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A luminosity-temperature relation for clusters of galaxies is derived. The two models used, take into account the angular momentum acquisition by the proto-structures during their expansion and collapse. The first one is a modification of…

Astrophysics · Physics 2009-11-13 A. Del Popolo , N. Hiotelis , J. Penarrubia

We investigate the luminosity-temperature ($L$-$T$) relation of galaxy clusters as a probe for testing modified gravity (MG) theories, focusing on $f(R)$ gravity and symmetron models. Using an improved semi-analytic framework that…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-31 Antonino Del Popolo , Saeed Fakhry , David F. Mota

We present results on the total mass and temperature determination using two samples of clusters of galaxies. One sample is constructed with emphasis on the completeness of the sample, while the advantage of the other is the use of the…

Astrophysics · Physics 2011-07-19 A. Finoguenov , T. H. Reiprich , H. Boehringer

The physical processes that define the spine of the galaxy cluster X-ray luminosity -- temperature (L-T) relation are investigated using a large hydrodynamical simulation of the Universe. This simulation models the same volume and phases as…

Astrophysics · Physics 2009-11-13 W. G. Hartley , L. Gazzola , F. R. Pearce , S. T. Kay , P. A. Thomas

Combining conservation of energy throughout nearly-spherical collapse of galaxy clusters with the virial theorem, we derive the mass-temperature relation for X-ray clusters of galaxies $T=CM^{2/3}$. The normalization factor $C$ and the…

Astrophysics · Physics 2009-08-29 Niayesh Afshordi , Renyue Cen

We derive the mass-temperature relation using an improved top-hat model and a continuous formation model which takes into account the effects of the ordered angular momentum acquired through tidal-torque interaction between clusters, random…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-21 Antonino Del Popolo , Francesco Pace , David F. Mota

We have obtained the first large sample of accurate temperatures for clusters at z>0.14 from ASCA. We compare the luminosity temperature (L-T) distribution for these clusters with the low redshift sample of David et al (1993) and find that…

Astrophysics · Physics 2009-10-30 R. F. Mushotzky , C. A. Scharf

We propose two hypotheses which characterize the quasi-equilibrium state that realizes after a cold collapse of self-gravitating system. The first hypothesis is the linear temperature-mass (TM) relation, which yields a characteristic…

Astrophysics · Physics 2007-05-23 Y. Sota , O. Iguchi , M. Morikawa , A. Nakamichi

In this paper based on ROSAT/PSPC data we investigate the emission measure profiles of a sample of hot clusters of galaxies (kT>3.5keV) in order to explain the differences between observed and theoretically predicted L_X-T relation. Looking…

Astrophysics · Physics 2009-11-06 D. M. Neumann , M. Arnaud

The relation between X-ray luminosity (L_X) and ambient gas temperature (T) among massive galactic systems is an important cornerstone of both observational cosmology and galaxy-evolution modeling. In the most massive galaxy clusters, the…

Astrophysics of Galaxies · Physics 2018-02-14 G. M. Voit , C. P. Ma , J. Greene , A. Goulding , V. Pandya , M. Donahue , M. Sun

I derive the mass-temperature relation and its time evolution for clusters of galaxies in different cosmologies by means of two different models. The first one is a modification and improvement of a model by Del Popolo & Gambera(1999),…

Astrophysics · Physics 2009-11-07 A. Del Popolo

The formation of self-gravitating systems is studied by simulating the collapse of a set of N particles which are generated from several distribution functions. We first establish that the results of such simulations depend on N for small…

Astrophysics · Physics 2009-11-10 F. Roy , J. Perez

This work is devoted to the thermodynamics of gravitational clustering, a collective phenomenon with a great relevance in the $N$-body cosmological problem. We study a classical self-gravitating gas of identical non-relativistic particles…

Statistical Mechanics · Physics 2016-11-03 F. Tello-Ortiz , L. Velazquez

While in the hierarchical model of structure formation, groups of galaxies are believed to be the scaled-down version of clusters of galaxies, a similarity breaking in the fundamental laws may occur on the group scale, reflecting a…

Astrophysics · Physics 2009-10-31 Yan-Jie Xue , Xiang-Ping Wu

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

We investigate the form and evolution of the X-ray luminosity-temperature (LT) relation of a sample of 114 galaxy clusters observed with Chandra at 0.1<z<1.3. The clusters were divided into subsamples based on their X-ray morphology or…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 B. J. Maughan , P. A. Giles , S. W. Randall , C. Jones , W. R. Forman

Most studies of correlations between X-ray and optical properties of galaxy clusters have used the largest samples of data available, regardless of the morphological types of clusters included. Given the increasing evidence that morphology…

Astrophysics · Physics 2009-10-28 Christina M. Bird , Richard F. Mushotzky , Christopher A. Metzler

The X-ray luminosity and temperature of clusters and groups of galaxies do not scale in a self-similar manner. This has often been interpreted as a sign that the intracluster medium has been substantially heated by non-gravitational…

Astrophysics · Physics 2009-10-31 Greg L. Bryan

The relationship between the X-ray determined temperature $T$ of the intracluster gas and the optical measured velocity dispersion $\sigma$ of the cluster galaxies is often believed to be not only a straightforward but also robust test for…

Astrophysics · Physics 2007-05-23 Xiang-Ping Wu , Li-Zhi Fang , Wen Xu

We derive constraints on the mass-temperature relation of galaxy clusters from their observed luminosity-temperature relation and X-ray temperature function. Adopting the isothermal gas in hydrostatic equilibrium embedded in the universal…

Astrophysics · Physics 2009-11-07 Mamoru Shimizu , Tetsu Kitayama , Shin Sasaki , Yasushi Suto
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