scholarly journals Mass calibration of the CODEX cluster sample using SPIDERS spectroscopy – II. The X-ray luminosity–mass relation

2020 ◽  
Vol 494 (2) ◽  
pp. 2736-2746 ◽  
Author(s):  
R Capasso ◽  
J J Mohr ◽  
A Saro ◽  
A Biviano ◽  
N Clerc ◽  
...  
Keyword(s):  
Mass Relation ◽  
Scaling Relation ◽  
X Ray ◽  
Mass Scaling ◽  
Systematic Uncertainties ◽  
Best Fitting ◽  
Mass Profile ◽  
Halo Masses ◽  
Fitting Parameters

ABSTRACT We perform the calibration of the X-ray luminosity–mass scaling relation on a sample of 344 CODEX clusters with z < 0.66 using the dynamics of their member galaxies. Spectroscopic follow-up measurements have been obtained from the SPIDERS survey, leading to a sample of 6658 red member galaxies. We use the Jeans equation to calculate halo masses, assuming an NFW mass profile and analysing a broad range of anisotropy profiles. With a scaling relation of the form $L_{\rm {X}} \propto \text{A}_{\rm {X}}M_{\text{200c}}^{\text{B}_{\rm {X}}} E(z)^2 (1+z)^{\gamma _{\rm {X}}}$, we find best-fitting parameters $\text{A}_{\rm {X}}=0.62^{+0.05}_{-0.06} (\pm 0.06)\times 10^{44}\, \mathrm{erg\, s^{-1}}$, $\text{B}_{\rm {X}}=2.35^{+0.21}_{-0.18}(\pm 0.09)$, $\gamma _{\rm {X}}=-2.77^{+1.06}_{-1.05}(\pm 0.79)$, where we include systematic uncertainties in parentheses and for a pivot mass and redshift of $3\times 10^{14}\, \mathrm{M}_\odot$ and 0.16, respectively. We compare our constraints with previous results, and we combine our sample with the SPT SZE-selected cluster subsample observed with XMM–Newton  extending the validity of our results to a wider range of redshifts and cluster masses.

scholarly journals Cosmological constraints from CODEX galaxy clusters spectroscopically confirmed by SDSS-IV/SPIDERS DR16

2020 ◽  
Vol 499 (4) ◽  
pp. 4768-4784
Author(s):  
J Ider Chitham ◽  
J Comparat ◽  
A Finoguenov ◽  
N Clerc ◽  
C Kirkpatrick ◽  
...  
Keyword(s):  
Cosmological Parameters ◽  
Galaxy Cluster ◽  
Selection Function ◽  
Mass Relation ◽  
Scaling Relation ◽  
X Ray ◽  
Mass Scaling ◽  
Systematic Uncertainties ◽  
Spectroscopic Information ◽  
Best Fitting

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, $\tilde{z} \in \left[0.1, 0.6 \right)$ and optical richness, $\tilde{\lambda } \in \left[25, 148 \right)$ 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.

scholarly journals Mass calibration of the CODEX cluster sample using SPIDERS spectroscopy – I. The richness–mass relation

2019 ◽  
Vol 486 (2) ◽  
pp. 1594-1607 ◽  
Author(s):  
R Capasso ◽  
J J Mohr ◽  
A Saro ◽  
A Biviano ◽  
N Clerc ◽  
...  
Keyword(s):  
Matched Filter ◽  
Mass Relation ◽  
Scaling Relation ◽  
Cluster Galaxy ◽  
X Ray ◽  
Mass Scaling ◽  
Sky Survey ◽  
The Impact ◽  
Parameter Constraints ◽  
Red Sequence

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.

scholarly journals Validation of selection function, sample contamination and mass calibration in galaxy cluster samples

2020 ◽  
Vol 498 (1) ◽  
pp. 771-798
Author(s):  
S Grandis ◽  
M Klein ◽  
J J Mohr ◽  
S Bocquet ◽  
M Paulus ◽  
...  
Keyword(s):  
Cosmological Parameters ◽  
Galaxy Cluster ◽  
Selection Function ◽  
Scaling Relation ◽  
X Ray ◽  
Mass Scaling ◽  
Dark Energy Survey ◽  
Cross Calibration ◽  
Number Counts

ABSTRACT We construct and validate the selection function of the MARD-Y3 galaxy cluster sample. This sample was selected through optical follow-up of the 2nd ROSAT faint source catalogue with Dark Energy Survey year 3 data. The selection function is modelled by combining an empirically constructed X-ray selection function with an incompleteness model for the optical follow-up. We validate the joint selection function by testing the consistency of the constraints on the X-ray flux–mass and richness–mass scaling relation parameters derived from different sources of mass information: (1) cross-calibration using South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) clusters, (2) calibration using number counts in X-ray, in optical and in both X-ray and optical while marginalizing over cosmological parameters, and (3) other published analyses. We find that the constraints on the scaling relation from the number counts and SPT-SZ cross-calibration agree, indicating that our modelling of the selection function is adequate. Furthermore, we apply a largely cosmology independent method to validate selection functions via the computation of the probability of finding each cluster in the SPT-SZ sample in the MARD-Y3 sample and vice versa. This test reveals no clear evidence for MARD-Y3 contamination, SPT-SZ incompleteness or outlier fraction. Finally, we discuss the prospects of the techniques presented here to limit systematic selection effects in future cluster cosmological studies.

scholarly journals Stellar mass to halo mass scaling relation for X-ray-selected low-mass galaxy clusters and groups out to redshiftz≈ 1

2016 ◽  
Vol 458 (1) ◽  
pp. 379-393 ◽  
Author(s):  
I. Chiu ◽  
A. Saro ◽  
J. Mohr ◽  
S. Desai ◽  
S. Bocquet ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Stellar Mass ◽  
Scaling Relation ◽  
X Ray ◽  
Mass Scaling ◽  
Low Mass

X-RAY ABSORPTION SPECTROSCOPY IN NaCo2O4, LaCoO3andSrCoO3

2002 ◽  
Vol 09 (02) ◽  
pp. 1327-1331 ◽  
Author(s):  
TOMOHIRA MATSUSHITA ◽  
MASAICHIRO MIZUMAKI ◽  
NAOSHI IKEDA ◽  
MAKOTO NAKAZAWA ◽  
AKANE AGUI ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Absorption Spectroscopy ◽  
Mixed Valence ◽  
Layered System ◽  
X Ray ◽  
Best Fitting ◽  
Ionic States ◽  
X Ray Absorption ◽  
Fitting Parameters ◽  
Oxygen Atoms

We have performed Co 2p X-ray absorption spectroscopy (XAS) on a mixed valence hexagonal layered system NaCo 2 O 4, which shows large thermopower and metallic conductivity. We also measured XAS for SrCoO 3 and LaCoO 3 as examples of typical Co ionic states. The Co ions of the last two materials are octahedrally surrounded by oxygen atoms. A Co atom in NaCo 2 O 4 also has octahedral coordination with oxygen atoms but it is distorted slightly. The Co ions in SrCoO 3 and LaCoO 3 are in the d5 and d6 configuration respectively. The spectrum of NaCo 2 O 4 resembles that of LaCoO 3 rather than that of SrCoO 3; the Co ions in NaCo 2 O 4 can be regarded as the d6 configuration. Also, we have tried to calculate the XAS spectra by using the charge-transfer multiplet model (CT-M). Although we could not find out the best-fitting parameters, the results suggested the itinerancy of the Co 3d states.

The solid solutions CeRu1–xPdxSn and CeRh1–xPdxSn – Applicability of the ICF model to determine intermediate cerium valencies by comparison with XANES data

2015 ◽  
Vol 70 (4) ◽  
pp. 253-264 ◽  
Author(s):  
Oliver Niehaus ◽  
Paula M. Abdala ◽  
Rainer Pöttgen
Keyword(s):  
Solid Solutions ◽  
Valence Electron ◽  
Magnetic Measurements ◽  
Edge Structure ◽  
X Ray ◽  
Arc Melting ◽  
Best Fitting ◽  
Icf Model ◽  
X Ray Absorption ◽  
Fitting Parameters

AbstractSeveral samples of the solid solutions CeRu1–xPdxSn and CeRh1–xPdxSn have been synthesized by arc-melting and characterized by X-ray powder diffraction. Guinier powder patterns prove that the ZrNiAl-type structure is the dominating one, besides the CeRuSn and TiNiSi type structures. The structures of CeRu0.28Pd0.72Sn (ZrNiAl type, P6̅2m, a = 751.95(3), c = 418.70(2) pm, wR2 = 0.0274, 332 F2 values, 14 variables) and CeRh0.66Pd0.34Sn (ZrNiAl type, P6̅2m, a = 750.26(3), c = 411.59(2) pm, wR2 = 0.0533, 358 F2 values, 14 variables) were refined from single crystal diffractometer data. Magnetic measurements in combination with XANES (X-Ray Absorption Near Edge Structure) clearly proved intermediate cerium valencies for most compounds and revealed the best fitting parameters for those with the ICF model (Interconfiguration fluctuation). The electrical resistivity is also influenced by the substitutions. At low and high valence electron counts (VECs) metallic character is present, while around the VEC of CeRhSn the typical resistivity behavior for valence fluctuating compounds is observed.

scholarly journals Imprints of mass accretion history on the shape of the intracluster medium and the TX–M relation

2019 ◽  
Vol 490 (2) ◽  
pp. 2380-2389 ◽  
Author(s):  
Huanqing Chen ◽  
Camille Avestruz ◽  
Andrey V Kravtsov ◽  
Erwin T Lau ◽  
Daisuke Nagai
Keyword(s):  
Galaxy Clusters ◽  
Bimodal Distribution ◽  
Characteristic Time Scale ◽  
Intracluster Medium ◽  
X Ray ◽  
Mass Scaling ◽  
Systematic Uncertainties ◽  
The Galaxy ◽  
Statistical Sample ◽  
The Impact

ABSTRACT We use a statistical sample of galaxy clusters from a large cosmological N-body + hydrodynamics simulation to examine the relation between morphology, or shape, of the X-ray emitting intracluster medium (ICM) and the mass accretion history of the galaxy clusters. We find that the mass accretion rate (MAR) of a cluster is correlated with the ellipticity of the ICM. The correlation is largely driven by material accreted in the last ∼4.5 Gyr, indicating a characteristic time-scale for relaxation of cluster gas. Furthermore, we find that the ellipticity of the outer regions (R ∼ R500c) of the ICM is correlated with the overall MAR of clusters, while ellipticity of the inner regions (≲0.5 R500c) is sensitive to recent major mergers with mass ratios of ≥1:3. Finally, we examine the impact of variations in cluster mass accretion history on the X-ray observable–mass scaling relations. We show that there is a continuous anticorrelation between the residuals in the TX–M relation and cluster MARs, within which merging and relaxed clusters occupy extremes of the distribution rather than form two peaks in a bimodal distribution, as was often assumed previously. Our results indicate that the systematic uncertainties in the X-ray observable–mass relations can be mitigated by using the information encoded in the apparent ICM ellipticity.

scholarly journals Exploring black hole scaling relations via the ensemble variability of Active Galactic Nuclei

2021 ◽  
Author(s):  
A Georgakakis ◽  
I Papadakis ◽  
M Paolillo
Keyword(s):  
Black Hole ◽  
Galactic Nuclei ◽  
Stellar Mass ◽  
Mass Relation ◽  
Black Hole Mass ◽  
X Ray ◽  
Mass Scaling ◽  
Spectrum Density ◽  
First Time ◽  
Black Hole Masses

Abstract An empirical model is presented that links, for the first time, the demographics of AGN to their ensemble X-ray variability properties. Observations on the incidence of AGN in galaxies are combined with (i) models of the Power Spectrum Density (PSD) of the flux variations of AGN and (ii) parameterisations of the black hole mass versus stellar-mass scaling relation, to predict the mean excess variance of active black hole populations in cosmological volumes. We show that the comparison of the model with observational measurements of the ensemble excess variance as a function of X-ray luminosity provides a handle on both the PSD models and the black hole mass versus stellar mass relation. We find strong evidence against a PSD model that is described by a broken power-law and a constant overall normalization. Instead our analysis indicates that the amplitude of the PSD depends on the physical properties of the accretion events, such as the Eddington ratio and/or the black hole mass. We also find that current observational measurements of the ensemble excess variance are consistent with the black hole mass versus stellar mass relation of local spheroids based on dynamically determined black hole masses. We also discuss future prospects of the proposed approach to jointly constrain the PSD of AGN and the black hole mass versus stellar mass relation as a function of redshift.

scholarly journals X-ray spectroscopy of newly identified ULXs associated with M87’s globular cluster population

2020 ◽  
Vol 497 (1) ◽  
pp. 596-608 ◽  
Author(s):  
Kristen C Dage ◽  
Stephen E Zepf ◽  
Erica Thygesen ◽  
Arash Bahramian ◽  
Arunav Kundu ◽  
...  
Keyword(s):  
Globular Cluster ◽  
Component Model ◽  
X Ray ◽  
Two Component ◽  
Long Time ◽  
Order Of Magnitude ◽  
Best Fitting ◽  
Component Models ◽  
Best Fit

ABSTRACT We have identified seven ultraluminous X-ray sources (ULXs) that are coincident with globular cluster candidates (GC) associated with M87. ULXs in the old GC environment represent a new population of ULXs, and ones likely to be black holes. In this study, we perform detailed X-ray spectroscopic follow-up to seven GC ULXs across a wealth of archival Chandra observations and long time baseline of 16 yr. This study brings the total known sample of GC ULXs to 17. Two of these sources show variability in their X-ray luminosity of an order of magnitude over many years, and one of these sources shows intra-observational variability on the scale of hours. While the X-ray spectra of the majority of GC ULXs are best fit by single-component models, one of the sources studied in this paper is the second GC ULX to be best fit by a two-component model. We compare this new sample of GC ULXs to the previously studied sample, and compare the X-ray and optical properties counterparts across the samples. We find that the clusters that host ULXs in M87 have metallicities from g − z = 1.01 to g − z = 1.70. The best-fitting power-law indices of the X-ray spectra range from Γ = 1.37 to 2.21, and the best-fitting inner blackbody disc temperatures range from kT = 0.56 to 1.90 keV.

scholarly journals On the vanishing orbital X-ray variability of the eclipsing binary millisecond pulsar 47 Tuc W

2020 ◽  
Vol 500 (1) ◽  
pp. 1139-1150
Author(s):  
P R Hebbar ◽  
C O Heinke ◽  
D Kandel ◽  
R W Romani ◽  
P C C Freire
Keyword(s):  
State Transition ◽  
Uv Light ◽  
Light Curves ◽  
X Rays ◽  
Millisecond Pulsar ◽  
X Ray ◽  
Pulsar Radiation ◽  
Best Fitting ◽  
Pulsar Wind ◽  
Fitting Parameters

ABSTRACT Redback millisecond pulsars (MSPs) typically show pronounced orbital variability in their X-ray emission due to our changing view of the intrabinary shock (IBS) between the pulsar wind and stellar wind from the companion. Some redbacks (‘transitional’ MSPs) have shown dramatic changes in their multiwavelength properties, indicating a transition from a radio pulsar state to an accretion-powered state. The redback MSP 47 Tuc W showed clear X-ray orbital variability in the Chandra ACIS-S observations in 2002, which were not detectable in the longer Chandra HRC-S observations in 2005–06, suggesting that it might have undergone a state transition. However, the Chandra observations of 47 Tuc in 2014–15 show similar X-ray orbital variability as in 2002. We explain the different X-ray light curves from these epochs in terms of two components of the X-ray spectrum (soft X-rays from the pulsar versus harder X-rays from the IBS), and different sensitivities of the X-ray instruments observing in each epoch. However, when we use our best-fitting spectra with HRC response files to model the HRC light curve, we expect a more significant and shorter dip than that observed in the 2005–06 Chandra data. This suggests an intrinsic change in the IBS of the system. We use the icarus stellar modelling software, including calculations of heating by an IBS, to model the X-ray, optical, and UV light curves of 47 Tuc W. Our best-fitting parameters point towards a high-inclination system ($i \sim 60 \deg$), which is primarily heated by the pulsar radiation, with an IBS dominated by the companion wind momentum.

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