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Using an analytical model and numerical simulations, we show that acoustic waves generated by turbulent motion in intracluster medium effectively heat the central region of a so-called ``cooling flow'' cluster. We assume that the turbulence…

Astrophysics · Physics 2009-11-10 Yutaka Fujita , Takeru Ken Suzuki , Keiichi Wada

Recent X-ray observations revealed that strong cooling flow of intracluster gas is not present in galaxy clusters, even though predicted theoretically if there is no additional heating source. I show that relativistic particles produced by…

Astrophysics · Physics 2009-11-10 Tomonori Totani

We study the effects of externally imposed turbulence on the thermal properties of galaxy cluster cores, using three-dimensional numerical simulations including magnetic fields, anisotropic thermal conduction, and radiative cooling. The…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Ian J. Parrish , Eliot Quataert , Prateek Sharma

Cool gas should be present in galaxy clusters due to stripping of galactic gas, infall onto the cluster, and from cooling flows. We searched for this gas through resonance absorption line observations from low-ionization metal line gas…

Astrophysics · Physics 2007-05-23 Eric D. Miller , Joel N. Bregman , Patricia M. Knezek

Precision cosmology studies based on wide-field surveys of galaxy clusters benefit from constraints on intrinsic scatter in mass-observable relationships. In principle, two-parameter models combining direct measurements of galaxy cluster…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 D. A. Ventimiglia , G. M. Voit , E. Rasia

Gas clouds under the influence of gravitation in thermodynamic equilibrium cannot be isothermal due to the Dufour effect, the energy flux induced by density gradients. In galaxy clusters this effect may be responsible for most of the…

Astrophysics · Physics 2007-05-23 E. Fischer

We analyzed Chandra X-ray observations of five galaxy clusters whose atmospheric cooling times, entropy parameters, and cooling time to free-fall time ratios within the central galaxies lie below 1 Gyr, below 30 keV cm^2, and between 20 <…

Many processes within galaxy clusters, such as those believed to govern the onset of thermally unstable cooling and AGN feedback, are dependent upon local dynamical timescales. However, accurately mapping the mass distribution within…

Astrophysics of Galaxies · Physics 2017-03-08 M. T. Hogan , B. R. McNamara , F. Pulido , P. E. J. Nulsen , H. R. Russell , A. N. Vantyghem , A. C. Edge , R. A. Main

In galaxy clusters, the hot intracluster medium (ICM) can develop a striking multi-phase structure around the brightest cluster galaxy. Much work has been done on understanding the origin of this central nebula, but less work has studied…

Astrophysics of Galaxies · Physics 2022-12-01 Fred Jennings , Ricarda Beckmann , Debora Sijacki , Yohan Dubois

The nature of the interaction between low-excitation gas filaments at ~10^4 K, seen in optical line emission, and diffuse X-ray emitting coronal gas at ~10^7 K in the centers of galaxy clusters remains a puzzle. The presence of a strong,…

Observations of gravitational lensing indicate that the mass distribution in clusters of galaxies (where most of the mass is dark matter) is highly peaked towards the center, while X-ray observations imply that the gas is more extended. The…

Astrophysics · Physics 2009-10-28 Eli Waxman , Jordi Miralda-Escudé

We examine the relationship between the mass and x-ray gas temperature of galaxy clusters using data drawn from the literature. Simple theoretical arguments suggest that the mass of a cluster is related to the x-ray temperature as $M…

Astrophysics · Physics 2009-10-31 Donald J. Horner , Richard F. Mushotzky , Caleb A. Scharf

We examine the effects of cooling flows on the T_X-L_Bol relation for a sample of the most X-ray luminous (L_Bol > 10^45 erg/s) clusters of galaxies known. Using high-quality ASCA X-ray spectra and ROSAT images we explicitly account for the…

Astrophysics · Physics 2009-10-30 S. W. Allen , A. C. Fabian

Iron abundance distribution is now known for 12 clusters of galaxies. For some clusters (e.g. Centaurus) the observed abundance increases toward the cluster center, while for the others (e.g. Coma and Hydra-A) no significant inhomogeneity…

Astrophysics · Physics 2009-10-22 Yutaka Fujita , Hideo Kodama

It has been proposed that the cool cores of galaxy clusters are stably heated by cosmic rays (CRs). If this is the case, radio mini-halos, which are often found in the central regions of cool core clusters, may be attributed to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Yutaka Fujita , Yutaka Ohira

In this letter we present a study of the central regions of cool-core clusters hosting radio mini-halos, which are diffuse synchrotron sources extended on cluster-scales surrounding the radio-loud brightest cluster galaxy. We aim to…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-04 Luca Bravi , Myriam Gitti , Gianfranco Brunetti

Cold fronts (CFs) - density and temperature plasma discontinuities - are ubiquitous in cool cores of galaxy clusters, where they appear as X-ray brightness edges in the intracluster medium, nearly concentric with the cluster center. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Uri Keshet , Maxim Markevitch , Yuval Birnboim , Abraham Loeb

We present an analysis of a 40 ksec Chandra observation of the galaxy group AWM 5. It has a small ($\sim8$ kpc) dense cool core with a temperature of $\sim1.2$ keV and the temperature profile decreases at larger radii, from $\sim3.5$ keV…

Astrophysics · Physics 2011-02-11 A. Baldi , W. Forman , C. Jones , P. Nulsen , L. David , R. Kraft , A. Simionescu

Results from a large sample of hydrodynamical/N-body simulations of galaxy clusters in a LCDM cosmology are used to simulate cluster X-ray observations as expected from Chandra observations. The physical modeling of the gas includes…

Astrophysics · Physics 2009-11-11 R. Valdarnini

We apply to radio mini-halo candidates a model for electron re-acceleration in cooling flows (Gitti, Brunetti & Setti 2002). In agreement with the basic idea of the model, we find that the power required for the re-acceleration of the…

Astrophysics · Physics 2007-05-23 Myriam Gitti , Gianfranco Brunetti , Giancarlo Setti , Luigina Feretti