2005A&A...442...29G


C.D.S. - SIMBAD4 rel 1.7 - 2019.10.18CEST19:36:32

2005A&A...442...29G - Astronomy and Astrophysics, volume 442, 29-41 (2005/10-4)

Internal dynamics of the z∼0.8 cluster RXJ0152.7-1357.

GIRARDI M., DEMARCO R., ROSATI P. and BORGANI S.

Abstract (from CDS):

We present the results from the dynamical analysis of the cluster of galaxies RXJ0152.7-1357, which shows a complex structure in its X-ray emission, with two major clumps in the central region and a third clump in the Eastern region. Our analysis is based on redshift data for 187 galaxies. We find that RXJ0152.7-1357appears as a well isolated peak in the redshift space at z=0.836, which includes 95 galaxies recognized as cluster members. We compute the line-of-sight velocity dispersion of galaxies, σV=1322+74–68km/s, which is significantly larger than what is expected in the case of a relaxed cluster with an observed X-ray temperature of 5-6keV. We find evidence that this cluster is far from dynamical equilibrium, as shown by the non Gaussianity of the velocity distribution, the presence of a velocity gradient and a significant substructure. Our analysis shows that the high value of σV is due to the complex structure of RXJ0152.7-1357, i.e. to the presence of three galaxy clumps of different mean velocities. Using optical data we detect a low-velocity clump (with σV=300-500km/s) in the central southwest region and a high-velocity clump (with σV∼700km/s) in the Eastern region, corresponding well to the South-West and East peaks detected in the X-ray emission. The central North-East X-ray peak is associated to the main galaxy structure with a velocity which is intermediate between those of the other two clumps and σV∼900km/s. The mass of the whole system within 2Mpc is estimated to lie in the range (1.2-2.2)x1015M, depending on the model adopted to describe the cluster dynamics. Such values are comparable to those of very massive clusters at lower redshifts. Analytic calculations based on the two-body model indicate that the system is most likely bound and currently undergoing merging. In particular, we suggest that the southwestern clump is not a small group, but rather the dense cluster-core of a massive cluster, most likely destined to survive tidal disruption during the merger.

Abstract Copyright:

Journal keyword(s): galaxies: clusters: general - galaxies: clusters: individual: RXJ0152.7-1357 - galaxies: distances and redshifts - cosmology: observations

Simbad objects: 11

goto Full paper

goto View the reference in ADS

Number of rows : 11

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2019
#notes
1 [DRL2005] 1239 GiC 01 52 36.10 -13 56 05.7           ~ 3 0
2 [DRL2005] 650 EmG 01 52 37.33 -13 56 33.4           ~ 4 0
3 [DRL2005] 509 GiC 01 52 39.41 -13 58 06.0           ~ 3 0
4 [MJE2003] J015239.89-135827.48 GrG 01 52 39.590 -13 58 27.48           ~ 7 1
5 [DRL2005] 1146 EmG 01 52 39.64 -13 55 45.9           ~ 4 0
6 2XMM J015239.8-135741 AGN 01 52 39.9 -13 57 40       20.48   ~ 7 0
7 [DRL2005] 895 GiC 01 52 40.89 -13 54 31.8           ~ 3 0
8 ClG J0152-1358 ClG 01 52 41.3 -13 58 13           ~ 237 3
9 [MJE2003] J015244.18-135715.84 GrG 01 52 44.180 -13 57 15.84           ~ 7 1
10 [DRL2005] 306 EmG 01 52 49.66 -13 58 28.0           ~ 4 0
11 [MJE2003] J015252.42-135805.52 X 01 52 52.420 -13 58 05.52           ~ 2 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2005A&A...442...29G and select 'bookmark this link' or equivalent in the popup menu


2019.10.18-19:36:32

© Université de Strasbourg/CNRS

    • Contact