Large scale structure of the universe at high redshifts
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Large Scale Structure of the Universe at high redshifts. M. Demianski , A. Doroshkevich and S.Gottloeber. LSS at small redshifts – luminous matter. Ly- forest-LSS in DM & barions. Three characteristics of absorber Redshift – z Width - b km/s Depth - N HI cm -2

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Large Scale Structure of the Universe at high redshifts

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Large Scale Structureof the Universeat high redshifts

M.Demianski,A.Doroshkevich

and S.Gottloeber


LSS at small redshifts – luminous matter


Ly- forest-LSS in DM & barions

  • Three characteristics

    of absorber

    Redshift – z

    Width - b km/s

    Depth - NHIcm-2

    and

    UV background


Cosmological model


Properties of ~6000 absorbers 1015cm-2 >NHI > 1012cm-2


Metal systems (CIV)


Properties of observed LSS


PUZZLES

  • 1. Weak redshift dependence of the PDFs,

    P(b/<b>), P(NHI/<NHI>), P(dsep/<dsep>)

  • 2. <b>=const.(z), b < bbg

  • 3. Slow regular redshift variations of

    <NHI> ~(1+z)2 and <dsep>~(1+z)-2


DM simulation

  • Lbox =150h-1Mpc, Np= 2563 , Lcell=0.6h-1Mpc

  • Mass resolution: 2 107Mo,

  • Force resolution: 20h-1kpc,

  • Selected clusters: 10 < Np < 5000, =1.76


For colder

clusters

Np~<Np>/3

For hotter

clusters

Np~3<Np>

Relaxation:

frel~0.6-0.8

Simulated clusters


Core-sampling approachLcore=0.5h-1Mpc


Conclusions


Probable causes of self similarity

  • Deterministic character of simulations:

    all structure properties are determined by

    the initial power spectrum.

  • Zeldovich’ approximation

  • ri=(1+z)-1[qi-B(z) Si(q)]

  • Power spectrum

  • P(k)~k-3, k/k0> 1, k0~0.15Mpc-1


Real and simulated BBKS power spectrum


The end


Possible interpretation

  • <b>=const(z), W(xi)=const(z)

  • <dsep/(1+z)>~(1+z)-3~1/<nabsSabs>

  • Version 1 – relaxed clouds

  • nabs~(1+z)3, Sabs~const.

  • BUT <NHI>~(1+z)2

  • Version 2 -- expanded clouds

  • Sabs~(1+z)-p, nabs~(1+z)3+p

  • BUT <b>=const., W(xi)=const(z)


Comparison with simulations.

Lbox=100 h-1Mpc, Np=(256)3 , Lcell=0.4Mpc

  • Z=0, 1, 1.5, 2, 2.5, 3, 4, 5

  • Two populations of clouds, and

  • Strongly deterministic approach

  • Previously – relaxed halos only

  • (galaxies, clusters of galaxies)


60 Mpc/h


PDFs for cloud velocities, W(U), mass function, W(M), and surface density, W(q)


PDFs for three principle sizes of clouds, L, w, h


PDFs for the velocity dispersionsalong three principle axes of clouds


Mean characteristics

High density clouds,

L~ (1+z)1/4, w~ (1+z)1/2, h~(1+z)1/2

Vh~ (1+z)-1/2.

Low density clouds,

L~w~h~ const(z)

Vh~ const(z).

Cores and envelopes


Measured power spectrum


Problems and prospects

  • 1. Ly-ά emitters and population

    of earlier galaxies (~20 000 LBG)

  • 2. DM compact objects

  • 3. First luminous objects -

    stars or galaxies

  • 4. Spatial distribution of metal

    systems – bubbles ~2Mpc


DM simulation

  • Lbox =150h-1Mpc, Np= 2563

  • Mass resolution 2 107Mo, Force resolution 20kpc/h

  • Selected clusters: 10 < Np < 5000, > 1.7

  • Mean comoving principal sizes:

  • L~0.5h-1Mpc, W~0.2h-1Mpc, S~0.1h-1Mpc

  • Velocity dispersions along principal directions:


Z~2 - 3

  • Lgal ~1026 erg/s/Hz/Mpc3

    Giavalisco et al. 2004, GOODS,

  • LQSO~1023 – 1024 erg/s/Hz/Mpc3,


Next Steps

  • Detailed analysis of evolution of the Universe.

  • Properties of DM particles

    (composition, masses, stability).

  • Shape of the small scale initial power spectrum at L<100 kpc.

  • Galaxy and quasar formation.

  • Reheating and reionization of the

    Universe.

  • Etc….


Real and simulated power spectrum


Period of reionization


Metal systems (CIV)


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