroscopy mode. A dichroic was used to split light at
    5600{AA} between red and blue detectors. We observed four masks over
    two nights 2008 April 2 and 3 (resolution of ~200km/s).

    This work is part of the Hubble Space Telescope/Advanced Camera for
    Surveys (HST/ACS) Coma Cluster Treasury Survey (Carter et al.
    2008ApJS..176..424C), a two-passband imaging survey originally
    designed to cover 740arcmin^2^ in the Coma Cluster to a depth of
    I_C_~26.6 for point sources and {mu}_e,I_<26.0mag/arcsec^2^ for
    extended sources. Over 200arcmin^2^ have been completed.

File Summary:
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 FileName   Lrecl  Records   Explanations
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ReadMe         80        .   This file
table2.dat    120      101   LRIS (membership test sample) redshift results
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See also:
  VII/42 : GMP catalogue: galaxies in the Coma cluster (Godwin+ 1983)
  J/MNRAS/411/2439  : Coma Treasury Survey. Structural parameters (Hoyos+, 2011)
  J/MNRAS/404/1745  : Dwarf galaxies in Coma supercluster (Mahajan+, 2010)
  J/MNRAS/392/1265  : Faint galaxies in Coma cluster spectroscopy (Smith+, 2009)
  J/ApJS/175/462    : Spectroscopy of Coma early-type galaxies (Corsini+, 2008)
  J/ApJS/169/225    : Photometry in the Coma cluster (Eisenhardt+, 2007)
  J/A+A/451/1159    : BVRI imaging of the Coma cluster (Adami+, 2006)
  J/A+A/459/679     : RB photometry of LSBG in Coma (Adami+, 2006)
  J/ApJ/602/664     : Morphology of galaxies in Coma cluster (Gutierrez+, 2004)
  J/A+A/395/753     : Spectroscopy of Coma galaxies. II. (Wegner+, 2002)
  J/AJ/121/2331     : SDSS redshifts in the Coma cluster (Castander+, 2001)
  J/ApJS/137/279    : Spectroscopic Survey in Coma (Mobasher+, 2001)
  J/A+A/296/643     : LSB galaxies in Coma (Karachentsev+ 1995)
  J/A+AS/111/265    : Velocities in Coma cluster (Biviano+ 1995)
  J/ApJS/97/77      : Catalog of Coma Cluster Galaxies (Doi+ 1995)
  J/MNRAS/243/390   : Galaxy redshift survey in a Coma (Karachentsev+ 1990)
  http://astronomy.swin.edu.au/coma : Coma Cluster Treasury Survey homepage

Byte-by-byte Description of file: table2.dat
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   Bytes Format Units     Label   Explanations
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   1-  2  A2    ---       S       Status (Mm, Bg, Un, PM, or PB) (1)
   4- 10  I7    ---       ID      [10162/4042826] Identification number
      11  A1    ---     f_ID      [he] Note on the observation (2)
      13  I1    ---       PT      ?=x [1/5] Membership probability defined by
                                  N.T. on HST/ACS image (3)
      15  I1    ---       PF      ?=x [1/4] Membership probability defined by
                                  H.F. on HST/ACS image (3)
  17- 21  F5.2  mag       Rmag    [18.68/23.41]? R-band magnitude (4)
      22  A1    ---     f_Rmag    [f] Blended photometry (2)
  24- 28  F5.2  mag       F814Wc  ? HST/ACS F814W magnitude; corrected (5)
  30- 34  F5.2  mag       F814W   ? HST/ACS F814W magnitude (5)
  36- 39  F4.2  mag       B-V     ? (B-V) color index (3" aperture) (4)
      40  A1    ---     f_B-V     [f] Blended photometry (2)
  42- 46  F5.2  mag       g-I     ? (F475W-F814W) color index (2.25" aperture)
  48- 52  F5.2 mag/arcsec2 mu0    ? Central surface brightness ({mu}_0_(R))
  54- 58  F5.2 mag/arcsec2 mue    ? Mean effective surface brightness
                                  (<{mu}_e,F814W_>)
  60- 61  I2    h         RAh     [12/13] Hour of right ascension (J2000)
  63- 64  I2    min       RAm     Minute of right ascension (J2000)
  66- 70  F5.2  s         RAs     Second of right ascension (J2000)
      72  A1    ---       DE-     [+] Sign of declination (J2000)
  73- 74  I2    deg       DEd     [27/28] Degree of declination (J2000)
  76- 77  I2    arcmin    DEm     Arcminute of declination (J2000)
  79- 83  F5.2  arcsec    DEs     Arcsecond of declination (J2000)
  85- 90  I6    km/s      czA     ? Absorption redshift
  92- 94  I3    km/s    e_czA     ? czA uncertainty (6)
  96- 99  F4.1 aW/m2/nm   Rfx     ? Relative flux (in 10^-16^erg/s/cm2/{AA})
 101-106  I6    km/s      czE     ? Emission redshift
     107  A1    ---     f_czE     [g] redshift from red-side (2)
 109-111  I3    km/s    e_czE     ? czE uncertainty
 113-116  F4.1  ---       S/N     [3.7/61.1]? Signal to noise ratio per
                                  Angstrom around 5000{AA}
 118-120  A3    ---       MType   Morphological type
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Note (1): Membership status as follows:
    Mm = Member
    Bg = Background
    Un = Uncertain
    PM = Possible member (failed)
    PB = Possible background (failed)
Note (2): Flag as follows:
     e = Object was observed in a separate run in 2009.
     f = Photometry is for two blended components including the UCD target and
         another source centered 0.9 arcsec west of it.
     g = Redshift measurement from red-side data.
     h = Object was observed in two masks.
Note (3): Membership probability classes of the authors (N.Trenton and
          H.Ferguson) as follows:
     1 = expected member
     2 = probable member
     3 = possible member
     4 = expected background
     5 = the galaxy was an extra object that landed in the slit
     x = no membership probability assigned
          See section 2.1.1 for further explanations.
Note (4): BVR photometry from catalog of Adami et al. (2006,
          Cat. J/A+A/451/1159).
Note (5): F814W photometry comes from SExtractor measurements from our ACS data
          (Hammer et al. 2010ApJS..191..143H).
Note (6): Errors include contributions from the cross-correlation measurement
          uncertainty and from the uncertainties in the sky line wavelength
          calibration shift.
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History:
    From electronic version of the journal

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(End)                                     Emmanuelle Perret [CDS]    13-Jul-2012