J/ApJ/682/821ivo://CDS.VizieR/J/ApJ/682/821doi:10.26093/cds/vizier.16820821CDSCavagnolo K.W.Donahue M.Voit G.M.Sun M.2017-06-22T14:29:30Z2010-11-23T15:08:16ZCDS support team

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

cds-question@unistra.frgalaxy-clustersx-ray-sourcesspectroscopyWe explore the band dependence of the inferred X-ray temperature of the intracluster medium (ICM) for 192 well-observed galaxy clusters selected from the Chandra Data Archive. If the hot ICM is nearly isothermal in the projected region of interest, the X-ray temperature inferred from a broadband (0.7-7.0keV) spectrum should be identical to the X-ray temperature inferred from a hard-band (2.0-7.0keV) spectrum. However, if unresolved cool lumps of gas are contributing soft X-ray emission, the temperature of a best-fit single-component thermal model will be cooler for the broadband spectrum than for the hard-band spectrum. Using this difference as a diagnostic, the ratio of best-fitting hard-band and broadband temperatures may indicate the presence of cooler gas even when the X-ray spectrum itself may not have sufficient signal-to-noise ratio (S/N) to resolve multiple temperature components. To test this possible diagnostic, we extract X-ray spectra from core-excised annular regions for each cluster in our archival sample. We compare the X-ray temperatures inferred from single-temperature fits when the energy range of the fit is 0.7-7.0keV (broad) and when the energy range is 2.0/(1+z)-7.0keV (hard). We find that the hard-band temperature is significantly higher, on average, than the broadband temperature. On further exploration, we find this temperature ratio is enhanced preferentially for clusters which are known merging systems. In addition, cool-core clusters tend to have best-fit hard-band temperatures that are in closer agreement with their best-fit broadband temperatures. We show, using simulated spectra, that this diagnostic is sensitive to secondary cool components (T_X_=0.5-3.0keV) with emission measures >=10-30% of the primary hot component.2008ApJ...682..821Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/682/821CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/chandra : The Chandra Archive Log (CXC, 1999-)J/ApJ/412/479 : Intracluster gas temperatures catalog (David+, 1993)J/ApJ/504/27 : The L_X_-T Relation for Nearby Clusters (Markevitch, 1998)J/PASJ/56/965 : X-ray properties of ASCA objects (Fukazawa+, 2004)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/682/821https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/682/821http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/682/821https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/682/821https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/682/821http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/682/821GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/682/821/table1 (Summary of sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/682/821/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/682/821/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/682/821/table1?GETtext/xml+votable180.050000true104.623425-55.944386110.0055555555555555566/206 207 247 821 4206 4406 4512 4965 5016 5067 5099 5100 5299 5536 5585 5701 5795 5881 5975 5985 6069 6337 6383 6441 6539 7178 7242 7273 7345 7756 7768 7904 8033 8043 8066 8220 8268 8282 8921 8969 9036 9050 9052 9168 9272 9466 9476 9498 9632 9764 9997 10182 10312 10527 10607 10664 10743 10992 11042 11080 11467 11591 11626 11632 11685 11802 11807 11974 12121 12253 12642 12664 13314 13384 15003 15045 16410 16486 16492 16609 16787 16806 16953 17171 17222 17300 17457 17472 17499 17741 17840 18011 18016 18328 18475 18534 18746 18800 18894 19009 19097 19283 19542 19846 19848 19935 19950 20481 20536 21134 21211 21766 22607 22661 22722 22771 22915 22949 22970 22972 23173 23324 23349 23366 23451 23474 24853 25102 25188 25451 25675 25981 26037 26135 26177 26189 26302 26707 26756 26785 27009 27075 27428 27476 27574 27664 27740 28086 28174 28220 28376 28448 28535 28622 30946 31509 31537 32379 32500 32503 33605 33628 33649 33917 33968 34139 34159 34165 34360 35147 35310 35696 36048 36082 36089 36423 36846 38973 39079 40615 41326 43945 44563 45044 45421 45962 46474 46571 46911 47043 48076 48174 48272 48423 48489 49012 49125https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/682/821?format=asciiX-rayOpticaldefaultJ/ApJ/682/821/table1Summary of samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameCluster name (1)meta.id;meta.maincharprimaryf_Name[di] Note on cluster (2)meta.codecharObsIDChandra observation identification numbermeta.id;obs.param;obsintRAJ2000Cluster center hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Cluster center degree of Declination (J2000)pos.eq.dec;meta.mainExpTExposure timekstime.duration;obs.exposurefloatModeObserving modeinstr.setupcharACISACIS CCD location of centroidinstr.setupcharzRedshift taken from Horner, 2001PhDT........88H (all redshifts confirmed with NED)src.redshiftfloatLbolBolometric luminosity in units of 10^+44^erg/s1e+37Wphys.luminosityfloatSimbadNameSimbad column added by the CDSmeta.idcharNEDSimbad column added by the CDScharJ/ApJ/682/821/fitsSummary of spectral fitsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameCluster name (1)meta.id;meta.maincharn_Name[*] Indicates multiple observationsmeta.notecharRcExcluded core region sizekpcphys.angSize;obs.fieldintRSimbad column added by the CDSphys.density;arith.ratiointnullableRadCluster radius (2)kpcphys.angSize;srcintNHIGalactic neutral hydrogen column density1e+20cm**-2phys.columnDensity;pos.galacticfloatE_NHI? Upper limit uncertainty in NHI1e+20cm**-2stat.error;stat.maxfloatnullablee_NHI? Lower limit uncertainty in NHI1e+20cm**-2stat.errorfloatnullableT77Best fit 0.7-7keV MeKaL temperaturekeVphys.temperaturefloatE_T77Upper limit uncertainty in T77keVstat.error;stat.maxfloate_T77Lower limit uncertainty in T77keVstat.errorfloatT27Best fit 2-7keV MeKaL temperaturekeVphys.temperaturefloatE_T27Upper limit uncertainty in T27keVstat.error;stat.maxfloate_T27Lower limit uncertainty in T27keVstat.errorfloatTHBRThe T77/T22 ratiophys.temperaturefloatE_THBRUpper limit uncertainty in THBRstat.error;stat.maxfloate_THBRLower limit uncertainty in THBRstat.errorfloatZ77Best-fit 0.7-7keV MeKaL abundanceSunphys.abundfloatE_Z77Upper limit uncertainty in Z77Sunstat.error;stat.maxfloate_Z77Lower limit uncertainty in Z77Sunstat.errorfloatchi77Reduced {chi}^2^ for best-fit 0.7-7keV modelstat.fit.chi2floatchi27Reduced {chi}^2^ for best-fit 2-7keV modelstat.fit.chi2floatSrcPercentage of emission attributable to source%meta.noteint