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MATTEO VIEL

STRUCTURE FORMATION. MATTEO VIEL. INAF and INFN Trieste. SISSA LECTURE #4 - March 23 th 2010. 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 23th 2010

  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 - III No Feedback Feedback Density Temperature

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

  9. 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

  10. 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

  11. Springel & Hernquist 2002,2003

  12. 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

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

  14. POD technique and proximity -IV UV background and metallicity Schaye, Aguirre et al. 2004,2005 Lyman-break galaxies proximity effect (and galaxy-metals connection) Adelberger, Steidel et al. 2003-2006

  15. Still problems from simulations? Aguirre et al. 2005 SIMULATIONS’ PROBLEM: ENRICHED GAS IS 1) TOO HOT 2) NOT DENSE ENOUGH 3) TOO INHOMOGENEOUSLY DISTRIBUTED Energy driven Momentum driven Oppenheimer & Dave’, aph/0605651 PROBLEMS ALLEVIATED ?? NEW KEY INPUTS: metal line cooling Vel wind ~ s galaxy x lum. factor

  16. When did the IGM become enriched – I ? EARLY METAL ENRICHMENT at z>6 CIV-LBG cross correlationfunction Porciani & Madau 2005

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

  18. The future-I cw : costant speed wind mw: momentum driven nw: no wind Exploring the parameter space… (multi fitting as many observables As possible SFR, HI evolution, CDDF…)

  19. The future-II …with motivated chemodynamical models Kawata & Rauch 2007

  20. 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

  21. UV BACKGROUND

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

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

  24. Ionizing background and Helium reionization - III Bolton, Haehnelt, MV, Carswell, 2006, MNRAS, 366, 1368

  25. Ionizing background and the proximity effect DATA SIMULATIONS

  26. 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

  27. WHIM

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

  29. 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

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

  31. = 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)

  32. NOVII(W>0.1eV)/z=1-4 NOVIII(W>0.1eV)/z=0.1-0.4

  33. X-ray background source candidates Bright Blazars with fluence of ~ 2.510-5 erg cm-2 in ~70 ks Pros: Very Bright. Cons: Rare Bright QSOs with fluxes> 5*10-12 erg cm-2 s –1 keV –1 Pros: Not too Rare. Cons: Very Nearby (faint) GRB afterglows with fluence of ~ 310-6 erg cm-2 in ~60 ks Cons: Bright (distant). Not too rare (~10 per year). 8 Estimated using BeppoSAX results. confirmed by Swift

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

  35. 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

  36. Minimum flux (fluence) for detection The ratio of the EWs of 2 lines from ions of the same element uniquely define the ionization balance of the absorber. - From 30 GRBs with fluence 3.2 x 10-6 erg/cm2 one expects 10-20 line pairs of at least 2 oxygen ions. -10-20 detections would bring relative errors down to a ~20 % level

  37. Measuring WWHIM: Systematic errors OVII R-space d Vp OVII z-space Departures from ionization equilibrium (Yoshikawa and Sasaki 2006) and the inhomogeneous distribution of WHIM (Kawahara et al. 2006) are potential sources of systematic errors. However some systematics may actually increase the chance of WHIM detection. Coherent infall motions boost the EW of the strongest OVII absorbers up by ~30% (OVIII by ~15%)

  38. Joint emission-absorption analysis Emission ~ r2 – Absorption ~ r

  39. Joint emission-absorption analysis -I

  40. QSO pairs? Viel, Branchini, Cen, Matarrese, Mazzotta, Ostriker, 2003, MNRAS, 341,792

  41. WHIM as a mass tracer Sigad Branchini & Dekel 2001 The large scatter in the gas vs. DM relation makes WHIM a poor tracer of the underlying mass density fluctuation field.

  42. Probing WHIM spatial distribution Absorption analyses could measure the “size of the WHIM filaments’ using nearby ~20 bright QSOs pairs separated by <20’ (Viel et al 2003). A 3s level determination, however, requires ~40 Msec observation. A much better option is to study the angular correlation properties of the WHIM emission signal. Theoretical models provide robust prediction for the WHIM 2-point angular correlation function

  43. 3C273 VIRGO

  44. 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

  45. 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

  46. 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

  47. WHIM and feedback No feedback Galactic winds Galactic winds coupled Black holes

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