A catalog of galaxy clusters observed by XMM-Newton

Snowden, S. L.; Mushotzky, R. F.; Küntz, K. D.; Davis, David

doi:10.1051/0004-6361:20077930

Cited by 373 publications

(512 citation statements)

References 56 publications

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“…This is consistent with our observations 3 , especially since n e (r) varies much more than T (r) in the Coma cluster (see e.g. Arnaud et al 2001;Snowden et al 2008). Jeltema & Profumo (2011) derive a lower limit for the average field in Coma of 1.7 μG, from limits on the Fermi γ-ray 3 In the case that α = 1 + δ, the relationship would be r ∝ (y/T ) 1+δ/2 , if we assume B ∝ √ n e .…”

Section: Quasi-linear Sz-radio Relationsupporting

confidence: 82%

Planckintermediate results

Collaboration¹,

Ade

Aghanim

et al. 2013

A&A

101

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We present an analysis of Planck satellite data on the Coma cluster observed via the Sunyaev-Zeldovich effect. Thanks to its great sensitivity, Planck is able, for the first time, to detect SZ emission up to r ≈ 3 × R 500 . We test previously proposed spherically symmetric models for the pressure distribution in clusters against the azimuthally averaged data. In particular, we find that the Arnaud et al. (2010, A&A, 517, A92) "universal" pressure profile does not fit Coma, and that their pressure profile for merging systems provides a reasonable fit to the data only at r < R 500 ; by r = 2 × R 500 it underestimates the observed y profile by a factor of 2. This may indicate that at these larger radii either: i) the cluster SZ emission is contaminated by unresolved SZ sources along the line of sight; or ii) the pressure profile of Coma is higher at r > R 500 than the mean pressure profile predicted by the simulations used to constrain the models. The Planck image shows significant local steepening of the y profile in two regions about half a degree to the west and to the south-east of the cluster centre. These features are consistent with the presence of shock fronts at these radii, and indeed the western feature was previously noticed in the ROSAT PSPC mosaic as well as in the radio. Using Planck y profiles extracted from corresponding sectors we find pressure jumps of 4.9 +0.4 −0.2 and 5.0 +1.3 −0.1 in the west and south-east, respectively. Assuming Rankine-Hugoniot pressure jump conditions, we deduce that the shock waves should propagate with Mach number M w = 2.03 +0.09 −0.04 and M se = 2.05 +0.25 −0.02 in the west and south-east, respectively. Finally, we find that the y and radio-synchrotron signals are quasi-linearly correlated on Mpc scales, with small intrinsic scatter. This implies either that the energy density of cosmic-ray electrons is relatively constant throughout the cluster, or that the magnetic fields fall off much more slowly with radius than previously thought.

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Section: Quasi-linear Sz-radio Relationsupporting

confidence: 82%

Planckintermediate results

Collaboration¹,

Ade

Aghanim

et al. 2013

A&A

101

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“…3 Snowden et al (2008) have shown that temperatures determined with Chandra are overestimated due to a calibration problem, which has been only corrected in the Chandra CALDB as of version 3.5.2. This issue is however only relevant for temperatures > ∼ 5 keV, so we do not expect it to affect our results, as the hottest object in our sample is at ∼3 keV.…”

Section: Discussionmentioning

confidence: 99%

Testing the low-mass end of X-ray scaling relations with a sample ofChandragalaxy groups

Eckmiller

Hudson

Reiprich

2011

A&A

126

183

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Context. Well-determined scaling relations between X-ray observables and cluster mass are essential for using large cluster samples to constrain fundamental cosmological parameters. Scaling relations between cluster masses and observables, such as the luminositytemperature, mass-temperature, luminosity-mass relations, have been investigated extensively, however the question of whether these relations hold true also for poor clusters and groups remains unsettled. Some evidence supports a "break" at the low end of the group/cluster mass range, possibly caused by the stronger influence of non-gravitational physics on low-mass systems. Aims. The main goal of this work is to test local scaling relations for the low-mass range in order to check whether or not there is a systematic difference between clusters and groups, and to thereby extend this method of reliable and convenient cluster mass determination for future large samples down to the group regime. Methods. We compiled a statistically complete sample of 112 X-ray galaxy groups, 26 of which have usable Chandra data. Temperature, metallicity, and surface brightness profiles were created for these 26 groups, and used to determine the main physical quantities and scaling relations. We then compared the group properties to those of the HIFLUGCS clusters, as well as several other group and cluster samples. Results. We present radial profiles for the individual objects and scaling relations of the whole sample (. Temperature and metallicity profiles behave universally, except for the core regions.and L x − Y x relations of the group sample are generally in good agreement with clusters. The L x − T relation steepens for T < 3 keV, which could point to a larger impact of heating mechanisms on cooler systems. We found a significant drop in the gas mass fraction below < ∼ 1 keV, as well as a correlation with radius, which indicates the ICM is less dominant in groups compared to clusters and the galaxies have a stronger influence on the global properties of the system. In all relations the intrinsic scatter for groups is larger than for clusters, which appears not to be correlated with merger activity but could be due to scatter caused by baryonic physics in the group cores. We also demonstrate the importance of selection effects. Conclusions. We have found some evidence for a similarity break between groups and clusters. However this does not have a strong effect on the scaling relations.

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“…The knowledge of these components has been growing thanks to the many efforts involved in collecting suitable blank sky fields to be used as template background by the XMM-Newton users [4,5], the analysis of the XMM-Newton Guest Observer Facility leading to the XMMNewton Extended Source Analysis Software [6,7], the efforts of the XMMNewton SOC 1 and the contributions of various research teams, among them our in Milan has been particularly active on this topic [8,9,10]. A summary table of the EPIC instrumental background components is available at this link 2 .…”

Section: The Current Knowledge Of the Xmm-newton Backgroundmentioning

confidence: 99%