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For the low density filamentary and sheet-like structures in the warm ($\sim 10^4$ to $\sim 10^6$ K) IGM predicted by numerical simulations the resonant line scattering of X-ray background (XRB) photons by He and H-like ions of heavy…

Astrophysics · Physics 2009-10-31 E. Churazov , M. Haehnelt , O. Kotov , R. Sunyaev

High-spectral resolution observations of clusters of galaxies are a powerful tool to understand the physical processes taking place in these massive objects. Their hot multi-million-degree X-ray emitting cluster atmospheres, containing most…

High Energy Astrophysical Phenomena · Physics 2025-02-27 Jeremy S. Sanders

Cool-core clusters are characterized by strong surface brightness peaks in the X-ray emission from the Intra Cluster Medium (ICM). This phenomenon is associated with complex physics in the ICM and has been a subject of intense debate and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Joana S. Santos , Paolo Tozzi , Piero Rosati , Hans Boehringer

For a detailed comparison of the appearance of cluster of galaxies in X-rays and in the optical, we have compiled a comprehensive database of X-ray and optical properties of a sample of clusters based on the largest available X-ray and…

Astrophysics · Physics 2009-11-10 P. Popesso , H. Boehringer , J. Brinkmann , W. Voges , D. G. York

Inverse Compton (IC) scattering of nuclear photons with relativistic electrons in the lobes of powerful radio galaxies and quasars can give detectable extended X-ray emission from the radio lobes if relativistic electrons with a Lorentz…

Astrophysics · Physics 2009-11-06 G. Brunetti , M. Cappi , G. Setti , L. Feretti , D. E. Harris

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

We suggest that the luminous extreme ultraviolet (EUV) emission which has been detected recently from clusters of galaxies is Inverse Compton (IC) scattering of Cosmic Microwave Background (CMB) radiation by low energy cosmic ray electrons…

Astrophysics · Physics 2009-10-30 Craig L. Sarazin , Richard Lieu

(abridged) We use a theoretical model to predict the clustering properties of galaxy clusters. Our technique accounts for past light-cone effects on the observed clustering and follows the non-linear evolution of the dark matter correlation…

Astrophysics · Physics 2009-10-31 Lauro Moscardini , Sabino Matarrese , H. J. Mo

We report the detection of extended X-ray emission around several powerful 3CR quasars with redshifts out to 0.73. The ROSAT HRI images of the quasars have been corrected for spacecraft wobble and compared with an empirical point-spread…

Astrophysics · Physics 2009-10-31 C. S. Crawford , I. Lehmann , A. C. Fabian , M. N. Bremer , G. Hasinger

We present a new treatment of two popular models for the growth of structure, examining the X-ray emission from hot gas with allowance for spectral line emission from various atomic species, primarily ``metals". The X-ray emission from the…

Astrophysics · Physics 2016-08-30 Renyue Cen , Hyesung Kang , Jeremiah P. Ostriker , Dongsu Ryu

The spatial clustering of galaxies in galaxy clusters implies that the background of infrared (IR) light in the intracluster medium (ICM) may exceed the universal background. Cosmic rays injected within the ICM propagate diffusively and at…

Astrophysics · Physics 2009-11-13 Daniel De Marco , Pasquale Blasi , Patricia Hansen , Todor Stanev

Star-forming galaxies which are too faint to be detected individually produce intensity fluctuations in the cosmic background light. This contribution needs to be taken into account as a foreground when using the primordial signal to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Han-Seek Kim , C. G. Lacey , S. Cole , C. M. Baugh , C. S. Frenk , G. Efstathiou

The presence of a diffuse stellar component in galaxy clusters has been established by a number of observational works in recent years. In this contribution I summarize our results (Zibetti et al. 2005) obtained by stacking SDSS images of…

Astrophysics · Physics 2009-11-13 Stefano Zibetti

Measurements of the Sunyaev-Zeldovich (hereafter SZ) distorsion of the cosmic microwave background can give interesting physical informations on clusters of galaxies, provided that the electronic temperature of the gas is known. Previous…

Astrophysics · Physics 2007-05-23 E. Pointecouteau , M. Giard , D. Barret

We use simulations to predict the X-ray surface brightness distribution arising from hot, cosmologically distributed diffuse gas. The distribution is computed for two bands: 0.5-2 keV and 0.1-0.4 keV, using a cosmological-constant dominated…

Astrophysics · Physics 2009-11-06 Greg L. Bryan , G. Mark Voit

BeppoSAX observations of the high redshift (z=4.72) blazar GB 1428+4217 confirm the presence of a complex soft X-ray spectrum first seen with the ROSAT PSPC. Flattening below a rest frame energy of 5 keV can be accounted for by absorption…

Astrophysics · Physics 2009-09-17 A. C. Fabian , A. Celotti , K. Iwasawa , G. Ghisellini

We use gas-dynamical simulations of galaxy clusters to compare their X-ray and strong lensing properties. Special emphasis is laid on mass estimates. The cluster masses range between 6 x 10^14 solar masses and 4 x 10^15 solar masses, and…

Astrophysics · Physics 2015-06-24 Matthias Bartelmann , Matthias Steinmetz

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

We perform Monte Carlo simulations of cosmic ray-induced hard X-ray radiation from the Earth's atmosphere. We find that the shape of the spectrum emergent from the atmosphere in the energy range 25-300 keV is mainly determined by Compton…

Astrophysics · Physics 2008-11-26 S. Sazonov , E. Churazov , R. Sunyaev , M. Revnivtsev

We compute the contribution from clusters of galaxies to the diffuse neutrino and $\gamma-$ray background. Due to their unique magnetic-field configuration, cosmic rays (CRs) with energy $\leq10^{17}$ eV can be confined within these…

High Energy Astrophysical Phenomena · Physics 2023-08-01 Saqib Hussain , Giulia Pagliaroli , Elisabete M. de Gouveia Dal Pino