J/ApJ/869/124 Redshift survey of the nearby galaxy cluster A2107 (Song+, 2018)
A redshift survey of the nearby galaxy cluster A2107: global rotation of the
cluster and its connection to large-scale structures in the universe.
Song H., Hwang H.S., Park C., Smith R., Einasto M.
<Astrophys. J., 869, 124 (2018)>
=2018ApJ...869..124S 2018ApJ...869..124S
ADC_Keywords: Surveys; Clusters, galaxy; Photometry, SDSS; Redshifts;
Spectra, optical
Keywords: galaxies: clusters: individual (A2107) ;
galaxies: distances and redshifts ; galaxies: kinematics and dynamics;
large-scale structure of universe ; methods: observational ; surveys
Abstract:
We study the rotational motion of the galaxy cluster A2107 at redshift
z=0.04 and its connection to nearby large-scale structures using a
large amount of spectroscopic redshift data. By combining 978 new
redshifts from the MMT/Hectospec observations with data in the
literature, we construct a large sample of 1968 galaxies with measured
redshifts at clustercentric radius R<60'. Our sample has high (80%)
and spatially uniform completeness at r-band apparent magnitude
mr,Petro,0<19.1. We first apply the caustic method to the sample and
identify 285 member galaxies of A2107 at R<60'. Then the rotation
amplitude and the position angle of the rotation axis are measured. We
find that the member galaxies show strong global rotation at R<20'
(vrot/σv∼0.6) with a significance of >3.8σ, which is
confirmed by two independent methods. The rotation becomes weaker in
outer regions. There are at least five filamentary structures that are
connected to the cluster and that consist of known galaxy groups.
These structures are smoothly connected to the cluster, which seem to
be inducing the global rotation of the cluster through inflow of
galaxies.
Description:
We select targets for spectroscopic observations from the photometric
data of the SDSS data release 12 (DR12; Alam+ 2015 V/147). We select
galaxies without measured redshifts in the literature from the
photometric data and impose no selection criteria other than magnitude.
We use the Hectospec installed on the MMT 6.5m telescope for
spectroscopic observations in 2015 May 25, 2015 Jun 21, 2016 Apr 16.
The Hectospec is a 300 fiber multiobject spectrograph with a circular
field of view (FOV) of 1° diameter. We use the 270line/mm grating
of Hectospec that provides a dispersion of 1.2Å/pixel and a
resolution of ∼6Å. We observe four fields with 3x15 (or 20) minute
exposure each, and obtained spectra covering the wavelength range
3500-9150Å.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 75 1968 Redshifts in the field of A2107 within 1°
of the cluster center
--------------------------------------------------------------------------------
See also:
VII/250 : The 2dF Galaxy Redshift Survey (2dFGRS) (2dFGRS Team,1998-2003)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
J/AJ/104/2078 : cD Galaxy in Abell 2107 (Oegerle+ 1992)
J/ApJS/126/133 : The FIRST bright quasar survey. II. (White+, 2000)
J/AJ/122/2222 : Superclusters of Abell and X-ray clusters (Einasto+, 2001)
J/AJ/128/1558 : NOAO Fundamental Plane Survey (Smith+, 2004)
J/A+A/495/707 : WINGS spectroscopy of 48 galaxy clusters (Cava+, 2009)
J/A+A/499/47 : Lick indices of EDCSN galaxies (Sanchez-Blazquez+, 2009)
J/ApJ/767/15 : Hectospec Cluster Survey (HeCS) (Rines+, 2013)
J/ApJ/783/52 : Redshifts in the field of A383 (Geller+, 2014)
J/ApJS/213/35 : SHELS: complete galaxy z survey for R≤20.6 (Geller+, 2014)
J/ApJ/797/106 : Redshifts in nine galaxy cluster fields (Hwang+, 2014)
J/A+A/566/A1 : Flux and volume-limited groups for SDSS gal. (Tempel+, 2014)
J/ApJS/224/11 : SHELS: redshift survey of the F1 DLS field (Geller+, 2016)
J/A+A/607/A131 : Abell 520 galaxies redshifts (Deshev+, 2017)
J/MNRAS/465/1789 : SCUBA-2 Cosmology Legacy Survey (Geach+, 2017)
J/MNRAS/465/2616 : Galaxy cluster's rotation (Manolopoulou+, 2017)
J/ApJ/842/88 : Redshift survey of the central region of A2199 (Song+, 2017)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- Seq Sequential running number
6- 24 I19 --- objID SDSS-DR12 unique object identifier
26- 35 F10.6 deg RAdeg [233.8/236] SDSS-DR12 right ascension (J2000)
37- 45 F9.6 deg DEdeg [20.8/22.8] SDSS-DR12 declination (J2000)
47- 52 F6.3 mag rPmag0 [12.8/21.3] SDSS-DR12 r-band Petrosian magnitude,
extinction corrected
54- 54 I1 --- Ext? [0/1] SDSS-DR12 PSF probability based upon r band
(0=extended or 1=point source)
56- 63 F8.5 --- z [-0.01/4] Redshift
65- 71 F7.5 --- e_z [0/0.03] Uncertainty in redshift
73- 73 I1 --- r_z [1/7] Redshift source (1)
75- 75 I1 --- Mm [0/1] Membership flag (1 = A2107 members;
285 occurrences)
--------------------------------------------------------------------------------
Note (1): Reference as follows:
1 = This study (Hectospec/MMT; 978 occurrences)
2 = SDSS DR12 (V/147 ; 977 occurrences)
3 = Cava et al. 2009, J/A+A/495/707
4 = Oegerle & Hill 1992, J/AJ/104/2078
5 = Smith et al. 2004, J/AJ/128/1558
6 = White et al. 2000, J/ApJS/126/133
7 = FAST Spectrograph Archive (http://tdc-www.harvard.edu/cgi-bin/arc/fsearch)
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie FIX [CDS] 07-Nov-2019