The structure and evolution of X-ray clusters

Jones, C.; Mandel, Eric; Schwarz, J.; Forman, W.; Murray, S. S.; Harnden, F. R.

doi:10.1086/183102

Cited by 80 publications

(38 citation statements)

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“…Under the influence of gravity, diffuse matter and smaller collapsed halos fall into larger halos, and occasionally halos of comparable mass merge with one another. X-ray observations of substructures in clusters of galaxies (see, for instance, Jones et al 1979;Jones & Forman 1984;Mohr et al 1995;Buote & Tsai 1996;Jones & Forman 1999;Jeltema et al 2005;Böhringer et al 2010;Laganá et al 2010;Andrade-Santos et al 2012 and measurements of the growth of structure (Vikhlinin et al 2009b;Mantz et al 2010;Allen et al 2011;Benson et al 2013;Planck Collaboration et al 2014 demonstrate that clusters are still in the process of formation.…”

Section: Introductionmentioning

confidence: 99%

The Fraction of Cool-core Clusters in X-Ray versus SZ Samples Using Chandra Observations

Andrade-Santos

Jones

Forman

et al. 2017

ApJ

115

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We derive and compare the fractions of cool-core clusters in the Planck Early Sunyaev-Zel'dovich sample of 164 clusters with  z 0.35 and in a flux-limited X-ray sample of 100 clusters with  z 0.30, using Chandra observations. We use four metrics to identify cool-core clusters: (1) the concentration parameter, which is the ratio of the integrated emissivity profile within 0.15 r 500 to that within r 500 ; (2) the ratio of the integrated emissivity profile within 40 kpc to that within 400 kpc; (3) the cuspiness of the gas density profile, which is the negative of the logarithmic derivative of the gas density with respect to the radius, measured at 0.04 r 500 ; and (4) the central gas density, measured at 0.01 r 500 . We find that the sample of X-ray-selected clusters, as characterized by each of these metrics, contains a significantly larger fraction of cool-core clusters compared to the sample of SZ-selected clusters (44%±7% versus 28%±4% using the concentration parameter in the 0.15-1.0 r 500 range, 61%±8% versus 36%±5% using the concentration parameter in the 40-400 kpc range, 64%±8% versus 38%±5% using the cuspiness, and 53%±7% versus 39±5% using the central gas density). Qualitatively, cool-core clusters are more X-ray luminous at fixed mass. Hence, our X-ray, flux-limited sample, compared to the approximately masslimited SZ sample, is overrepresented with cool-core clusters. We describe a simple quantitative model that uses the excess luminosity of cool-core clusters compared to non-cool-core clusters at fixed mass to successfully predict the observed fraction of cool-core clusters in X-ray-selected samples.

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Section: Introductionmentioning

confidence: 99%

The Fraction of Cool-core Clusters in X-Ray versus SZ Samples Using Chandra Observations

Andrade-Santos

Jones

Forman

et al. 2017

ApJ

115

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“…The response of this hot ( 10 7 K) plasma, known as the intracluster medium (ICM), to the evolving gravitational potential is one of our best probes of the current state and evolution of galaxy clusters. X-ray imaging and spectroscopy of the ICM allow estimates of the cluster mass profile via the spectroscopic temperature and gas density (e.g., Forman & Jones 1982;Nevalainen et al 2000;Sanderson et al 2003;Arnaud et al 2005Arnaud et al , 2007Kravtsov et al 2006;Vikhlinin et al 2006), the enrichment history of the cluster via the ICM metallicity (e.g., De Young 1978;Matteucci & Greggio 1986;de Plaa et al 2007;Bregman et al 2010;Bulbul et al 2012), the cooling history via the cooling time or entropy (e.g., White et al 1997;Peres et al 1998;Cavagnolo et al 2008;McDonald et al 2013), the feedback history via the presence of X-ray bubbles (e.g., Rafferty et al 2006;McNamara & Nulsen 2007;Rafferty et al 2008;Hlavacek-Larrondo et al 2012), and the current dynamical state and merger history of the cluster via the X-ray morphology (e.g., Jones et al 1979;Mohr et al 1995;Roettiger et al 1996;Schuecker et al 2001;Jeltema et al 2005;Nurgaliev et al 2013).…”

Section: Introductionmentioning

confidence: 99%

The Redshift Evolution of the Mean Temperature, Pressure, and Entropy Profiles in 80 SPT-Selected Galaxy Clusters

McDonald

Benson

Vikhlinin

et al. 2014

ApJ

Self Cite

109

102

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We present the results of an X-ray analysis of 80 galaxy clusters selected in the 2500 deg 2 South Pole Telescope survey and observed with the Chandra X-ray Observatory. We divide the full sample into subsamples of ∼20 clusters based on redshift and central density, performing a joint X-ray spectral fit to all clusters in a subsample simultaneously, assuming self-similarity of the temperature profile. This approach allows us to constrain the shape of the temperature profile over 0 < r < 1.5R 500 , which would be impossible on a per-cluster basis, since the observations of individual clusters have, on average, 2000 X-ray counts. The results presented here represent the first constraints on the evolution of the average temperature profile from z = 0 to z = 1.2. We find that high-z (0.6 < z < 1.2) clusters are slightly (∼30%) cooler both in the inner (r < 0.1R 500 ) and outer (r > R 500 ) regions than their low-z (0.3 < z < 0.6) counterparts. Combining the average temperature profile with measured gas density profiles from our earlier work, we infer the average pressure and entropy profiles for each subsample. Confirming earlier results from this data set, we find an absence of strong cool cores at high z, manifested in this analysis as a significantly lower observed pressure in the central 0.1R 500 of the high-z cool-core subset of clusters compared to the low-z cool-core subset. Overall, our observed pressure profiles agree well with earlier lower-redshift measurements, suggesting minimal redshift evolution in the pressure profile outside of the core. We find no measurable redshift evolution in the entropy profile at r 0.7R 500 -this may reflect a long-standing balance between cooling and feedback over long timescales and large physical scales. We observe a slight flattening of the entropy profile at r R 500 in our high-z subsample. This flattening is consistent with a temperature bias due to the enhanced (∼3×) rate at which group-mass (∼2 keV) halos, which would go undetected at our survey depth, are accreting onto the cluster at z ∼ 1. This work demonstrates a powerful method for inferring spatially resolved cluster properties in the case where individual cluster signal-to-noise is low, but the number of observed clusters is high.

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“…The properties of cD galaxies are generally consistent with the galaxy lying at the bottom of the cluster potential well. They are located at cluster centers (Matthews, Morgan, & Schmidt 1964) and they are located at the peak of the cluster X-ray emission (Jones et al 1979). Quintana & Lawrie (1982) investigated the kinematics of nine cD clusters and concluded that all the cD galaxies in their sample were at rest with respect to their parent clusters within the observational uncertainties.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of [CLC]c[/CLC]D Clusters of Galaxies. IV. Conclusion of a Survey of 25 Abell Clusters

Oegerle

Hill

2001

The Astronomical Journal

149

152

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We present the Ðnal results of a spectroscopic study of a sample of cD galaxy clusters. The goal of this program has been to study the dynamics of the clusters, with emphasis on determining the nature and frequency of cD galaxies with peculiar velocities. Redshifts measured with the MX Spectrometer have been combined with those obtained from the literature to obtain typically 50È150 observed velocities in each of 25 galaxy clusters containing a central cD galaxy. We present a dynamical analysis of the Ðnal 11 clusters to be observed in this sample. All 25 clusters are analyzed in a uniform manner to test for the presence of substructure and to determine peculiar velocities and their statistical signiÐcance for the central cD galaxy. These peculiar velocities were used to determine whether or not the central cD galaxy is at rest in the cluster potential well. We Ðnd that 30%È50% of the clusters in our sample possess signiÐcant subclustering (depending on the cluster radius used in the analysis), which is in agreement with other studies of non-cD clusters. Hence, the dynamical state of cD clusters is not di †erent than that of other present-day clusters. After careful study, four of the clusters appear to have a cD galaxy with a signiÐcant peculiar velocity. Dressler-Shectman tests indicate that three of these four clusters have statistically signiÐcant substructure within 1.5Mpc of the cluster center. The dispersion of the cD h 75 1 peculiar velocities is km s~1 around the mean cluster velocity. This represents a signiÐcant detec-164~3 4 41 tion of peculiar cD velocities but at a level that is far below the mean velocity dispersion for this sample of clusters. The picture that emerges is one in which cD galaxies are nearly at rest with respect to the cluster potential well but have small residual velocities due to subcluster mergers.

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The structure and evolution of X-ray clusters

Cited by 80 publications

References 0 publications

The Fraction of Cool-core Clusters in X-Ray versus SZ Samples Using Chandra Observations

The Fraction of Cool-core Clusters in X-Ray versus SZ Samples Using Chandra Observations

The Redshift Evolution of the Mean Temperature, Pressure, and Entropy Profiles in 80 SPT-Selected Galaxy Clusters

Dynamics of [CLC]c[/CLC]D Clusters of Galaxies. IV. Conclusion of a Survey of 25 Abell Clusters

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