Search

A systematic comparison of the models of the circumgalactic medium (CGM) and their observables is crucial to understanding the predictive power of the models and constraining physical processes that affect the thermodynamics of CGM. This paper compares four analytic CGM models: precipitation, isentropic, cooling flow, and baryon pasting models for the hot, volume-filling CGM phase, all assuming hydrostatic or quasi-hydrostatic equilibrium. We show that for fiducial parameters of the CGM of a Milky Way (MW)-like galaxy (⁠|$M_{\rm vir} \sim 10^{12}~{\rm M}_{\odot }$| at |$z\sim 0$|⁠), the thermodynamic profiles – entropy, density, temperature, and pressure – show most significant differences between different models at small (⁠|$r\lesssim 30$|  kpc) and large scales (⁠|$r\gtrsim 100$|  kpc) while converging at intermediate scales. The slope of the entropy profile, which is one of the most important differentiators between models, is |$\approx 0.8$| for the precipitation and cooling flow models, while it is |$\approx 0.6$| and 0 for the baryon pasting and isentropic models, respectively. We make predictions for various observational quantities for an MW mass halo for the different models, including the projected Sunyaev–Zeldovich effect, soft X-ray emission (0.5–2 keV), dispersion measure, and column densities of oxygen ions (O  vi , O  vii , and O  viii) observable in absorption. We provide Python packages to compute the thermodynamic and observable quantities for the different CGM models. [ABSTRACT FROM AUTHOR]

We present an extension to a Sunyaev–Zel'dovich Effect (SZE) selected cluster catalogue based on observations from the South Pole Telescope (SPT); this catalogue extends to lower signal to noise than the previous SPT–SZ catalogue and therefore includes lower mass clusters. Optically derived redshifts, centres, richnesses, and morphological parameters together with catalogue contamination and completeness statistics are extracted using the multicomponent matched filter (MCMF) algorithm applied to the S/N > 4 SPT–SZ candidate list and the Dark Energy Survey (DES) photometric galaxy catalogue. The main catalogue contains 811 sources above S/N = 4, has 91  per cent purity, and is 95 per cent complete with respect to the original SZE selection. It contains in total 50 per cent more clusters and twice as many clusters above z  = 0.8 in comparison to the original SPT-SZ sample. The MCMF algorithm allows us to define subsamples of the desired purity with traceable impact on catalogue completeness. As an example, we provide two subsamples with S/N > 4.25 and S/N > 4.5 for which the sample contamination and cleaning-induced incompleteness are both as low as the expected Poisson noise for samples of their size. The subsample with S/N > 4.5 has 98 per cent purity and 96 per cent completeness and is part of our new combined SPT cluster and DES weak-lensing cosmological analysis. We measure the number of false detections in the SPT-SZ candidate list as function of S/N, finding that it follows that expected from assuming Gaussian noise, but with a lower amplitude compared to previous estimates from simulations. [ABSTRACT FROM AUTHOR]

Taking advantage of the reduced levels of noise and systematics in the data of the latest Planck release (PR4, also known as NPIPE), we construct a new all-sky Compton- y parameter map (hereafter, y -map) of the thermal Sunyaev–Zeldovich (SZ) effect from the Planck PR4 data. A tailored Needlet Internal Linear Combination (NILC) pipeline, first validated on detailed sky simulations, is applied to the nine single-frequency Planck PR4 sky maps, ranging from 30 to 857 GHz, to produce the PR4 y -map over 98 per cent of the sky. Using map comparisons, angular power spectra, and one-point statistics, we show that the PR4 NILC y -map is of improved quality compared to that of the previous PR2 release. The new y -map shows reduced levels of large-scale striations associated with 1/ f noise in the scan direction. Regions near the Galactic plane also show lower residual contamination by Galactic thermal dust emission. At small angular scales, the residual contamination by thermal noise and cosmic infrared background (CIB) emission is found to be reduced by around 7 and 34 per cent, respectively, in the PR4 y -map. The PR4 NILC y -map is made publicly available for astrophysical and cosmological analyses of the thermal SZ effect. [ABSTRACT FROM AUTHOR]

Line-intensity mapping (LIM) is an emerging technique to probe the large-scale structure of the Universe. By targeting the integrated intensity of specific spectral lines, it captures the emission from all sources and is sensitive to the astrophysical processes that drive galaxy evolution. Relating these processes to the underlying distribution of matter introduces observational and theoretical challenges, such as observational contamination and highly non-Gaussian fields, which motivate the use of simulations to better characterize the signal. In this work we present skyline  , a computational framework to generate realistic mock LIM observations that include observational features and foreground contamination, as well as a variety of self-consistent tracer catalogues. We apply our framework to generate realizations of LIM maps from the multidark planck 2 simulations coupled to the universemachine galaxy formation model. We showcase the potential of our scheme by exploring the voxel intensity distribution and the power spectrum of emission lines such as 21 cm, CO, [C  ii ], and Lyman-α, their mutual cross-correlations, and cross-correlations with galaxy clustering. We additionally present cross-correlations between LIM and submillimetre extragalactic tracers of large-scale structure such as the cosmic infrared background and the thermal Sunyaev-Zel'dovich effect, as well as quantify the impact of galactic foregrounds, line interlopers, and instrument noise on LIM observations. These simulated products will be crucial in quantifying the true information content of LIM surveys and their cross-correlations in the coming decade, and to develop strategies to overcome the impact of contaminants and maximize the scientific return from LIM experiments. [ABSTRACT FROM AUTHOR]

Current models of galaxy formation require strong feedback from active galactic nuclei (AGN) to explain the observed lack of star formation in massive galaxies since z ≈ 2, but direct evidence of this energy input is limited. We use the SIMBA cosmological galaxy formation simulations to assess the ability of thermal Sunyaev–Zel'dovich (tSZ) measurements to provide such evidence, by mapping the pressure structure of the circumgalactic medium around massive z ≈ 0.2–1.5 galaxies. We undertake a stacking approach to calculate the total tSZ signal and its radial profile in simulations with varying assumptions of AGN feedback, and we assess its observability with current and future telescopes. By convolving our predictions with the 2.′1 beam of the Atacama Cosmology Telescope, we show that current observations at z ≈ 1 are consistent with SIMBA's fiducial treatment of AGN feedback and inconsistent with SIMBA models without feedback. At z ≈ 0.5, observational signals lie between SIMBA run with and without AGN feedback, suggesting AGN in SIMBA may inject too much energy at late times. By convolving our data with a 9.″5 beam corresponding to the TolTEC camera on the Large Millimeter Telescope Alfonso Serrano, we predict a unique profile for AGN feedback that can be distinguished with future higher-resolution measurements. Finally, we explore a novel approach to quantify the nonspherically symmetric features surrounding our galaxies by plotting radial profiles representing the component of the stack with m-fold symmetry. [ABSTRACT FROM AUTHOR]

We introduce a novel unbiased, cross-correlation estimator for the one-point statistics of cosmological random fields. One-point statistics are a useful tool for analysis of highly non-Gaussian density fields, while cross-correlations provide a powerful method for combining information from pairs of fields and separating them from noise and systematics. We derive a new Deconvolved Distribution Estimator that combines the useful properties of these two methods into one statistic. Using two example models of a toy Gaussian random field and a line intensity mapping survey, we demonstrate these properties quantitatively and show that the deconvolved distribution estimator can be used for inference. This new estimator can be applied to any pair of overlapping, non-Gaussian cosmological observations, including large-scale structure, the Sunyaev–Zeldovich effect, weak lensing, and many others. [ABSTRACT FROM AUTHOR]

We present the first systematic follow-up of Planck Sunyaev–Zeldovich effect (SZE) selected candidates down to signal-to-noise (S/N) of 3 over the 5000 deg2 covered by the Dark Energy Survey. Using the MCMF cluster confirmation algorithm, we identify optical counterparts, determine photometric redshifts, and richnesses and assign a parameter, f cont, that reflects the probability that each SZE-optical pairing represents a random superposition of physically unassociated systems rather than a real cluster. The new PSZ-MCMF cluster catalogue consists of 853 MCMF confirmed clusters and has a purity of 90 per cent. We present the properties of subsamples of the PSZ-MCMF catalogue that have purities ranging from 90 per cent to 97.5 per cent, depending on the adopted f cont threshold. Halo mass estimates M 500, redshifts, richnesses, and optical centres are presented for all PSZ-MCMF clusters. The PSZ-MCMF catalogue adds 589 previously unknown Planck identified clusters over the DES footprint and provides redshifts for an additional 50 previously published Planck -selected clusters with S/N>4.5. Using the subsample with spectroscopic redshifts, we demonstrate excellent cluster photo- z performance with an RMS scatter in Δ z /(1 + z) of 0.47 per cent. Our MCMF based analysis allows us to infer the contamination fraction of the initial S/N>3 Planck -selected candidate list, which is ∼50 per cent. We present a method of estimating the completeness of the PSZ-MCMF cluster sample. In comparison to the previously published Planck cluster catalogues, this new S/N>3 MCMF confirmed cluster catalogue populates the lower mass regime at all redshifts and includes clusters up to z ∼1.3. [ABSTRACT FROM AUTHOR]

The kinetic Sunyaev–Zeldovich (kSZ) effect has now become a clear target for ongoing and future studies of the cosmic microwave background (CMB) and cosmology. Aside from the bulk cluster motion, internal motions also lead to a kSZ signal. In this work, we study the rotational kSZ effect caused by coherent large-scale motions of the cluster medium using cluster hydrodynamic cosmological simulations. To utilize the rotational kSZ as a cosmological probe, simulations offer some of the most comprehensive data sets that can inform the modelling of this signal. In this work, we use the MACSIS data set to investigate the rotational kSZ effect in massive clusters specifically. Based on these models, we test stacking approaches and estimate the amplitude of the combined signal with varying mass, dynamical state, redshift, and map-alignment geometry. We find that the dark matter, galaxy and gas spins are generally misaligned, an effect that can cause a suboptimal estimation of the rotational kSZ effect when based on galaxy motions. Furthermore, we provide halo-spin–mass scaling relations that can be used to build a statistical model of the rotational kSZ. The rotational kSZ contribution, which is largest in massive unrelaxed clusters (≳100  |$\mu$| K), could be relevant to studies of higher order CMB temperature signals, such as the moving lens effect. The limited mass range of the MACSIS sample strongly motivates an extended investigation of the rotational kSZ effect in large-volume simulations to refine the modelling, particularly towards lower mass and higher redshift, and provide forecasts for upcoming cosmological CMB experiments (e.g. Simons Observatory, SKA-2) and X-ray observations (e.g. Athena /X-IFU). [ABSTRACT FROM AUTHOR]

The peculiar velocities of dark matter haloes are crucial to study many issues in cosmology and galaxy evolution. In this study, by using the state-of-the-art deep learning technique, a UNet-based neural network, we propose to reconstruct the peculiar velocity field from the redshift-space distribution of dark matter haloes. Through a point-to-point comparison and examination of various statistical properties, we demonstrate that, the reconstructed velocity field is in generally good agreement with the ground truth. The power spectra of various velocity field components, including velocity magnitude, divergence, and vorticity, can be successfully recovered when k ≲ 1.1 |$h\,\rm Mpc^{-1}$| (the Nyquist frequency of the simulations) at about 80 per cent accuracy. This approach is very promising and presents an alternative method to correct the redshift-space distortions using the measured 3D spatial information of haloes. Additionally, for the reconstruction of the momentum field of haloes, UNet achieves similar good results. Hence the applications in various aspects of cosmology are very broad, such as correcting redshift errors and improving measurements in the structure of the cosmic web, the kinetic Sunyaev–Zel'dovich effect, BAO reconstruction, etc. [ABSTRACT FROM AUTHOR]

As cosmic microwave background (CMB) photons traverse the universe, anisotropies can be induced via Thomson scattering (proportional to the electron density; optical depth) and inverse Compton scattering (proportional to the electron pressure; thermal Sunyaev–Zel'dovich effect). Measurements of anisotropy in optical depth τ and Compton y parameters are imprinted by the galaxies and galaxy clusters and are thus sensitive to the thermodynamic properties of the circumgalactic medium and intergalactic medium. We use an analytic halo model to predict the power spectrum of the optical depth (τ τ), the cross-correlation between the optical depth and the Compton y parameter (τ y), and the cross-correlation between the optical depth and galaxy clustering (τ g), and compare this model to cosmological simulations. We constrain the optical depths of halos at z ≲ 3 using a technique originally devised to constrain patchy reionization at a higher redshift range. The forecasted signal-to-noise ratio is 2.6, 8.5, and 13, respectively, for a CMB-S4-like experiment and a Vera C. Rubin Observatory–like optical survey. We show that a joint analysis of these probes can constrain the amplitude of the density profiles of halos to 6.5% and the pressure profiles to 13%. These constraints translate to astrophysical parameters, such as the gas mass fraction, f g, which can be constrained to 5.3% uncertainty at z ∼ 0. The cross-correlations presented here are complementary to other CMB and galaxy cross-correlations since they do not require spectroscopic galaxy redshifts and are another example of how such correlations are a powerful probe of the astrophysics of galaxy evolution. [ABSTRACT FROM AUTHOR]

The galaxy cluster Zwicky 3146 is a sloshing cool-core cluster at z = 0.291 that in Sunyaev–Zel'dovich (SZ) imaging does not appear to exhibit significant pressure substructure in the intracluster medium. We perform a surface brightness fluctuation analysis via Fourier amplitude spectra on SZ (MUSTANG-2) and X-ray (XMM-Newton) images of this cluster. These surface brightness fluctuations can be deprojected to infer pressure and density fluctuations from the SZ and X-ray data, respectively. In the central region (Ring 1, r < 100″ = 440 kpc, in our analysis), we find fluctuation spectra that suggest injection scales around 200 kpc (∼140 kpc from pressure fluctuations and ∼250 kpc from density fluctuations). When comparing the pressure and density fluctuations in the central region, we observe a change in the effective thermodynamic state from large to small scales, from isobaric (likely due to the slow sloshing) to adiabatic (due to more vigorous motions). By leveraging scalings from hydrodynamical simulations, we find an average 3D Mach number ≈0.5. We further compare our results to other studies of Zwicky 3146 and, more broadly, to other studies of fluctuations in other clusters. [ABSTRACT FROM AUTHOR]

Considering possible solutions to the S8 tension between the Planck cosmic microwave background (CMB) measurement and low-redshift probes, we extended the standard ΛCDM cosmological model by including decay of dark matter (DDM). We first tested the DDM model in which dark matter decays into a form of noninteracting dark radiation. Under this DDM model, we investigated the impacts of DDM on the Sunyaev Zel'dovich (SZ) effect by varying the decay lifetime, Γ−1, including the background evolution in cosmology and the nonlinear prescription in the halo mass function. We performed a cosmological analysis under the assumption of this extended cosmological model by combining the latest high-redshift Planck CMB measurement and low-redshift measurements of the SZ power spectrum as well as the baryonic acoustic oscillations (BAO) and luminosity distances to type Ia supernovae (SNIa). Our result shows a preference for Γ−1 ∼ 220 Gyr with a lower bound on the decay lifetime of ∼38 Gyr at 95% confidence level. Additionally, we tested the other DDM model in which dark matter decays into warm dark matter and dark radiation. This model supports Γ−1 ∼ 137 Gyr to resolve the S8 tension with a lower bound on the decay lifetime of ∼24 Gyr at 95% confidence level. Comparing these two models, we find that the second leads to slightly better reconciliation of the S8 tension. [ABSTRACT FROM AUTHOR]

While observations of molecular gas at cosmic noon and beyond have focused on the gas within galaxies (i.e. the interstellar medium, ISM), it is also crucial to study the molecular gas reservoirs surrounding each galaxy (i.e. in the circumgalactic medium, CGM). Recent observations of galaxies and quasars hosts at high redshift (z > 2) have revealed evidence for cold gaseous haloes of scale r CGM ∼ 10 kpc, with one discovery of a molecular halo with r CGM ∼ 200 kpc, and a molecular gas mass one order of magnitude larger than the ISM of the central galaxy. As a follow up, we present deep ACA and ALMA observations of CO(3–2) from this source and two other quasar host galaxies at z ∼ 2.2. While we find evidence for CO emission on scales of r ∼ 10 kpc, we do not find evidence for molecular gas on scales larger than r > 20 kpc. Therefore, our deep data do not confirm the existence of massive molecular haloes on scales of ∼100 kpc for these X-ray selected quasars. As an interesting byproduct of our deep observations, we obtain the tentative detection of a negative continuum signal on scales larger than r > 200 kpc, which might be tracing the Sunyaev–Zeldovich effect associated with the halo heated by the active galactic nucleus (AGN). If confirmed with deeper data, this could be direct evidence of the preventive AGN feedback process expected by cosmological simulations. [ABSTRACT FROM AUTHOR]

We discuss the secondary cosmic microwave background (CMB) anisotropy due to kinetic Sunyaev–Zel'dovich (kSZ) effect from ionized bubbles around individual quasars prior to the reionization of the Universe. The bubbles create local ionization modulations which move with the large-scale structure linear bulk flow and act as sources for kSZ. We improve upon previous calculations of this effect, using a halo model based description of quasar abundance, and find that the kSZ distortion power spectrum, C ℓ, from the bubbles to be sub-dominant to kSZ from patchy reionization driven by galaxies. However, the shape of the two C ℓ's are very different with the quasar bubble C ℓ having a peak at ℓ ≈ 500–700 whereas the C ℓ due to patchy reionization flattening out at ℓ > 1000 thus making it plausible to separate the two using C ℓ template-fitting in a future survey like CMB-HD. Next, we look at the imprint of a single quasar bubble on the CMB and show that it can be detected in a high-resolution, ambitious effort like CMB-HD. A detection of a high redshift quasar bubble in the CMB would carry complimentary information to its detection in H  i or Lyman-α and a joint analysis can be used to break parameter degeneracies. [ABSTRACT FROM AUTHOR]

Where the cosmic baryons lie in and around galactic dark matter haloes is only weakly constrained. We develop a method to quickly paint on models for their distribution. Our approach uses the statistical advantages of N -body simulations, while painting on the profile of gas around individual haloes in ways that can be motivated by semi-analytic models or zoom-in hydrodynamic simulations of galaxies. Possible applications of the algorithm include extragalactic dispersion measures to fast radio bursts (FRBs), the Sunyaev–Zeldovich effect, baryonic effects on weak lensing, and cosmic metal enrichment. As an initial application, we use this tool to investigate how the baryonic profile of foreground galactic-mass haloes affects the statistics of the dispersion measure (DM) towards cosmological FRBs. We show that the distribution of DM is sensitive to the distribution of baryons in galactic haloes, with viable gas profile models having significantly different probability distributions for DM to a given redshift. We also investigate the requirements to statistically measure the circumgalactic electron profile for FRB analyses that stack DM with impact parameter to foreground galaxies, quantifying the size of the contaminating 'two-halo' term from correlated systems and the number of FRBs for a high significance detection. Publicly available python modules implement our CGMBrush algorithm. [ABSTRACT FROM AUTHOR]

The precise estimation of the mass of galaxy clusters is a major issue for cosmology. Large galaxy cluster surveys rely on scaling laws that relate cluster observables to their masses. From the high-resolution observations of ∼45 galaxy clusters with the NIKA2 and XMM-Newton instruments, the NIKA2 Sunyaev-Zel'dovich Large Program should provide an accurate scaling relation between the thermal Sunyaev-Zel'dovich effect and the hydrostatic mass. In this paper we present an exhaustive analysis of the hydrostatic mass of the well-known galaxy cluster CL J1226.9+3332, the highest-redshift cluster in the NIKA2 Sunyaev-Zel'dovich Large Program at z = 0.89. We combined the NIKA2 observations with thermal Sunyaev-Zel'dovich data from the NIKA, Bolocam, and MUSTANG instruments and XMM-Newton X-ray observations, and tested the impact of the systematic effects on the mass reconstruction. We conclude that slight differences in the shape of the mass profile can be crucial when defining the integrated mass at R500, which demonstrates the importance of the modelling in the mass determination. We prove the robustness of our hydrostatic mass estimates by showing the agreement with all the results found in the literature. Another key factor for cosmology is the bias of the masses estimated assuming the hydrostatic equilibrium hypothesis. Based on the lensing convergence maps from the Cluster Lensing And Supernova survey with Hubble (CLASH) data, we obtain the lensing mass estimate for CL J1226.9+3332. From this we are able to measure the hydrostatic-to-lensing mass bias for this cluster, which spans from 1 − bHSE/lens ∼ 0.7 to 1, presenting the impact of data sets and mass reconstruction models on the bias. [ABSTRACT FROM AUTHOR]

Context. The current observational status of the hot (log T(K) > 5.5) intergalactic medium (IGM) remains incomplete. While recent X-ray emission and Sunyaev-Zeldovich effect observations from stacking large numbers of Cosmic Web filaments have yielded statistically significant detections of this phase, direct statistically significant measurements of single objects remain scarce. The lack of such a sample currently prevents a robust analysis of the cosmic baryon content composed of the hot IGM, which would potentially help solve the cosmological missing baryons problem. Aims. In order to improve the observationally challenging search for the missing baryons, we utilise the theoretical avenue afforded by the EAGLE simulations. Our aim is to get insights into the metal enrichment of the Cosmic Web and the distribution of highly ionised metals in the IGM. Our goal is to aid in the planning of future X-ray observations of the hot intergalactic plasma. Methods. We detected the filamentary network by applying the Bisous formalism to galaxies in the EAGLE simulation. We characterised the spatial distributions of oxygen and O VII and studied their mass and volume filling fractions in the filaments. Since oxygen is formed in and expelled from galaxies, we also studied the surroundings of haloes. We used this information to construct maps of the O VII column density and determine the feasibility of detecting it via absorption with Athena X-IFU. Results. Within EAGLE, the oxygen and O VII number densities drop dramatically beyond the virial radii of haloes. In the most favourable scenario, the median extent of O VII above the Athena X-IFU detection limit is ≈700 kpc. Since galaxies are relatively far apart from one another, only ∼1% of the filament volumes are filled with O VII at high enough column densities to be detectable by X-IFU. The highly non-homogeneous distribution of the detectable O VII complicates the usage of the measurements of the intergalactic O VII absorbers for tracing the missing baryons and estimating their contribution to the cosmic baryon budget. Instead, the detectable volumes form narrow and dense envelopes around haloes, while the rest of the O VII is diluted at low densities within the full filament volumes. This localised nature, in turn, results in a low chance (∼10−20% per sight line) of detecting intergalactic O VII with Athena X-IFU within the observational SDSS catalogue of nearby filaments. Fortunately, with deeper filament samples, such as those provided via the future 4MOST 4HS survey, the chances of intercepting an absorbing system are expected to increase up to a comfortable level of ∼50% per sight line. Conclusions. Based on EAGLE results, targeting the Cosmic Web with Athena may only result in tip-of-the-iceberg detections of the intergalactic O VII, which is located in the galaxy outskirts. This would not be enough to conclusively solve the missing baryon problem. However, the projection of many filaments into a single line of sight will enable a useful X-ray observation strategy with Athena X-IFU for the hot cosmic baryon gas, reducing the amount of baryons still missing by up to ∼25%. [ABSTRACT FROM AUTHOR]

A macroscopic and kinetic relativistic description for a decoupled multi-fluid cosmology endowed with gravitationally induced particle production of all components is proposed. The temperature law for each decoupled particle species is also kinetically derived. The present approach points to the possibility of an exact (semi-classical) quantum-gravitational kinetic treatment by incorporating back reaction effects for an arbitrary set of dominant decoupled components. As an illustration we show that a cosmology driven by creation of cold dark matter and baryons (without dark energy) evolves like Λ CDM. However, the complete physical emulation is broken when photon creation is added to the mixture thereby pointing to a crucial test in the future. The present analysis also open up a new window to investigate the Supernova-CMB tension on the values of H 0 , as well as the S 8 tension since creation of all components changes slightly the CMB results and the expansion history both at early and late times. Finally, it is also argued that cross-correlations between CMB temperature maps and the Sunyaev–Zeldovich effect may provide a crucial and accurate test confronting extended CCDM and Λ CDM models. [ABSTRACT FROM AUTHOR]

We present the updated galaxy cluster catalog of the second Planck catalog of Sunyaev–Zel’dovich sources (PSZ2) through the compilation of the data for clusters and galaxies with spectroscopically measured redshifts in the literature. The original version of PSZ2 comprises 1653 Sunyaev–Zel’dovich (SZ) sources, of which 1203 have been validated as genuine galaxy clusters, while the remaining 450 sources are yet to be validated. To increase the number of genuine clusters in PSZ2, we first update the validations of the cluster candidates and their redshift information using the data compiled for the confirmed clusters and the member galaxies in the literature. We then use the galaxy redshift data in the fields of the remaining cluster candidates by searching for possible member galaxies with measured spectroscopic redshifts around the SZ centroids. In this search process, we classify clusters as strong candidates if they contain more than nine galaxies within a 4500 km s ^−1 velocity range and within 15′ around the SZ centroids. This process results in the validation of 139 new genuine clusters, the update of redshift information on 399 clusters, and the identification of 10 strong candidates, which increases the number of validated clusters up to 1334 among the 1653 SZ sources. Our updated galaxy cluster catalog will be very useful for studies of galaxy formation and cosmology through a combination with other all-sky surveys including the Wide-field Infrared Survey Explorer and SPHEREx.

The Sunyaev–Zeldovich effect towards clusters of galaxies has become a standard probe of cosmology. It is caused by the scattering of photons from the cosmic microwave background (CMB) by the hot cluster electron gas. In a similar manner, other photon backgrounds can be scattered when passing through the cluster medium. This problem has been recently considered for the radio and the cosmic infrared background. Here, we revisit the discussion of the cosmic infrared background (CIB) including several additional effects that were omitted before. We discuss the intracluster scattering of the CIB and the role of relativistic temperature corrections to the individual cluster and all-sky averaged signals. We show that the all-sky CIB distortion introduced by the scattering of the photon field was underestimated by a factor of ≃1.5 due to neglecting the intracluster scattering contribution. The CIB photons can scatter with the thermal electrons of both the parent halo or another halo, meaning that there are two ways to gain energy. Therefore, energy is essentially transferred twice from the thermal electrons to the CIB. We carefully clarify the origin of various effects in the calculation of the average CIB and also scattered signals. The single-cluster CIB scattering signal also exhibits a clear redshift dependence, which can be used in cosmological analyses, as we describe both analytically and numerically. This may open a new way for cosmological studies with future CMB experiments. [ABSTRACT FROM AUTHOR]

We present a fast methodology to produce mock observations of the thermal and kinetic Sunyaev–Zel'dovich (SZ) effects based on the dark matter only N -body simulations coupled with the analytic intracluster medium model. The methods employ two different approaches: halo-based pasting (HP) and particle-based pasting (PP). The former pastes gas density and pressure on to haloes and requires only a halo catalogue, and the latter considers the contribution from field particles as well, i.e. particles that do not belong to any haloes and thus utilize the full particle information. Therefore, the PP algorithm incorporates secondary effects beyond the HP algorithm: asphericity of haloes and contribution from diffuse gas. In particular, such a diffuse component is the dominant source of the kinetic SZ effect. As validation of our methods, we have produced 108 all-sky maps with HP and 108 flat-sky maps, which cover |$5 \times 5 \, \mathrm{deg}^2$| with both HP and PP, and measured power spectra of the maps. Our method can produce a mock map within a few hours, even for all-sky coverage with a parallel computational environment. The power spectra of HP maps are consistent with the halo model prediction of the thermal SZ effect. On the other hand, the power spectra of PP maps are suppressed due to the halo asphericity but can reproduce better the theoretical prediction for the kinetic SZ effect. We discuss the utility of baryon-pasted mock SZ maps for estimating the covariance matrix of SZ statistics and modelling the selection and projection effects for cluster cosmology. [ABSTRACT FROM AUTHOR]

X-ray emission and the thermal Sunyaev–Zel'dovich distortion to the cosmic microwave background are two important handles on the gas content of the Universe. The cross-correlation between these effects eliminates noise bias and reduces observational systematics. Using analytic models from Battaglia et al. for the cluster profile, we develop a halo model formalism and forecast the signal-to-noise of measurements from eROSITA and Simons Observatory. With this, we can learn which parameters from our cluster profile are crucial in understanding the gas content of these clusters. In the soft X-ray band (0.5–2 keV), we forecast a signal-to-noise of 174 for the cross-power spectrum. Over a wide range of the scales, the X-rays will be signal-dominated, and so sample variance is important. In particular, non-Gaussian (four-point) contributions to the errors highlight the utility of masking massive clusters. Masking clusters down to |$10^{14}\, {\rm M}_{\odot }$| increases the signal-to-noise of the cross-spectrum to 201. We perform a Fisher analysis on the fitting coefficients of the gas density and pressure. We find that the cross-spectrum is most sensitive to the overall scale of the profiles of pressure and electron density, as well as cosmological parameters σ8 and H 0, but that the large number of parameters form a degenerate set, which makes extracting the information challenging. Our modelling framework is flexible, and in the future, we can easily extend it to forecast the spatial cross-correlations of surveys of X-ray lines available to high-energy-resolution microcalorimetry, to studies of the warm-hot intergalactic medium, and other effects. [ABSTRACT FROM AUTHOR]

With the advent of high-resolution, low-noise CMB measurements, the ability to extract cosmological information from thermal Sunyaev–Zel'dovich effect and kinetic Sunyaev–Zel'dovich effect will be limited not by statistical uncertainties but rather by systematic and theoretical uncertainties. The theoretical uncertainty is driven by the lack of knowledge about the electron pressure and density. Thus, we explore the electron pressure and density distributions in the IllustrisTNG hydrodynamical simulations, and we demonstrate that the cluster properties exhibit a strong dependence on the halo concentration – providing some of the first evidence of cluster assembly bias in the electron pressure and density. Further, our work shows evidence for a broken power-law mass dependence, with lower pressure in lower mass haloes than previous work and a strong evolution with mass of the radial correlations in the electron density and pressure. Both of these effects highlight the differing impact of active galactic nuclei and supernova feedback on the gas in galaxy groups compared to massive clusters. We verified that we see qualitatively similar features in the SIMBA hydrodynamical simulations, suggesting these effects could be generic features. Finally, we provide a parametric formula for the electron pressure and density profile as a function of dark matter halo mass, halo concentration, and redshift. Despite our extensions, the best-fitting formulae are not able to fully capture the features seen in certain mass, radius, and redshift regimes, thereby highlighting the challenges of precision modelling gas profiles. [ABSTRACT FROM AUTHOR]

We present an analysis aimed at combining cosmological constraints from number counts of galaxy clusters identified through the Sunyaev–Zeldovich effect, obtained with the South Pole Telescope (SPT), and from Lyman  α spectra obtained with the MIKE/HIRES and X-shooter spectrographs. The SPT cluster analysis relies on mass calibration based on weak lensing measurements, while the Lyman  α analysis is built over mock spectra extracted from hydrodynamical simulations. The resulting constraints exhibit a tension (∼3.3 σ) between the low σ 8 values preferred by the low-redshift cluster data, |$\sigma _8=0.74 ^{+0.03}_{-0.04}$|⁠ , and the higher one preferred by the high-redshift Lyman  α data, |$\sigma _8=0.91 ^{+0.03}_{-0.03}$|⁠. We present a detailed analysis to understand the origin of this tension and to establish whether it arises from systematic uncertainties related to the assumptions underlying the analyses of cluster counts and/or Lyman  α forest. We found this tension to be robust with respect to the choice of modelling of the IGM, even when including possible systematics from unaccounted sub-Damped Lyman  α (DLA) and Lyman-limit systems (LLS) in the Lyman  α data. We conclude that to solve this tension would require a large bias on the cluster mass estimate, or large unaccounted errors on the Lyman  α mean fluxes. Our results have important implications for future analyses based on cluster number counts from future large photometric surveys (e.g. Euclid and LSST) and on larger samples of high-redshift quasar spectra (e.g. DESI and WEAVE surveys). If confirmed at the much higher statistical significance reachable by such surveys, this tension could represent a significant challenge for the standard ΛCDM paradigm. [ABSTRACT FROM AUTHOR]