J/MNRAS/452/3304 AC114 galaxy cluster dynamical analysis (Proust+, 2015)
The structure and dynamics of the AC114 galaxy cluster revisited.
Proust D., Yegorova I., Saviane I., Ivanov V.D., Bresolin F., Salzer J.J.,
Capelato H.V.
<Mon. Not. R. Astron. Soc., 452, 3304-3318 (2015)>
=2015MNRAS.452.3304P 2015MNRAS.452.3304P (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies, photometry ; Redshifts
Keywords: galaxies: clusters: general - galaxies: distances and redshifts -
galaxies: evolution - cosmology: observations - distance scale -
large-scale structure of Universe
Abstract:
We present a dynamical analysis of the galaxy cluster AC114 based on a
catalogue of 524 velocities. Of these, 169 (32 percent) are newly
obtained at European Southern Observatory (Chile) with the Very Large
Telescope and the VIsible MultiObject spectrograph. Data on individual
galaxies are presented and the accuracy of the measured velocities is
discussed. Dynamical properties of the cluster are derived. We obtain
an improved mean redshift value z=0.31665±0.0008 and
velocity dispersion σ=1893+73-82km/s. A large velocity
dispersion within the core radius and the shape of the infall pattern
suggests that this part of the cluster is in a radial phase of
relaxation with a very elongated radial filament spanning 12000km/s.
A radial foreground structure is detected within the central
0.5h-1Mpc radius, recognizable as a redshift group at the same
central redshift value. We analyse the colour distribution for this
archetype Butcher-Oemler galaxy cluster and identify the separate red
and blue galaxy sequences. The latter subset contains 44 percent of
confirmed members of the cluster, reaching magnitudes as faint as
Rf=21.1 (1.0mag fainter than previous studies). We derive a
mass M200=(4.3±0.7)x1015M☉h-1. In a subsequent paper, we
will utilize the spectral data presented here to explore the
mass-metallicity relation for this intermediate redshift cluster.
Description:
The observations were carried out in service mode with the VIsible
MultiObject Spectrograph (VIMOS) mounted on the Very Large Telescope
(VLT), ESO (083.A-0566).
The 14 awarded hours of observations were done on 2009 August 16 and
21, and September 17, 21 and 25.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 107 169 Positions, photometric data and velocities for
galaxies of AC114
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1 I1 --- Q [1/4] Quadrant number
3- 4 I2 --- ID Galaxy ID within the quadrant
5 A1 --- n_ID [ab] Multiplicity index on ID
7- 8 I2 h RAh right ascension (J2000)
10- 11 I2 min RAm right ascension (J2000)
13- 17 F5.2 s RAs right ascension (J2000)
19 A1 --- DE- Declination sign (J2000)
20- 21 I2 deg DEd Declination (J2000)
23- 24 I2 arcmin DEm Declination (J2000)
26- 29 F4.1 arcsec DEs Declination (J2000)
31- 34 F4.1 mag Bjmag ? SUPERCOSMOS Bj magnitude
36- 39 F4.1 mag Rfmag ? SUPERCOSMOS Rf magnitude
41- 44 F4.1 mag Rcomp ? Computed R magnitude
46- 52 F7.5 --- z Redshift
53 A1 --- u_z [?] Uncertainty flag on z
55- 61 F7.5 --- e_z ? rms uncertainty on z
63- 67 F5.2 --- R ? Correlation peak height to the amplitude
of the antisymmetric noise
69-107 A39 --- Notes Notes
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 15-Feb-2016