J/MNRAS/434/772 Velocities in ZwCl2341.1+0000 field (Boschin+, 2013)
The dynamical status of ZwCl 2341.1+0000: a very elongated galaxy structure
with a complex radio emission.
Boschin W., Girardi M., Barrena R.
<Mon. Not. R. Astron. Soc., 434, 772-783 (2013)>
=2013MNRAS.434..772B 2013MNRAS.434..772B
ADC_Keywords: Clusters, galaxy ; Galaxies, spectra ; Radial velocities
Keywords: galaxies: clusters: general -
galaxies: clusters: individual: ZwCl 2341.1+0000 -
galaxies: kinematics and dynamics; X-rays: galaxies: clusters
Abstract:
We study the dynamical status of the galaxy system ZwCl 2341.1+0000, a
filamentary multi-Mpc galaxy structure associated with a complex
diffuse radio emission.
Our analysis is mainly based on new spectroscopic data for 128
galaxies acquired at the Italian Telescopio Nazionale Galileo. We also
use optical data available in the Sloan Digital Sky Survey and X-ray
data from the Chandra archive.
We select 101 cluster member galaxies and compute the cluster redshift
∼0.2693 and the global line-of-sight velocity dispersion
σV∼1000km/s.
Our optical analysis agrees with the presence of at least three,
likely four or more, optical subclusters causing the
south-south-east-north-north-west (SSE-NNW) elongation of the galaxy
distribution and a significant velocity gradient in the south-north
direction. In particular, we detect an important low-velocity subclump
in the southern region, roughly coincident with the brightest peak of
the diffuse radio emission but with a clear offset between the optical
and radio peaks. We also detect one (or two) optical subcluster(s) at
north, in correspondence with the second brightest radio emission, and
another one in the central cluster region, where a third diffuse radio
source has been recently detected. A more refined analysis involving
the study of the 2D galaxy distribution suggests an even more complex
structure. Depending on the adopted model, we obtain a mass estimate
Msys∼1-3x1015h70-1M_☉ for the whole system.
As for the X-ray analysis, we confirm the SSE-NNW elongation of the
intracluster medium and detect four significant peaks. The X-ray
emission is strongly asymmetric and offsetted with respect to the
galaxy distribution, thus suggesting a merger caught in the phase of
post-core-core passage.
Our findings support two possible hypotheses for the nature of the
diffuse radio emission of ZwCl 2341.1+0000: a two relics + halo
scenario or diffuse emission associated with the infall and merging of
several galaxy groups during the first phase of the cluster formation.
Description:
Multi-object spectroscopic observations of ZwCl 2341+00 were carried
out at the TNG in 2009 October, 2011 August and 2011 December. We used
the instrument Device Optimized for the Low Resolution (DOLORES) in
multi-object spectroscopy (MOS) mode with the LR-B Grism. In summary,
we observed four MOS masks for a total of 142 slits. The total
exposure time was 3600s for three masks and 5400s for the last one.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 45 128 Radial velocities of 128 galaxies in the field
of ZwCl 2341+00
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/128] Sequential number
4 A1 --- f_Seq [*] * : non-member galaxy
6- 7 I2 h RAh Right ascension (J2000)
9- 10 I2 min RAm Right ascension (J2000)
12- 16 F5.2 s RAs Right ascension (J2000)
18 A1 --- DE- Declination sign (J2000)
19- 20 I2 deg DEd Declination (J2000)
22- 23 I2 arcmin DEm Declination (J2000)
25- 28 F4.1 arcsec DEs Declination (J2000)
30- 34 F5.2 mag r'mag [17.5/22.2]?=- SDSS (dereddened) r' magnitude
36- 41 I6 km/s HRV [20657/191834] Heliocentric radial velocity cz
43- 45 I3 km/s e_HRV [27/242] rms uncertainty on HRV
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 29-Jul-2014