A Primer on SZ Surveys

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A Primer on SZ Surveys

• Gil Holder

Institute for Advanced Study
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Outline

• Sunyaev-Zeldovich effect
• Upcoming surveys
• Whats next?

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Optical Image of Cl 001616(Clowe et al. 2000)
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2 h-1 Mpc
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Hot Gas in Cl 001616
(Reese)
kT 7.5 keV
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Sunyaev-Zeldovich Effect
I
Hot electrons
CMB
CMB
?
Optical depth t 0.01 Fractional energy gain
per scatter
0.01
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SZ Observables I
Along a line of sight
DEPENDS ONLY ON CLUSTER PROPERTIES !!!!
Independent of redshift
Temperature weighted electron column density
Unique spectral signature
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Non-Thermal Spectrum
Abell 2163 Data from 3 experiments
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SZ Observables II
Integrated effect from cluster

• proportional to total thermal energy of
  electrons
• Temperature weighted electron inventory
• angular diameter distance, not luminosity
  distance

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SZ Observables III
In reasonable units ( i.e., 1/h)
Assume a virial relation
uncertainties come in mass limit as (0.6)
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SZE Regularity
Metzler astro-ph/9812295
dTo
ltdTgt
Average SZ flux vs Mass 10 scatter
Central decrement vs Mass 40 scatter
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Searching for Galaxy Clusters

• Small area very deep
• - AMI, AMIBA, BOLOCAM, SZA
• Large area relatively shallow
• - ACBAR, PLANCK
• Large area very deep
• - ACT, SPT

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Mass Limits
Fluxes at 30 GHz
PLANCK
SZA
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Foregrounds

• CMB need good angular resolution and/or good
  spectral resolution problem at all SZ
  frequencies
• Radio point sources need good angular
  resolution for frequencies lt90 GHz
• Dusty point sources need good angular
  resolution and/or spectral resolution at
  frequencies gt200 GHz
• Radio halos and ghosts could be a problem at
  frequencies lt 15 GHz

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SZA

• Survey 10 square degrees to a few uK at
  resolution of 2-3 arcminutes at 30 GHz
• Expected mass limit
• Follow up catalog at 90 GHz for high resolution
  (lt20)
• 100 500 clusters expected

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Example RXJ1347-1145
Reese
X-ray (colours)
SZ only
SZ (contours)
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CMB contamination??

• clusters are clearly at a different spatial
  scale
• close amplitudes means beam dilution catches up
  fast !!!

Roughly 1 deg x 1deg labels are uK
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Cosmology With the SZA
Holder, Haiman Mohr 2001
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Dark Energy With the SZA

• 12 square degrees
• assume NO systematic errors
• assume redshifts measured to z2

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PLANCK

• Survey the full sky to a few uK at resolution of
  5-10 arcminutes at many frequencies
• Expected mass limit
• Cluster detections will be unresolved point
  sources with SZE-like spectra
• 1000 50000 clusters expected

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Cosmology With Planck
Black all z Red zlt0.5 only
Holder, Haiman Mohr 2001
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SPT/ACT/???

• Survey 1000 square degrees to a few uK at
  resolution of 1-2 arcminutes at several
  frequencies
• Expected mass limit
• Most powerful for cosmology
• 5000 200000 clusters expected

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Cosmology with the SPT
Holder, Haiman Mohr 2001
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dN/dz for SPT
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Dark Energy With the SPT
Also sensitive to time dependent equation of
state (Weller, Battye Kneissl 2001)
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Possible Plan of Action

1. Use AMI/AMIBA/BOLOCAM/SZA to define a significant
   SZE-selected sample
2. Follow up at many wavelengths optical, X-ray,
   radio, cm, mm (including SZA!)
3. Do a very large, deep survey for precise
   measurements of cosmological parameters

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On the Horizon
uK imaging between 30-400 GHz with arcminute
resolution -- SPT, ACT, dedicated
interferometers, ALMA, etc.
New science opportunities challenges --
peculiar velocities, -- spectral SZ --
CMB lensing
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Peculiar Velocities (Kinetic SZ)

• Pure redshift, blueshift gt thermal spectrum

Arcminutes scales gt CMB 1 uK -- CMB noise
contribution 10 km/s (0.01/t)
Other contamination 50 km/s ? (Fischer Lange
1993)
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Relativistic Corrections
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Lensing of the CMB
Typical CMB gradient -- 15 uK/arcmin
Typical deflection angle -- 0.1-1 arcmin
(Seljak and Zaldarriaga )
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Summary

• New cluster surveys coming soon
• Detailed follow-up will be required of some
  sample of SZE-selected clusters
• Ambitious survey machines in proposal stages
  could be extremely powerful

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Gallery of SZ Images
Z0.83
Z0.14
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Green shift in matter density by 10
Holder Carlstrom 2001
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Counting Galaxy Clusters
Mass limit
Mass function
Volume element
(Jenkins, Press-Schechter)
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Self-Similar Evolution
Holder Carlstrom 2001
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Effects of Gas Evolution
Holder Carlstrom 2001
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Angular Power Spectrum of SZ Sources
Holder Carlstrom 2001