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Large Scale Structure of the Universe at high redshifts. M. Demianski & A. Doroshkevich. LSS at small redshifts. Three characteristics of absorber Redshift – z Depth - N HI cm -2 Width - b km/s blending of absorbers. QSO spectra used.
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Large Scale Structureof the Universeat high redshifts M.Demianski &A.Doroshkevich
Three characteristics of absorber Redshift – z Depth - NHIcm-2 Width - b km/s blending of absorbers
QSO spectra used QSR Z_emZ_minZ_maxNo HI lines Ref. 1055+461 4.16 2.8 4.16 998 Rough & Sargent 0000-260 4.11 3.4 4.1 431 Lu et al. 0055-259 3.66 3.0 3.6 534 Kim 1422+230 3.6 2.7 3.6 811 Rough & Sargent 0014+813 3.41 2.7 3.2 262 Hu et al. 0956+122 3.30 2.6 3.1 256 Hu et al. 0302-003 3.29 2.6 3.1 356 Kim 0636+680 3.17 2.5 3.0 531 Rough & Sargent 0636+680 3.17 2.4 3.1 313 Hu et al. 1759+754 3.05 2.4 3.0307 Djorgovski et al. 1946+766 3.02 2.4 3.0 461 Kirkman & Tytler 1107+485 3.0 2.1 3.0 609 Rough & Sargent 1347-246 2.63 2.1 2.6 361 Kim 1122-441 2.42 1.9 2.4 353 Kim 2217-282 2.41 1.9 2.3 262 Kim 1626-???2.32 1.5 2.2 281 Rough & Sargent 2233-606 2.24 1.5 2.2 293 Cristiani & D'Odorico 1101-264 2.15 1.6 2.1 277 Kim 0515-4411.72 1.5 1.7 76 Kim
Self similarity and weak regular redshift variations of measured characteristics.
1. All PDFs are weakly dependent from redshift. 2. Rapidly expanded regions. 3. Gaussianity of perturbations
PUZZLES • 1. Weak redshift dependence of the PDFs, P(b/<b>), P(NHI/<NHI>), P(dsep/<dsep> • 2. <b>=const.(z) • 3. Slow regular redshift variations of <NHI> ~(1+z)2 and <dsep>~(1+z)-2
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)
PDFs for cloud velocities, W(U), mass function, W(M), and surface density, W(q)
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
Probable causes of self similarity • Zeldovich’ approximation • ri=(1+z)-1[qi-B(z)Si(q)] • Power spectrum • P(k)~k-3, k/k0> 1, k0~0.15/Mpc
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
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….