J/A+A/575/A30ivo://CDS.VizieR/J/A+A/575/A30doi:10.26093/cds/vizier.35750030CDSSchellenberger G.Reiprich T.H.Lovisari L.Nevalainen J.David L.2017-12-07T07:27:23Z2015-06-16T07:58:53ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxy-clustersRobust X-ray temperature measurements of the intracluster medium (ICM) of galaxy clusters require an accurate energy-dependent effective area calibration. Since the hot gas X-ray emission of galaxy clusters does not vary on relevant timescales, they are excellent cross-calibration targets. Moreover, cosmological constraints from clusters rely on accurate gravitational mass estimates, which in X-rays strongly depend on cluster gas temperature measurements. Therefore, systematic calibration differences may result in biased, instrument-dependent cosmological constraints. This is of special interest in light of the tension between the Planck results of the primary temperature anisotropies of the cosmic microwave background (CMB) and Sunyaev-Zel'dovich-plus-X-ray cluster-count analyses. We quantify in detail the systematics and uncertainties of the cross-calibration of the effective area between five X-ray instruments, EPIC-MOS1/MOS2/PN onboard XMM-Newton and ACIS-I/S onboard Chandra, and the influence on temperature measurements. Furthermore, we assess the impact of the cross-calibration uncertainties on cosmology. Using the HIFLUGCS sample, consisting of the 64 X-ray brightest galaxy clusters, we constrain the ICM temperatures through spectral fitting in the same, mostly isothermal regions and compare the different instruments. We use the stacked residual ratio method to evaluate the cross-calibration uncertainties between the instruments as a function of energy. Our work is an extension to a previous one using X-ray clusters by the International Astronomical Consortium for High Energy Calibration (IACHEC) and is carried out in the context of IACHEC. Performing spectral fitting in the full energy band, (0.7-7)keV, as is typical of the analysis of cluster spectra, we find that best-fit temperatures determined with XMM-Newton/EPIC are significantly lower than Chandra/ACIS temperatures. This confirms the previous IACHEC results obtained with older calibrations with high precision. The difference increases with temperature, and we quantify this dependence with a fitting formula. For instance, at a cluster temperature of 10keV, EPIC temperatures are on average 23% lower than ACIS temperatures. We also find systematic differences between the three XMM-Newton/EPIC instruments, with the PN detector typically estimating the lowest temperatures. Testing the cross-calibration of the energy-dependence of the effective areas in the soft and hard energy bands, (0.7-2)keV and (2-7)keV, respectively, we confirm the previously indicated relatively good agreement between all instruments in the hard and the systematic differences in the soft band. We provide scaling relations to convert between the different instruments based on the effective area, gas temperature, and hydrostatic mass. We demonstrate that effects like multitemperature structure and different relative sensitivities of the instruments at certain energy bands cannot explain the observed differences. We conclude that using XMM-Newton/EPIC instead of Chandra/ACIS to derive full energy band temperature profiles for cluster mass determination results in an 8% shift toward lower {Omega}_M_ values and <1% change of {sigma}_8_ values in a cosmological analysis of a complete sample of galaxy clusters. Such a shift alone is insufficient to significantly alleviate the tension between Planck CMB primary anisotropies and Sunyaev-Zel'dovich-plus-XMM-Newton cosmological constraints.2015A&A...575A..30Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/575/A30CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/575/A30https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/575/A30http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/575/A30https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/575/A30https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/575/A30http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/575/A30GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/575/A30/clusters (HIFLUGCS clusters (without Abell 2244, table A1) and best-fit temperatures (table A2))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/575/A30/clusters?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/575/A30/clusters?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/575/A30/clusters?GETtext/xml+votable180.050000true54.67149.96720.0055555555555555566/50 87 206-207 306 2251 2432 7026 8220 8264 8268 8271 8520 9036 9354 9468 10312 10379 11591 12121 16434 16543 16713 17141 17237 18016 19608 20021 20355 20481 22577 22722 23306 23451 24943 24951 25981 26135 26208 26302 26313 27652 28249 30946 31537 33235 33628 34443 34535 38853 39077 39079 40777 40809 43626 43837-43838 43849 43977 44554 45044 45984 46484https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/575/A30?format=asciiOpticaldefaultJ/A+A/575/A30/clustersHIFLUGCS clusters (without Abell 2244, table A1) and best-fit temperatures (table A2)SimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterCluster name as used in the papermeta.id;meta.maincharRAJ2000Right ascension (J2000) (1)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) (1)degpos.eq.dec;meta.mainz[0.0037/0.22] Redshift (2)src.redshiftfloatNHHydrogen column density (2)1e+21cm**-2phys.columnDensityfloatr.cc? Radius of the cool core region for CC (Cool Core) clusters only (details in Sect.2)kpcphys.size.radius;obs.fieldfloatnullableObsIDC[319/14024] Chandra obsid usedmeta.id;obsintn_ObsIDC[*] * marks Chandra/ACIS-S observationsmeta.notecharObsIDX[2960101/674560201] XMM obsid usedmeta.id;obslongtACIS[9/135] Cleaned exposure time for Chandra/ACISkstime.duration;obs.exposurefloattPN[2/80] Cleaned exposure time for XMM/EPIC-PNkstime.duration;obs.exposurefloatkT.C[1.5/11.8]? Chandra-ACIS temperature kTkeVphys.temperaturefloatnullableE_kT.C? Error on kT.C (upper value)keVstat.error;stat.maxfloatnullablee_kT.C? Error on kT.C (lower value)keVstat.errorfloatnullablekT.M1? XMM-.OS1 temperature kTkeVphys.temperaturefloatnullableE_kT.M1? Error on kT.M1 (upper value)keVstat.error;stat.maxfloatnullablee_kT.M1? Error on kT.M1 (lower value)keVstat.errorfloatnullablekT.M2? XMM-MOS2 temperature kTkeVphys.temperaturefloatnullableE_kT.M2? Error on kT.M2 (upper value)keVstat.error;stat.maxfloatnullablee_kT.M2? Error on kT.M2 (lower value)keVstat.errorfloatnullablekT.PN? XMM-PN temperature kTkeVphys.temperaturefloatnullableE_kT.PN? Error on kT.PN (upper value)keVstat.error;stat.maxfloatnullablee_kT.PN? Error on kT.PN (lower value)keVstat.errorfloatnullablekT.EP? XMM-EPIC combined temperature kTkeVphys.temperaturefloatnullableE_kT.EP? Error on kT.EP (upper value)keVstat.error;stat.maxfloatnullablee_kT.EP? Error on kT.EP (lower value)keVstat.errorfloatnullableS/bg? Ratio of source and background count rates in the (0.7-2.0)keV bandstat.likelihood;obsfloatnullable