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The presence of a volume density gradient in molecular clumps allow them to raise their star formation rate compared to what they would experience were their gas uniform in density. This higher star formation rate yields in turn a higher…

Astrophysics of Galaxies · Physics 2020-04-22 Genevieve Parmentier

X-ray observations of galaxy clusters potentially provide powerful cosmological probes if systematics due to our incomplete knowledge of the intracluster medium (ICM) physics are understood and controlled. In this paper, we present mock…

Astrophysics · Physics 2008-11-26 Daisuke Nagai , Alexey Vikhlinin , Andrey V. Kravtsov

We test the reliability of mass determination in clusters of galaxies by X-ray observations. The true mass in cluster models is compared to the mass derived by the X-ray emission and X-ray temperature of a model assuming hydrostatic…

Astrophysics · Physics 2016-08-30 Sabine Schindler

Cosmological information is encoded in the structure of galaxy clusters. In Universes with less matter and larger initial density perturbations, clusters form earlier and have more time to accrete material, leading to a more extended infall…

We present results on the X-ray properties of clusters and groups of galaxies, extracted from a large hydrodynamical simulation. We used the GADGET code to simulate a LambdaCDM model within a box of 192 Mpc/h on a side, with 480^3 dark…

Likelihood fitting to two-point clustering statistics made from galaxy surveys usually assumes a multivariate normal distribution for the measurements, with justification based on the central limit theorem given the large number of…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-23 Mike Shengbo Wang , Will J. Percival , Santiago Avila , Robert Crittenden , Davide Bianchi

Numerical simulations with varying realism indicate an emergent principle -- multiphase condensation and large cavity power occur when the ratio of the cooling time to the free-fall time ($t_{\rm cool}/t_{\rm ff}$) falls below a threshold…

Astrophysics of Galaxies · Physics 2022-08-22 Kartick C Sarkar , Arjun Dey , Prateek Sharma

We report the results of our study of fractional entropy enhancement in the intra-cluster medium (ICM) of the clusters from the representative XMM-Newton cluster structure survey (REXCESS). We compare the observed entropy profile of these…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Anya Chaudhuri , Biman B. Nath , Subhabrata Majumdar

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 cosmological implications from a new estimate of the local X-ray galaxy cluster abundance are summarized. The results are then compared to independent observations. It is suggested that `low' values for the mean cosmic matter density…

Astrophysics · Physics 2007-05-23 Thomas H. Reiprich

Recent Suzaku X-ray observations revealed that the observed entropy profile of the intracluster medium (ICM) deviates significantly from the prediction of hydrodynamical simulations of galaxy clusters. In this work, we show that gas…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Daisuke Nagai , Erwin Lau

We study the relative fraction of galaxy morphological types in clusters, as a function of the projected local galaxy density and different global parameters: cluster projected gas density, cluster projected total mass density , and reduced…

Astrophysics · Physics 2016-08-30 Mariano Dominguez , Hernan Muriel , Diego G. Lambas

Observations and numerical simulations have shown that the relation between the mass scaled with the critical density of the universe and the X-ray temperature of galaxy clusters is approximately represented by $M_\Delta \propto T_X^{3/2}$…

Astrophysics of Galaxies · Physics 2018-08-15 Yutaka Fujita , Keiichi Umetsu , Stefano Ettori , Elena Rasia , Nobuhiro Okabe , Massimo Meneghetti

We use a self-consistent modeling of x-ray cluster properties to constrain cosmological scenarios of structure formation in the case of open cosmological models. We first show that an unbiased open model can reproduce present day…

Astrophysics · Physics 2019-08-15 J. Oukbir , A. Blanchard

In this work, we use two gas mass fraction samples of galaxy clusters obtained from their X-ray surface brightness observations jointly with recent $H(z)$ data in a flat $\Lambda$CDM framework to impose limits on cosmic opacity. It is…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-01 R. F. L. Holanda , Kamilla V. R. A. Silva , V. C. Busti

The reconstruction of galaxy cluster's gas density profiles is usually performed by assuming spherical symmetry and averaging the observed X-ray emission in circular annuli. In the case of a very inhomogeneous and asymmetric gas…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 D. Eckert , M. Roncarelli , S. Ettori , S. Molendi , F. Vazza , F. Gastaldello , M. Rossetti

The study of galaxy cluster outskirts has emerged as one of the new frontiers in extragalactic astrophysics and cosmology with the advent of new observations in X-ray and microwave. However, the thermodynamic properties and chemical…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-24 Camille Avestruz , Erwin T. Lau , Daisuke Nagai , Alexey Vikhlinin

The exploitation of clusters of galaxies as cosmological probes relies on accurate measurements of their total gravitating mass. X-ray observations provide a powerful means of probing the total mass distribution in galaxy clusters, but…

Astrophysics · Physics 2009-11-13 Rocco Piffaretti , Riccardo Valdarnini

New extragalactic measurements of the cloud population-averaged star formation (SF) efficiency per freefall time $\rm\epsilon_{\rm ff}$ from PHANGS show little sign of theoretically predicted dependencies on cloud-scale virial level or…

We use the Allen et al. (2008) galaxy cluster gas mass fraction versus redshift data to constrain parameters of three different dark energy models: a cosmological constant dominated one ($\Lambda$CDM); the XCDM parameterization of dark…

Astrophysics · Physics 2010-11-11 Lado Samushia , Bharat Ratra
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