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Cluster Lenses & High Redshift Clusters (MACS) A Status Report

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## Cluster Lenses & High Redshift Clusters (MACS) A Status Report

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### Cluster Lenses & High Redshift Clusters (MACS)A Status Report

### RXJ0152-29 a massive cluster at z~0.83

Jean-Paul KNEIB

Observatoire Astronomique Marseille Provence, Marseille, France

H. Ebeling, G. Smith, A. Gal-Yam, I. Smail, A. Edge, J. Greene, P. Hudelot, S. Bardeau, G. Soucail, P. Marshall, E. Egami, G. Covone, E.Jullo and many others

Outline

- Lensing in Clusters
- Mass Distribution in Cluster:

strong & weak lensing at low-z

- MACS Clusters (0.3<z<0.8):
- ACS deep survey
- MACS Snapshot, RXJ0152
- (SN search)
- Future prospects

Ringberg, Hi-z clusters

Theory: Lens Diagram

CFHT BRI 1990

Z_cluster=0.375

Z_arc=0.725 (Soucail et al 1988)

Ringberg, Hi-z clusters

Science with Cluster Lenses

- Study the mass distribution of cluster => cosmology?
- Study the distant lensed Universe
- Direct constrain on cosmological parameters

Ringberg, Hi-z clusters

Theory: Lens Mapping

a

The lensing equation is a mapping from image plane to source plane:

q - b = Dls/Ds. a = Dls/Ds df/dq

For a point mass, the deflection angle is: a = 4GM/bc2

(b is the impact parameter) -> typically 10” for a 1014 Solar mass

Amplification

matrix:

Ringberg, Hi-z clusters

Cluster Lenses

- Insensitive to:
- Nature of matter
- Physical state of matter
- Cleanest available probe of Dark Matter

Strong Lensing in the core,

Weak lensing on large scale

Most massive clusters

Einstein radius: 10-45”

Ned Wrigth, UCLA

Ringberg, Hi-z clusters

Mass distribution in cluster cores

Ringberg, Hi-z clusters

Cluster Lens: Mass Reconstruction

- Parameterized mass distribution, involving various multiple image system (works better, less free parameters)
- Need to include galaxy scale mass components
- using scaling relations (dominate locally the mass)

Ringberg, Hi-z clusters

An Example from space:Cl0024+1654 HST wide field sparse mosaic

- 76 orbits, 38 pointings
- Probe regions up to ~5Mpc
- Aim: learn cluster physics of clusters by comparing with other mass estimates: X-ray, dynamics

(Treu et al 2003, Kneib et al 2003)

Ringberg, Hi-z clusters

0024: Shear Profile

SIS fitting strong lensing data

- Extrapolate strong lensing models at large scale by exploring various cluster mass profile.
- Rule out SIS model
- NFW (with large c~20) or Power-law models give comparatively good model.

NFW fitting strong

And weak lesning

~3 Mpc

Ringberg, Hi-z clusters

Cl0024: Mass vs. Light

- NFW and Power-Law model fit the strong+weak lensing
- But high concentration compared to expectations
- (similar results on other clusters: A1689 …)
- SIS does not fit the strong+weak lensing
- M/L is constant with radius with M/LK~40

Red sequence selection

Light profile

NFW model

Broader sequence selection

SIS model fitting

weak lensing

Kneib et al 2003

Ringberg, Hi-z clusters

Questions for Cluster Physics

- What are the total mass and structural properties of massive clusters?
- How are the mass and structure of clusters related to the global thermodynamics (Tx, Lx)?
- How do cluster substructure and thermodynamics evolve with redshift?
- Implications of cluster mass and substructure for cluster Cosmology?

Ringberg, Hi-z clusters

Multi-wavelength/epoch study

Dt~2Gyr

2Gyr

2Gyr

- z=0.21+/-0.04
- Lx>8x1044erg/s

A68

A209

A267

A383

A773

A963 Ellis et al. 1991

A1763

A1835

A2218 Kneib et al. 1996

A2219 Smail et al. 1995

- Study of 10 clusters at z~0.2
- HST, WFPC2, F702W, 75ksec
- Chandra, ACIS-I(S), 4-40ksec
- UKIRT, UFTI, 9ksec
- CFHT12k, BRI, weak shear

X-ray Luminosity

z=0

z=0.2

z=0.5

z~1

Ringberg, Hi-z clusters

R-K=5.4

z=1.6

Smith et al 2001,2003,2005

Example:Abell 68 (z=0.25)Data and constraints

- ID multiple image systems (HST)
- Spectroscopic redshifts (Keck+)
- Weak lensing constraints (HST)

Measurements

- Cluster mass (R<500kpc)
- Dark matter morphology

Ringberg, Hi-z clusters

Quantitative structural classification

Typical Unrelaxed

Relaxed

Smith et al., 2005

Mass

[Lensing]

Ndm1 2 1

Mcen/Mtot0.97±0.01 0.77±0.01 0.96±0.01

Ttot/Tann0.8±0.1 1.0±0.1 1.0±0.2

Δr (arcsec) <1 10±2 22±1

ICM

[X-ray]

- 70% of X-ray luminous cluster cores at z=0.2 are dynamically immature and strongly heterogeneous

Ringberg, Hi-z clusters

[~40%]

Possible

Systematics?

[~10-20%]

M-T relation or M-T scatter plot?Smith et al., 2005

Finoguenov et al., 2001

- Unrelaxed clusters are 40% hotter than relaxed clusters (2.5σ)
- Consistent with hydro simulations of cluster-cluster mergers

(Ricker & Sarazin 2001, Randall et al. 2003)

Ringberg, Hi-z clusters

Better agreement with weak lensing?

Ringberg, Hi-z clusters

weak lensing shear profile

Ringberg, Hi-z clusters

Offset between dynamics and mass: sign of merger due to optical selection ? Or the fact that those systems are still young?

A big scatter between Tx and Mass: we can probably do better (including strong lensing) but … limited by cluster substructure

Need better data and statistics …

ie. go from sample of 10s to sample of 100s

Better agreement with weak lensing?Ringberg, Hi-z clusters

The MAssive Cluster Survey (MACS)

- MACS is covering a very wide area and thus is able to discover the most x-ray luminous clusters unlike other surveys.
- Most massive clusters should be strong lenses
- ~120 z>0.3 MACS clusters to be observed with Chandra & ACS SNAP
- 10 MACS cluster have been observed with HST/ACS

Ringberg, Hi-z clusters

10 clusters at z~0.55

HST/ACS imaging

F555W, F814W

5ksec/filter

Keck/LRIS + VLT/FORS spectroscopy (arcs and cluster galaxies)

Blue and Red spectroscopy

SUBARU/Suprime imaging

Weak lensing and galaxy population

Dt~2Gyr

2Gyr

2Gyr

X-ray Luminosity

z=0

z=0.2

z=0.5

z~1

MACS clusters at 0.5<z<0.6Ringberg, Hi-z clusters

MACS/HST weak lensing

Ringberg, Hi-z clusters

Simulation data

MACS/HST weak lensingCluster mass reconstruction method using (NFW) blobs that can combine strong+weak lensing data: using

MCMC techniques

To cope with complex

Shape seen at high-z

Atomic Inference

Classical 2D reconstruction

Ringberg, Hi-z clusters

4Mpc filament in MACSJ0717.5+3745Ebeling et al (GO: 10420, cycle 14)

X-ray+Gal density

Lensing Subaru+Gal density+ ACS survey

Ringberg, Hi-z clusters

4Mpc filament in MACSJ0717.5+3745Ebeling, Barrett, Donovan, 2004

Galaxies with Spectra

Redshift distribution

Ringberg, Hi-z clusters

3

9

1

Does cluster substructure evolve?- Current status of MACS strong lensing analysis
- Candidate gravitational multiple images identified
- [Ground-based spectroscopy of arcs <~50% complete]
- Broad brush demographics:-

z=0.2z=0.55

Strong lensing clusters 8/10 10/10

Unrelaxed clusters 4/10 9/10

Candidate unrelaxed clusters 3/10 0/10

Relaxed cool core clusters 2/10 1/10

Relaxed non cool core clusters 1/10 0/10

Ringberg, Hi-z clusters

MACS Snapshot ACSEbeling et al (GO: 10491, cycle 14)

- List of 124 MACS clusters to be observed with HST/ACS in SNAP mode in F814W
- Aim at finding effective lensing clusters and strongly distorted arcs (statistics and magnified sources)
- 5 clusters already observed

Ringberg, Hi-z clusters

MACS Snapshot ACSEbeling et al (GO: 10491) First Strong Lensing IDs

Ringberg, Hi-z clusters

VIMOS/IFU

Field of view

X-ray luminous cluster at z=0.83

At least 8 multiple image systems, one at z=3.9 (Umetsu et al 2005)=> high ellipticity for DM, indicative of a merger.

Ideal probe for VIMOS/IFU

Potential interest for cosmology (Golse et al 2002)

Lensing for Cluster Physics

- Lensing is probing mass relatively easily, measuring substructure gets more difficult at higher z, but is clearly seen!
- Scattered relation between Mass and X-ray - depends on physical state and substructure (merger/relaxed)
- Higher substructures at higher redshift (lots of lensing till z~0.8 in massive systems)?
- Cosmology with cluster is likely to be hard - at least with current cluster sample size (10s) need much larger sample, but will learn some physics.

Ringberg, Hi-z clusters

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