Using the Sunyaev-Zeldovich Effect to Constrain H0

• Introduction
• Importance of H0 to Cosmology
• Constrain age, expansion history of universe
• Get distances to galaxies via Hubble's law
  
• Traditional Method: Distance Ladder
• Cepheid distance scale
• Secondary Indicators: TF, FP, SNeIa, etc
• Results, ie from HST Key Project Team showing H0=72
• Uncertainties: how distance errors add up
• Describe need for a direct distance indicator
• CMB constraints on H0
• Quick description of physics
• Results from WMAP5: H0=73, consistent w/ HST KP results
• Why do it w/ SZ?
• Different systematic effects
• Doesn't rely on ladder w/ error buildup
• Good to have cross-checks
• SZ Physics - Ideal case
  
• CMB properties: temp, spectrum, temp fluctuations
• Properties of clusters: hot gas, emitting X-rays through free-free radiation, characteristic mass, luminosity, temp
• Compton Scattering
• Physical description
• Effect on spectrum
• Discriminating SZ fluctuations from CMB fluctuations
  
• SZ signal
• Dependancy on cluster properties: ne, T, size
• Dependancy on H0
• Solving for H0
• Data Source
  
• Millimeter arrays: OVRO, BIMA, others
• X-ray satellites: Einstein, ROSAT, Chandra, etc
• Data for imaging: need X-ray maps
• Data for spectroscopy: to get cluster temperature
• Complications
• Clusters not relaxed
• Describe cluster accretion history
  
• Destroys symmetry (show pictures of unrelaxed clusters from Chandra)
  
• Artificially heats clusters beyond the virial temperature
• Simulations show this bias; allow us to correct (e.g., Roettiger etal 1997)
• Need high data quality
• Show uncertainty in spectral fits, and how that translates to uncertainty in T
• Need good spatial resolution to get ne,T profiles (show good and bad data)
  
• Modeling needed to turn projected T, ne into 3-D profiles
• Results
• Early work (1990s)
• Data source: OVRO/ROSAT
  
• Individual cluster variations (eg Abell 2218)
• H0 fits: all over the pllace
• More recent work (2000s)
• New millimeter arrays (CARMA, DASI)
• New Xray data (Chandra)
• Show examples of good data, ie SZ signal and X-ray maps
• Bigger samples (Bonamente et al sample)
• Recent H0 determinations
  
• H0=66 (Jones etal 2005)
• H0=77 (Bonemente etal 2006)
• Dominant source of uncertainty
• Cluster X-ray profile fitting
• Temperature effects
• Future work
• H0
• Bigger SZ samples
• New arrays, better spatial resolution (examples)
  
• Simulations: what N-body simulations need to give (ie in terms of corrections for accretion effects)
• Other parameters -- briefly how SZ can constrain
• OM, OL
• sigma8
• w
• New projects coming online:
• SZA
• SPT
• others
• Summary
• References

(and you should have a dozen or so references in place by now, and they should come from advanced textbooks, journal articles, conference reviews, project webpages, etc...)