Simulating the ionisation and metal enrichment history of the Intergalactic Medium Tom Theuns Institute for Computational Cosmology, Durham, UK Department of Physics, Antwerp, Belgium

26/06/2015Tom Theuns: IGM ionisation and enrichment 2 The  CDM paradigm WMAP et al + 2dF/Sloan et al

26/06/2015Tom Theuns: IGM ionisation and enrichment 3 How to go from to

26/06/2015Tom Theuns: IGM ionisation and enrichment 4 Semi-analytic galaxy formation and the large-scale galaxy distribution Durham incarnation

26/06/2015Tom Theuns: IGM ionisation and enrichment 5 Distribution of galaxies in 2dF GRS

26/06/2015Tom Theuns: IGM ionisation and enrichment 6 Distribution of galaxies in simulated 2dF GRS

26/06/2015Tom Theuns: IGM ionisation and enrichment 7 Springel & Hernquist 2003 Simulations and the starformation history

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26/06/2015Tom Theuns: IGM ionisation and enrichment 9 Okamoto et al 05 Stars Gas Simulations and stellar archaeology Single galaxy and the importance of feedback

26/06/2015Tom Theuns: IGM ionisation and enrichment 10 Stellar Archeology: Harris & Zaritsky

26/06/2015Tom Theuns: IGM ionisation and enrichment 11 The importance of “feedback”: galaxy-wide winds? M82Springel

26/06/2015Tom Theuns: IGM ionisation and enrichment 12 More evidence for super winds? Sauron observations of a Ly  ”blob” at z=3 Wilman et al 05

26/06/2015Tom Theuns: IGM ionisation and enrichment 13 Wilman et al 05 Lyman  profile suggests presence of “sheet” of neutral gas, expelled by an earlier superwind phase

26/06/2015Tom Theuns: IGM ionisation and enrichment 14 Pettini et al Absorption lines of several (low-ionization state) transitions are off-set from the velocity of the stars by many 100s of km/s in cB58, a Lyman-break

26/06/2015Tom Theuns: IGM ionisation and enrichment 15 M33 (UV)M33 (Visual ) A new ISM multi-phase implementation: use sticky particles to represent molecular clouds (with Craig Booth)

26/06/2015Tom Theuns: IGM ionisation and enrichment 16 Thermal instability leads to cloud formation (McKee & Ostriker) Small clouds coagulate to make more massive clouds GMCs collapse after 10Myr, converting 10% of mass into stars Stellar winds and Sne explosions destroy GMC (feedback) Hot gas evaporates small clouds Sticky particle scheme: (Craig Booth) Nearly resolution independent!

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26/06/2015Tom Theuns: IGM ionisation and enrichment 18 Time F SFR T[K] Star formation in a closed box

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26/06/2015Tom Theuns: IGM ionisation and enrichment 20 Position of clouds formed in a collapsing rotating sphere … and in M33

26/06/2015Tom Theuns: IGM ionisation and enrichment 21 X-ray observations of the Perseus galaxy clusters show hot cavities, plausibly inflated by AGN Chandra Feedback from AGN

26/06/2015Tom Theuns: IGM ionisation and enrichment 22 Buoyant bubbles from an AGN heating the gas and quench cooling (flow). Della Vecchia Flash/AMR

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26/06/2015Tom Theuns: IGM ionisation and enrichment 24 Flash AMR code at Durham:  Radiative transfer (Crash)  Star formation and feedback  Gravity (fftw version)

26/06/2015Tom Theuns: IGM ionisation and enrichment 25 Maselli et al Investigate radiative transfer effects

26/06/2015Tom Theuns: IGM ionisation and enrichment 26 X-ray preheating from early black holes Kuhlen & Madau

26/06/2015Tom Theuns: IGM ionisation and enrichment 27 Simulated spectra look very similar to the data Mock versus Keck spectrum: which is which? Theuns

26/06/2015Tom Theuns: IGM ionisation and enrichment 28 Simulations look very realistic: use them to estimate contamination in interpreting metal optical depths, and to compute other sources of bias. Schaye et al, Aguirre et al. Pixel Optical Depth Method

26/06/2015Tom Theuns: IGM ionisation and enrichment 29 Schaye et al 2003 Metals (C IV ) found to low densities. No obvious evolution with redshift. Galactic winds? Pop III Stars? density redshift Abundance

26/06/2015Tom Theuns: IGM ionisation and enrichment 30 Simulation with metal enrichment due to galactic winds appears to reproduce the observed CIV-HI scatter Theuns et al 2001 Can feedback implementation explain observed metals?

26/06/2015Tom Theuns: IGM ionisation and enrichment 31 The winds generated have little effect on the Ly  forest

26/06/2015Tom Theuns: IGM ionisation and enrichment 32 But do reasonably well in reproducing the C IV lines

26/06/2015Tom Theuns: IGM ionisation and enrichment 33 N Carbon N Hydrogen

26/06/2015Tom Theuns: IGM ionisation and enrichment 34 Are the metals in the simulations too hot? Aguirre et al ‘05 In simulations, there are a lot of metals in hot gas. Pixel Optical Depth analysis: C III / C IV C IV

26/06/2015Tom Theuns: IGM ionisation and enrichment 35 Using QSO sightlines to probe density structure around galaxies and QSOs

26/06/2015Tom Theuns: IGM ionisation and enrichment 36 Adelberger et al 03

26/06/2015Tom Theuns: IGM ionisation and enrichment 37 Density structure around QSOs and the proximity effect Rollinde et al 05 Fraction of pixels with given scaled optical depth,  =  0 (z 0 ) (1+z) 

26/06/2015Tom Theuns: IGM ionisation and enrichment 38 Rollinde et al 05

26/06/2015Tom Theuns: IGM ionisation and enrichment 39 Ly  forest becomes very dense at z>6: end of reionisation?

26/06/2015Tom Theuns: IGM ionisation and enrichment 40 Haardt & Madau ‘96 What is evolution of ionizing background?

26/06/2015Tom Theuns: IGM ionisation and enrichment 41 Estimate of  from simulations (diamonds) and inferrred from sources (triangles, squares) Bolton et al ’04 Jena et al ‘04 Galaxies must dominated  at z > 5

26/06/2015Tom Theuns: IGM ionisation and enrichment 42 Evidence for He II reionisation from Sloan Bernardi et al 02 Theuns et al 02

26/06/2015Tom Theuns: IGM ionisation and enrichment 43 IGM temperature as function of redshift. Schaye et al.

26/06/2015Tom Theuns: IGM ionisation and enrichment 44 If no other heat sources, HI reionization late? Theuns et al.

26/06/2015Tom Theuns: IGM ionisation and enrichment 45 Yes: Barkana & Loeb Does reionization affect galaxy formation?

26/06/2015Tom Theuns: IGM ionisation and enrichment 46 Does reionization affect galaxy formation? No: Benson et al

26/06/2015Tom Theuns: IGM ionisation and enrichment 47 Summary Feedback Reionisation Ionising background. First objects Importance of AGN? Thank you

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26/06/2015Tom Theuns: IGM ionisation and enrichment Numerical simulations: c) photo-ionisation

26/06/2015Tom Theuns: IGM ionisation and enrichment Numerical simulations: c) photo-ionisation Reionisation heats the Universe to T=10 4 K

26/06/2015Tom Theuns: IGM ionisation and enrichment Numerical simulations: c) photo-ionisation Photo-ionisation heating produces a well-defined  -T relation in the low-density IGM that produces the Ly  -forest. (Hui & Gnedin 1997)

26/06/2015Tom Theuns: IGM ionisation and enrichment Numerical simulations: c) photo-ionisation shocked gas unshocked, photo-ionised gas

26/06/2015Tom Theuns: IGM ionisation and enrichment Numerical simulations: d) simulation codes

26/06/2015Tom Theuns: IGM ionisation and enrichment Numerical simulations: d) simulation codes

26/06/2015Tom Theuns: IGM ionisation and enrichment Results: successes Simulated and observed P(N H ) look very similar. (Theuns et al ’98, Muecket et al, Dave et al, Cen et al)

26/06/2015Tom Theuns: IGM ionisation and enrichment Results: successes Redshift evolution as function of column density (Theuns et al ’98, Dave et al ’99)

26/06/2015Tom Theuns: IGM ionisation and enrichment Results: successes Line-width (b) and temperature are related Column-density (NH) and density are related Hence can determine  -T relation Schaye et al, Ricotti et al, McDonald et al

26/06/2015Tom Theuns: IGM ionisation and enrichment Results: successes T(z) as expected, but only if reionisation happenend late? Other heating mechanisms?

26/06/2015Tom Theuns: IGM ionisation and enrichment Results: successes Effect of T increase on optical depth evolution

26/06/2015Tom Theuns: IGM ionisation and enrichment Results: successes A wavelet analysis finds no evidence for T fluctuations, but does confirm evidence for T change at z=3.4: He+ reionisation? Theuns et al 2001

26/06/2015Tom Theuns: IGM ionisation and enrichment Results: successes Simulations look very realistic: use them to estimate contamination in interpreting metal optical depths, and to compute other sources of bias. Schaye et al, Aguirre et al.

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26/06/2015Tom Theuns: IGM ionisation and enrichment Results: problems Evolution of the optical depth: high vs low resolution. Bernardi et al ‘02

26/06/2015Tom Theuns: IGM ionisation and enrichment Results: problems Power-spectrum may be strongly affected by few strong lines Viel et al 2004

26/06/2015Tom Theuns: IGM ionisation and enrichment Results: problems How much feedback will destroy the Ly  forest? Theuns et al ‘02

26/06/2015Tom Theuns: IGM ionisation and enrichment The future Better control of numerical limitations (box size, resolution) Properly include rapid evolution of optical depth. Observations: high vs low resolution? Which statistics to use? Metal pollution: where, when, how UV-background in space and time.