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X-Ray Observations of RCS Clusters at High Redshift. Erica Ellingson, U. Colorado Amalia Hicks, U. Colorado/ U. Virginia Mark Bautz, MIT Henk Hoekstra (U. Victoria) Mike Gladders, Carnegie Obs. Howard Yee, U. Toronto. The RCS Surveys. - PowerPoint PPT Presentation
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X-Ray Observations of RCS Clusters at High Redshift
X-Ray Observations of RCS Clusters at High Redshift
Erica Ellingson, U. Colorado
Amalia Hicks, U. Colorado/ U. Virginia
Mark Bautz, MIT
Henk Hoekstra (U. Victoria)
Mike Gladders, Carnegie Obs.
Howard Yee, U. Toronto
Erica Ellingson, U. Colorado
Amalia Hicks, U. Colorado/ U. Virginia
Mark Bautz, MIT
Henk Hoekstra (U. Victoria)
Mike Gladders, Carnegie Obs.
Howard Yee, U. Toronto
The RCS SurveysThe RCS Surveys
Review by H. Yee earlier today: optically selected clusters via their red sequence
RCS-1; 90 square degrees (completed)RCS-2: 1000 square degreesZ ~ 1
Still needed: calibration of cluster mass estimates for optically selected clusters
Review by H. Yee earlier today: optically selected clusters via their red sequence
RCS-1; 90 square degrees (completed)RCS-2: 1000 square degreesZ ~ 1
Still needed: calibration of cluster mass estimates for optically selected clusters
RCS Chandra ObservationsRCS Chandra ObservationsChosen from the sample: 9 clusters (now 12)(0.64) 0.75< z< 1.1
Some initial emphasis on the most massive, lensing systems from the first available RCS catalogs; sample is becoming representative of rich systems
ACIS exposures: (10) 30-90Ksec
Chosen from the sample: 9 clusters (now 12)(0.64) 0.75< z< 1.1
Some initial emphasis on the most massive, lensing systems from the first available RCS catalogs; sample is becoming representative of rich systems
ACIS exposures: (10) 30-90Ksec
Optical/Chandra ObservationsOptical/Chandra Observations
Z=0.78
Z=0.64
z=1.0
8 out of 9 detected with > 5(2112-6326 at zph=1.1 is 2-3)3 additional cluster detections on the way(final data arrived this week)
20ksec first exposure (more just arrived):Three new detections: z ~ 0.6-0.9
“Low Redshift” Comparisons“Low Redshift” Comparisons
14 X-Ray selected CNOC (EMSS + Abell 2390)
0.17 < z < 0.55
Well determined masses via dynamics, lensing, Xrays
(ROSAT +Chandra)
14 X-Ray selected CNOC (EMSS + Abell 2390)
0.17 < z < 0.55
Well determined masses via dynamics, lensing, Xrays
(ROSAT +Chandra)
Carlberg, Yee & Ellingson 1997van der Marel et al. 2000Lewis et al. 1999Hicks et al. 2005
Lensing Masses for CNOCLensing Masses for CNOC
Weak lensing comparisons at z=0.2-0.55
(with Henk Hoekstra)
Slight systematic mass overestimate (10%) for weak lensing masses
Weak lensing comparisons at z=0.2-0.55
(with Henk Hoekstra)
Slight systematic mass overestimate (10%) for weak lensing masses
Calibrating Optical Richness with X-ray properties
Calibrating Optical Richness with X-ray properties
Initial mass estimator for RCS is the optical richness from the survey data: Bgc
CNOC: Good agreement with expected relationships:
Bgc vs. ,Lx,Tx,M200
Yee & Ellingson 2003, updated for Chandra by Hicks, et al., 2005
Initial mass estimator for RCS is the optical richness from the survey data: Bgc
CNOC: Good agreement with expected relationships:
Bgc vs. ,Lx,Tx,M200
Yee & Ellingson 2003, updated for Chandra by Hicks, et al., 2005
Black: weak lensing shear composites (Hoekstra)Red: CNOC cluster dynamics
RCS: Lx-BgcRCS: Lx-BgcRCS clusters are
under-luminous for their optical richness
See also:Donahue et al. 99,Gilbank, 2004Lubin et al., 2004…
RCS clusters are under-luminous for their optical richness
See also:Donahue et al. 99,Gilbank, 2004Lubin et al., 2004…
L2500
CNOC, CF corrected : diamondsRCS: squares
Tx-Bgc Tx-Bgc Temperatures show general
agreement with lower-z X-ray samples
Slightly systematically lower temperature for their optical richnesses
Outlier: superposition of groups in small z range (e.g., Gilbank’s talk,
also Gonzales’ supergroup?): predicted to be ~5% of RCS?
Temperatures show general agreement with lower-z X-ray samples
Slightly systematically lower temperature for their optical richnesses
Outlier: superposition of groups in small z range (e.g., Gilbank’s talk,
also Gonzales’ supergroup?): predicted to be ~5% of RCS?
Diamonds= CNOC Squares = 6 RCS clusters with enough signal to measure Tx
Lx-TxLx-TxRCS: clusters underluminous for expected Tx? Large uncertainties…
Solid: slope=2.2Dotted = 2.0Dashed= best fit slope 4+/-
2See also Lubin, et al., 2004
RCS: clusters underluminous for expected Tx? Large uncertainties…
Solid: slope=2.2Dotted = 2.0Dashed= best fit slope 4+/-
2See also Lubin, et al., 2004
CNOC: diamondsRCS: squares
Redshift Evolution of Optical/X-ray mass estimates?
Redshift Evolution of Optical/X-ray mass estimates?
Tx-Bgc is scaled by M200-Bgc-Tx relation to reduce to a mass ratio
Evolution seen in X-ray-selected
CNOC sample at z < 0.6?
Mass ~ Bgc (1+z) = -0.5 +/- 0.5
Tx-Bgc is scaled by M200-Bgc-Tx relation to reduce to a mass ratio
Evolution seen in X-ray-selected
CNOC sample at z < 0.6?
Mass ~ Bgc (1+z) = -0.5 +/- 0.5 Consistent with self-calibrating
model for RCS (Majumdar, later today)
SZ detectionsSZ detections
BIMA/OVRO observations from Kyle Dawson &
J. Carlstrom’s group
6 RCS clusters detected
Agreement with X-ray results for Mtot and Mgas requires factor of 2 variation in gas fractions, consistent with lowered X-ray luminosities
BIMA/OVRO observations from Kyle Dawson &
J. Carlstrom’s group
6 RCS clusters detected
Agreement with X-ray results for Mtot and Mgas requires factor of 2 variation in gas fractions, consistent with lowered X-ray luminosities
AGN in ClustersAGN in Clusters
CNOC: excess of X-ray point sources in a few clusters….
Overall, no strong excess
CNOC: excess of X-ray point sources in a few clusters….
Overall, no strong excess
Straight line = expected backgroundHisto = 2-8 keV point sourcesEllingson et al. 2005
RCS: analysis just beginning
RCS0224-002, z=0.78- regular, lensing cluster, possible small cooling core
Excess of sources just inside the virial radius (see also Rudman & Ebeling 2005)
Significant energy ejection by AGN?
(e.g., talk by Donahue)
RCS: analysis just beginning
RCS0224-002, z=0.78- regular, lensing cluster, possible small cooling core
Excess of sources just inside the virial radius (see also Rudman & Ebeling 2005)
Significant energy ejection by AGN?
(e.g., talk by Donahue)
ConclusionsConclusions RCS Clusters at z > 0.75 are X-ray sources- all detected
“Contamination” by “super group” structures at ~zcluster 1 or 2 out of 12, also X-ray sources
X-ray luminosities and gas fractions within R2500 scatter systematically low. Lx-Tx is not unreasonable- ?steeper? (large error bars!). Virialization of all components is required to produce uniform X-ray/optical relations.
Tx-richness relation shows that red galaxies reliably indicate mass (not
necessarily virialized). Relation shows some evolution, consistent with self-calibrating N(M,z) models.
Further comparisons with dynamics, lensing (HST) , IR luminosity (Spitzer) are under way!
RCS Clusters at z > 0.75 are X-ray sources- all detected
“Contamination” by “super group” structures at ~zcluster 1 or 2 out of 12, also X-ray sources
X-ray luminosities and gas fractions within R2500 scatter systematically low. Lx-Tx is not unreasonable- ?steeper? (large error bars!). Virialization of all components is required to produce uniform X-ray/optical relations.
Tx-richness relation shows that red galaxies reliably indicate mass (not
necessarily virialized). Relation shows some evolution, consistent with self-calibrating N(M,z) models.
Further comparisons with dynamics, lensing (HST) , IR luminosity (Spitzer) are under way!