wz via 2dF QSO Galaxy Redshift Surveys

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w(z) via 2dF QSO Galaxy Redshift Surveys

• Tom Shanks, Phil Outram, Jose Cruz da Angela,
  Bill Frith and Nic Ross
• University of Durham
• SDSS-2dF LRGQSO collaboration

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Summary

• 2QZSDSS-2dF QSO Redshift Surveys
• 2QZ P(k) vs SDSS DR2 LRG P(k)
• AAOmega QSO LRG Z survey
• AAOmega QSO science aims
• w(z) via baryon wiggles
• w(z) via QSO lensing
• w(z) via Alcock-Pacynzki test
• Conclusions

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2dF QSO Redshift Survey
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2QZ vs SDSS-2dF surveys
LRG/QSO survey
2QZ
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SDSS-2dF QSO Spectra

• 4hrs exposure AAT 2dF
• Mag limit glt21.8
• Top right panel shows stellar spectrum
• Other 3 are broad-line QSOs

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SDSS-2dF QSO n(z) - glt21.8
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z4.8 QSO detected
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SDSS-2dF QSO Wedge Plot
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SDSS-2dF LRG Wedge Plot
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(No Transcript)
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SDSS-2dF QSO Science Aims

• Observed redshifts for 1500/10000 20.5ltglt21.8
  QSOs
• Break Luminosity-Redshift Degeneracy in studies
  of QSO ClusteringBias Evolution
• QSO Luminosity Evolution at LltL at 1ltzlt3
• QSO-LRG clustering environment out to zlt0.7
• QSO line-strengths as function of L and z
• QSO lensing by groups and clusters
• Also will benefit from UKIDSS (and XMM?) surveys
  in same areas

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Breaking L-Z Degeneracy
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2dF QSO clustering amplitude at fixed z vs MB
(Loaring, Miller et al)
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2dF QSO composite spectra as a function of MB
(divided by average composite spectrum)
(Croom et al 2002)
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2QZ Gravitational Lensing
SDSS Groups and Clusters in 2QZ NGC area
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SDSS-2dF QSO Lensing

• Foreground 2dfGRS groups lens background 2QZ QSOs
• Reduced lensed area behind group ? reduced QSO
  count near group
• Significant signal seen in 2QZ
• Higher sky density of faint SDSS-2dF QSOs will
  improve statistics

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SDSS DR2 LRG Redshift Survey
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SDSS-2dF LRG n(z) ilt19.5
DR1 LRGs
SDSS-2DF LRGs
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SDSS-DR2 LRG Clustering
Preliminary DR1 DR2 LRG z-space correlation
functions
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SDSS-2dF LRG Correlation Function(Preliminary
based on 3034 galaxies)
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2QZ vs DR2 LRG P(k)

• P(k) from 23000 QSOs (Outram et al 2003)
• P(k) from 24500 DR2 LRGs (Ross et al in prep.)
• z0.5 LRGs have 2.6x higher P(k) amplitude than
  z1.4 QSOs

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QSO vs LRG

• 2 accuracy on peak positions requires-
• 300000 QSOs
• 150000 LRGs
• (after Blake Glazebrook, 2003)

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2
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DR2 LRG P(k) wiggles?
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Previous detections of wiggles

• Durham-AAT Galaxy Z survey ?(s) (Shanks et al
  1985) - 1.5 ?
• 2QZ P(k) (Outram et al 2001) - again 1-2 ? - used
  as standard rod by splitting by z
• 2dFGRS - pre-publication - window function problem

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AAOmega LRGQSO Survey?

• 2 accurate peak positions require 150000
  SDSS-2dF z0.5 LRGs in 1000 2dF pointings
• Simultaneously observe 150000 glt21.8 z1.4 QSOs ?
  3 accurate peak positions ?w?0.15
• Good redshift coverage for w(z) ? complements
  Gemini WFMOS at z3?

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AAOmega LRGQSO Survey

• QSO Survey will give unique constraints on dark
  energy equation of state at z1.4
• QSO Survey will also constrain w(z) via lensing
  as function of QSO redshift
• QSO Survey will also constrain w(z) via
  Alcock/Pacynzki z-distortion

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Discussion Points!

• Will AAOmega throughput improve by as much as
  2.5x at medium dispersion?
• Does steep LRG LF limit the accuracy of estimates
  of P(k) due to likely errors in photometry and
  incompleteness masks?
• Require 3000deg2 of CCD photometry in S sky -
  SDSSVST???
• Should we also be completing S Sky z survey to
  2dFGRS2QZ limit?

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Conclusions

• SDSS-2dF LRGQSO survey forms excellent pilot for
  AAOmega LRGQSO survey
• AAOmega LRGQSO survey will map w(z) from z0.5
  to z2.2 via baryon wiggles
• AAOmega QSO survey will also map w(z) via QSO
  lensing and the Alcock/Pacynzki test

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Current 2dF medium dispersion grating
efficiencies
?
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Baryon wiggles z dependence

• Solid line - angle
• Dashed line - redshift