1 st Subaru Intl Conference Subaru Weak Lensing

1 st Subaru Intl. Conference Subaru Weak Lensing Study of Merging Clusters of Galaxies Reference: Okabe & Umetsu 2008, PASJ in press (astro-ph/00702649) Keiichi Umetsu (Academia Sinica IAA [ASIAA], Taiwan) Collaborator: Nobuhiro Okabe (Tohoku, Japan)

Introduction: Clusters of Galaxies Dark Matter Baryons DM governs the Dynamics Mbaryon~ 20 % Mtot Stars (In galaxies) M* ~ a few % Mtot MDM~ 80 % Mtot Total mass distributions could be derived from Xray data alone: ICM (hot baryons) MICM ~ 20 % Mtot … but with the hydrostatic equilibrium assumption

2. Motivation Chandra and XMM-Newton X-ray satellites have revealed complex ICM structures associated with cluster mergers: A 520 A 2142 Cold front (NW) Cold front (S) (NW) (S) Density Shock Front Density (S) Temperature (NW) Cold Fronts = “contact discontinuities”, associated with a dense cold core Temperature Far from hydrostatic equilibrium!!

3. Method: Gravitational Lensing The images of BG sources carry the imprint of F(x) of intervening cosmic structures: WL distortions of BG images can be used to derive the underlying mass map in a model independent way!! Unlensed Lensed Weak Strong Fort & Mellier

Power of Subaru Weak Lensing A 1689 (z=0. 183) Mass (~DM) A relaxed, massive cluster with large Einstein radius q. E=45” (z_s=1) 5. 5 Mpc r=20 -2000 (rvir) kpc/h Cluster Galaxies Umetsu & Broadhurst 2007, Ap. J submitted Subaru+ACS

4. Distributions of Mass and Baryons in “Merging Clusters” Various Merging Stages Main Cluster Binary On-going 2 nd impact Mergers are driven by F (Mass~DM)… What is the relation between Mass (~DM) and Baryons during the merging process? ?

Cluster Targets Merging clusters with detailed Chandra ar XMM data in the local universe (z=0. 05 -0. 3) S 05 A-159 (PI: Okabe) This talk Archival data This talk will only focus on the results for the 3 merging clusters of different merging stages…

Pre-Merger (Binary)

A 1750 (z=0. 086) Optical vs. X-ray Subaru image + X-ray contours (XMM) XMM image. Belsole+ (2004) + contours A 1750 N 2. 8 ke. V BCGs Merger shocks: M~1. 6 900 kpc 3. 9 ke. V Temperature map A 1750 C Dv_los~1300 km/s Entropy excess in A 1750 C

A 1750 (z=0. 086) Mass vs. Baryons XMM image + mass contours Gaussian 1. ’ 25 FWHM (~120 kpc) Optical light map + mass contours Distributions of the ICM ~ Member galaxies 5. 9 ~ Mass (~DM) at an initial stage of the merging process Mass 7. 7 substructure coincides with a slight X-excess Subaru image + mass contours Mvir~2 e 15 M_sun/h (N) Mvir~3 e 15 M_sun/h (C)

On-going Mergers

A 1914 (z=0. 172) Optical vs. X-ray Subaru image + Chandra contours 16’x 16’ (2. 8 Mpc on a side) Chandra image + contours 2 small cores embedded in a round shaped halo (Govoni et al. 2004)

A 1914 (z=0. 172) Mass vs. Baryons Subaru image + mass contours X-ray image + mass contours 9. 1σ 7. 8σ ICM distribution is fairly round, while the DM distribution is highly disturbed by the merger, showing an irregular morphology. 0. ’ 75 Gaussian (130 kpc) Merging structure (DM & Galaxies) The collisionless galaxy distribution coincides well the DM (~mass) distribution. Light and mass Optical light map + mass contours peaks of the primary cluster coincide well

Cold Front Clusters

A 2034 (z=0. 113) Optical vs. X-ray Subaru image + XMM contours XMM image + contours Sharp discontinuity South X-ray excess (Kempner & Sarazin 03) ~19’ (2. 3 Mpc) on a side n Northern sharp-discontinuity in X-ray emission – but no significant jump in Tx n Kempner & Sarazin 03 argued the excess emission likely to be a background structure

A 2034 (z=0. 1130) Mass vs. Baryons Subaru Image + Mass Contours XMM Image + Mass Contours 5. 4σ 4. 9σ 6. 4σ 6. 3σ 5. 1σ South X-ray excess 1. ’ 2 FWHM Gaussian (140 kpc) Detections of significant “mass clumps” associated with [1] primary cluster (6. 4 ), [2] northern structure (5. 4 ) ahead of the cold front, [3] south X-ray excess (6. 3 ), and (4) western structures

A 2034 (z=0. 1130) Filament? Light map + mass contours 1. ’ 2 FWHM Gaussian (~140 kpc) Line-of-sight Velocity distribution Sample # 96 (SDSS+2 MASS) BCG 2, 3 BCG 1 BCG 3 Western structure “Western mass structures” found to be associated with structures filamentary structure of background galaxies LOS com. separation of ~ 10 Mpc/h (assuming v_pec=0)

4. Tx vs. WL-derived Virial Temperature Tx: from the literatures Twl: this study (w/ red background gals. ) Ongoing Cold front Pre-merger Tx / Twl Tx is (2 -3) times higher than Twl in ongoing mergers: Merger boosts? Tx=Twl Virial Twl from WL (Sarazin & Ricker 02) A 1750 C: : Entropy excess A 520: : Tx including the preshock (low-T) region, underestimated by ~1. 7

Summary n Joint WL/X-ray/Optical analysis: : analysis - 1 st systematic WL study of merging clusters cf. Clowe+ 04 on Bullet cluster; Bradac+ 06 on 1 ES 0657@z~0. 3 Provides an important clue to understand the cluster merger n Distributions of Baryons & DM: : DM - Initial phase: ICM and Galaxies tracing the Mass phase - Ongoing: “Mass ~ Galaxies” but highly irregular, offset from Ongoing “ICM” in a various way - Cold front: DM clumps always found in front of dense cores front (all of 3 cold fronts) as found in the Bullet Cluster (Clowe+04) n Cluster global properties: : properties - Tx ~ Twl in a pre-merging phase - Tx ~ (2 -3) Twl during mergers merger boosts? (Sarazin & Ricker 02; Rowley+ 04) as a boosts function of dynamical-phase, initial merger conditions, & masses.

Future Work Ongoing Project

Lo. Cu. SS: Local Cluster Substructure Survey Flux limited, unbiased sample of >100 clusters in the local universe (Lx>5 x 10^44 erg/s、0. 15<z<0. 3) Utilizing HST(SL/WL) + Subaru(SL/WL) + XMM/Chandra + Spizter + SZ (SPT…) WL analysis of 29 clusters completed Subaru/S-Cam A 209 (Okabe, Takada, Umetsu & Futamase in prep) CFHT/12 K (Bardeau et al 2007)

Special Thanks to Lensing Collaborators Lo. Cu. SS Ø N. Okabe, M. Takada, T. Futamase (Tohoku) , G. P. Smith (P. I. ) AMi. BA SZE + WL Ø AMi. BA Science Team (ASIAA, NTU/Phys) See the AMi. BA poster by K. Y. Lin HSC WL Working Group S. Miyazaki, T. Hamana, H. Furusawa, Y. Utsumi (NAOJ), M. Takada (Tohoku), K. Yamamoto (Hiroshima), H. Nishioka (ASIAA) Fexion and HOLICs Ø Y. Okura, T. Futamase (Tohoku) Dark Halo Density Profiles Ø T. Broadhurst, E. Medezinski (Tel Aviv)

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