Astron. Astrophys. 337, 17-24 (1998)

A redshift survey between the clusters of galaxies A 548 and A 3367 ^*

G. Andreuzzi ^{1, 2}, S. Bardelli ³, R. Scaramella ² and E. Zucca <sup>4

1</sup> Osservatorio Astronomico di Capodimonte, Via Moiariello 16, I-80131 Napoli, Italy
² Osservatorio Astronomico di Roma, Via Osservatorio 2, I-00040 Monteporzio Catone (RM), Italy
³ Osservatorio Astronomico di Trieste, Via G.B. Tiepolo 11, I-34131 Trieste, Italy
⁴ Osservatorio Astronomico di Bologna, Via Zamboni 33, I-40126 Bologna, Italy

Received 16 April 1998 / Accepted 9 June 1998

Abstract

In this paper we present the results of a spectroscopic survey of galaxies in an area between the two clusters of galaxies A 548 and A 3367, suspected to be a close and interacting pair. With the use of multifiber spectroscopy, we measured 180 new velocities of galaxies in the central part of A 3367 and in the external regions of A 548.

The redshift histogram shows the presence of three velocity peaks, at km/s, km/s and km/s, respectively. For these we estimate the density excess, the mean velocity, and the velocity dispersion.

The first clump corresponds to an elongation of A 548: in particular we found a correspondence between the features of this peak and the substructures of A 548. The second peak has a velocity dispersion which is typical of clusters and the distribution of its members on the plane of the sky corresponds to the highest density peak in A 3367. We therefore suggest that the name A 3367 has to be attributed to this clump.

Our general conclusion is that, differently from expected, A 548 and A 3367 do not form a close pair of merging clusters, since the two structures are at significantly different redshifts. Moreover, we found that the complex dynamical structure of A 548 has large coherence, with a projected extension in the range of 1-3 h^-1 Mpc.

Key words: galaxies: clusters: individual: A 548; A 3367 galaxies: clusters: general galaxies: distances and redshifts

* based on observations collected at the European Southern Observatory, La Silla, Chile

Send offprint requests to: S. Bardelli, (bardelli@astrts.oat.ts.astro.it)

SIMBAD Objects

Contents

• 1. Introduction
• 2. The sample
  • 2.1. The photometric catalogue
  • 2.2. Observations
  • 2.3. Data reduction
  • 2.4. Redshift data
• 3. Discussion
  • 3.1. Peak A
  • 3.2. Peaks B and C
• 4. Summary
• Acknowledgements
• References

© European Southern Observatory (ESO) 1998

Online publication: August 6, 1998
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