ASCA Measurements of Silicon and Iron Abundances in the Intracluster Medium

Fukazawa, Yasushi; Makishima, Kazuo; Tamura, Takayuki; Ezawa, H.; Xu, Haiguang; Ikebe, Y.; Kikuchi, K.; Ohashi, T.

doi:10.1093/pasj/50.1.187

Cited by 200 publications

(276 citation statements)

References 18 publications

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“…The cooling function Λ(T, Z) is calculated by using a MEKAL plasma model (Mewe et al 1985(Mewe et al , 1986Liedahl et al 1995) implemented in the XSPEC software package (Arnaud 1996). For the metallicity, we adopt the typical value Z = 0.3 Z (Fukazawa et al 1998;Schindler 1999; see also Bartelmann & White 2003). Finally, dV i = m i /ρ i is the volume of the ith gas particle of mass m i .…”

Section: X-ray Luminositiesmentioning

confidence: 99%

Strong lensing in the MARENOSTRUM UNIVERSE

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Fedeli

Pace

et al. 2010

A&A

152

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Context. Strong lensing is one of the most direct probes of mass distribution in the inner regions of galaxy clusters. It can be used to constrain the density profiles and to measure the mass of the lenses. Moreover, the abundance of strong lensing events can be used to constrain structure formation and cosmological parameters through the so-called "arc-statistics" approach. However, several issues related to the use of strong lensing clusters in cosmological applications are still controversial, leading to the suspicion that several biases may affect this very peculiar class of objects. Aims. With this study we aim a better understanding of the properties of galaxy clusters that can potentially act as strong lenses. Methods. We do so by investigating the properties of a large sample of galaxy clusters extracted from the N-body/hydrodynamical simulation MareNostrum Universe. We perform ray-tracing simulations with each of them and identify those objects capable of producing strong lensing effects. We explore the correlation between the cross section for lensing and many properties of clusters, such as mass, three-dimensional and projected shapes, their concentrations, the X-ray luminosity, and the dynamical activity. Results. We quantify the minimal cluster mass required for producing both multiple images and large distortions. While we do not measure a significant excess of triaxiality in strong lensing clusters, we find that the probability of strong alignments between the major axes of the lenses and the line of sight is a growing function of the lensing cross section. In projection, the strong lenses appear rounder within R 200 , but we find that their cores tend to be more elliptical as the lensing cross section increases. As a result of the orientation bias, we also find that the cluster concentrations estimated from the projected density profiles tend to be biased high. The X-ray luminosity of strong lensing clusters tend to be higher than for normal lenses of similar mass and redshift. This is particularly significant for the least massive lenses. Finally, we find that the strongest lenses generally exhibit an excess of kinetic energy within the virial radius, thus indicating that they are more dynamically active than the usual clusters. Conclusions. We conclude that strong lensing clusters are a very peculiar class of objects, affected by many selection biases that need to be properly modeled when using them to study the inner structure of galaxy clusters or to constrain the cosmological parameters.

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Section: X-ray Luminositiesmentioning

confidence: 99%

Strong lensing in the MARENOSTRUM UNIVERSE

Meneghetti

Fedeli

Pace

et al. 2010

A&A

152

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“…Buote (2000b) shows that this effect is the most important for the hotter clusters of galaxies. This bias may have played a role in the excess Si/Fe ratios and trends derived using ASCA data (Mushotzky et al 1996;Fukazawa et al 1998;Finoguenov et al 2000;Baumgartner et al 2005).…”

Section: Spectral Modelling and The Most Common Biasesmentioning

confidence: 99%

Observations of Metals in the Intra-Cluster Medium

et al. 2008

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Because of their deep gravitational potential wells, clusters of galaxies retain all the metals produced by the stellar populations of the member galaxies. Most of these metals reside in the hot plasma which dominates the baryon content of clusters. This makes them excellent laboratories for the study of the nucleosynthesis and chemical enrichment history of the Universe. Here we review the history, current possibilities and limitations of the abundance studies, and the present observational status of X-ray measurements of the chemical composition of the intra-cluster medium. We summarise the latest progress in using the abundance patterns in clusters to put constraints on theoretical models of supernovae and we show how cluster abundances provide new insights into the star-formation history of the Universe.

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“…Tracing back the origin of these differences is not an easy task. Besides the different descriptions of the relevant physical processes treated in the SAMs and in the chemo-dynamical simulations, a proper comparison would also require using exactly the Peterson et al (2003), Fukazawa et al (1998) and Baumgartner et al (2005) (see Nagashima et al 2005 for details). All abundances have been rescaled to the Solar abundances by Grevesse and Sauval (1998) same model of chemical evolution and the same sets of yields for different stellar populations.…”

Section: Global Abundancesmentioning

confidence: 99%

The Chemical Enrichment of the ICM from Hydrodynamical Simulations

et al. 2008

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The study of the metal enrichment of the intra-cluster and inter-galactic media (ICM and IGM) represents a direct means to reconstruct the past history of star formation, the role of feedback processes and the gas-dynamical processes which determine the evolution of the cosmic baryons. In this paper we review the approaches that have been followed so far to model the enrichment of the ICM in a cosmological context. While our presentation will be focused on the role played by hydrodynamical simulations, we will also discuss other approaches based on semi-analytical models of galaxy formation, also critically discussing pros and cons of the different methods. We will first review the concept of the model of chemical evolution to be implemented in any chemo-dynamical description. We will emphasise how the predictions of this model critically depend on the choice of the stellar initial mass function, on the stellar life-times and on the stellar yields. We will then overview the comparisons presented so far between X-ray observations of the ICM enrichment and model predictions. We will show how the most recent chemo-dynamical models are able to capture the basic features of the observed metal content of the ICM and its evolution. We will conclude by highlighting the open questions in this study and the direction of improvements for cosmological chemo-dynamical models of the next generation.

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ASCA Measurements of Silicon and Iron Abundances in the Intracluster Medium

Cited by 200 publications

References 18 publications

Strong lensing in the MARENOSTRUM UNIVERSE

Strong lensing in the MARENOSTRUM UNIVERSE

Observations of Metals in the Intra-Cluster Medium

The Chemical Enrichment of the ICM from Hydrodynamical Simulations

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