Constraints on the Fluctuation Amplitude and Density Parameter from X‐Ray Cluster Number Counts

We find that the observed logN-logS relation of X-ray clusters (Ebeling et al. 1997; Rosati et al. 1997) can be reproduced remarkably well with a certain range of values for the fluctuation amplitude σ8 and the cosmological density parameter Ω0 in cold dark matter (CDM) universes (Kitayama & Suto 1997). The 1σ confidence limits on σ8 in the CDM models with n = 1 and h = 0.7 are expressed as (0.54 ± 0.02)Ω−0.35-0.82Ω0+0.55Ω200 (λ0 = 1 - Ω0) and (0.54 ± 0.02) Ω−0.28-0.91Ω0+0.68Ω200 (λ0 = 0), where n is the primordial spectral index, and h and λ0 are the dimensionless Hubble and cosmological constants. The errors quoted above indicate the statistical ones from the observed logN-logS only, and the systematic uncertainty from our theoretical modelling of X-ray flux in the best-fit value of σ8 is about 15%. In the case of n = 1, we find that the CDM models with (Ω0, λ0, h, σ8) ≃ (0.3, 0.7, 0.7, 1) and (0.45, 0, 0.7, 0.8) simultaneously account for the cluster logN-logS, X-ray temperature functions, and the normalization from the COBE 4 year data. The derived values assume the observations are without systematic errors, and we discuss in details other theoretical uncertainties which may change the limits on Ω0 and σ8 from the logN-logS relation. We have shown the power of this new approach which will become a strong tool as the observations attain more precision.

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Number Counts of Clusters of Galaxies in X-ray and Submm Bands

Symposium - International Astronomical Union ◽

10.1017/s0074180900132723 ◽

1999 ◽

Vol 183 ◽

pp. 255-255 ◽

Cited By ~ 1

Author(s):

Tetsu Kitayama ◽

Shin Sasaki ◽

Yasushi Suto

Keyword(s):

Theoretical Models ◽

Model Parameters ◽

Clusters Of Galaxies ◽

Cluster Number ◽

Parameter Region ◽

X Ray ◽

Background Radiations ◽

The Press ◽

Number Counts ◽

Acceptable Parameter

We compute the number counts of clusters of galaxies, the logN-logS relation, in several X-ray and submm bands on the basis of the Press—Schechter theory (Kitayama et al. 1998). We pay particular attention to a set of theoretical models which well reproduce the ROSAT 0.5–2 keV band logN-logS (Ebeling et al. 1997; Rosati et al. 1997), and explore possibilities to further constrain the models from future observations with ASCA and/or at submm bands. The latter is closely related to the European PLANCK mission and the Japanese LMSA project. We exhibit that one can break the degeneracy in an acceptable parameter region on the Ω0–σ8 plane by combining the ROSAT logN-logS and the submm number counts. Models which reproduce the ROSAT band logN-logS will have N(> S) ∼ (150–300)(S/10−12 erg cm−2 s−) −1.3 str−1 at S ≳ 10−12 erg cm−2 s−1 in the ASCA 2–10 keV band, and N(> Sv) ∼ (102–104)(Sv/100 mJy)−1.5 str−1 at Sv ≳ 100m J y in the submm (0.85mm) band. The amplitude of the logN-logS is very sensitive to the model parameters in the submm band. We also compute the redshift evolution of the cluster number counts and compare with that of the X-ray brightest Abell-type clusters (Ebeling et al. 1996). The results, although still preliminary, point to low density (Ω0 ∼ 0.3) universes. The contribution of clusters to the X-ray and submm background radiations is shown to be insignificant in any model compatible with the ROSAT logN-logS.

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A Monte Carlo study of cosmological parameter estimators from galaxy cluster number counts

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314011041 ◽

2014 ◽

Vol 10 (S306) ◽

pp. 262-265

Author(s):

Mariana Penna-Lima ◽

Martín Makler ◽

Carlos A. Wuensche

Keyword(s):

Monte Carlo ◽

Dark Energy ◽

Cold Dark Matter ◽

High Redshift ◽

Cosmological Parameters ◽

State Parameter ◽

Monte Carlo Study ◽

Density Parameter ◽

Cluster Number ◽

Number Counts

AbstractModels for galaxy clusters abundance and their spatial distribution are sensitive to cosmological parameters. Present and future surveys will provide high-redshift sample of clusters, such as Dark Energy Survey (z ⩽ 1.3), making cluster number counts one of the most promising cosmological probes. In the literature, some cosmological analyses are carried out using small cluster catalogs (tens to hundreds), like in Sunyaev-Zel'dovich (SZ) surveys. However, it is not guaranteed that maximum likelihood estimators of cosmological parameters are unbiased in this scenario. In this work we study different estimators of the cold dark matter density parameter Ωc, σ8 and the dark energy equation of state parameter w0 obtained from cluster abundance. Using an unbinned likelihood for cluster number counts and the Monte Carlo approach, we determine the presence of bias and how it varies with the size of the sample. Our fiducial models are based on the South Pole Telescope (SPT). We show that the biases from SZ estimators do not go away with increasing sample sizes and they may become the dominant source of error for an all sky survey at the SPT sensitivity.

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The XXL Survey

Astronomy and Astrophysics ◽

10.1051/0004-6361/201833238 ◽

2018 ◽

Vol 620 ◽

pp. A1 ◽

Cited By ~ 6

Author(s):

F. Marulli ◽

A. Veropalumbo ◽

M. Sereno ◽

L. Moscardini ◽

F. Pacaud ◽

...

Keyword(s):

Correlation Function ◽

Galaxy Clusters ◽

Cluster Number ◽

X Ray ◽

Mass Scaling ◽

Cosmological Constraints ◽

Density Peaks ◽

Point Correlation ◽

Point Correlation Function ◽

Number Counts

Context.Galaxy clusters trace the highest density peaks in the large-scale structure of the Universe. Their clustering provides a powerful probe that can be exploited in combination with cluster mass measurements to strengthen the cosmological constraints provided by cluster number counts.Aims.We investigate the spatial properties of a homogeneous sample of X-ray selected galaxy clusters from the XXL survey, the largest programme carried out by theXMM-Newtonsatellite. The measurements are compared to Λ-cold dark matter predictions, and used in combination with self-calibrated mass scaling relations to constrain the effective bias of the sample,beff, and the matter density contrast, ΩM.Methods.We measured the angle-averaged two-point correlation function of the XXL cluster sample. The analysed catalogue consists of 182 X-ray selected clusters from the XXL second data release, with median redshift ⟨z⟩ = 0.317 and median mass ⟨M500⟩≃ 1.3 × 1014M⊙. A Markov chain Monte Carlo analysis is performed to extract cosmological constraints using a likelihood function constructed to be independent of the cluster selection function.Results.Modelling the redshift-space clustering in the scale range 10 <r[h−1Mpc] < 40, we obtain ΩM= 0.27−0.04+0.06andbeff= 2.73−0.20+0.18.This is the first time the two-point correlation function of an X-ray selected cluster catalogue at such relatively high redshifts and low masses has been measured. The XXL cluster clustering appears fully consistent with standard cosmological predictions. The analysis presented in this work demonstrates the feasibility of a cosmological exploitation of the XXL cluster clustering, paving the way for a combined analysis of XXL cluster number counts and clustering.

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A Medium Survey of the Hard X‐Ray Sky with theASCAGas Imaging Spectrometer: The (2–10 keV) Number Counts Relationship

The Astrophysical Journal ◽

10.1086/305097 ◽

1998 ◽

Vol 493 (1) ◽

pp. 54-61 ◽

Cited By ~ 51

Author(s):

I. Cagnoni ◽

R. Della Ceca ◽

T. Maccacaro

Keyword(s):

Imaging Spectrometer ◽

X Ray ◽

Number Counts

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The Fall of Active Galactic Nuclei and the Rise of Star-forming Galaxies: A Close Look at the Chandra Deep Field X-Ray Number Counts

The Astronomical Journal ◽

10.1086/424859 ◽

2004 ◽

Vol 128 (5) ◽

pp. 2048-2065 ◽

Cited By ~ 231

Author(s):

F. E. Bauer ◽

D. M. Alexander ◽

W. N. Brandt ◽

D. P. Schneider ◽

E. Treister ◽

...

Keyword(s):

Active Galactic Nuclei ◽

Galactic Nuclei ◽

X Ray ◽

Star Forming ◽

Number Counts

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Evolution and Statistics from the Number Counts of X-Ray Cluster and Intergalactic Medium

Primordial Nucleosynthesis and Evolution of Early Universe - Astrophysics and Space Science Library ◽

10.1007/978-94-011-3410-1_87 ◽

1991 ◽

pp. 569-570

Author(s):

Hitoshi Hanami

Keyword(s):

Intergalactic Medium ◽

X Ray ◽

Number Counts

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Using quasar X-ray and UV flux measurements to constrain cosmological model parameters

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa1855 ◽

2020 ◽

Vol 497 (1) ◽

pp. 263-278 ◽

Cited By ~ 3

Author(s):

Narayan Khadka ◽

Bharat Ratra

Keyword(s):

Cosmological Parameters ◽

Hubble Constant ◽

Acoustic Oscillation ◽

Joint Analysis ◽

Model Parameters ◽

Density Parameter ◽

Current Standard ◽

X Ray ◽

Flux Measurements ◽

Parameter Constraints

ABSTRACT Risaliti and Lusso have compiled X-ray and UV flux measurements of 1598 quasars (QSOs) in the redshift range 0.036 ≤ z ≤ 5.1003, part of which, z ∼ 2.4 − 5.1, is largely cosmologically unprobed. In this paper we use these QSO measurements, alone and in conjunction with baryon acoustic oscillation (BAO) and Hubble parameter [H(z)] measurements, to constrain cosmological parameters in six different cosmological models, each with two different Hubble constant priors. In most of these models, given the larger uncertainties, the QSO cosmological parameter constraints are mostly consistent with those from the BAO + H(z) data. A somewhat significant exception is the non-relativistic matter density parameter Ωm0 where QSO data favour Ωm0 ∼ 0.5 − 0.6 in most models. As a result, in joint analyses of QSO data with H(z) + BAO data the 1D Ωm0 distributions shift slightly towards larger values. A joint analysis of the QSO + BAO + H(z) data is consistent with the current standard model, spatially-flat ΛCDM, but mildly favours closed spatial hypersurfaces and dynamical dark energy. Since the higher Ωm0 values favoured by QSO data appear to be associated with the z ∼ 2 − 5 part of these data, and conflict somewhat with strong indications for Ωm0 ∼ 0.3 from most z < 2.5 data as well as from the cosmic microwave background anisotropy data at z ∼ 1100, in most models, the larger QSO data Ωm0 is possibly more indicative of an issue with the z ∼ 2 − 5 QSO data than of an inadequacy of the standard flat ΛCDM model.

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