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We examine the systematics affecting the X-ray mass estimators applied to a set of five simulated galaxy clusters. They have been processed through the X-ray Map Simulator, X-MAS, to provide Chandra-like long exposures that are analyzed to…

Astrophysics · Physics 2009-11-11 E. Rasia , S. Ettori , L. Moscardini , P. Mazzotta , S. Borgani , K. Dolag , G. Tormen , L. M. Cheng , A. Diaferio

We investigate the impact of mergers on the mass estimation of galaxy clusters using $N$-body + hydrodynamical simulation data. We estimate virial mass from these data and compare it with real mass. When the smaller subcluster's mass is…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Motokazu Takizawa , Ryo Nagino , Kyoko Matsushita

We exmaine the distribution of hot gas in a standard CDM model of the universe using high resolution hydrodynamic simulations. Adopting standard parameters determined from COBE and light element nucleosynthesis, $\sigma_8=1.05$,…

Astrophysics · Physics 2009-10-22 Hyesung Kang , Renyue Cen , Jeremiah P. Ostriker , Dongsu Ryu

Heating of charged particles via collisionless shocks, while ubiquitous in the universe, is an intriguing yet puzzling plasma phenomenon. One outstanding question is how electrons and ions approach an equilibrium after they were heated to…

High Energy Astrophysical Phenomena · Physics 2024-05-16 Masahiro Ichihashi , Aya Bamba , Yuichi Kato , Satoru Katsuda , Hiromasa Suzuki , Tomoaki Kasuga , Hirokazu Odaka , Kazuhiro Nakazawa

Depending on the topology of the magnetic field and characteristics of turbulent motions, diffusion can significantly affect the distribution of elements, in particular helium, in the intracluster medium (ICM). As has been noted previously,…

High Energy Astrophysical Phenomena · Physics 2015-11-25 P. Medvedev , M. Gilfanov , S. Sazonov , P. Shtykovskiy

We investigate the growth over time of 20 massive (> 3 keV) clusters in a hydrodynamical simulation of the LambdaCDM cosmology with radiative cooling. The clusters show a variety of formation histories: some accrete most of their mass in…

Astrophysics · Physics 2009-11-10 David R. Rowley , Peter A. Thomas , Scott T. Kay

Knowing the characteristic relaxation time of free electrons in a dense plasma is crucial to our understanding of plasma equilibration and transport. However, experimental investigations of electron relaxation dynamics have been hindered by…

Plasma Physics · Physics 2024-08-27 Yuanfeng Shi , Shenyuan Ren , Hyun-kyung Chung , Justin S. Wark , Sam M. Vinko

In this paper we have made an attempt to derive the radial profiles of density and temperature of intracluster gas based on the two well-established facts at present: the X-ray observed surface brightness of clusters described by the…

Astrophysics · Physics 2009-10-31 Xiang-Ping Wu , Tzihong Chiueh

Accurate mass determination of clusters of galaxies is crucial if they are to be used as cosmological probes. However, there are some discrepancies between cluster masses determined based on gravitational lensing, and X-ray observations…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 S. M. Molnar , I. -N. Chiu , K. Umetsu , P. Chen , N. Hearn , T. Broadhurst , G. Bryan , C. Shang

The evolution of the properties of the hot gas that fills the potential well of galaxy clusters is poorly known, since models are unable to give robust predictions and observations lack a sufficient redshift leverage and are affected by…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 S. Andreon , G. Trinchieri , F. Pizzolato

In this article, we study the production of Hydrogen and Helium isotopes in heavy-ion collisions in the incident energy range between 80 and 150 MeV/nucleon. We compare their inclusive multiplicities emitted in the transverse plane of the…

We run adiabatic N-body/hydrodynamical simulations of isolated self-gravitating gas clouds to test whether conformal gravity, an alternative theory to General Relativity, is able to explain the properties of X-ray galaxy clusters without…

Astrophysics · Physics 2009-11-13 Antonaldo Diaferio , Luisa Ostorero

The gas in the cores of many clusters and groups of galaxies has a short radiative cooling time. Energy from the central black hole is observed to flow into this gas by means of jets, bubbles and sound waves. Cooling is thus offset by…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 A. C. Fabian , J. S. Sanders

In this paper we investigate the feasibility of bremsstrahlung radiation from `nonthermal' electrons as a source of hard X-rays from the intracluster medium of clusters of galaxies. With an exact treatment of the Coulomb collisions in a…

Astrophysics · Physics 2013-03-08 Vahé Petrosian , William E. East

We investigate evolution of the intracluster medium (ICM), considering the relaxation process between the ions and electrons. According to the standard scenario of structure formation, ICM is heated by the shock in the accretion flow to the…

Astrophysics · Physics 2009-10-30 Motokazu Takizawa

Clusters of galaxies generally form by the gravitational merger of smaller clusters and groups. Mergers drive shocks in the intracluster gas which heat the intracluster gas. Mergers disrupt cluster cooling cores. Mergers produce large,…

Astrophysics · Physics 2007-05-23 Craig L. Sarazin

We investigate the predicted present-day temperature profiles of the hot, X-ray emitting gas in galaxy clusters for two cosmological models - a current best-guess LCDM model and standard cold dark matter (SCDM). Our numerically-simulated…

Astrophysics · Physics 2008-11-26 C. Loken , M. L. Norman , E. Nelson , J. Burns , G. L. Bryan , P. Motl

We propose a Bayesian inference estimation of in-medium modification of the cluster self-energies from light nuclei multiplicities measured in selected samples of central $^{136,124}$Xe$+^{124,112}$Sn collisions with the INDRA apparatus.…

Using a large and well-controlled sample of clusters of galaxies, we investigate the relation between cluster velocity dispersions and X-ray temperatures of intra-cluster gas. In order to obtain a reliable estimate of the total velocity…

Astrophysics · Physics 2009-10-28 M. Girardi , D. Fadda , G. Giuricin , F. Mardirossian , M. Mezzetti , A. Biviano

Recent analyses of XMM and Chandra data of the cores of X-ray bright clusters of galaxies show that modeling with a multi-phase gas in which several temperatures and densities are in equilibrium might not be appropriate. Instead, a…

Astrophysics · Physics 2009-11-07 S. Ettori
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