E L Comma galaxies. The Cosmic Runner (Park et al. 2005; Choi et al. 2010)

E L

Comma galaxies

The Cosmic Runner (Park et al. 2005; Choi et al. 2010)

Morphology – Luminosity – Local Density relation (Park et al. 2007)

Mr

(~5h-1Mpc)

Mor

ph

olog

y (

)

Early-type fraction vs clustercentric radius / luminosity

-17~-19

-19~-20.5

-20.5~-22.5

clustercentric radius

T H E H O R I Z O N R U N

Kim, Park, Gott & Dubinski (2009)

http://astro.kias.re.kr/Horizon_Run

Here

Now

The Observed Universe on a past light cone surface

Decou

plin

g

Ep

ochD

ark

A

ges

Th

e F

irst

Ob

jects

HI +

+

He

p +

e- +

+

He

Reio

niza

tion

Ep

och

Structure Formation & Evolution

Acceleration (Dark Energy

Dominated)

Deceleration (Matte

r

Dominated)

Infl

ati

on

Simulation of the SDSS Survey Region of the Universe

KASI-YITP Joint-Workshop Feb. 18, 2012

Changbom Park (Korea Institute for Advanced Study)

and Juhan Kim (KIAS), Yun-Young Choi (Kyunghee), Hyunbae Park(Austin), Inh Jee(Austin)

KASI 2012. 2. 18

A progress report

Simulation of the SDSS Survey region

Purposes

To study the past history of environmental effects on the objects in the SDSS survey region. Possible because the evolution of the matter field on small scales is affected by the large-scale structures through the transfer of power from large to small scales.

Method

Given a galaxy catalog in redshift space together with survey mask & SF

Cluster identification and compression

Calculate galaxy mass density field ρr,g

Map ρr,g to the matter density field ρr,m(z=0)

Estimate vpec using the 2nd-order perturbation theory

of the continuity equation, and correct galaxy positions for redshift effects

goto @ if a convergence for correction is not reached, and iterate

Calculate the smooth g (z=0) from ρr,m(z=0) and evolve it backward in time using the 2nd-order perturbation theory

Get the reconstructed initial density field ρr,m(initial)

Gaussianize the field.

@

Add small-scale power to match the CDM P(k)

Forward evolve the initial conditions

Reconstruction Method




Map ρr,g to the matter density field ρr,m



goto @ if a convergence is not reached, and iterate




@

We need the galaxy – halo – matter relation (biasing).

Popular halo bias model δhalo = Σbi δmatteri does not work.

(Even worse for the halo number density field.)

* Subhalos from an N-body simulation (20483m20483p10243v & WMAP3y CDM )

halo

# d

ensi

ty

halo

mas

s de

nsit

y

ln(1+δh)

ln(1

+δ m

)z=0 z=0.5 z=1












@

(Jenkins 2010; Gramann 1993)

where ∇2ф(2)=δ(2)=m2v

where ∇2ф(2)=δ(2)=m2v

Estimation of the peculiar velocities (2nd-order Lagrangian perturbation theory)

and ∇g












@

λ=5RG

Backward evolution

of the potential g at high z initial

Halos at z=0 estimate matter at z=0 g at high z initial

Genuine initial

-2, -1, +1, +2σ contours











@



Final conditions from the true initial density field

Final conditions from the reconstructed initial density field with random small-scale fluctuations

초기 현재

Final conditions from the true or reconstructed initial conditions

More works to do1. Constrained small-scale field

2. Application to the SDSS with non-periodic boundaries

(Park, Kim & Park 2010)

Effects of non-periodic boundaries

Gravitational shear tensor from full 1024h-

1Mpc cube

from a 512h-

1Mpc subcube

From a 256h-

1Mpc subcube

SDSS DR7: KIAS-VAGC Northern Galactic Cap (Choi, Han & Kim, JKAS, 2010; http://jkas.kas.org)

A SDSS galaxy catalog with 597.1K(10<r<17.6) + 114.3K(17.6<r<17.77) redshifts

SDSS DR7: KIAS-VAGC Northern Galactic Cap (Choi et al. 2010)A SDSS galaxy catalog with 597.1K(10<r<17.6) + 114.3K(17.6<r<17.77) redshifts

(bright galaxies added, extinction & K-corrections, L-evolution corrected)

7698 sq. deg

0°

10°

9h10h

The Sloan Great Wall (Gott et al. 2005)

BESTA volume-limited sample with the largest # of galaxies with Mr < -20.09

(Park, Park & Kim 2011)

Boundary Effects: a case when the analyses remain 60 h-1Mpc away from all boundaries

Eff

ects

of

non

-peri

od

ic

‘SD

SS

’ b

ou

nd

ari

es











@



Large-scale background density 20

200 h-

1Mpc

E/S0 & S/Irr galaxies with Mr<-19

SUMMARY

Reconstructing the initial density field within the SDSS survey region.

Replaying the structure formation in this local volume of the universe.

For this purpose we studied

1. halo-matter density connection

2. effects of non-periodic boundaries

3. 2nd-order perturbation theory of the continuity equation for peculiar velocity correction and initial density reconstruction.

Properties of the objects formed in the simulation can be statistically compared with those of the observed SDSS galaxies.

* Possible to know the past history of evolution of objects located in different environments, and also gives us information on the environmental parameters that cannot be directly obtained observationally.

Better understanding of formation and evolution of galaxies in conjunction with large-scale structures in the universe.

* Understanding cosmology & GF closely coupled. GF depends on environment.

Cosmology at KASI !

Thanks & Best Wishes

Title: Simulation of the SDSS Survey Region of the Universe Speaker: Prof. Changbom Park (Korea Institute for Advanced Study) Date & Time:Place:

Abstract: We plan to reconstruct the large-scale initial density field from the distribution of galaxies observed by the Sloan Digital Sky Survey (SDSS). After adding the small-scale fluctuations to match the power spectrum to that of the standard LCDM model, we make a cosmological N-body simulation of structure formation from the initial conditions. Properties of the objects formed in the simulation can be statistically compared with those of the observed SDSS galaxies. The simulation makes it possible to know the past history of evolution of objects located in different environments, and also gives us information on the environmental parameters that cannot be directly obtained observationally. It is hoped that this comparative study leads us to better understanding of formation and evolution of galaxies in conjunction with large-scale structures in the universe.

Documents

E L Comma galaxies. The Cosmic Runner (Park et al. 2005; Choi et al. 2010)