ABSTRACT
This paper presents a cosmological analysis based on the properties of X-ray selected clusters of galaxies from the CODEX survey which have been spectroscopically followed up within the ...SPIDERS programme as part of the sixteenth data release (DR16) of SDSS-IV. The cosmological sub-sample contains a total of 691 clusters over an area of 5350 deg2 with newly measured optical properties provided by a reanalysis of the CODEX source catalogue using redMaPPer and the DESI Legacy Imaging Surveys (DR8). Optical richness is used as a proxy for the cluster mass, and the combination of X-ray, optical, and spectroscopic information ensures that only confirmed virialized systems are considered. Clusters are binned in observed redshift, $\tilde{z} \in \left0.1, 0.6 \right)$ and optical richness, $\tilde{\lambda } \in \left25, 148 \right)$ and the number of clusters in each bin is modelled as a function of cosmological and richness–mass scaling relation parameters. A high-purity sub-sample of 691 clusters is used in the analysis and best-fitting cosmological parameters are found to be $\Omega _{m_{0}}=0.34^{+0.09}_{-0.05}$ and $\sigma _8=0.73^{+0.03}_{-0.03}$. The redshift evolution of the self-calibrated richness–mass relation is poorly constrained due to the systematic uncertainties associated with the X-ray component of the selection function (which assumes a fixed X-ray luminosity–mass relation with h = 0.7 and $\Omega _{m_{0}}=0.30$). Repeating the analysis with the assumption of no redshift evolution is found to improve the consistency between both cosmological and scaling relation parameters with respect to recent galaxy cluster analyses in the literature.
Context. Galaxy clusters are the most recent, gravitationally bound products of the hierarchical mass accretion over cosmological scales. How the mass is concentrated is predicted to correlate with ...the total mass in the halo of the cluster, wherein systems at higher mass are less concentrated at given redshift and, for any given mass, systems with lower concentration are found at higher redshifts. Aims. Through a spatial and spectral X-ray analysis, we reconstruct the total mass profile of 47 galaxy clusters observed with Chandra in the redshift range 0.4 <z< 1.2, which we selected to exclude major mergers, to investigate the relation between the mass and dark matter concentration and the evolution of this relation with redshift. This sample is the largest investigated so far at z> 0.4, and is well suited to providing the first constraint on the concentration–mass relation at z> 0.7 from X-ray analysis. Methods. Under the assumption that the distribution of the X-ray emitting gas is spherically symmetric and in the hydrostatic equilibrium with the underlined gravitational potential, we combine the deprojected gas density and spectral temperature profiles through the hydrostatic equilibrium equation to recover the parameters that describe a Navarro-Frenk-White total mass distribution. The comparison with results from weak-lensing analysis reveals a very good agreement both for masses and concentrations. The uncertainties are however too large to make any robust conclusion about the hydrostatic bias of these systems. Results. The distribution of concentrations is well approximated by a log-normal function in all the mass and redshift ranges investigated. The relation is well described by the form c ∝ MB(1 + z)C with B = −0.50 ± 0.20, C = 0.12 ± 0.61 (at 68.3% confidence). This relation is slightly steeper than that predicted by numerical simulations (B ~ −0.1) and does not show any evident redshift evolution. We obtain the first constraints on the properties of the concentration–mass relation at z> 0.7 from X-ray data, showing a reasonable good agreement with recent numerical predictions.
Uncertainty in the mass-observable scaling relations is currently the limiting factor for galaxy cluster based cosmology. Weak gravitational lensing can provide a direct mass calibration and reduce ...the mass uncertainty. We present new ground-based weak lensing observations of 19 South Pole Telescope (SPT) selected clusters and combine them with previously reported space-based observations of 13 galaxy clusters to constrain the cluster mass scaling relations with the Sunyaev-Zel'dovich effect (SZE), the cluster gas mass $M_\mathrm{gas}$, and $Y_\mathrm{X}$, the product of $M_\mathrm{gas}$ and X-ray temperature. We extend a previously used framework for the analysis of scaling relations and cosmological constraints obtained from SPT-selected clusters to make use of weak lensing information. Here, we introduce a new approach to estimate the effective average redshift distribution of background galaxies and quantify a number of systematic errors affecting the weak lensing modelling. These errors include a calibration of the bias incurred by fitting a Navarro-Frenk-White profile to the reduced shear using $N$-body simulations. We blind the analysis to avoid confirmation bias. We are able to limit the systematic uncertainties to 6.4% in cluster mass (68% confidence). Our constraints on the mass-X-ray observable scaling relations parameters are consistent with those obtained by earlier studies, and our constraints for the mass-SZE scaling relation are consistent with the the simulation-based prior used in the most recent SPT-SZ cosmology analysis. We can now replace the external mass calibration priors used in previous SPT-SZ cosmology studies with a direct, internal calibration obtained on the same clusters.
Abstract
We use galaxy dynamical information to calibrate the richness–mass scaling relation of a sample of 428 galaxy clusters that are members of the CODEX sample with redshifts up to z ∼ 0.7. ...These clusters were X-ray selected using the ROSAT All-Sky Survey (RASS) and then cross-matched to associated systems in the redMaPPer (the red sequence Matched-filter Probabilistic Percolation) catalogue from the Sloan Digital Sky Survey. The spectroscopic sample we analyse was obtained in the SPIDERS program and contains ∼7800 red member galaxies. Adopting NFW mass and galaxy density profiles and a broad range of orbital anisotropy profiles, we use the Jeans equation to calculate halo masses. Modelling the scaling relation as $\lambda \propto \text{A}_{\lambda } {M_{\text{200c}}}^{\text{B}_{\lambda }} ({1+z})^{\gamma _{\lambda }}$, we find the parameter constraints $\text{A}_{\lambda }=38.6^{+3.1}_{-4.1}\pm 3.9$, $\text{B}_{\lambda }=0.99^{+0.06}_{-0.07}\pm 0.04$, and $\gamma _{\lambda }=-1.13^{+0.32}_{-0.34}\pm 0.49$, where we present systematic uncertainties as a second component. We find good agreement with previously published mass trends with the exception of those from stacked weak lensing analyses. We note that although the lensing analyses failed to account for the Eddington bias, this is not enough to explain the differences. We suggest that differences in the levels of contamination between pure redMaPPer and RASS + redMaPPer samples could well contribute to these differences. The redshift trend we measure is more negative than but statistically consistent with previous results. We suggest that our measured redshift trend reflects a change in the cluster galaxy red sequence (RS) fraction with redshift, noting that the trend we measure is consistent with but somewhat stronger than an independently measured redshift trend in the RS fraction. We also examine the impact of a plausible model of correlated scatter in X-ray luminosity and optical richness, showing it has negligible impact on our results.
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Patients with ulcerative colitis (UC) using marijuana have been reported to experience symptomatic benefit. Cannabidivarin (CBDV) is a safe non-psychoactive phytocannabinoid able to ...activate and desensitize TRPA1, a member of the TRP channels superfamily, which plays a pivotal role in intestinal inflammation. Here, we have investigated the potential intestinal anti-inflammatory effect of CBDV in mice and in biopsies from pediatric patients with active UC. Colonic inflammation was induced in mice by dinitrobenzenesulfonic acid (DNBS). The effect of orally administered CBDV on macroscopic and microscopic damage, inflammatory parameters (i.e. myeloperoxidase activity, intestinal permeability and cytokine production) and faecal microbiota composition, was evaluated 3 days after DNBS administration. TRPA1 expression was studied by RT-PCR in inflamed colons of mice as well as in mucosal colonic biopsies of children with active UC, whose response to incubation with CBDV was also investigated. CBDV attenuates, in a TRPA1-antagonist sensitive manner, DNBS-induced signs of inflammation including neutrophil infiltration, intestinal permeability, and cytokine (i.e. IL-1β, IL-6 and the chemokine MCP-1) production. CBDV also alters the dysregulation of gut microbiota associated to colitis. Finally, CBDV lessens cytokine expression in colonic biopsies from pediatric patients with ulcerative colitis, a condition in which TRPA1 was up-regulated. Our preclinical study shows that CBDV exerts intestinal anti-inflammatory effects in mice via TRPA1, and in children with active UC. Since CBDV has a favorable safety profile in humans, it may be considered for possible clinical trials in patients with UC.
Background and Purpose
The non‐psychotropic cannabinoid cannabichromene is known to activate the transient receptor potential ankyrin‐type1 (TRPA1) and to inhibit endocannabinoid inactivation, both ...of which are involved in inflammatory processes. We examined here the effects of this phytocannabinoid on peritoneal macrophages and its efficacy in an experimental model of colitis.
Experimental Approach
Murine peritoneal macrophages were activated in vitro by LPS. Nitrite levels were measured using a fluorescent assay; inducible nitric oxide (iNOS), cyclooxygenase‐2 (COX‐2) and cannabinoid (CB1 and CB2) receptors were analysed by RT‐PCR (and/or Western blot analysis); colitis was induced by dinitrobenzene sulphonic acid (DNBS). Endocannabinoid (anandamide and 2‐arachidonoylglycerol), palmitoylethanolamide and oleoylethanolamide levels were measured by liquid chromatography‐mass spectrometry. Colonic inflammation was assessed by evaluating the myeloperoxidase activity as well as by histology and immunohistochemistry.
Key Results
LPS caused a significant production of nitrites, associated to up‐regulation of anandamide, iNOS, COX‐2, CB1 receptors and down‐regulation of CB2 receptors mRNA expression. Cannabichromene significantly reduced LPS‐stimulated nitrite levels, and its effect was mimicked by cannabinoid receptor and TRPA1 agonists (carvacrol and cinnamaldehyde) and enhanced by CB1 receptor antagonists. LPS‐induced anandamide, iNOS, COX‐2 and cannabinoid receptor changes were not significantly modified by cannabichromene, which, however, increased oleoylethanolamide levels. In vivo, cannabichromene ameliorated DNBS‐induced colonic inflammation, as revealed by histology, immunohistochemistry and myeloperoxidase activity.
Conclusion and Implications
Cannabichromene exerts anti‐inflammatory actions in activated macrophages – with tonic CB1 cannabinoid signalling being negatively coupled to this effect – and ameliorates experimental murine colitis.
Context. Galaxy clusters are the most recent products of hierarchical accretion over cosmological scales. The gas accreted from the cosmic field is thermalized inside the cluster halo. Gas entropy ...and pressure are expected to have a self-similar behaviour with their radial distribution following a power law and a generalized Navarro-Frenk-White profile, respectively. This has also been shown in many different hydrodynamical simulations. Aims. We derive the spatially resolved thermodynamical properties of 47 X-ray galaxy clusters observed with Chandra in the redshift range 0.4 <z< 1.2, which is one of the largest samples investigated so far with X-ray spectroscopy and masses reconstructed via the hydrostatic equilibrium equation, with particular care taken to reconstruct the gas entropy and pressure radial profiles. We search for deviation from the self-similar behaviour and look for possible evolution with redshift. Methods. Under the assumption of a spherically symmetric distribution of the intracluster plasma, we combine the deprojected gas density and deprojected spectral temperature profiles via the hydrostatic equilibrium equation to constrain the concentration and scale radius, which are the parameters that describe a Navarro-Frenk-White profile for each of the clusters in our sample. The temperature profile, which combined with the observed gas density profile reproduces the best-fit mass model, is then used to reconstruct the profiles of entropy and pressure. These profiles cover a median radial interval of 0.04 R500–0.76 R500. After interpolating on the same radial grid and partially extrapolating up to R500, these profiles are then stacked in three independent redshift bins to increase the precision of the analysis. The gas mass fraction is then used to improve the self-similar behaviour of the profiles by reducing the scatter among the profiles by a factor 3. Results. The entropy and pressure profiles lie very close to the baseline prediction from gravitational structure formation. We show that these profiles deviate from the baseline prediction as function of redshift, in particular at z> 0.75, where, in the central regions, we observe higher values of the entropy (by a factor of ~2.2) and systematically lower estimates (by a factor of ~2.5) of the pressure. The effective polytropic index, which retains information about the thermal distribution of the gas, shows a slight linear positive evolution with the redshift and concentration of the dark matter distribution. A prevalence of non-cool core, disturbed systems, as we observe at higher redshifts, can explain such behaviours.
Abstract
We forecast the impact of weak lensing (WL) cluster mass calibration on the cosmological constraints from the X-ray selected galaxy cluster counts in the upcoming eROSITA survey. We employ a ...prototype cosmology pipeline to analyze mock cluster catalogs. Each cluster is sampled from the mass function in a fiducial cosmology and given an eROSITA count rate and redshift, where count rates are modeled using the eROSITA effective area, a typical exposure time, Poisson noise and the scatter and form of the observed X-ray luminosity– and temperature–mass–redshift relations. A subset of clusters have mock shear profiles to mimic either those from DES and HSC or from the future Euclid and LSST surveys. Using a count rate selection, we generate a baseline cluster cosmology catalog that contains 13k clusters over 14,892 deg2 of extragalactic sky. Low mass groups are excluded using raised count rate thresholds at low redshift. Forecast parameter uncertainties for ΩM, σ8 and w are 0.023 (0.016; 0.014), 0.017 (0.012; 0.010), and 0.085 (0.074; 0.071), respectively, when adopting DES+HSC WL (Euclid; LSST), while marginalizing over the sum of the neutrino masses. A degeneracy between the distance–redshift relation and the parameters of the observable–mass scaling relation limits the impact of the WL calibration on the w constraints, but with BAO measurements from DESI an improved determination of w to 0.043 becomes possible. With Planck CMB priors, ΩM (σ8) can be determined to 0.005 (0.007), and the summed neutrino mass limited to ∑mν < 0.241 eV (at 95%). If systematics on the group mass scale can be controlled, the eROSITA group and cluster sample with 43k objects and LSST WL could constrain ΩM and σ8 to 0.007 and w to 0.050.
ABSTRACT
SPIDERS is the spectroscopic follow-up effort of the Sloan Digital Sky Survey IV (SDSS-IV) project for the identification of X-ray selected galaxy clusters. We present our catalogue of 2740 ...visually inspected galaxy clusters as part of the SDSS Data Release 16 (DR16). Here we detail the target selection, our methods for validation of the candidate clusters, performance of the survey, the construction of the final sample, and a full description of what is found in the catalogue. Of the sample, the median number of members per cluster is approximately 10, with 818 having 15 or greater. We find that we are capable of validating over 99 per cent of clusters when five redshifts are obtained below z < 0.3 and when nine redshifts are obtained above z > 0.3. We discuss the improvements in this catalogue’s identification of cluster using 33 340 redshifts, with Δzphot/Δzspec ∼ 100, over other photometric and spectroscopic surveys, as well as presenting an update to previous (σ–LX) and (σ–λ) relations. Finally, we present our cosmological constraints derived using the velocity dispersion function.
We present the brightest cluster galaxies (BCGs) catalog for SPectroscoic IDentification of eROSITA Sources (SPIDERS) DR14 cluster program value-added catalog. We list the 416 BCGs identified as part ...of this process, along with their stellar mass, star formation rates (SFRs), and morphological properties. We identified the BCGs based on the available spectroscopic data from SPIDERS and photometric data from SDSS. We computed stellar masses and SFRs of the BCGs on the basis of SDSS, WISE, and GALEX photometry using spectral energy distribution fitting. Morphological properties for all BCGs were derived by Sersic profile fitting using the software package SIGMA in different optical bands (g,r,i). We combined this catalog with the BCGs of galaxy groups and clusters extracted from the deeper AEGIS, CDFS, COSMOS, XMM-CFHTLS, and XMM-XXL surveys to study the stellar mass–halo mass relation using the largest sample of X-ray groups and clusters known to date. This result suggests that the mass growth of the central galaxy is controlled by the hierarchical mass growth of the host halo. We find a strong correlation between the stellar mass of BCGs and the mass of their host halos. This relation shows no evolution since z ∼ 0.65. We measure a mean scatter of 0.21 and 0.25 for the stellar mass of BCGs in a given halo mass at low (0.1 < z < 0.3) and high (0.3 < z < 0.65) redshifts, respectively. We further demonstrate that the BCG mass is covariant with the richness of the host halos in the very X-ray luminous systems. We also find evidence that part of the scatter between X-ray luminosity and richness can be reduced by considering stellar mass as an additional variable.
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