EDP Sciences
Free access
Volume 407, Number 1, August III 2003
Page(s) 31 - 40
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20030826

A&A 407, 31-40 (2003)
DOI: 10.1051/0004-6361:20030826

The cluster of galaxies Abell 376

D. Proust1, H. V. Capelato2, G. Hickel2, 3, L. Sodré Jr.4, G. B. Lima Neto4 and H. Cuevas4, 5

1  Observatoire de Paris-Meudon, GEPI, 92195 Meudon, France
2  Divisão de Astrofísica, INPE/MCT, 12227-010, São José dos Campos/SP, Brazil
3  Universidad do Vale do Paraoba, Av. S. Hifumi 2911, São José dos Campos/SP, Brazil
4  Instituto de Astronomia, Geofísica e Ciências Atmos., Universidade de São Paulo (IAG/USP), 01065-970 São Paulo/SP, Brazil
5  Universidad La Serena, Casilla 544, La Serena, Chile

(Received 18 April 2003 / Accepted 22 May 2003 )

We present a dynamical analysis of the galaxy cluster Abell 376 based on a set of 73 velocities, most of them measured at Pic du Midi and Haute-Provence observatories and completed with data from the literature. Data on individual galaxies are presented and the accuracy of the determined velocities is discussed as well as some properties of the cluster. We obtained an improved mean redshift value z = 0.0478+0.005-0.006 and velocity dispersion $\sigma = 852^{+120}_{-76}\ {\rm km\,s^{-1}}$. Our analysis indicates that inside a radius of ~ $ 900 \,h_{70}^{-1}\,$kpc (~ $ 15\,$arcmin) the cluster is well relaxed without any remarkable features and the X-ray emission traces fairly well the galaxy distribution. A possible substructure is seen at 20 arcmin from the centre towards the Southwest direction, but is not confirmed by the velocity field. This SW clump is, however, kinematically bound to the main structure of Abell 376. A dense condensation of galaxies is detected at 46 arcmin (projected distance $2.6\,
h_{70}^{-1}\,$ Mpc) from the centre towards the Northwest and analysis of the apparent luminosity distribution of its galaxies suggests that this clump is part of the large scale structure of Abell 376. X-ray spectroscopic analysis of ASCA data resulted in a temperature $kT = 4.3\,
\pm\, 0.4\,$ keV and metal abundance $Z = 0.32 \pm 0.08~Z_{\odot}$. The velocity dispersion corresponding to this temperature using the TX- $\sigma$ scaling relation is in agreement with the measured galaxies velocities.

Key words: galaxies: distances and redshifts -- galaxies: clusters: general -- galaxies: clusters: individual: Abell 376 -- X-rays: galaxies: clusters

Offprint request: D. Proust, Dominique.Proust@obspm.fr

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© ESO 2003