Access to Astronomical Catalogues

J/ApJ/518/69        Deep Optical Catalog of galaxy systems      (Mahdavi+, 1999)
The dynamics of poor systems of galaxies.
    Mahdavi A., Geller M.J., Bohringer H., Kurtz M.J., Ramella M.
   <Astrophys. J. 518, 69 (1999)>
   =1999ApJ...518...69M
ADC_Keywords: Clusters, galaxy ; Redshifts

Keywords: galaxies: clusters: general - galaxies: fundamental parameters -
          X-rays: galaxies

Abstract:
    We assemble and observe a sample of poor galaxy systems that is
    suitable for testing N-body simulations of hierarchical clustering and
    other dynamical halo models. We (1) determine the parameters of the
    density profile Ρ(r) and the velocity dispersion profile
    σp(R), (2) separate emission-line galaxies from
    absorption-line galaxies, examining the model parameters, β, and
    as a function of spectroscopic type, and (3) for the best-behaved
    subsample, constrain the velocity anisotropy parameter, β, which
    determines the shapes of the galaxy orbits. Our sample consists of 20
    systems, 12 of which have extended X-ray emission in the ROSAT All-Sky
    Survey. We measure the 877 optical spectra of galaxies brighter than
    mR∼15.4 within 1.5h-1Mpc of the system centers (we take
    H0=100h*km/s/Mpc). Thus, we sample the system membership to a radius
    typically three times larger than other recent optical group surveys.
    The average system population is 30 galaxies, and the average
    line-of-sight velocity dispersion is ∼300km/s. The Navarro, Frenk, &
    White universal profile and the Hernquist model both provide good
    descriptions of the spatial data. In most cases an isothermal sphere
    is ruled out. Systems with declining σp(R) are well-matched by
    theoretical profiles in which the star-forming galaxies have
    predominantly radial orbits (β>0); many of these galaxies are
    probably falling in for the first time. There is significant evidence
    for spatial segregation of the spectroscopic classes regardless of
    σp(R).

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table1.dat        79       20   The Deep Optical Catalog: basic data
table2.dat        45      877   Galaxy positions and measured velocities


See also:
     VII/193    : The CfA Redshift Catalogue, Version June 1995 (Huchra+ 1995)
  J/AJ/116/1    : Southern Sky Redshift Survey (SSRS2) (Da Costa+, 1998)
  J/ApJ/534/114 : RASSCALS:  X-ray and optical study (Mahdavi+, 2000)


Byte-by-byte Description of file: table1.dat

   Bytes Format Units   Label    Explanations

   1-  7  A7    ---     DOC      Group identification (Deep Optical Catalog)
                                  (<DOC SRGaNNN>, <DOC NRGaNNN> in Simbad)
   8-  9  A2    ---     n_DOC    [abcde ] Individual Notes (1)
  11- 12  I2    h       RAh      Right ascension (J2000)
  14- 15  I2    min     RAm      Right ascension (J2000)
  17- 20  F4.1  s       RAs      Right ascension (J2000)
      22  A1    ---     DE-      Declination sign (J2000)
  23- 24  I2    deg     DEd      Declination (J2000)
  26- 27  I2    arcmin  DEm      Declination (J2000)
  29- 30  I2    arcsec  DEs      Declination (J2000)
  32- 33  I2    ---     NCSOC    Number of galaxies classified as members in the
                                  CSOC (combined CfA-SSRS2 redshifts surveys,
                                  Ramella et al., 1999, in prep.)
  35- 36  I2    ---     Ntot     Total number of galaxies to mR∼15.4
                                  in the field of the system
  38- 39  I2    ---     Ndoc     Total number of galaxies classified as members
                                  in this work.
  41- 45  I5    km/s    <v>      Recession velocity of the system
  47- 48  I2    km/s    E_<v>    Error in <v> (upper limit)
  50- 51  I2    km/s    e_<v>    Error in <v> (lower limit)
  53- 55  I3    km/s    sigmap   Dispersion velocity
  57- 58  I2    km/s   E_sigmap  Error in sigmap (upper limit)
  60- 61  I2    km/s   e_sigmap  Error in sigmap (lower limit)
  63- 66  A4    ---     Com      Comments (2)
      68  A1    ---    l_Ppoint  Limit flag on Ppoint
  69- 73  F5.3  %       Ppoint   ? Probability that the X-ray emission in the
                                    field is due to a single point source.
      74  A1    ---     ---      [/]
  75- 79  F5.3  %       Ppoint2  ? Probability for NRGs156. See note (3)

Note (1): the footnotes have the following meaning:
      a = Also studied by Zabludoff & Mulchaey (1998, Cat. J/ApJ/496/39)
      b = Also studied by Ramella et al. (1995, J/AJ/109/1458)
      c = Contains Hickson Compact Group 37 (Hickson 1982, Cat. VII/213)
      d = Abell 779 (Abell, 1958, Cat. VII/4)
      e = Abell 1185 (Abell, 1958, Cat. VII/4)
Note (2): the symbols used have the following meaning:
      X = has X-ray emission
     XC = position quoted is the X-ray centroid
     OC = position quoted is the mean optical position
Note (3): Probabilities for the south (Ppoint) and the north (Ppoint2)
    X-ray emission peaks coincident with member galaxies.


Byte-by-byte Description of file: table2.dat

   Bytes Format Units   Label    Explanations

   1-  7  A7    ---     DOC      Group identification (SNGaNNN or NRGaNNN)
   8- 10  A3    ---     m_DOC    Galaxy number in the Group (.NN)
                                  (<DOC SRGaNNN.NN>, <DOC NRGaNNN.NN> in simbad)
  12- 13  I2    h       RAh      Right ascension (J2000)
  15- 16  I2    min     RAm      Right ascension (J2000)
  18- 21  F4.1  s       RAs      Right ascension (J2000)
      23  A1    ---     DE-      Declinatio sign (2000)
  24- 25  I2    deg     DEd      Declination (J2000)
  27- 28  I2    arcmin  DEm      Declination (J2000)
  30- 31  I2    arcsec  DEs      Declination (J2000)
  33- 37  I5    km/s    cz       Velocity (typical uncertainty = 40km/s)


History: From ApJ electronic version

(End)                           James Marcout, Patricia Bauer [CDS]  14-Sep-1999