Current cosmological constraints on the scalar spectral index of primordial fluctuations $n_{\rm s}$ in the $Λ$CDM model have excluded the minimal scale-invariant Harrison-Zel'dovich model ($n_{\rm s}=1$; hereafter HZ) at high significance, providing support for inflation. In recent years, however, some tensions have emerged between different cosmological datasets that, if not due to systematics, could indicate the presence of new physics beyond the $Λ$CDM model. In the light of these developments, we evaluate the Bayesian evidence against HZ in different data combinations and model extensions. Considering only the Planck temperature data, we find inconclusive evidence against HZ when including variations in the neutrino number $N_{\rm eff}$ and/or the Helium abundance $Y_{\rm He}$. Adding the Planck polarization data, on the other hand, yields strong evidence against HZ in the extensions we considered. Perhaps most interestingly, Planck temperature data combined with local measurements of the Hubble constant give as the most probable model an HZ spectrum, with additional neutrinos. However, with the inclusion of polarisation, standard $Λ$CDM is once again preferred, but the HZ model with extra neutrinos is not strongly disfavored. The possibility of fully ruling out the HZ spectrum is therefore ultimately connected with the solution to current tensions between cosmological datasets. If these tensions are confirmed by future data, then new physical mechanisms could be at work and an HZ spectrum could still offer a valid alternative.
The Data Release 4 of the Atacama Cosmology Telescope (ACT) shows an agreement with an Harrison-Zel'dovich primordial spectrum ($n_s=1.009 \pm 0.015$), introducing a tension with a significance of $99.3\%$ CL with the results from the Planck satellite. The discrepancy on the value of the scalar spectral index is neither alleviated with the addition of large scale structure information nor with the low multipole polarization data. We discuss possible avenues to alleviate the tension relying on either neglecting polarization measurements from ACT or in extending different sectors of the theory.
Harrison-Zeldovich attractor: From Planck to ACT results
Anhui Normal University（安徽师范大学）；Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所）；Asia Pacific Center for Theoretical Physics (APCTP)（亚太理论物理中心）
According to the Harrison-Zel'dovich prescription, the amplitude of matter density perturbations at horizon crossing is the same at all scales. Based on this prescription, we show how to construct the matter power spectrum of generic dark energy models from the power spectrum of a $Λ$CDM model without the need of solving in full the dynamical equations describing the evolution of all energy density perturbations. Our approach allows to make model predictions of observables that can be expressed in terms of the matter power spectrum alone, such as the amplitude of matter fluctuations, peculiar …
We show that flat spectrum of small perturbations of field(s) is generated in a simple way in a theory of multi-component scalar field provided this theory is conformally invariant, it has some global symmetry and the quartic potential is negative. We suggest a mechanism of converting these field perturbations into adiabatic scalar perturbations with flat spectrum.
We introduce a novel approach, the Cosmological Trajectories Method (CTM), to model nonlinear structure formation in the Universe by expanding gravitationally-induced particle trajectories around the Zel'dovich approximation. A new Beyond Zel'dovich approximation is presented, which expands the CTM to leading second-order in the gravitational interaction and allows for post-Born gravitational scattering. In the Beyond Zel'dovich approximation we derive the exact expression for the matter clustering power spectrum. This is calculated to leading order and is available in the CTM MODULE. We compa…
The Sunyaev-Zel'dovich effect provides a useful probe of cosmology and structure formation in the Universe. Recent years have seen rapid progress in both quality and quantity of its measurements. In this review, we overview cosmological and astrophysical implications of recent and near future observations of the effect. They include measuring the evolution of the cosmic microwave background radiation temperature, the distance-redshift relation out to high redshifts, number counts and power spectra of galaxy clusters, distributions and dynamics of intracluster plasma, and large-scale motions of…
Baryon acoustic oscillations are an excellent technique to constrain the properties of dark energy in the Universe. In order to accurately characterize the dark energy equation of state, we must understand the effects of both the nonlinearities and redshift space distortions on the location and shape of the acoustic peak. In this paper, we consider these effects using the Zel'dovich approximation and a novel approach to 2nd order perturbation theory. The second order term of the Zel'dovich power spectrum is built from convolutions of the linear power spectrum with polynomial kernels in Fourier…
We report the first results of the MUSIC project. It consists of two data sets of resimulates clusters extracted from two large dark matter only simulations: Marenostrum Universe and Multidark. In total, the MUSIC contains more than 400 clusters resimulated with high resolution both with radiative and non-radiative physics included. Here we present the first results on the properties of the baryon content and the Sunyaev Zeldovich scaling relations.
We present results from a joint X-ray/Sunyaev-Zel'dovich modeling of the intra-cluster gas using XMM-Newton and APEX-SZ imaging data. The goal is to study the physical properties of the intra-cluster gas with a non-parametric de-projection method that is, aside from the assumption of spherical symmetry, free from modeling bias. We demonstrate a decrease of gas temperature in the cluster outskirts, and also measure the gas entropy profile, both of which are obtained for the first time independently of X-ray spectroscopy, using Sunyaev-Zel'dovich and X-ray imaging data. The contribution of the A…
The Copernican principle, a cornerstone of modern cosmology, remains largely unproven at Gpc radial scale and above. Here we will show that, violations of this type will inevitably cause a first order anisotropic kinetic Sunyaev Zel'dovich (kSZ) effect. If large scale radial inhomogeneities have amplitude large enough to explain the "dark energy" phenomena, the induced kSZ power spectrum will be much larger than the ACT/SPT upper limit. This single test confirms the Copernican principle and rules out the adiabatic void model as a viable alternative to dark energy.
Motivated by the results presented in a companion paper, here we give a simple analytical expression for the matter n-point functions in the Zel'dovich approximation (ZA) both in real and in redshift space (including the angular case). We present numerical results for the 2-dimensional redshift-space correlation function, as well as for the equilateral configuration for the real-space 3-point function. We compare those to the tree-level results. Our analysis is easily extendable to include Lagrangian bias, as well as higher-order perturbative corrections to the ZA. The results should be especi…
We investigate the possibility of detecting the turbulent state of the IGM with the kinetic Sunyaev-Zel'dovich (kSZ) effect. Being sensitive to the divergence-free component of the momentum field of the IGM, the kSZ effect might be used to probe the vorticity of the turbulent IGM. With cosmological hydrodynamical simulation in the concordance $Λ$CDM universe, we find that the structure functions of 2D kSZ maps show strong intermittence, and the intermittent exponents follow a law similar to the She-Leveque scaling formula of fully developed turbulence. We also find that the intermittence is we…
The cosmic microwave background (CMB) photons that scatter off free electrons in the large-scale structure induce a linear polarization pattern proportional to the remote CMB temperature quadrupole observed in the electrons' rest frame. The associated blackbody polarization anisotropies are known as the polarized Sunyaev Zel'dovich (pSZ) effect. Relativistic corrections to the remote quadrupole field give rise to a non-blackbody polarization anisotropy proportional to the square of the transverse peculiar velocity field; this is the kinetic polarized Sunyaev Zel'dovich (kpSZ) effect. In this p…
We perform a joint analysis of X-ray and Sunyaev Zel'dovich (SZ) effect data using an analytic model that describes the gas properties of galaxy clusters. The joint analysis allows the measurement of the cluster gas mass fraction profile and Hubble constant independent of cosmological parameters. Weak cosmological priors are used to calculate the overdensity radius within which the gas mass fractions are reported. Such an analysis can provide direct constraints on the evolution of the cluster gas mass fraction with redshift. We validate the model and the joint analysis on high signal-to-noise …
We investigate the imprint of dark energy on the kinetic Sunyaev-Zel'dovich (kSZ) angular power spectrum on scales of $\ell=1000$ to $10000$, and find that the kSZ signal is sensitive to the dark energy parameter. For example, varying the constant $w$ by 20\% around $w=-1$ results in a $\gtrsim10\%$ change on the kSZ spectrum; changing the dark energy dynamics parametrized by $w_a$ by $\pm0.5$, a 30\% change on the kSZ spectrum is expected. We discuss the observational aspects and develop a fitting formula for the kSZ power spectrum. Finally, we discuss how the precise modeling of the post-rei…
This year marks the 100th anniversary of the birth of Yakov Zel'dovich. Amongst his many legacies is the Zel'dovich approximation for the growth of large-scale structure, which remains one of the most successful and insightful analytic models of structure formation. We use the Zel'dovich approximation to compute the two-point function of the matter and biased tracers, and compare to the results of N-body simulations and other Lagrangian perturbation theories. We show that Lagrangian perturbation theories converge well and that the Zel'dovich approximation provides a good fit to the N-body resu…
The thermal Sunyaev-Zel'dovich (tSZ) and the kinematic Sunyaev-Zel'dovich (kSZ) effects trace the distribution of electron pressure and momentum in the hot Universe. These observables depend on rich multi-scale physics, thus, simulated maps should ideally be based on calculations that capture baryonic feedback effects such as cooling, star formation, and other complex processes. In this paper, we train deep convolutional neural networks with a U-Net architecture to map from the three-dimensional distribution of dark matter to electron density, momentum and pressure at ~ 100 kpc resolution. The…
We present 30 GHz measurements of the angular power spectrum of the cosmic microwave background (CMB) obtained with the Sunyaev-Zel'dovich Array. The measurements are sensitive to arcminute angular scales, where secondary anisotropy from the Sunyaev-Zel'dovich effect (SZE) is expected to dominate. For a broad bin centered at multipole 4066 we find 67+77-50 uK^2, of which 26+/-5 uK^2 is the expected contribution from primary CMB anisotropy and 80+/-54 uK^2 is the expected contribution from undetected radio sources. These results imply an upper limit of 155 uK^2 (95% CL) on the secondary contrib…
Baryon acoustic oscillations (BAO) are a powerful probe of the expansion history of the universe, which can tell us about the nature of dark energy. In order to accurately characterize the dark energy equation of state using BAO, we must understand the effects of both nonlinearities and redshift space distortions on the location and shape of the acoustic peak. In a previous paper we introduced a novel approach to 2nd order perturbation theory in configuration space using the Zel'dovich approximation, and presented a simple result for the first nonlinear term of the correlation function. In thi…
We measure the Cosmic Microwave Background (CMB) skewness power spectrum in $\textit{Planck}$, using frequency maps of the HFI instrument and the Sunyaev-Zel'dovich (SZ) component map. The two-to-one skewness power spectrum measures the cross-correlation between CMB lensing and the thermal SZ effect. We also directly measure the same cross-correlation using $\textit{Planck}$ CMB lensing map and the SZ map and compare it to the cross-correlation derived from the skewness power spectrum. We model fit the SZ power spectrum and CMB lensing-SZ cross power spectrum via the skewness power spectrum to…
We show how the correlation between the thermal Sunyaev Zel'dovich effect (tSZ) from galaxy clusters and dust emission from cosmic infrared background (CIB) sources can be calculated in a halo model framework. Using recent tSZ and CIB models, we find that the size of the tSZ x CIB cross-correlation is approximately 20 per cent at 150 GHz. The contribution to the total angular power spectrum is of order -2 μK^2 at ell=3000, however, this value is uncertain by a factor of two to three, primarily because of CIB source modelling uncertainties. We expect the large uncertainty in this component to d…
We calculate the dark matter halo correlation function in redshift space using the Gaussian streaming model (GSM). To determine the scale dependent functions entering the streaming model we use local Lagrangian bias together with Convolution Lagrangian perturbation theory (CLPT) which constitutes an approximation to the Post-Zel'dovich approximation. On the basis of N-body simulations we demonstrate that a smoothing of the initial conditions with the Lagrangian radius improves the Zel'dovich approximation and its ability to predict the displacement field of proto-halos. Based on this observati…
We present a new methodology to generate mock halo or galaxy catalogues, which have accurate clustering properties, nearly indistinguishable from full $N$-body solutions, in terms of the one-point, two-point, and three-point statistics. In particular, the agreement is remarkable, within $1\%$ up to $k=0.55$ $h$Mpc$^{-1}$ and down to $r=10$ $h^{-1}$Mpc, for the power spectrum and two-point correlation function respectively, while the bispectrum agrees in general within $20\%$ for different scales and shapes. Our approach is based on the Zel'dovich approximation, however, effectively including w…
We report 31 GHz CARMA observations of IDCS J1426.5+3508, an infrared-selected galaxy cluster at z = 1.75. A Sunyaev-Zel'dovich decrement is detected towards this cluster, indicating a total mass of M200 = (4.3 +/- 1.1) x 10^{14} Msun in agreement with the approximate X-ray mass of ~5 x 10^{14} Msun. IDCS J1426.5+3508 is by far the most distant cluster yet detected via the Sunyaev-Zel'dovich effect, and the most massive z >= 1.4 galaxy cluster found to date. Despite the mere ~1% probability of finding it in the 8.82 deg^2 IRAC Distant Cluster Survey, IDCS J1426.5+3508 is not completely unexpec…
The Sunyaev-Zel'dovich effect is the ideal probe for investigating the outskirts of galaxy clusters. To map this signal, we apply a spectral imaging technique which combines parametric component separation and sparse representations. Our procedure is an improved version of an existing algorithm, which now features a better treatment of astrophysical contaminants, and the implementation of a new beam deconvolution. We use the most recent frequency maps delivered by \textsl{Planck}, and we consider the clusters analysed in the \textsl{XMM} Cluster Outskirts Project (X-COP). In particular, we foc…
In a recent article by Benson et al., 2011, the authors show the latest measurements from the South Pole Telescope (SPT) Sunyaev Zel'dovich (SZ) cluster survey to better constrain some cosmological parameters. In particular, the authors found that adding the SPT cluster data significantly improves the constraints on equation of state of dark energy, w, beyond those found when using measurements of the CMB, supernovae, BAO and the Hubble constant. The main aim of the present research note is to give a further quantitative estimation of the above better constraints, through the computation of th…
We consider the effect of the cosmic microwave background (CMB) frequency spectral distortions arising due to the Compton scattering of the anisotropic radiation on Sunyaev-Zel'dovich (SZ) clusters. We derive the correction to the thermal SZ effect due to the presence of multipoles with $\ell=1,2,3$ in the anisotropy of the CMB radiation. We show that this effect gives us an opportunity for an independent evaluation of the CMB dipole, quadrupole and octupole angular anisotropy in our location using distorted signal from the nearby galaxy clusters and to distinguish between the Sachs-Wolfe (SW)…
We present imaging simulations of the Sunyaev-Zel'dovich effect of galaxy clusters for the Atacama Large Millimeter/submillimeter Array (ALMA) including the Atacama Compact Array (ACA). In its most compact configuration at 90GHz, ALMA will resolve the intracluster medium with an effective angular resolution of 5 arcsec. It will provide a unique probe of shock fronts and relativistic electrons produced during cluster mergers at high redshifts, that are hard to spatially resolve by current and near-future X-ray detectors. Quality of image reconstruction is poor with the 12m array alone but impro…
Redshift-space distortions (RSD) in galaxy redshift surveys generally break both the isotropy and homogeneity of galaxy distribution. While the former aspect is particularly highlighted as a probe of growth of structure induced by gravity, the latter aspect, often quoted as wide-angle RSD but ignored in most of the cases, will become important and critical to account for as increasing the statistical precision in next-generation surveys. However, the impact of wide-angle RSD has been mostly studied using linear perturbation theory. In this paper, employing the Zel'dovich approximation, i.e., f…
We stack maps of the thermal Sunyaev-Zel'dovich effect produced by the Planck Collaboration around the centers of cosmic voids defined by the distribution of galaxies in the CMASS sample of the Baryon Oscillation Spectroscopic Survey, scaled by the void effective radii. We report a first detection of the associated cross-correlation at the $3.4σ$ level: voids are under-pressured relative to the cosmic mean. We compare the measured Compton-$y$ profile around voids with a model based solely on the spatial modulation of halo abundance with environmental density. The amplitude of the detected sign…
We derive a model-independent expression for the minimum line-of-sight extent of the hot plasma in a cluster of galaxies. The only inputs are the 1-5 keV X-ray surface brightness and the Comptonization from Sunyaev-Zel'dovich (SZ) data. No a priori assumptions regarding equilibrium or geometry are required. The method applies when the X-ray emitting material has temperatures anywhere between 0.3 keV and 20 keV and metallicities between 0 and twice solar---conditions fulfilled by nearly all intracluster plasma. Using this method, joint APEX-SZ and Chandra X-ray Observatory data on the Bullet Cl…
The accurate determination of cluster total mass is crucial for their use as probes of cosmology. Recently, the Sunyaev--Zel'dovich effect (SZE) has been exploited in surveys to find galaxy clusters, but X-ray or lensing follow up observations, or empirically-determined scaling relations between SZE flux and total mass, have been required to estimate their masses. Here we demonstrate a new method of mass determination from SZE observations, applicable in the absence of X-ray or lensing data. This method relies on the virial relation and a minimal set of assumptions, following an approach analo…
We present a technique to constrain galaxy cluster pressure profiles by jointly fitting Sunyaev-Zel'dovich effect (SZE) data obtained with MUSTANG and Bolocam for the clusters Abell 1835 and MACS0647. Bolocam and MUSTANG probe different angular scales and are thus highly complementary. We find that the addition of the high resolution MUSTANG data can improve constraints on pressure profile parameters relative to those derived solely from Bolocam. In Abell 1835 and MACS0647, we find gNFW inner slopes of $γ= 0.36_{-0.21}^{+0.33}$ and $γ= 0.38_{-0.25}^{+0.20}$, respectively when $α$ and $β$ are c…
In the standard hot cosmological model, the black-body temperature of the Cosmic Microwave Background (CMB), $T_{\rm CMB}$, increases linearly with redshift. Across the line of sight CMB photons interact with the hot ($\sim10^{7-8}$ K) and diffuse gas of electrons from galaxy clusters. This interaction leads to the well known thermal Sunyaev-Zel'dovich effect (tSZ), which produces a distortion of the black-body emission law, depending on $T_{\rm CMB}$. Using tSZ data from the ${\it Planck}$ satellite it is possible to constrain $T_{\rm CMB}$ below z=1. Focusing on the redshift dependance of $T…
We have measured the Sunyaev Zel'dovich (SZ) effect for a sample of ten strong lensing selected galaxy clusters using the Sunyaev Zel'dovich Array (SZA). The SZA is sensitive to structures on spatial scales of a few arcminutes, while the strong lensing mass modeling constrains the mass at small scales (typically < 30"). Combining the two provides information about the projected concentrations of the strong lensing clusters. The Einstein radii we measure are twice as large as expected given the masses inferred from SZ scaling relations. A Monte Carlo simulation indicates that a sample randomly …
Studying galaxy clusters through their Sunyaev-Zel'dovich (SZ) imprint on the Cosmic Microwave Background has many important advantages. The total SZ signal is an accurate and precise tracer of the total pressure in the intra-cluster medium and of cluster mass, the key observable for using clusters as cosmological probes. Band 5 observations with SKA-MID towards cluster surveys from the next generation of X-ray telescopes such as e-ROSITA and from Euclid will provide the robust mass estimates required to exploit these samples. This will be especially important for high redshift systems, arisin…
We consider the Stokes parameters' frequency spectral distortions arising due to Compton scattering of the anisotropic cosmic microwave background (CMB) radiation, the Sunyaev-Zel' dovich effect (SZ), towards clusters of galaxies. We single out a very special type of such distortions and find simple analytical formulas for them. We show that this kind of distortion has a very distinctive spectral shape and can be separated from other kinds of contaminants. We demonstrate that this effect gives us an opportunity for an independent estimation of the low-multipole angular CMB anisotropies, such a…
The Sunyaev-Zel'dovich (SZ) effect is a powerful probe of the evolution of structures in the universe, and is thus highly sensitive to cosmological parameters $σ_8$ and $Ω_m$, though its power is hampered by the current uncertainties on the cluster mass calibration. In this analysis we revisit constraints on these cosmological parameters as well as the hydrostatic mass bias, by performing (i) a robust estimation of the tSZ power-spectrum, (ii) a complete modeling and analysis of the tSZ bispectrum, and (iii) a combined analysis of galaxy clusters number count, tSZ power spectrum, and tSZ bispe…
While the arcminute-scale Cosmic Microwave Background (CMB) anisotropies are due to secondary effects, point sources dominate the total anisotropy power spectrum. At high frequencies the point sources are primarily in the form of dusty, star-forming galaxies. Both Herschel and Planck have recently measured the anisotropy power spectrum of cosmic infrared background (CIB) generated by dusty, star-forming galaxies from degree to sub-arcminute angular scales, including the non-linear clustering of these galaxies at multipoles of 3000 to 6000 relevant to CMB secondary anisotropy studies. We scale …
There has been considerable recent interest in cosmological models in which the current apparent acceleration is due to a very large local underdensity, or void, instead of some form of dark energy. Here we examine a new proposal to constrain such models using the linear kinetic Sunyaev-Zel'dovich (kSZ) effect due to structure within the void. The simplified "Hubble bubble" models previously studied appeared to predict far more kSZ power than is actually observed, independently of the details of the initial conditions and evolution of perturbations in such models. We show that the constraining…
Several anomalies have been identified which may imply a breakdown of the statistical isotropy of the cosmic microwave background (CMB). In particular, an anomalous alignment of the quadrupole and octopole and a hemispherical power asymmetry have increased in significance as the data have improved. There have been several attempts to explain these observations which explore isotropy breaking mechanisms within the early universe, but little attention has been given to the possibility that these anomalies have their origin within the local universe. We explore such a mechanism by considering the…
We present the results of a 6.1 square degree survey for clusters of galaxies via their Sunyaev- Zel'dovich (SZ) effect at 31 GHz. From late 2005 to mid 2007 the Sunyaev-Zel'dovich Array (SZA) observed four fields of roughly 1.5 square degrees each. One of the fields shows evidence for significant diffuse Galactic emission, and we therefore restrict our analysis to the remaining 4.4 square degrees. We estimate the cluster detectability for the survey using mock observations of simulations of clusters of galaxies; and determine that, at intermediate redshifts (z ~ 0.8), the survey is 50% comple…
This paper continues a series in which we intend to show how all observables of galaxy clusters can be combined to recover the two-dimensional, projected gravitational potential of individual clusters. Our goal is to develop a non-parametric algorithm for joint cluster reconstruction taking all cluster observables into account. In this paper, we begin with the relation between the Compton-y parameter and the Newtonian gravitational potential, assuming hydrostatic equilibrium and a polytropic stratification of the intracluster gas. We show how Richardson-Lucy deconvolution can be used to conver…
High-frequency, high-resolution imaging of the Sunyaev-Zel'dovich (SZ) effect is an important technique to study the complex structures of the atmospheres of merging galaxy clusters. Such observations are sensitive to the details of the electron spectrum. We show that the morphology of the SZ intensity maps in simulated galaxy clusters observed at 345 GHz, 600 GHz, and 857 GHz are significantly different because of SZ relativistic corrections. These differences can be revealed by high-resolution imaging instruments. We calculate relativistically corrected SZ intensity maps of a simulated, mass…
We present follow-up observations of two galaxy clusters detected blindly via the Sunyaev-Zel'dovich (SZ) effect and released in the Planck Early Release Compact Source Catalogue. We use the Arcminute Microkelvin Imager, a dual-array 14-18 GHz radio interferometer. After radio source subtraction, we find a SZ decrement of integrated flux density -1.08+/-0.10 mJy toward PLCKESZ G121.11+57.01, and improve the position measurement of the cluster, finding the centre to be RA 12 59 36.4, Dec +60 04 46.8, to an accuracy of 20 arcseconds. The region of PLCKESZ G115.71+17.52 contains strong extended e…
The thermal Sunyaev-Zel'dovich (tSZ) effect measures the line-of-sight projection of the thermal pressure of free electrons and lacks any redshift information. By cross correlating the tSZ effect with an external cosmological tracer we can recover a good fraction of this lost information. Weak lensing (WL) is thought to provide an unbiased probe of the dark Universe, with many WL surveys having sky coverage that overlaps with tSZ surveys. Generalising the tomographic approach, we advocate the use of the spherical Fourier-Bessel (sFB) expansion to perform an analysis of the cross-correlation be…
Cross-correlation analysis of the thermal Sunyaev-Zel'dovich (tSZ) effect and weak gravitational lensing (WL) provides a powerful probe of cosmology and astrophysics of the intra-cluster medium. We present the measurement of the cross-correlation of tSZ and WL from Planck and Subaru Hyper-Suprime Cam. The combination enables us to study cluster astrophysics at high redshift. We use the tSZ-WL cross-correlation and the tSZ auto-power spectrum measurements to place a tight constraint on the hydrostatic mass bias, which is a measure of the degree of non-thermal pressure support in galaxy clusters…
The thermal Sunyaev-Zel'dovich (tSZ) effect is a powerful probe of cosmology. The statistical errors in the tSZ power spectrum measurements are dominated by the presence of massive clusters in a survey volume that are easy to identify on individual cluster basis. First, we study the impact of super sample covariance (SSC) on the tSZ power spectrum measurements, and find that the sample variance is dominated by the connected non-Gaussian (cNG) covariance arising mainly from Poisson number fluctuations of massive clusters in the survey volume. Second, we find that removing such individually-dete…
At high angular frequencies, beyond the damping tail of the primary power spectrum, the dominant contribution to the power spectrum of cosmic microwave background (CMB) temperature fluctuations is the thermal Sunyaev-Zel'dovich (tSZ) effect. We investigate various important statistical properties of the Sunyaev-Zel'dovich maps, using well-motivated models for dark matter clustering to construct statistical descriptions of the tSZ effect to all orders enabling us to determine the entire probability distribution function (PDF). Any generic deterministic biasing scheme can be incorporated in our …
Several galaxy clusters host X-ray cavities, often filled with relativistic electrons emitting in the radio band. In the cluster MS 0735.6+7421 the cavities have been detected through the Sunyaev Zel'dovich (SZ) effect, but it has not been possible to determine if this effect is thermal (produced by a very high temperature gas filling the cavity) or non-thermal (produced by the relativistic electrons that produce the diffuse radio emission detected in the cavity). In this paper we discuss the role of the density of the high temperature gas inside the cavities in determining whether the dominan…
Giant radio haloes in galaxy clusters are the primary evidence for the existence of relativistic particles (cosmic rays) and magnetic fields over Mpc scales. Observational tests for the different theoretical models explaining their powering mechanism have so far been obtained through X-ray selection of clusters, e.g. by comparing cluster X-ray luminosities with radio halo power. Here we present the first global scaling relations between radio halo power and integrated Sunyaev-Zel'dovich (SZ) effect measurements, using the Planck all-sky cluster catalog and published radio data. The correlation…
Using $\sim$140 deg$^2$ Subaru Hyper Suprime-Cam (HSC) survey data, we stack the weak lensing (WL) signal around five Planck clusters found within the footprint. This yields a 15$σ$ detection of the mean Planck cluster mass density profile. The five Planck clusters span a relatively wide mass range, $M_{\rm WL,500c} = (2-30)\times10^{14}\,M_\odot/h$ with a mean mass of $M_{\rm WL,500c} = (4.15\pm0.61)\times10^{14}\,M_\odot/h$. The ratio of the stacked Planck Sunyaev-Zel'dovich (SZ) mass to the stacked WL mass is $ \langle M_{\rm SZ}\rangle/\langle M_{\rm WL}\rangle = 1-b = 0.80\pm0.14$. This m…
Using a Green's function approach, we compare the trajectories of classical Hamiltonian point particles in an expanding space-time to the effectively inertial trajectories in the Zel'dovich approximation. It is shown that the effective gravitational potential accelerating the particles relative to the Zel'dovich trajectories vanishes exactly initially as a consequence of the continuity equation, and acts only during a short, early period. The Green's function approach suggests an iterative scheme for improving the Zel'dovich trajectories, which can be analytically solved. We construct these tr…
By using exclusively the Sunyaev-Zel'dovich effect and X-ray surface brightness data from 25 galaxy clusters in the redshift range 0.023< z < 0.784 we access cosmic acceleration employing a kinematic description. Such result is fully independent on the validity of any metric gravity theory, the possible matter-energy contents filling the Universe, as well as on the SNe Ia Hubble diagram.
Simulations have become an indispensable tool for accurate modelling of observables measured in galaxy surveys, but can be expensive if very large dynamic range in scale is required. We describe how to combine Lagrangian perturbation theory models with N-body simulations to reduce the effects of finite computational volume in the prediction of ensemble average properties in the simulations within the context of control variates. In particular we use the fact that Zel'dovich displacements, computed during initial condition generation for any simulation, correlate strongly with the final density…
We construct a simple, spherical blastwave model to estimate the pressure structure of the intergalactic medium surrounding hyper-starburst galaxies, and argue that the effects of interaction with star-forming galaxy winds may be approximated at early times by an adiabatically expanding, self-similar `bubble' as described by Weaver et al. (1977) and Ostriker & McKee (1988). This model is used to make observational predictions for the thermal Sunyaev-Zel'dovich effect in the shocked bubble plasma. Radiative cooling losses are explored, and it is found that bremsstrahlung will limit the epoch of…
