CLUSTER MASS CLUSTER MASS MEASUREMENTS FROM X-RAY MEASUREMENTS FROM X-RAY

SURVEY DATASURVEY DATA

FABIO GASTALDELLO

IASF-INAF MILANO & UC IRVINE

S. ETTORI

OSS. BOLOGNA

• CLUSTER SURVEY QUALITY DATA: THE CASE OF THE C1 CLUSTERS IN PACAUD+07

• OVERVIEW OF SCALING RELATIONS IN X-RAYS

• PROBLEMS: FUNCTIONAL FORM AND ITS EVOLUTION WITH REDSHIFT

OUTLINE OUTLINE

C1 SAMPLE IN THE 5degC1 SAMPLE IN THE 5deg22

WITH THESE NUMBER OF COUNTS SCALING RELATIONS HAVE TO BE USED

Pacaud+07

C1 SAMPLE IN THE 5degC1 SAMPLE IN THE 5deg22

Pacaud+07

C1 SAMPLE IN THE 5degC1 SAMPLE IN THE 5deg22

Pacaud+07

X-RAY SCALING LAWS X-RAY SCALING LAWS From hydrostatic equilibrium equation (or isothermal sphere equation): M DM r2 dr R3 R T

Thus, R T1/2 & M T3/2

Assuming brehmsstrahlung emission & DM ngas,L ngas

2 (T) r2 dr ngas2 T1/2 R3

fgas2 T2 fgas

2 M4/3

Considering that we generally measure these quantities at fixed overdensity with respect to cr(z) = 3Hz / 8G, these relations scale as (Fz = 1/2 Hz / H0): • Fz M T3/2

• Fz-1 L T2

• Fz-1 L (Fz M)4/3

THE MASS PROXY Yx THE MASS PROXY Yx

Kravtsov+06

THE MASS PROXY Yx THE MASS PROXY Yx

Arnaud+07 Vikhlinin+09

THE L-M USING L-Yx THE L-M USING L-Yx

Maughan 07SCATTER IN L-M OF 17-21 %

THE L-M USING L-Yx THE L-M USING L-Yx

Pratt+07

A POSSIBLE RECIPEA POSSIBLE RECIPE• Use directly L-M with r500 from L-Y and Y-M (see

for example XMM-BCS Suhada+12)• Core excised quantities are really the low scatter

relations: try Pratt+09 suggestion of using central density as further parameter (if possible, given the uncertainties in the β model fit)

• Double check with M-T and/or β model estimate ?• Strategy for follow-up ?

A POSSIBLE RECIPEA POSSIBLE RECIPE

FOLLOW-UP OF XLSSC 029FOLLOW-UP OF XLSSC 029

Maughan+08

FOLLOW-UP OF XLSSC 029FOLLOW-UP OF XLSSC 029

Maughan+08

PROBLEM: NO SELF-SIMILARITYPROBLEM: NO SELF-SIMILARITY

Maughan+11

PROBLEM: NO SELF-SIMILARITYPROBLEM: NO SELF-SIMILARITY

Maughan+11

Pratt+09

PROBLEM: EVOLUTION WITH zPROBLEM: EVOLUTION WITH z

SELF-SIMILAR EVOLUTION: SLOPE IS z INDIPENDENT AND NORMALIZATION VARY IN PROPORTIONS TO POWER OF E(z). SELECTION BIASES ARE IMPORTANT !!!

Pacaud+07

Maughan+11

PROBLEM: EVOLUTION WITH zPROBLEM: EVOLUTION WITH zReichert et al. 12

PROBLEM: EVOLUTION WITH zPROBLEM: EVOLUTION WITH zReichert et al. 12

• THE SURVEY QUALITY OF THE DATA OF XXL REASONABLY ALLOWS FOR THE USE OF SCALING RELATIONS WITH L

• CENTRAL DENSITY, T AND SPATIAL DISTRIBUTION CAN BE USED

• DEPARTURE FROM SELF-SIMILAR POWER LAW EXACTLY AT THE BULK OF THE POPULATION OF XXL ? HOWEVER SUN+11 GOOD AGREEMENT BETWEEN IN THE PRESSURE OF GROUPS AND CLUSTERS

• FOR EVOLUTION WITH REDSHIFT THE KNOWLEDGE OF THE SELECTION FUNCTION WILL TEST SELF-SIMILARITY

SUMMARY SUMMARY