Redshift Surveys: New Challenges

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Redshift SurveysNew Challenges

• Galaxy bimodality and relative biasing
• High order moments
• Limits on Neutrino masses

Ofer Lahav University College London
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Bimodality in the 2dFGRS
With AAOmega Better spectra, IFU
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Clustering per Spectral Type
Correlation functions (Madgwick el al. 2003)
Stochastic biasing (Wild et al. 2004)
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2dF vs SDSS wiggles?
50 Mpc/h

Pope et al. 2004
Tegmark et al. 2003
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The two big Superclusters in 2dFa fair sample
for high order moments?
7 Abell clusters 77 groups (gt8)
20 Abell clusters 93 groups (gt8)
Baugh et al..
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The Cosmic Web Wiener reconstruction
Erdogdu, Lahav, Zaroubi et al., astro-ph/0312546
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Weighing Neutrinos with 2dFGRS

• Free streaming effect
• Wn/Wm lt 0.13
• Total n mass Mlt 1.8 eV
• 0.001 lt Wn lt 0.04
• (Oscillations) (2dF)
• a Four-Component Universe ?

Wn 0.05
0.01
0.00
Elgaroy , Lahav 2dFGRS team, astro-ph/0204152
, PRL
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P(k)A kn T2(k)

Neutrino Free Streaming DP(k)/P(k) -8 Wn /Wm
(Hu et al. 1998)
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Absolute Masses of Neutrinos

• Based on
• measured
• squared mass
• differences
• from solar and
• atmospheric
• oscillations
• Assuming
• m1 lt m2 lt m3

Elgaroy Lahav 2003
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Neutrino mass from Cosmology

All upper limits 95 CL, but different assumed
priors !