THE LYMAN- FOREST AS A PROBE OF FUNDAMENTAL PHYSICS

MATTEO VIEL

Shanghai, 16 March 2005

1. Cosmological significance of the Lyman- forest

2. LUQAS: The observational sample

3. Hydro-dynamical simulations of the Lyman-forest 4. Cosmological parameters – Implications for: inflation, neutrinos, gravitinos, warm dark matter particles

With M. Haehnelt, J. Lesgourgues, S. Matarrese, A. Riotto, V. Springel, J. Weller

GOAL: the primordial dark matter power spectrum

Tegmark & Zaldarriaga 2002

CMB physics z = 1100 dynamics

Lyphysics z < 6 dynamics + termodynamics

CMB + Lyman Long lever arm

Constrain spectral index and shape

Relation: P FLUX (k) - P MATTER (k) ??

Continuum fitting

Temperature, metals, noise

before WMAP

Croft et al. 2002

WMAP

Verde et al. 2003

the WMAP era

Tilt in the spectrum n<1 ?

Running spectral index dn/dlnk < 0 ?

DM

STARS

GAS

NEUTRALHYDROGEN

m = 0.26 = 0.74 b=0.0463 H = 72 km/sec/Mpc - 60 Mpc/h

COSMOS computer – DAMTP (Cambridge)

The LUQAS sample -I

Kim, MV, Haehnelt, Carswell, Cristiani, 2004, MNRAS, 347, 355

Large sample Uves Qso Absorption Spectra(LP-UVES program P.I. J. Bergeron)

high resolution 0.05 Angstrom, high S/N > 50low redshift, <z>=2.25, z = 13.75

Nr.

sp

ect

ra

redshift

The LUQAS sample –II systematic errors

Effective optical depth

<F> = exp (- eff) Power spectrum of F/<F>

Low resolution SDSS like spectra

High resolution UVES like spectra

Hydro-simulations: scalings

T = T0 ( 1 + )

Effective optical depth

P FLUX (k) = b2(k) P MATTER (k)

Viel, Haehnelt, Springel, MNRAS, 2004, 354, 684

Hydro-simulations: what have we learnt?Many uncertainties which contribute more or less equally

(statistical error is not an issue!)

Statistical error 4%

Systematic errors ~ 15 %

eff (z=2.125)=0.17 ± 0.02 8 %

eff (z=2.72) = 0.305 ± 0.030 7 %

= 1.3 ± 0.3 4 %

T0 = 15000 ± 10000 K 3 %

Method 5 %

Numerical simulations 8 %

Further uncertainties 5 %

ERRORS CONTRIBUTION TO FLUCT. AMPL.

Cosmological implications: combining the forest data with CMB - I

n = 1.01 ± 0.02 ± 0.06 8 = 0.93 ± 0.03 ± 0.09

Statistical error

Systematic error

SDSS Seljak et al. 2004

MV, Haehnelt, Springel 2004

Note that the flux bispectrum analysis agrees with these values MV, Matarrese, Heavens, Haehnelt, Kim, Springel, Hernquist, 2004

Cosmological implications: combining the forest data with CMB - II

SDSS Seljak et al. 2004

8= 0.93 ± 0.07 n=0.99 ± 0.03

8= 0.90 ± 0.03 n=0.98 ± 0.02 nrun = -0.003 ± 0.010 nrun=-0.033± 0.025

d ns/ d ln k

MV, Weller, Haehnelt, MNRAS, 2004, 355, L23

Cosmological implications: constraints on slow-roll inflation - III

SDSS Seljak et al. 2004

r < 0.45 (95% lim.)

r = 0.50 ± 0.30No evidence for gravity waves

T/S =

T/S

V = inflaton potential

MV, Weller, Haehnelt, MNRAS, 2004, 355, L23

Cosmological implications: Warm Dark Matter particles-I

CDM WDM 0.5 keV

30 comoving Mpc/h z=3

MV, Lesgourgues, Haehnelt, Matarrese, Riotto, PRD in press

k FS ~ 5 Tv/Tx (m x/1keV) Mpc-1

k FS ~ 1.5 (m x/100eV) h/Mpc

In general if light gravitinos

Set by relativistic degrees of freedom at decoupling

Cosmological implications: Warm Dark Matter particles-II

WDM CWDM (gravitino like)

Set limits on the scale ofSupersymmetry breaking

susy < 260 TeV

m WDM > 550 eV > 2keV sterile neutrino < 16 eV gravitino

Scale of free streaming

gravitino/ DM

Cosmological implications: constraints on neutrinos

m (eV) = 0.33 ± 0.27

WMAP + 2dF + Lyman-

HPM simulations of the forest

Full hydro 200^3 part. HPM PMGRID=600 HPM PMGRID=400

FLUX POWER

HIGH RESOLUTION HIGH S/N vs LOW RESOLUTION LOW S/N

LUQAS vs SDSS

SUMMARY

1. LUQAS: a unique high resolution view on the Universe at z=2.1

2. Hydro-dynamical simulations of the Lyman-forest. SystematicErrors? Differences between hydro codes?

3. Cosmological parameters: no fancy things going on 8 = 0.93 n = 1 no running substantial agreement between SDSS and LUQAS but SDSS has smaller error bars not because of the larger sample but because of the different theoretical modelling Constraints on inflationary models, neutrinos and WDM

HPM simulations of the forest-I

Gnedin & Hui 1998

equation of motion for gas element

if T = T0 ( 1 + )

Density

Temperature

No Feedback Feedback

Feedback effects: Galactic winds

Feedback effects: Galactic winds-III

Line widths distribution

Column density distribution function

Metal enrichment CIV systems at z=3

Strong Feedback =1 ---- Role of the UV background

Soft background ---- Role of different feedback

=1

=0

=0.1

Mori, Ferrara, Madau 2000; Rauch, Haehnelt, Steinmetz 1996; Schaye et al. 2003

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