EDP Sciences
Free access
Volume 423, Number 1, August III 2004
Page(s) 49 - 56
Section Cosmology (including clusters of galaxies)
DOI http://dx.doi.org/10.1051/0004-6361:20047170

A&A 423, 49-56 (2004)
DOI: 10.1051/0004-6361:20047170

X-ray spectroscopy on Abell 478 with XMM-Newton

J. de Plaa1, 2, J. S. Kaastra1, T. Tamura1, 3, E. Pointecouteau4, M. Mendez1 and J. R. Peterson5

1  SRON National Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
    e-mail: [j.s.kaastra;j.de.plaa]@sron.nl
2  Astronomical Institute, Utrecht University, PO Box 80000, 3508 TA Utrecht, The Netherlands
3  Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan
4  CEA/DSM/DAPNIA Saclay, Service d'Astrophysique, L'Orme des Merisiers, Bât. 709, 91191 Gif-sur-Yvette, France
5  KIPAC, Stanford University, PO Box 90450, MS 29, Stanford, CA 94039, USA

(Received 30 January 2004 / Accepted 7 May 2004)

We report the results from a spatially resolved spectroscopy study with XMM-Newton on the relaxed cluster of galaxies Abell 478 . From the EPIC data we extract a temperature profile and radial abundance profiles for Ne, Mg, Si, S, Ca, Fe and Ni. The abundance profiles follow the same trends as observed in other clusters. The spectra of the core of the cluster can be best fitted with a multi-temperature model. We argue that this multi-temperature behavior is mostly due to projection effects, because of the strong temperature gradient in the core. Contributions from other effects, for example, intrinsic temperature stratification cannot be fully excluded. For the first time we measure an underabundance of oxygen in the Galactic absorption component toward a cluster. The measured oxygen abundance in this absorber is about 0.5 times the solar oxygen abundance as determined by Anders & Grevesse (1989).

Key words: galaxies: clusters: general -- galaxies: clusters: individual: Abell 478 -- galaxies: cooling flows -- galaxies: intergalactic medium -- X-rays: galaxies: clusters -- ISM: abundances

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© ESO 2004