Issue |
A&A
Volume 484, Number 3, June IV 2008
|
|
---|---|---|
Page(s) | 621 - 630 | |
Section | Cosmology (including clusters of galaxies) | |
DOI | https://doi.org/10.1051/0004-6361:200809445 | |
Published online | 16 April 2008 |
The dynamical state of A548 from XMM-Newton data: X-ray and radio connection
1
CEA/DSM/DAPNIA, Service d'Astrophysique, L'Orme des Merisiers, Bât. 709, 91191 Gif-sur-Yvette, France e-mail: lilia.solovyeva@cea.fr
2
INAF Istituto di Radioastronomia, via P. Gobetti 101, 40129 Bologna, Italy
3
Dipartimento di Astronomia, Universita' di Bologna, via Ranzani 1, 40127 Bologna, Italy
4
INAF - Osservatorio Astronomico di Cagliari, Loc. Poggio dei Pini, Strada 54, 09012 Capoterra (CA), Italy
Received:
24
January
2008
Accepted:
14
March
2008
Context. We present a detailed study of the X-ray properties of the galaxy cluster
Abell 548b (), using XMM-Newton data, and discuss
the connection between the thermal properties and the presence
of two extended relic radio sources located at the cluster periphery.
Aims. We wish to analyze the dynamical state of the cluster and confirm the presence of a major merger. We will discuss the merger effects on the extended nonthermal emission.
Methods. We analyzed the X-ray brightness distribution, the surface brightness profiles in different directions, and the spectral properties in several cluster regions. Moreover, to better understand the dynamical history of this cluster, we performed an optical analysis of the cluster galaxies.
Results. From the analysis of the temperature distribution and of the surface
brightness profiles, we find evidence of a
shock in the northern cluster region,
just before the location of the two extended peripheral relics.
From the optical analysis, we find that the cluster galaxies show
a large , and two components are needed to fit their velocity
distribution.
Observational results were compared with a cluster simulation. The maps of gas temperature and density distribution from the simulation agree with
the observational data in the case of a cluster merger
nearly perpendicular to the plane of the sky and in the state
after the maximum core collapse.
Conclusions. We conclude that we are observing a galaxy cluster in a major merger phase, just after the maximum core collapse. The mass ratio is about 1:2, and the merger collision is nearly perpendicular to the plane of the sky. A shock is present in the northern cluster region, and it is very likely responsible for the electron reacceleration and the magnetic field amplification that will give cause the cluster relics. The relative position of the shock and the relics is strongly affected by projection effects.
Key words: galaxies: cluster: individual: Abell 548b / X-rays: galaxies: clusters
© ESO, 2008
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.