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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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