170 research outputs found
The temperature structure in the core of Sersic 159-03
We present results from a new 120 ks XMM-Newton observation of the cluster of
galaxies Sersic 159-03. In this paper we focus on the high-resolution X-ray
spectra obtained with the Reflection Grating Spectrometer (RGS). The spectra
allow us to constrain the temperature structure in the core of the cluster and
determine the emission measure distribution as a function of temperature. We
also fit the line widths of mainly oxygen and iron lines.Comment: 7 pages and 4 figures. Contribution to the proceedings of the COSPAR
Scientific Assembly, session E1.2 "Clusters of Galaxies: New Insights from
XMM-Newton, Chandra and INTEGRAL", july 2004, Paris (France). Accepted for
publication in Advances in Space Researc
Thermal radiation processes
We discuss the different physical processes that are important to understand
the thermal X-ray emission and absorption spectra of the diffuse gas in
clusters of galaxies and the warm-hot intergalactic medium. The ionisation
balance, line and continuum emission and absorption properties are reviewed and
several practical examples are given that illustrate the most important
diagnostic features in the X-ray spectra.Comment: 37 pages, 16 figures, accepted for publication in Space Science
Reviews, special issue "Clusters of galaxies: beyond the thermal view",
Editor J.S. Kaastra, Chapter 9; work done by an international team at the
International Space Science Institute (ISSI), Bern, organised by J.S.
Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeke
A highly-ionized absorber as a new explanation for the spectral changes during dips from X-ray binaries
Until now, the spectral changes observed from persistent to dipping intervals
in dipping low-mass X-ray binaries were explained by invoking progressive and
partial covering of an extended emission region. Here, we propose a novel and
simpler way to explain these spectral changes, which does not require any
partial covering and hence any extended corona, and further has the advantage
of explaining self-consistently the spectral changes both in the continuum and
the narrow absorption lines that are now revealed by XMM-Newton. In 4U 1323-62,
we detect Fe XXV and Fe XXVI absorption lines and model them for the first time
by including a complete photo-ionized absorber model rather than individual
Gaussian profiles. We demonstrate that the spectral changes both in the
continuum and the lines can be simply modeled by variations in the properties
of the ionized absorber. From persistent to dipping the photo-ionization
parameter decreases while the equivalent hydrogen column density of the ionized
absorber increases. In a recent work (see Diaz Trigo et al. in these
proceedings), we show that our new approach can be successfully applied to all
the other dipping sources that have been observed by XMM-Newton.Comment: 5 pages, 5 figures, to appear in the proceedings of "The X-ray
Universe 2005", San Lorenzo de El Escorial (Spain), 26-30 September 200
Parameterization of the level-resolved radiative recombination rate coefficients for the SPEX code
High Energy Astrophysic
Ionization by galaxy cluster photons alters the ionization state of the nearby warm-hot intergalactic medium
Galaxie
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