The inverse iron-bias in action in Abell 2028
Abstract
Recent work based on a global measurement of the ICM properties find evidence for an increase of the iron abundance in galaxy clusters with temperature around 2-4 keV. We have undertaken a study of the metal distribution in nearby clusters in this temperature range, aiming at resolving spatially the metal content of the ICM. The XMM observation of the first object of the sample, the cluster Abell 2028, reveals a complex structure of the cluster over scale of ~ 300 kpc, showing an interaction between two sub-clusters in a ``cometary'' configuration. We show that a naive one-component fit for the core of Abell 2028 returns a biased high metallicity. This is due to the inverse iron-bias, which is not related to the presence in the spectrum of both Fe-L and Fe-K emission lines but to the behavior of the fitting code in shaping the Fe-L complex of a one temperature component to adjust to the multi-temperature structure of the projected spectrum.
Cite
@article{arxiv.0909.4679,
title = {The inverse iron-bias in action in Abell 2028},
author = {Fabio Gastaldello and Stefano Ettori and Italo Balestra and Fabrizio Brighenti and David Buote and Sabrina De Grandi and Myriam Gitti and Paolo Tozzi},
journal= {arXiv preprint arXiv:0909.4679},
year = {2009}
}
Comments
2 pages, 2 figures, to appear in proceedings of the conference "The Energetic Cosmos: from Suzaku to Astro-H", July 2009, Otaru, Hokkaido, Japan