CLASH meeting 2013 - London 1

The Mass - Concentration Relation from Galaxy Kinematics

A. Biviano, E. Medezinski, P. Rosati, I. Balestra, S. Jouvel, M. Nonino, A. Molino, A. Mercurio, K.

Umetsu, M. Postman, H. Ford, D. Kelson, P. Melchior, M. Meneghetti, and the CLASH team

Doron Lemze (Johns Hopkins University)

CLASH meeting 2013 - London 2

MotivationA primary science goal of CLASH is to measure the mass profiles in galaxy clusters.

Measuring the profile shapes using different techniques enables a better understanding of the systematics and offers an observational test of the different techniques.

Why use galaxy kinematics?

There is a drawback in this technique, and it is the assumption of dynamical equilibrium. However, it has also strong advantages. Unlike lensing, galaxy kinematics are not contaminated by line-of-sight structures unrelated to the cluster, and unlike X-ray observation, kinematics can reach beyond the virial radius. Another advantage of this technique vs. lensing is that galaxy kinematics can be applied at lower redshifts where lensing is less sensitive and estimations for single clusters are very challenging.

CLASH meeting 2013 - London 3

The uniqueness of our spectroscopic sample

We will have the largest relaxed (X-ray selected) cluster sample with cluster members >~ 300 per cluster at 0.2<~ z <~0.6.

Not by chance, this redshift range is the ideal one for lensing. We’ll have accurate lensing estimations to compare with the ones derived by galaxy kinematics. This will give us an opportunity to estimate the real uncertainties of this technique.

CLASH meeting 2013 - London 4

Jeans Analysis

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Estimating and for the Jeans analysis

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Diaferio & Geller 1997Diaferio 1999

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Estimating and for the Jeans analysis – no VLT data

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CLASH meeting 2013 - London 7

Cleaning Subaru galaxies with available photometric redshifts

CLASH meeting 2013 - London 8

Galaxy surface number density

CLASH meeting 2013 - London 9

Galaxy surface number density

10

Fitting the data – A611 as an example

DataFit

DataFit

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11

C – M relation using galaxy kinematics vs. the theoretical expectation

ObservedExpected (Duffy et al. 2008)

MACSJ1206A383A209MACSJ1115MS2137A2261A611RXJ2129

CLASH meeting 2013 - London 12

Summary:We estimated the C-M relation using galaxy kinematics for 8 clusters.

Future work:Adding kurtosis (the forth-order velocity moment ) information?

More clusters - for how many more in the next few months see Piero’s talk.

Different dependencies on the substructure level.

Comparing to estimations from lensing and other techniques.

Summary and future work