Structure and evolution of galaxy clusters: Internal dynamics of ABCG 209 at 0.21

Free access article

Issue		A&A Volume 397, Number 2, January II 2003


Page(s)		431 - 443
Section		Extragalactic astronomy
DOI		http://dx.doi.org/10.1051/0004-6361:20021495

A&A 397, 431-443 (2003)
DOI: 10.1051/0004-6361:20021495

Structure and evolution of galaxy clusters: Internal dynamics of ABCG 209 at $z\;\sim$ 0.21

A. Mercurio¹, M. Girardi¹, W. Boschin¹, P. Merluzzi² and G. Busarello²

¹ Dipartimento di Astronomia, Università degli Studi di Trieste, via Tiepolo 11, 34100 Trieste, Italy
e-mail: mercurio,girardi,boschin@ts.astro.it
² INAF - Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80100 Napoli, Italy
e-mail: merluzzi,busarello@na.astro.it

(Received 24 July 2002 / Accepted 11 October 2002)

Abstract
We study the internal dynamics of the rich galaxy cluster ABGC 209 on the basis of new spectroscopic and photometric data. The distribution in redshift shows that ABCG 209 is a well isolated peak of 112 detected member galaxies at z=0.209, characterised by a high value of the line-of-sight velocity dispersion, $\mathrm{\sigma_v=1250}$ - 1400 km s ^-1, on the whole observed area (1 h^-1 Mpc $\;$ from the cluster center), that leads to a virial mass of M=1.6- $2.2\times 10^{15}$ ${h^{-1} \ M_{\odot} \;}$ within the virial radius, assuming the dynamical equilibrium. The presence of a velocity gradient in the velocity field, the elongation in the spatial distribution of the colour-selected likely cluster members, the elongation of the X-ray contour levels in the Chandra image, and the elongation of cD galaxy show that ABCG 209 is characterised by a preferential NW-SE direction. We also find a significant deviation of the velocity distribution from a Gaussian, and relevant evidence of substructure and dynamical segregation. All these facts show that ABCG 209 is a strongly evolving cluster, possibly in an advanced phase of merging.

Key words: galaxies: clusters: general -- galaxies: clusters: individual: ABCG 209 -- galaxies: distances and redshifts -- intergalactic medium -- cosmology: observations

Offprint request: A. Mercurio, mercurio@na.astro.it
or mercurio@ts.astro.it

SIMBAD Objects

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.