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MATTEO VIEL

STRUCTURE FORMATION. MATTEO VIEL. INAF and INFN Trieste. SISSA LECTURE #4 – March 14 th 2011. OUTLINE: LECTURES. Structure formation: tools and the high redshift universe The dark ages and the universe at 21cm IGM cosmology at z=2=6 IGM astrophysics at z=2-6

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MATTEO VIEL

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  1. STRUCTURE FORMATION MATTEO VIEL INAF and INFN Trieste SISSA LECTURE #4 – March 14th 2011

  2. OUTLINE: LECTURES • Structure formation: tools and the high redshift universe • The dark ages and the universe at 21cm • IGM cosmology at z=2=6 • IGM astrophysics at z=2-6 • 5. Low redshift: gas and galaxies • 6. Cosmological probes LCDM scenario

  3. OUTLINE: LECTURE 4 Galactic winds and metal enrichment The evolution of the UV background The Warm-Hot Intergalactic Medium

  4. GALACTIC WINDS

  5. Galactic winds –I Local galactic winds M82 X-ray Local galactic winds M82 optical and infra-red

  6. Theory: Galactic winds do they destroy the forest ? Galactic winds –II Log overdensity Log Temp Flux Temp. Dens. Theuns, MV, et al, 2002, ApJ, 578, L5

  7. Feedback effects: Galactic winds-IV Line widths distribution Column density distribution function

  8. Metal enrichment CIV systems at z=3 Strong Feedback e=1 ---- Role of the UV background Mori, Ferrara, Madau 2000; Rauch, Haehnelt, Steinmetz 1996; Schaye et al. 2003 Soft background ---- Role of different feedback e=0 e=1 e=0.1

  9. Observations: the POD technique Aguirre,Schaye, Theuns, 2002, ApJ, 576, 1 Cowie & Songaila, 1998, Nature, 394, 44 Pieri & Haehnelt, 2004, MNRAS, 347, 985 Pixel-by-pixel search using higher order transitions

  10. Springel & Hernquist 2002,2003

  11. Observations: the POD technique-II NO SCATTER IN THE Z-r relation SCATTER IN THE Z-r relation Good fit to the median but not for the scatter Schaye et al., 2003, ApJ, 596, 768

  12. Observations: the POD technique-III VARIANCE OF THE METALLICITY Lognormal fit Schaye et al., 2003, ApJ, 596, 768

  13. When did the IGM become enriched – II ? Adelberger et al. 2005

  14. GALAXY-IGM CONNECTION - Early or late metal enrichment???? PopIII objects?? Where are the metals? How far can they get? - Search for galactic winds. No definitive proof of galactic winds at high redshift. DEFINITIVE proof will be signatures of outflows in QUASAR PAIRS (within 2yrs)? - Lyman-break proximity effect? Is there still something odd? radiative transfer effects? - Better modelling of the ISM into cosmological hydro simulations ISM-IGM connection

  15. UV BACKGROUND

  16. Ionizing background – I t ~ 1/ G-12 With the fluctuating Gunn – Peterson approximation Photoionization rate Bolton, Haehnelt, MV, Springel, 2005, MNRAS, 357, 1178

  17. Ionizing background-II Bolton, Haehnelt, MV, Springel, 2005, MNRAS, 357, 1178

  18. Summary • Metal enrichment: Significant progress made on the • understanding of the IGM-galaxy connection but still: • No proofs of strong galactic winds at high redshfit • No clues of who is polluting the IGM and to what extent. • PopIII? Lyman-break galaxies? • the amplitude, shape of the (fluctuating?) UV background • is quite uncertain

  19. WHIM

  20. WHIM - I Cen & Ostriker 1999, ApJ, 514, 1L Fukugita, Hogan, Peebles, 1998, ApJ, 503, 518

  21. WHIM - II Possibility of detecting the WHIM in absorption with EDGE (Explorer of Diffuse Emission and Gamma-ray burst Explosions) characterize its physical state, spatial clustering and estimate the baryon mass density of the WHIM. - WHIM models and uncertainties. - Probability of WHIM detections. - WWHIMestimate. - Systematic effects. Joint emission+absorption analysis - Spatial distribution of WHIM and its bias

  22. WHIM: model uncertainties – I To asses model (random+systematic) uncertainties we have used different techniques to simulate WHIM

  23. = 0.7, m = 0.2457, b = 0.0463, h = 0.7, = 0.85 L = 60 h-1Mpc, , NDM = 4003,NGAS = 4003, = 2.5 h-1kpc WHIM: model uncertainties – II • Semi analytic model (Viel et al. 2003) • Hydro-dynamical model by Borgani • Hydro-dynamical model (Viel 2006) Gadget-2 SPH code. Metallicity model: Z/Zsun=min(0.2,0.025.r–1/3) Simple star formation prescription. No Feedback. Ions: OVI (KLL), OVIIKa, OVII Kb, OVIII, CV, NeIX, MgXI FeXVII. Hybrid collisional ionization + (X+UV) photoionization. Independent spectra drawn by stacking outputs out to z=0.5 (Dz=0.1)

  24. Minimum flux (fluence) for detection NOVII/Dz = 4–8 NOVIII/Dz=0.6–1.3

  25. OVII Ka @z=0.26 EW=0.1 eV OVII Ka @z=0.46 EW=0.1 eV OVII Kb @z=0.46 EW=0.072 OVI KLL@z=0.26 EW=0.06 eV

  26. WHIM as a mass tracer Eulerian Hydro-simulation. Flat LCDM L=25 Mpc/h. l=32.6 Kpc/h. Cen et al. 2003 GalaxyLight: TullyCatalog Biasing hypothesis + ADDING POWER IGM distribution Gas properties OVII distribution CLOUDY

  27. WHIM: the observational state of the art Nicastro et al 2002. PKS2155-304. 1 Absorber @ z~0 Nicastro et al 2005. Mark-421. 2 Absorbers @ z~0.011 and z~0.027 NeX OVIII OVII OVII NeIX NVI CVI OVIII But see Kaastra et al. 2006 and Rasmussen et al 2006

  28. Summary - WHIM • Best bright background sources ? GRBs • Unambiguous WHIM at detection at z>0 ? Yes • Measuring WWHIM ? Yes. e~20% • Tracing Dark Matter (Wm) ? No • WHIM spatial distribution ? Yes. Emission ..alternative observational strategies are also possible

  29. WHIM and feedback - II

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