Cosmic Momentum Field and Matter Fluctuation Study of Matter through Motions of Galaxies Changbom Park (Korea Institute for Advanced Study) KIAS

Peculiar velocity v pec = Total velocity – Hubble expansion velocity (true distance) = Total velocity – Hubble expansion velocity (true distance) Cosmic Velocity & Momentum Fields p = (ρ/ρ b )v = (1+δ) v &

Motivations 1. Mass fluctuation field 2. Biasing (mass vs galaxy fields) 3. LSS free of redshift space distortions 4. Gravitational Instability

Our Local Universe

Overall Plan Galaxy Distance using redshift-independent distance indicators x & v r (x) of galaxies P ρ (k) & P p (k) Ω m 1.2 P ρ (k) & Ω m 0.6 /b ‘Total’ Matter Distribution Cosmological Models

Peculiar velocity v pec = Total velocity – Hubble expansion velocity (true distance) = Total velocity – Hubble expansion velocity (true distance) Why should this work?

Distance Indicators Spirals * Tully-Fisher Relation : Spirals (Luminosity – Circular Velocity) Ellipticals * D n -σ Relation : Ellipticals (Diameter – Velocity dispersion) (Distance error of ~ 20%)

1. Mark III: ~3300 galaxies. TF & D n -σ indicators A82 + 7S88 + HMCL W91PP + MAT92 + W91CL + CF SFI: 1216 Sbc~Sc galaxies SCI: ~800 galaxies in 24 clusters SCI: ~800 galaxies in 24 clusters 3. ENEARf: ~1400, T =<-2. B<14.5, cz < 7000km/s ENEARc: ~500, E & S0 galaxies in 28 clusters ENEARc: ~500, E & S0 galaxies in 28 clusters EFAR: 736 early types in 85 clusters EFAR: 736 early types in 85 clusters 4. KLUN+: 6229 galaxies. cz<8000km/s Observations

Momentum Field Momentum PS (prediction) ≈ Observed Momentum PS  β estimation p = (1+δ) v

SFI Galaxy Sample Giovanelli et al. (1997) 1289 Spiral Galaxies with I-band Tully-Fisher Distance SFI Main Galaxies + MAT Sample (δ < – 45º region, D ≥ 1.7') 661 Galaxies with D ≥ 1.7'

ENEAR Galaxy Sample 1145 early-type galaxies with D n -σ distances (m B <=14.5, cz <= 7000 km/s) 261 Groups/Clusters (734 gals) 364 Field Galaxies merging (625 objects; |b|>15º )

Measuring Density & Momentum PS Fourier Transform Power Spectrum

Density and Momentum Power Spectra 100 Mock Obs. (ENEAR)

Estimating β=Ω 0.6 /b At linear regime (>~ 80 h -1 Mpc) At quasi-linear regime (>~ 40 h -1 Mpc) ENEAR

SFI results ENEAR ENEAR vs SFI SFI

Comparison with Other Results β E,S σ 8 Ω m 0.6 DataMethodRef ENEAR Mom. PS This Study SFI Mom. PS This Study 0.50 ENEAR, IRAS PSCz OME Nusser et al. (2001) 0.51ENEARCF Borgani et al. (2000a) 1.10ENEARML Zaroubi et al. (2001) 0.6 SFI, IRAS 1.2 Jy OME Da Costa et al. (1998) 0.42 SFI, IRAS PSCz VELMOD Branchini et al. (2001) 0.82SFIML Freudling et al. (1999) 0.3SFICF Borgani et al. (2000b) 0.63SFIML Silberman et al. (2001) MAT Mom. PS Park (2000) 0.51 SFI+ENEAR, PSCz UMV (v-v) Zaroubi et al. (2002) 0.57 SFI+ENEAR, PSCz UMV (d-d) Zaroubi et al. (2002) 0.40 SNIa, IRAS 1.2 Jy χ2 fit Riess et al. (1997) 0.55 SNIa, PSCz χ2 fit Radburn-Smith et al. (2004)

Future Works 1. All sky deep sample 2. Theories applicable to noisy but large samples  (2dF, SDSS, etc.) 3. Accurate distance estimator 4. Cluster galaxy survey 5. Well-defined survey Era of Mass Fluctuation Exploration !