scholarly journals New observational constraints on interacting dark energy using galaxy clusters virial equilibrium states

2019 ◽  
Vol 490 (2) ◽  
pp. 1944-1952
Author(s):  
M Le Delliou ◽  
R J F Marcondes ◽  
G B Lima Neto

ABSTRACT The nature of the dark sector components of the Universe still remains one of the largest unknown. Among many possibilities, it has been speculated that dark matter and dark energy may be more tightly coupled than usually thought, one component interacting with the other. Here, we continue to explore the possible dark sector interaction through means of the Layzer–Irvine equation together with a model of an interacting dark sector applied to clusters of galaxies. We have selected galaxy clusters that have their mass profiles determined by gravitational lensing effect (optical observations) and have their intracluster gas temperatures measured from X-ray observations and spectral fit found in the literature. Using a simple model based on semi-analytical simulations, we derived a putative dynamical evolution of the clusters and used it to estimate the coupling parameter of the dark sector interaction. Through a Bayesian analysis, we obtain a 3σ detection of the interaction strength for 11 clusters at −0.027 ± 0.009 that translates in a compounded Universal equilibrium virial ratio, U/T, of $-0.61^{+0.04}_{-0.03}$. We note that the X-ray temperature determination is sometimes inconsistent, depending on the instrument and/or methodology used. The level of detection and these inconsistencies call for caution. We expect that future observations will give us a clearer indication of an eventual dark sector interaction.

Author(s):  
Alexander Bonilla Rivera ◽  
Jairo Ernesto Castillo Hernandez

The Sunyaev-Zeldovich effect (SZe) is a global distortion of Cosmic Microwave Bckground (CMB) spectrum as result of its interaction with a hot electron plasma in the intracluster medium for large gravitational virialized structures such as galaxy clusters. Furthermore, this hot gas of electrons emits X-Rays due to its fall in the gravitational potential well of the cluster. The analysis of SZe and X-Ray data, provide a method for calculating distances to galaxy clusters at any redshift (Angular diameter distance (dA) and gas mass fraction (fgas)). On the other side, many of these galaxy clusters produce a Strong Gravitational Lens effect (SGL), which has become an useful astrophysical tool for cosmology. We use these cosmological tests, in addition to the more traditional ones (SNIa, CMB, BAO), to constraint alternative models of dark energy (ωCDM, CPL, IDE, EDE) and study the history of expansion through the cosmographic parameters (H(z), q(z), j(z)). Using Akaike and Bayesian Information Criterion (AIC, BIC) we find that the ωCDM and ΛCDM models are the most favored by the observational data. In addition, we found that at low redshift appears an peculiar behavior of slowdown of aceleration, which occurs only on dynamical dark energy models using only galaxy clusters (dA,clusters + fgas).


2019 ◽  
Vol 488 (3) ◽  
pp. 3646-3662 ◽  
Author(s):  
Andrew Robertson ◽  
David Harvey ◽  
Richard Massey ◽  
Vincent Eke ◽  
Ian G McCarthy ◽  
...  

ABSTRACT We present bahamas-SIDM, the first large-volume, $(400 \, h^{-1} \mathrm{\, Mpc})^{3}$, cosmological simulations including both self-interacting dark matter (SIDM) and baryonic physics. These simulations are important for two primary reasons: (1) they include the effects of baryons on the dark matter distribution and (2) the baryon particles can be used to make mock observables that can be compared directly with observations. As is well known, SIDM haloes are systematically less dense in their centres, and rounder, than CDM haloes. Here, we find that that these changes are not reflected in the distribution of gas or stars within galaxy clusters, or in their X-ray luminosities. However, gravitational lensing observables can discriminate between DM models, and we present a menu of tests that future surveys could use to measure the SIDM interaction strength. We ray-trace our simulated galaxy clusters to produce strong lensing maps. Including baryons boosts the lensing strength of clusters that produce no critical curves in SIDM-only simulations. Comparing the Einstein radii of our simulated clusters with those observed in the CLASH survey, we find that at velocities around $1000 \mathrm{\, km \, s^{-1}}$ an SIDM cross-section of $\sigma /m \gtrsim 1 \, \mathrm{cm^2 \, g^{-1}}$ is likely incompatible with observed cluster lensing.


Author(s):  
Alexander Bonilla Rivera ◽  
Jairo Ernesto Castillo Hernandez

The Sunyaev-Zeldovich effect (SZe) is a global distortion of Cosmic Microwave Bckground (CMB) spectrum as result of its interaction with a hot electron plasma in the intracluster medium for large gravitational virialized structures such as galaxy clusters. Furthermore, this hot gas of electrons emits X-Rays due to its fall in the gravitational potential well of the cluster. The analysis of SZe and X-Ray data, provide a method for calculating distances to galaxy clusters at any redshift (Angular diameter distance (dA) and gas mass fraction (fgas)). On the other side, many of these galaxy clusters produce a Strong Gravitational Lens effect (SGL), which has become an useful astrophysical tool for cosmology. We use these cosmological tests, in addition to the more traditional ones (SNIa, CMB, BAO), to constraint alternative models of dark energy (ωCDM, CPL, IDE, EDE) and study the history of expansion through the cosmographic parameters (H(z), q(z), j(z)). Using Akaike and Bayesian Information Criterion (AIC, BIC) we find that the ωCDM and ΛCDM models are the most favored by the observational data. In addition, we found that at low redshift appears an peculiar behavior of slowdown of aceleration, which occurs only on dynamical dark energy models using only galaxy clusters (dA,clusters + fgas).


2005 ◽  
Vol 216 ◽  
pp. 373-380
Author(s):  
Marguerite Pierre

We outline the main arguments in favor of cosmological X-ray surveys of galaxy clusters. We summarize recent advances in our understanding of cluster physics. After a short review of past surveys, we present the scientific motivations of the XMM Large Scale Structure survey. We further illustrate how such a survey can help constrain the nature of the dark energy as well as cluster scaling law evolution, i.e. non-gravitational physics.


2012 ◽  
Vol 423 (3) ◽  
pp. 2503-2517 ◽  
Author(s):  
B. Sartoris ◽  
S. Borgani ◽  
P. Rosati ◽  
J. Weller

2008 ◽  
Vol 387 (3) ◽  
pp. 1179-1192 ◽  
Author(s):  
A. Mantz ◽  
S. W. Allen ◽  
H. Ebeling ◽  
D. Rapetti
Keyword(s):  

Author(s):  
D. RAPETTI ◽  
S. W. ALLEN ◽  
A. MANTZ ◽  
R. G. MORRIS ◽  
H. EBELING ◽  
...  
Keyword(s):  

2018 ◽  
Vol 614 ◽  
pp. A38 ◽  
Author(s):  
C. Tchernin ◽  
M. Bartelmann ◽  
K. Huber ◽  
A. Dekel ◽  
G. Hurier ◽  
...  

Context. The mass of galaxy clusters is not a direct observable, nonetheless it is commonly used to probe cosmological models. Based on the combination of all main cluster observables, that is, the X-ray emission, the thermal Sunyaev–Zel’dovich (SZ) signal, the velocity dispersion of the cluster galaxies, and gravitational lensing, the gravitational potential of galaxy clusters can be jointly reconstructed. Aims. We derive the two main ingredients required for this joint reconstruction: the potentials individually reconstructed from the observables and their covariance matrices, which act as a weight in the joint reconstruction. We show here the method to derive these quantities. The result of the joint reconstruction applied to a real cluster will be discussed in a forthcoming paper. Methods. We apply the Richardson-Lucy deprojection algorithm to data on a two-dimensional (2D) grid. We first test the 2D deprojection algorithm on a β-profile. Assuming hydrostatic equilibrium, we further reconstruct the gravitational potential of a simulated galaxy cluster based on synthetic SZ and X-ray data. We then reconstruct the projected gravitational potential of the massive and dynamically active cluster Abell 2142, based on the X-ray observations collected with XMM-Newton and the SZ observations from the Planck satellite. Finally, we compute the covariance matrix of the projected reconstructed potential of the cluster Abell 2142 based on the X-ray measurements collected with XMM-Newton. Results. The gravitational potentials of the simulated cluster recovered from synthetic X-ray and SZ data are consistent, even though the potential reconstructed from X-rays shows larger deviations from the true potential. Regarding Abell 2142, the projected gravitational cluster potentials recovered from SZ and X-ray data reproduce well the projected potential inferred from gravitational-lensing observations. We also observe that the covariance matrix of the potential for Abell 2142 reconstructed from XMM-Newton data sensitively depends on the resolution of the deprojected grid and on the smoothing scale used in the deprojection. Conclusions. We show that the Richardson-Lucy deprojection method can be effectively applied on a grid and that the projected potential is well recovered from real and simulated data based on X-ray and SZ signal. The comparison between the reconstructed potentials from the different observables provides additional information on the validity of the assumptions as function of the projected radius.


2017 ◽  
Vol 95 (11) ◽  
pp. 1049-1061 ◽  
Author(s):  
Rakesh Raushan ◽  
R. Chaubey

In this paper, we study the dynamical evolution of locally rotationally symmetric (LRS) Bianchi type I cosmological model with coupling of dark sector. We investigate the phase-plane analysis when dark energy is modelled as exponential quintessence, and is coupled to dark energy matter via linear coupling between both dark components. The evolution of cosmological solutions is studied by using dynamical systems techniques. Stability and viability issues for three different physically viable linear couplings between both dark components are presented and discussed in detail.


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