1. 1 Studying clusters and cosmology with Chandra Licia Verde Princeton University Some thoughts…

2. 2 Overview The potential of combining: X-rays + optical + CMB….. Clusters scaling relations with X-rays and the Sunyaev-Zeldovich effect constraining dark energy (Quintessence) Conclusions

3. 3 Coordinated Cluster Measurements X-ray Flux: Temperature and luminosity probe mass mm-Wave: SZ – Compton Scattering Optical: Redshift velocity dispersion Photometry and lensing Galaxy Cluster HOT Electrons chandra

4. 4 SZ Signature Hot electron gas imposes a unique spectral signature NO SZ Contribution in Central Band 145 GHz decrement 220 GHz null 270 GHz increment 1.4 ° x 1.4 ° Easy to find!

5. 5 Multiple uses Standard candles Standard rulers Probes of volume Probes of velocity field Probes of initial conditions Clusters as Cosmological Probes Multiple observables Clusters counts (*) SZ luminosity Central SZ decrement X-ray temperature (*) X-ray luminosity(*) Angular size(*) Velocity Dispersion Redshift Lensing Mass Kinetic SZ amplitude Linked theoretical/observational effort essential for using these observables as cosmological probes. Amplitude of fluctuations Scaling relations Gravitational lensing of CMB gives  Kinetic SZ gives v 2 Cluster counts give –N(M,z) –N(F SZ,z) Need to know cluster physics

6. 6 Clusters scaling relations Mohr et al 1997, Mohr et al 2000 (e.g., size temperature, mass-temperature) (Verde et al. 2000)

7. 7 New scaling relations that include the SZ decrement Observables: SZ, angular size, redshift,Temperature “ constraints”: M-T relation Virial relation Total SZ decrement (Verde, Haiman, Spergel 2002) chandra THSC

8. 8 If our understanding of cluster physics is correct Clusters should occupy a fundamental plane Narrow

9. 9 Different cluster physics and/or cosmology Modifications in the Position, orientation and redshift evolution of the plane Scaling relations with SZ narrow broad (THSC prediction)

10. 10 Formation redshift? Only formation redshiftOnly stochastic Mathiessen 2001 finds no evidence for zf being relevant to clusters properties

11. 11 2D KS test fM Lacey & Cole 94 parameter for the formation redshift distribution Assume cosmology, study cluster physics 300 clusters with follow up

12. 12 Back to: Observations e.g., Xu et al. 2001, Mohr, Evrard 1997, Mohr et al 1999 Effect of formation redshift Deviations from virialization parameterized by Can constrain a fiducial model: For a fiducial model

13. 13 Assume formation redshift distribution is important Constraints from Used KS, Lokelihood is much more sensitive Assume cluster physics, study cosmology

14. 14 MAP 2 yr Cluster abundance

15. 15 ADD information about dN/dz (mass function) Break the cluster physics/cosmology degeneracy With Z. Haiman

16. 16  Shown a “taste” of the many possibilites  The fundamental plane/scaling relations approach can be generalized to include other observables such as velocity dispersion, X-ray luminosity, shear, central SZ decrement….  Used KS test, likelihood is much more sensitive  Insensitive to the mass function and independent from it  Can be used in tandem with dN/dz (clusters counts) to lift degeneracies between cosmology and cluster physics  Important to constrain clusters physics (fixed cosmology)

17. 17 Perlmutter et al. 1998 deBernardis et al. 2001 Verde et al 2002 Nature? Equation of state? Dark energy  From Verde et al. 2002

18. 18 MAP will constrain   and cosmological parameters The growth of structure (i.e. cluster abundance evolution) Nature of dark energy (once we know clusters physics) Haiman et al. 2000

19. 19 X-ray +CMB +optical + theory Clusters scaling relations with SZ (Tx) (study cluster physics and cosmology) constrain dark energy exploiting growth rate of structure Conclusions

20. 20 END