J/ApJ/741/122 Spectroscopic redshifts in A2142 and RXJ1720.1+2638 (Owers+, 2011)
Minor merger-induced cold fronts in Abell 2142 and RXJ1720.1+2638.
Owers M.S., Nulsen P.E.J., Couch W.J.
<Astrophys. J., 741, 122 (2011)>
=2011ApJ...741..122O 2011ApJ...741..122O
ADC_Keywords: Redshifts ; Galaxies, spectra ; Clusters, galaxy
Keywords: galaxies: clusters: individual (Abell 2142, RXJ1720.1+2638) -
X-rays: galaxies: clusters
Abstract:
We present evidence for the existence of substructure in the "relaxed
appearing" cold front clusters Abell 2142 and RXJ1720.1+2638. The
detection of these substructures was made possible by comprehensive
multi-object optical spectroscopy obtained with the Hectospec and DEep
Imaging Multi-Object Spectrograph instruments on the 6.5m MMT and 10m
Keck II telescope, respectively. These observations produced 956 and
400 spectroscopically confirmed cluster members within a projected
radius of 3Mpc from the centers of A2142 and RXJ1720.1+2638,
respectively. The substructure manifests itself as local peaks in the
spatial distribution of member galaxies and also as regions of
localized velocity substructure. For both Abell 2142 and
RXJ1720.1+2638, we identify group-scale substructures which, when
considering the morphology of the cold fronts and the time since
pericentric passage of a perturber estimated from the cold front
radii, could plausibly have perturbed the cluster cores and generated
the cold fronts observed in Chandra images. The results presented here
are consistent with cold fronts being the result of merger activity
and with cold fronts in relaxed appearing clusters being due to minor
merger activity.
Description:
The majority of the spectra used in this paper were collected at the
6.5m MMT using the Hectospec multi-object spectrograph with ∼6Å
resolution covering the wavelength range 3500-10000Å, from 2006 May
4 to 2007 Apr 20 for RXJ1720.1+2638 and from 2009 Feb 5 to 2009 Apr 24
for A2142.
The MMT/Hectospec data for RXJ1720 were supplemented with spectra
obtained at the Keck II telescope using DEIMOS, with a spectral
resolution of ∼7.0Å.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 53 1635 Combined redshift catalog for ACO 2142
table4.dat 53 1121 Combined redshift catalog for RXJ1720.1+2638
--------------------------------------------------------------------------------
See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
VII/193 : The CfA Redshift Catalogue, Version June 1995 (Huchra+ 1995)
VII/165 : Measured Redshifts of Abell Clusters of Galaxies (Andernach 1991)
VII/177 : Redshifts & Velocity Dispersions for Abell Clusters (Struble+ 1991)
VIII/43 : Radio survey of clusters of galaxies (Andernach+ 1978)
J/MNRAS/416/2840 : The 2M++ galaxy redshift catalogue (Lavaux+, 2011)
J/ApJ/384/404 : Redshifts of rich clusters of galaxies (Postman+ 1992)
Byte-by-byte Description of file: table[34].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
12- 20 F9.6 deg DEdeg Declination in decimal degrees (J2000)
22- 31 F10.2 km/s cz [2639/1162416] Spectroscopic redshift
33- 39 F7.2 km/s e_cz [3/1009] Uncertainty in cz
41- 53 A13 --- Inst Instrument for cz (Keck/DEIMOS, MMT/Hectospec,
SDSS)
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 04-Mar-2013