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!