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MATTEO VIEL

NEUTRINOS FROM THE LYMAN- a FOREST: MYTH or REALITY ?. Trieste. MATTEO VIEL. OUTLINE. - What is the Lyman- a forest ? Is it a cosmological probe ? - Constraints on sterile neutrinos - Constraints on active neutrinos.

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MATTEO VIEL

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  1. NEUTRINOS FROM THE LYMAN-a FOREST: MYTH or REALITY ? Trieste MATTEO VIEL OUTLINE - What is the Lyman-a forest ? Is it a cosmological probe ? - Constraints on sterile neutrinos - Constraints on active neutrinos NOW 2006 - Conca Specchiulla (Italy) – 12th September 2006

  2. Physics of the simulations is simple: dark matter, Gas cooling, photoionization heating, star formation 80 % of the baryons at z=3 are in the Lyman-a forest Bi & Davidsen (1997), Rauch (1998) baryons as tracer of the dark matter density field dIGM~dDMat scales larger than the Jeans length ~ 1 com Mpc t ~ (dIGM )1.6 T -0.7

  3. GOAL: the primordial dark matter power spectrum from the observed flux spectrum CMB physics z = 1100 dynamics Continuum fitting Lya physics z < 6 dynamics + termodynamics Temperature, metals, noise Tegmark & Zaldarriaga 2002 CMB + Lyman a Long lever arm Relation: P FLUX (k) - P MATTER (k) ?? Constrain spectral index and shape

  4. SDSS vs LUQAS McDonald et al. astro-ph/0405013 Kim, Viel et al. 2004, MNRAS, 347, 355 SDSS LUQAS 3000 LOW RESOLUTION LOW S/N 30 HIGH RESOLUTION HIGH S/N

  5. Lyman-a forest + CMB - I VHS(LUQAS): high res Ly-a from Viel, Haehnelt, Springel 2004 SDSS: low res Ly-a from McDonald et al. 2005 Ly-a + WMAP1 Ly-a + WMAP3 VHS+WMAP1 POWER SPECTRUM AMPLITUDE SDSS+WMAP1 POWER SPECTRUM SLOPE Viel , Haehnelt, Lewis, 2006, MNRAS Lett., 370, 51

  6. RESULTS STERILES Warm dark matter

  7. Lyman-a and Warm Dark Matter - I WDM 0.5 keV LCDM 30 comoving Mpc/h z=3 See Bode, Ostriker, Turok 2001 Abazajian, Fuller, Patel 2001 In general k FS ~ 5 Tv/Tx (m x/1keV) Mpc-1 Set by relativistic degrees of freedom at decoupling Viel, Lesgourgues, Haehnelt, Matarrese, Riotto, PRD, 2005, 71, 063534

  8. Lyman-a and Warm Dark Matter - II WDM LCWDM (gravitinos) neutrinos m WDM > 550 eV thermal > 2keV sterile neutrino Viel et al. (2005)from high-res z=2.1 sample Seljak et al. 2006, astro-ph/0602430 m WDM > 2 keV thermal > 14 keV sterile neutrino

  9. Lya-WDM III: analysis with flux derivatives z < 4.2 z < 3.2 z < 3.8 L n = 0 Viel, Lesgourgues, Haehnelt, Matarrese, Riotto, Phys.Rev.Lett., 2006, 97, 071301

  10. Decaying channel into photons and active neutrinos line with E=ms/2 (X-band) Perseus Cluster (Jeremy Sanders) 5.66 keV

  11. COLD (a bit) WARM sterile 7 keV

  12. RESULTS ACTIVE

  13. S m n = 0.138 eV • m n = 1.38 eV Lyman-a forest Lesgourgues & Pastor 2006

  14. Active neutrinos -II WDM neutrinos • mn (eV) < 1 eV (95 % C.L.) WMAP1 + 2dF + LYa Good agreement with the latest Tegmark et al. results…..

  15. Active neutrinos - III Seljak, Slosar. McDonald, 2006, a-ph/0604335 normal 3 1,2 inverted 2 3 1 Tight constraints because data Are not compatible!!!! • mn (eV) < 0.17 (95 %C.L.) r < 0.22 (95 % C.L.) running = -0.020 ±0.12 CMB + SN + SDSS gal+ SDSS Ly-a Goobar et al. (aph/0602155) get upper limits 2-3 times larger……

  16. Hydro-simulations: what can we learn? Many uncertainties which contribute more or less equally (statistical error seems not to be an issue!) VERY CONSERVATIVE ERRORS CONTRIBUTION TO FLUCT. AMPL. Mean flux Thermal history

  17. SUMMARY • Lyman-a forest is a complementary measurement of • the matter power spectrum and can be use to constrain cosmology • together with the CMB • There are no other observables at the forest scales and redshifts • Tension for cosmological parameters • SDSS+WMAP3 : s8=0.86 ± 0.03, n=0.96 ±0.02 • SDSS+VHS: s8=0.78 ±0.05, n = 0.96 ±0.02 (not constraining anymore) • Tight constraints on neutrino mass fraction • Sterile neutrino probably ruled out in the standard production mechanism < 0.9 eV > 10 keV

  18. Implementation of neutrino particles treated self-consistently into GADGET-II DM GAS NEUTRINOS (1eV) z = 30 z = 8 z = 1

  19. Numerical modelling: HydroParticleMesh simulations of the forest Full hydro 200^3 part. HPM NGRID=600 HPM NGRID=400 MV, Haehnelt, Springel 2006 FLUX POWER

  20. Neutrinos S mn (eV) = 0.6 S mn (eV) = 0.15 S mn (eV) = 0.3 Neutrino mass effect on the CMB 3 massless 1 massive S mn (eV) = 0.9 Neutrino mass effect on P(k) Seljak et al. 2004 Note that WMAP only has <1% uncertainties at l~300!!! …and Planck will improve this… especially at high l values

  21. Lyman-a forest + CMB - II SDSS: McDonald et al. 2005, Seljak et al. 2005 Hydro Particle Mesh simulations SDSS-d: Viel & Haehnelt 2006: analysis of SDSS flux power using flux derivatives and full hydrodynamical simulations Flux power P F (k, z; p) = P F (k, z; p0) + Si=1,N  P F (k, z; pi) (pi - pi0)  pi p = p0 Best fit p: astro and cosmo param.

  22. Lyman-a forest + CMB - II • With WMAP3 like-priors: • M = 0.235 ± 0.035 • H 0 = 73 ± 3 km/s/Mpc SDSS amplitude and “slope” are 2s away WMAP3

  23. 5.66 keV !!!

  24. Wm = 0.26 WL = 0.74 Wb=0.0463 H0 = 72 km/sec/Mpc - 60 Mpc/h 2x4003 GAS+DM 2.5 com. kpc/h softening length GADGET –II code COSMOS computer – DAMTP (Cambridge) DM GAS STARS NEUTRAL HYDROGEN

  25. Wm = 0.26 WL = 0.74 Wb=0.0463 H0 = 72 km/sec/Mpc - 60 Mpc/h 2x4003 GAS+DM 2.5 com. kpc/h softening length GADGET –II code COSMOS computer – DAMTP (Cambridge) DM GAS STARS NEUTRAL HYDROGEN

  26. LUQAS SDSS DATA 27 high res z~2.125 QSO spectra 3000 QSO spectra z>2.2 THEORY: SIMULATIONS full hydro simulations `calibrated’ simulations THEORY: METHOD 3D flux inversion 1D flux modelling ADVANTAGES band power large redshift range DRAWBACKS only z=2.1 (and 2.72) and 34 parameters modelling larger error bars RESULTSno large running, scale invariant, `high’ power spectrum amplitude

  27. Fitting SDSS data with GADGET-2 this is SDSS Ly-a only !! M sterile neutrino > 10 KeV 95 % C.L. SDSS data only s8 = 0.91 ± 0.07 n = 0.97 ± 0.04

  28. Isocurvature perturbations This is a model in agreement with WMAP3! Beltran, Garcia-Bellido, Lesgourgues, Viel, 2005, PRD, D72, 103515 Fully correlated a:isocurvature fraction at k=0.05 Mpc-1 b:quantifies correlation between ISO and ADIABATIC modes n iso=1.9 ± 1.0 95% C.L. Anti correlated No iso Only iso n ad=0.95 n iso =3 n ad = 0.95 n iso =2

  29. Mean flux Effective optical depth Low resolution SDSS like spectra High resolution UVES like spectra <F> = exp (- t eff) Power spectrum of F/<F>

  30. Thermal state T = T0 ( 1 + d) g-1 Thermal histories Flux power fractional differences Statistical SDSS errors on flux power

  31. Lack of power in the RSI model: haloes form later. Contrast with the large t inferred (Yoshida et al. 2003) Spergel et al. 2003 Peiris et al. 2003 Lyman-a does most of the job in constraining running!!!

  32. The LUQAS sample Large sample Uves Qso Absorption Spectra (LP-UVES program P.I. J. Bergeron) high resolution 0.05 Angstrom, high S/N > 50 low redshift, <z>=2.25, Dz = 13.75 # spectra redshift Kim, MV, Haehnelt, Carswell, Cristiani, 2004, MNRAS, 347, 355

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