1. CfA Oct 8 2003 Determining the Cosmic Distance Scale with Galaxy Clusters Erik Reese University of California, Berkeley

2. CfA Oct 8 2003 The Sunyaev-Zel’dovich Effect

3. CfA Oct 8 2003 BIMA & OVRO

4. CfA Oct 8 2003

5. Distance Calculation With geometry of the cluster

6. CfA Oct 8 2003 Hubble Constant With z and geometry of the universe Independent of the extra-galactic distance ladder! For a sample of clusters, fit to the theoretical D A relation, where H 0 is the normalization

7. CfA Oct 8 2003 Angular Diameter Distances: Present

8. CfA Oct 8 2003 H 0 Current Results Ryle → 5 clusters (Jones et al. 2003) OVRO 5m → 7 clusters (Mason et al. 2000) OVRO/BIMA → 18 clusters (Reese et al. 2002)

9. CfA Oct 8 2003 H 0 Current Results Combined → 41 distances Reminder: All ROSAT data

10. CfA Oct 8 2003 Systematics SZE calibration [H 0 ~(∆T 0 ) -2 ]± 8% X-ray calibration±10% NHNH ± 5% Asphericity ● ± 5% Isothermality±10% Clumping−20% Undetected radio sources±12% Kinetic SZE ● ± 2% Primary CMB ● ± 1% Radio Halos± 4% Primary Beam± 3% Total+22% −30%

11. CfA Oct 8 2003 Chandra

12. CfA Oct 8 2003 Angular Diameter Distances: Chandra

13. CfA Oct 8 2003 D A Future

14. CfA Oct 8 2003 Supernovae Type Ia

15. CfA Oct 8 2003 Challenges Systematics Modeling Sample selection –Sample sizes –Unbiassed selection criteria –Wonky clusters Convince X-ray TACs High redshift→cosmology

16. CfA Oct 8 2003 SZE Surveys Large samples of clusters High redshift clusters Clean selection function Holder et al. 2000

17. CfA Oct 8 2003 Simulations Courtesy of Martin White

18. CfA Oct 8 2003 Summary H 0 independent of extragalactic distance ladder Systematics are approachable SZE Surveys –Large numbers of clusters –High redshift –Sample selection Symbiotic with cluster number counts