Simulating Cosmic Reionization and the 21cm Background from the Epoch of Reionization

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1 Simulating Cosmic Reionization and the 21cm Background from the Epoch of Reionization Paul Shapiro The University of Texas at Austin Collaborators in the work described today include: Ilian Iliev 2, Garrelt Mellema 3, Kyungjin Ahn 4, Yi Mao 1, Jun Koda 1,5, Ue-Li Pen 6, Martina Friedrich 3, Kanan Datta 3, Hyunbae Park 1, Eiichiro Komatsu 1, Elizabeth Fernandez 7, Anson D Aloisio 1, Hannes Jensen 3 (1)U Texas at Austin (2)U Sussex, UK (3)U Stockholm, Sweden (4)Chosun U, Korea (5)U Swineburne, Australia (6)CITA/U Toronto, Canada (7)U Paris-Sud Innovative Techniques in 21cm Analysis, CCAPP,OSU April 18, 2013

2 N-body + Radiative Transfer Reionization simulation N-body simulation yields the density field and sources of ionizing radiation - New: 2 nd generation N-body code CUBEP 3 M, a P 3 M code, massively paralleled (MPI+Open MP), = 29 billion particles, 6,144 3 cells, particle mass = 5 x 10 6 M solar (163 Mpc box), = 165 billion particles, 10,976 3 cells, particle mass = 5 x 10 3 M solar (30 Mpc box), + particle mass = 5 x 10 7 M solar (607 Mpc box), - Halo finder on-the-fly yields location, mass, other properties of all galaxies, M 10 5 M solar (30 Mpc box), 10 8 M solar (163 Mpc box), 10 9 M solar (607 Mpc box)

3 Structure formation in ΛCDM simulation volume = (163 cmpc) 3 ; (29 billion) particles on cells resolves all atomic-cooling halos : M 10 8 M solar Projection of cloud-in-cell densities of 1/h Mpc thick slice Blue = IGM density; Yellow = halos Z = cmpc (full box) Iliev, Mellema, Shapiro, Pen, Mao, Koda & Ahn (2012) MNRAS, 423, 2222 (arxiv )

4 Structure formation in ΛCDM simulation volume = (163 cmpc) 3 ; (29 billion) particles on cells resolves all atomic-cooling halos : M 10 8 M solar Projection of cloud-in-cell densities of 1/h Mpc thick slice Blue = IGM density; Yellow = halos Z = cmpc (full box) Iliev, Mellema, Shapiro, Pen, Mao, Koda & Ahn (2012) MNRAS, 423, 2222 (arxiv )

Structure formation in ΛCDM simulation volume = (163 cmpc) 3 ; 3072 3 (29 billion) particles on 6144 3 cells resolves all atomic-cooling halos : M 10 8 M solar Projection of cloud-in-cell

5 Structure formation in ΛCDM simulation volume = (163 cmpc) 3 ; (29 billion) particles on cells resolves all atomic-cooling halos : M 10 8 M solar Projection of cloud-in-cell densities of 1/h Mpc thick slice Blue = IGM density; Yellow = halos Z = cmpc (full box) (Zoom-in) 26 cmpc Iliev, Mellema, Shapiro, Pen, Mao, Koda & Ahn (2012) MNRAS, 423, 2222 (arxiv )

6 The Largest Formation N-body of Simulation Early Cosmic that Structures: Resolves Minihalos The Very : Small (30 cmpc) Scales 3 (in prep.) CUBEP 3 M = 165 billion particles 10, cells Z = 8 Resolves all halos with M 10 5 M sun First halos form at z = 43 More than 10 8 halos by z = 8 Length resolution = 182 pc 30 cmpc IGM density = green halos = yellow

Largest Volume N-body Simulation for Reionization : (607 cmpc) 3 CUBEP 3 M 5488 3 = 165 billion particles 10, 976 3 cells Z = 6 Resolves all halos with M 10 9 M sun First

7 Largest Volume N-body Simulation for Reionization : (607 cmpc) 3 CUBEP 3 M = 165 billion particles 10, cells Z = 6 Resolves all halos with M 10 9 M sun First halos form at z = 26 4 x 10 7 halos by z = 8 ~ 2 x 10 8 halos by z = 2.5 IGM density = violet halos = blue 607 cmpc Box size ~ volume of the LOFAR EOR 21cm background survey

8 N-body + Radiative Transfer Reionization simulation Radiative transfer simulations evolve the radiation field and nonequilibrium ionization state of the gas - New, fast, efficient C 2 -Ray code (Conservative, Causal Ray-Tracing) (Mellema, Iliev, Alvarez, & Shapiro 2006, New Astronomy, 11, 374) uses shortcharacteristics to propagate radiation throughout the evolving gas density field provided by the N-body results, on coarser grid of ~ (256) 3 to (512) 3 cells, for different resolution runs, from each and every galaxy halo source in the box. e.g. N halo ~ 4 x 10 5 by z ~ 8 (WMAP1) ( > 2 x 10 9 M sun ) ~ 3 x 10 5 by z ~ 6 (WMAP3) ( > 2 x 10 9 M sun ) ~ 10 7 by z ~ 8 (WMAP5) ( > 10 8 M sun ) for simulation volumes ~ (100 h -1 Mpc) 3

9 Every galaxy in the simulation volume emits ionizing radiation We assume a constant mass-to-light ratio for simplicity: f γ = # ionizing photons released by each galaxy per halo baryon f γ = f f esc N i, where f = star-forming fraction of halo baryons, f esc = ionizing photon escape fraction, N i = # ionizing photons emitted per stellar baryon over stellar lifetime e.g. N i = 50,000 (top-heavy IMF), f = 0.2, f esc = 0.2 f γ = 2000 or N i = 4,000 (Salpeter IMF), f = 0.1, f esc = 0.1 f γ = 40 This yields source luminosity: dn γ /dt = f γ M bary /(µm H t ), t = source lifetime (e.g. 2 x 10 7 yrs), M bary = halo baryonic mass = M halo (Ω bary / Ω m ) halo star formation rate: SFR = (f γ / t )(M bary / f esc N i )

10 Every galaxy in the simulation volume emits ionizing radiation We assume a constant mass-to-light ratio for simplicity: f γ = # ionizing photons released by each galaxy per halo baryon f γ = f f esc N i, where f = star-forming fraction of halo baryons, f esc = ionizing photon escape fraction, N i = # ionizing photons emitted per stellar baryon over stellar lifetime e.g. N i = 50,000 (top-heavy IMF), f = 0.2, f esc = 0.2 f γ = 2000 or N i = 4,000 (Salpeter IMF), f = 0.1, f esc = 0.1 f γ = 40 halo star formation rate: SFR = (f γ / t )(M bary / f esc N i ) SFR 1.7 (f γ /40) (0.1/f esc ) (4000/N i ) (10 Myr/ t ) (M halo /10 9 M solar ) M solar / yr e.g. f γ = 40, f esc = 0.1, f = 0.1, t = 2 x 10 7 yrs SFR (0.8 M solar /yr) (M halo /10 9 M solar )

Self-Regulated Reionization Iliev, Mellema, Shapiro, & Pen (2007), MNRAS, 376, 534; (astro-ph/0607517) Jeans-mass filtering low-mass source halos (M < 10 9 M solar ) cannot form inside H II regions ;

11 Self-Regulated Reionization Iliev, Mellema, Shapiro, & Pen (2007), MNRAS, 376, 534; (astro-ph/ ) Jeans-mass filtering low-mass source halos (M < 10 9 M solar ) cannot form inside H II regions ; 35/h Mpc box, radiative transfer simulation, WMAP3, f γ = 250; resolved all halos with M > 10 8 M solar (i.e. all atomically-cooling halos), (blue dots = source cells); Evolution: z=21 to z ov = 7.5.

Self-Regulated Reionization with Minihalo Sources and their Suppression by the H 2

in the LW bands of H 2 to grow When J -21 > J threshold in some region, minihalos there are

either form without baryons or evaporate them all away Mean Intensity J LW 163 Mpc box 163

12 Self-Regulated Reionization with Minihalo Sources and their Suppression by the H 2 -Dissociating UV Background Ahn, Iliev, Shapiro, Mellema, Koda, and Mao 2012, ApJL, 756, L16; arxiv: Minihalos born in neutral IGM make Pop III stars their starlight causes a UV background in the LW bands of H 2 to grow When J -21 > J threshold in some region, minihalos there are sterilized no stars form in them minihalos inside H II regions also do not form stars; they either form without baryons or evaporate them all away Mean Intensity J LW 163 Mpc box 163 Mpc box with minihalos J -21 threshold level for suppressing H 2 inside MHs mean intensity of LW background contributed by sources of reionization Lyman Werner ( LW ) Bands ev

<J LW > rises above threshold level for suppressing H 2 inside minihalos long before reionization ends, as suggested by Haiman, Abel and Rees (2000) The Inhomogeneous Background of H 2 Dissociating

13 <J LW > rises above threshold level for suppressing H 2 inside minihalos long before reionization ends, as suggested by Haiman, Abel and Rees (2000) The Inhomogeneous Background of H 2 Dissociating Radiation During Cosmic Reionization Ahn, Shapiro, Iliev, Mellema, and Pen (2009) ApJ, 695, 1430 Lyman Werner ( LW ) Bands ev Used our reionization N-body + RT simulation to locate all the galactic halo sources of LW background at each epoch, for atomic-cooling halos above 10 8 M solar Cosmological RT of LW photons: every point in space sees LW background by summing over all the sources within its past light-cone, filtered by IGM H Lyman series opacity

14 Number of Minihalos Per Unit Volume Varies in Space and Time Along with the Underlying Total Matter Density need to know the minihalo bias relative to the total matter density NEW : Add the Minihalo sources and keep track of their suppression, too. But 163 Mpc box is too big to resolve individual minihalos Use smaller box sim that resolves minihalos, to assign the subgrid minihalo abundance that varies in time and space, correlated with local variation of the matter density!

15 Self-Regulated Reionization with Minihalo Sources and their Suppression by the H 2 -Dissociating UV Background Ahn, Iliev, Shapiro, Mellema, Koda, and Mao 2012, ApJL, 756, L16; arxiv: Minihalos born in neutral IGM make Pop III stars their starlight causes a UV background in the LW bands of H 2 to grow When J -21 > J threshold in some region, minihalos there are sterilized no stars form in them minihalos inside H II regions also do not form stars; they either form without baryons or evaporate them all away Mean Intensity J LW 163 Mpc box 163 Mpc box with minihalos J -21 threshold level for suppressing H 2 inside MHs mean intensity of LW background contributed by sources of reionization Lyman Werner ( LW ) Bands ev

16 Large-scale, self-regulated reionization by atomic-cooling halos Three generations of simulation 163 Mpc 607 Mpc 50 Mpc

17 Time Evolution of the Reionization Simulation Box in 3D white4.wmv

18 Radiative Transfer of Energetic Photons: X-rays and Helium Ionization in C 2 -Ray Friedrich, Mellema, Iliev, and Shapiro (2012) MNRAS, 421, 2232 (arxiv: )

19 Other cosmological radiative transfer simulation methods, too, including: Gnedin (2000); Gnedin & Abel (2001) Rasoumov et al. (2002) Sokasian et al. (2003) Ciardi et al. (2003); Maselli et al. (2003); Maselli et al. (2009) Kohler et al. (2005) Alvarez et al. (2006) McQuinn et al. (2007) Shin et al. (2007) Trac & Cen (2007) Baek et al. (2009) Aubert & Teyssier (2008) Finlator et al. (2009) Petkova and Springel (2008) Semelin et al. (2007) Altay et al. (2008) Pawlik and Schaye (2009) Susa (2006)..And more [e.g. see Cosmological RT Comparison Project below] Also exist approximate semi-analytical or semi-numerical methods, too, including: Furlanetto et al. (2004); Zahn et al. (2007) Thomas et al. (2009) Mesinger and Furlanetto (2007) Geil and Wyithe (2008) Santos et al. (2009)

20 Cosmological Radiative Transfer Codes Comparison Project I. : The Static Density Field Tests Iliev, Ciardi,, Shapiro, (2006) MNRAS, 371, 1057

21 Cosmological Radiative Transfer Comparison Project II. : The Radiation- HydrodynamicTests Iliev, Whalen,, Shapiro, 2009, MNRAS, 400, 1283 (astro-ph/ )

22 Halo mass function now simulated for LCDM over full mass range from IGM Jeans mass before EOR to the largest halos that form during the EOR

23 Q: Are there observable consequences of reionization we can predict which will allow us to determine which of these sources contribute most significantly to reionization?

24 Q: Are there observable consequences of reionization we can predict which will allow us to determine which of these sources contribute most significantly to reionization? A : Radiation backgrounds from the EoR, including: 1. 21cm 2. Near-IR 3. CMB (polarization & kinetic Sunyaev-Zel dovich)

25 Q: Are there observable consequences of reionization we can predict which will allow us to determine which of these sources contribute most significantly to reionization? A : Radiation backgrounds from the EoR, including: 1. 21cm FOCUS OF THIS TALK 2. Near-IR 3. CMB (polarization & kinetic Sunyaev-Zel dovich)

26 Low Frequency Array (LOFAR) Murchison Widefield Array (MWA) Precision Array To Probe Epoch of Reionization (PAPER) Giant Meterwave Radio Telescope (GMRT) Square Kilometer Array (SKA)

The 21-cm Background from the Cosmic Dark Ages: Minihalos and the Intergalactic Medium Before Reionization : Collisionally Pumped Spin Temperature Iliev, Shapiro, Ferrara &

27 The 21-cm Background from the Cosmic Dark Ages: Minihalos and the Intergalactic Medium Before Reionization : Collisionally Pumped Spin Temperature Iliev, Shapiro, Ferrara & Martel 2002, ApJL, 572, L123 Iliev, Scannapieco, Shapiro, & Martel 2003, MNRAS, 341, 81 Shapiro, Ahn, Alvarez, Iliev, Martel & Ryu (2006), ApJ, 646, 681; (astro-ph/ )

28 The Redshifted 21cm Signal From the EoR The measured radio signal is the differential brightness temperature δt b =T b -T CMB : (for WMAP7 cosmological parameters). Depends on: x HI : neutral fraction δ: overdensity T s : spin temperature ν time θ y For T s»t CMB, the dependence on T s drops out The signal is a spectral line: carries spatial, temporal, and velocity information. and z θ x The image cube: images stacked in frequency space

29 Simulated 21cm brightness temperature tomographic map Unfiltered (log 10 scale) Today z=0 z Past Unfiltered (linear scale) LOFAR-Gaussian-beam filtered vs obs. freq. Iliev, Mellema, Shapiro, Pen, Mao, Koda & Ahn 2012, MNRAS, 423, 2222; arxiv:

Here illustrated evolving redshifted 21cm signal: High density neutral regions are yellow

30 Sky Maps of 21cm Background Brightness Temperature Fluctuations During Epoch of Reionization : Travel through Time Reionization has a complex geometry of growing and overlapping HII regions. Here illustrated evolving redshifted 21cm signal: High density neutral regions are yellow Ionized regions are blue/black. LOFAR-like beam: 3 resolution & average signal is zero. 607 cmpc box

31 The GMRT EoR Experiment: A new upper limit on the neutral hydrogen power spectrum at z ~ 8.6 (Paciga et al. 2011, MNRAS, 413, 1174;arXiv: ) 50 hours of data upper limit δt b,rms < 70 mk for 21cm signal at z = 8.6 Consistent with predictions for epoch of reionization, i.e. neutral patches of IGM at z = 8.6 heated so T spin >> T CMB 3D Power Spectrum of 21cm δt b cold IGM theoretical predictions of illustrative reionization simulation (Iliev, Mellema, Pen, Bond, & Shapiro 2008, MNRAS, 384, 863)

32 A refined foreground-corrected limit on the H I power spectrum at z = 8.6 from the GMRT EoR Experiment New 2σ upper limit (248mK ) 2 for k = 0.5 h Mpc -1 simulation prediction (Iliev, Mellema, Pen, Bond, & Shapiro 2008, MNRAS, 384, 863)

33 21-cm fluctuations: rms and skewness Frequency Redshift

34 Notation Our simulation cases are labelled as follows: Suppression of type 2 sources 163Mpc_g8.7_130S_256 Density fields and halo sources from 163 Mpc cubep3m simulation Efficiency of type 3 (high mass) sources Efficiency of type 2 (low mass) sources RT mesh = where efficiency g γ is related to f γ according to : g γ = f γ (10 Myr/ t )

35 Density Fluctuations: Matter Power Spectrum

36 21-cm power spectra: early

37 21-cm power spectra: middle

38 21-cm power spectra: late

The Prospects of Observing a Quasar H II Region during the Epoch of Reionization with Redshifted 21cm Datta, Friedrich, Mellema, Iliev, and Shapiro (2012) MNRAS, 424, 762 (arxiv:1203.

39 The Prospects of Observing a Quasar H II Region during the Epoch of Reionization with Redshifted 21cm Datta, Friedrich, Mellema, Iliev, and Shapiro (2012) MNRAS, 424, 762 (arxiv: ) 21cm brightness temperature Region A Region B Region A = Quasar H II region Region B = non-quasar H II region Circles show the radii found by the 21cm survey matched-filter technique

Can 21-cm Observations Discriminate Between High-Mass and Low-Mass Galaxies as Reionization Sources? Iliev, Mellema, Shapiro, Pen, Mao, Koda, & Ahn 2012, MNRAS, 423, 2222 (arxiv: 1107.

40 Can 21-cm Observations Discriminate Between High-Mass and Low-Mass Galaxies as Reionization Sources? Iliev, Mellema, Shapiro, Pen, Mao, Koda, & Ahn 2012, MNRAS, 423, 2222 (arxiv: ) 163 Mpc boxes at the 50% ionized epoch High efficiency = early reionization Low efficiency = late reionization High efficiency = early reionization HMACHs + LMACHs Low-Mass Atomic Cooling Halos, or LMACHs 10 8 < M < 10 9 Msolar (suppressed inside H II regions by photoheating) HMACHs only High-Mass Atomic Cooling Halos, or HMACHs M > 10 9 Msolar

Effects of the First Stars and Minihalos on Reionization Ahn, Iliev, Shapiro, Mellema, Koda, and Mao 2012, ApJL, 756, L16 ; arxiv:1206.

41 Effects of the First Stars and Minihalos on Reionization Ahn, Iliev, Shapiro, Mellema, Koda, and Mao 2012, ApJL, 756, L16 ; arxiv: Minihalos + LMACHs + HMACHs LMACHs + HMACHs 163 Mpc box, with and without minihalo sources Minihalos suppressed in H II regions and when LW intensity exceeds J LW,th Z = 15 Z = 10 Z = 8 Z = 7 Ionized Fraction Field of IGM Lyman-Werner Background Intensity Field at z = 32, 16, 12, 11 (with minihalos) Global ionization history Electron Scattering Optical depth Mean Lyman- Werner Intensity

42 Q: Can 21cm Fluctuations Tell Us Which Galaxies Reionized the Universe? 3 mass ranges of reionization source halos (in solar mass units) possible: M >10 9 High- Mass Atomic-Cooling Halos ( HMACHs ) 10 8 <M < 10 9 Low-Mass Atomic- Cooling Halos ( LMACHs ) M < 10 8 Minihalos ( MHs ) H 2 molecules cool gas to form stars A: Yes, distinguishes HMACH - only from HMACHs+ LMACHs or HMACHs + LMACHs+ MHs BUT, cannot distinguish HMACHs+ LMACHs (no MHs) from HMACHs + LMACHs+ MHs MWA Forecast Error Bars HMACHs + LMACHs no MHs HMACHs ONLY HMACHs + LMACHs + MHs

43 Q: Can CMB Polarization Fluctuations Tell Us Which Galaxies Reionized the Universe? 3 mass ranges of reionization source halos (in solar mass units) possible: M >10 9 High- Mass Atomic-Cooling Halos ( HMACHs ) 10 8 <M < 10 9 Low-Mass Atomic- Cooling Halos ( LMACHs ) M < 10 8 Minihalos ( MHs ) H 2 molecules cool gas to form stars (a) Global Ionization Histories for Three Cases HMACHs ONLY HMACHs + LMACHs + MHs HMACHs + LMACHs no MHs WMAP7: τ es = (1-sigma) WMAP7 1-sigma range (b) Electron Scattering Optical Depths for Three Cases, compared with value from CMB polarization fluctuations

44 Q: Can CMB Polarization Fluctuations Tell Us Which Galaxies Reionized the Universe? HMACHs + LMACHs + MHs HMACHs + LMACHs no MHs HMACHs ONLY (fiducial) HMACHs ONLY A: Yes, distinguishes HMACH - only from HMACHs+ LMACHs or HMACHs + LMACHs+ MHs BUT, can hardly distinguish HMACHs+ LMACHs (no MHs) from HMACHs + LMACHs+ MHs

45 Q: Can CMB Polarization Fluctuations Tell Us Which Galaxies Reionized the Universe? A: UNLESS, reionization ended as late as z < 7 HMACHs+ LMACHs (no MHs) makes τ es too small to explain WMAP polarization, but HMACHs + LMACHs+ MHs ok signature of MHs! HMACHs + LMACHs (early reionization) no MHs HMACHs + LMACHs + MHs HMACHs + LMACHs no MHs (late reionization) HMACHs + LMACHs no MHs (late reionization)

47 HMACHs + LMACHs + MHs HMACHs + LMACHs (early reionization) no MHs Conclusion: With minihalo sources, reionization began much earlier and was greatly extended, which boosts the intergalactic electronscattering optical depth and large-angle polarization fluctuations of the CMB significantly. HMACHs + LMACHs HMACHs + LMACHs no MHs (late reionization) (fiducial) no MHs (late reionization) Although within current WMAP uncertainties, this boost should be readily detectable by Planck. If reionization ended as late as z ~ 7, as suggested by other observations, Planck will thereby see the signature of the first stars at high redshift, currently undetectable by any other probe.

48 Redshift Space Distortion of the 21cm Background from the Epoch of Reionization I: Methodology Re-examined Mao, Shapiro, Mellema, Iliev, Koda, Ahn 2012, MNRAS, 422, 926; (arxiv ) s = apparent comoving position of object, moving with peculiar velocity v along the LOS, at real-space distance r when light was emitted at cosmological redshift z cos, if z obs misinterpreted as z cos z obs = observed redshift, combining cosmological and peculiar velocity Doppler shifts,

49 Redshift Space Distortion of the 21cm Background from the Epoch of Reionization I: Methodology Re-examined Mao, Shapiro, Mellema, Iliev, Koda, Ahn 2012, MNRAS, 422, 926; (arxiv ) 3D 21cm Power Spectrum Without peculiar velocity, P(k) is isotropic 3D P(k) same as angle-averaged P(k) : Peculiar velocity Redshift Space Distortion ( RSD ) Anisotropic Power Spectrum

50 Redshift Space Distortion of the 21cm Background from the Epoch of Reionization I: Methodology Re-examined Mao, Shapiro, Mellema, Iliev, Koda, Ahn 2012, MNRAS, 422, 926; (arxiv ) Peculiar velocity neglected Quasi-linear approx. Fully nonlinear results 3D power spectra of 21cm brightness temperature fluctuations. The panels show a slice through the kx-ky plane, with the LOS along the x-axis, calculated from our numerical simulation at the 50% ionized epoch Measurement of this anisotropy by future 21cm surveys is a promising tool for separating cosmology from 21cm astrophysics: P(k,µ k ) where µ k k / k If linear fluctuations in density, velocity, and ionized fraction, can expand P(k,µ k ) as 4 th order polynomial in µ k (Barkana and Loeb 2005) BUT ionized fraction fluctuations not linear so we derived quasi-linear approximation which accounts for nonlinear ionization fluctuations, too :

Redshift Space Distortion of the 21cm Background from the Epoch of Reionization I: Methodology Re-examined Mao, Shapiro, Mellema, Iliev, Koda, Ahn 2012, MNRAS, 422, 926; (arxiv1104.

The panels show a slice through the kx-ky plane, with the LOS along the x-axis, calculated from our numerical simulation at the 50% ionized epoch Measurement of this anisotropy by future 21cm surveys

51 Redshift Space Distortion of the 21cm Background from the Epoch of Reionization I: Methodology Re-examined Mao, Shapiro, Mellema, Iliev, Koda, Ahn 2012, MNRAS, 422, 926; (arxiv ) Peculiar velocity neglected Quasi-linear approx. Fully nonlinear results 3D power spectra of 21cm brightness temperature fluctuations. The panels show a slice through the kx-ky plane, with the LOS along the x-axis, calculated from our numerical simulation at the 50% ionized epoch Measurement of this anisotropy by future 21cm surveys is a promising tool for separating cosmology from 21cm astrophysics: P(k,µ k ) where µ k k / k quasi-linear approximation δ ϱ, δ v linear, but δ x nonlinear Cross-correlation term mixes cosmology with astrophysics of ionization + T spin Matter density autocorrelation cosmology alone! where

Q: Will nonlinear peculiar velocity and inhomogeneous reionization spoil 21cm Cosmology from the EoR? Shapiro, Mao, Iliev, Mellema, Datta, Ahn, Koda 2013 PRL, in press; arxiv:1211.

52 Q: Will nonlinear peculiar velocity and inhomogeneous reionization spoil 21cm Cosmology from the EoR? Shapiro, Mao, Iliev, Mellema, Datta, Ahn, Koda 2013 PRL, in press; arxiv: Curve: matter overdensity power spectrum Dots: best-fit 4 th -moment of 3D 21cm power spectrum Error-bars: sample variance of (607 Mpc) 3 sim volume Black dots: artificially homogeneous reionization (nonlinear velocity caused distortion) Red dots: actual ionization fluctuations (nonlinear velocity+ ionization patchiness caused distortion)

53 Q: Will nonlinear peculiar velocity and inhomogeneous reionization spoil 21cm Cosmology from the EoR? Shapiro, Mao, Iliev, Mellema, Datta, Ahn, Koda 2013 PRL, in press; arxiv: Curve: matter overdensity power spectrum Dots: best-fit 4 th -moment of 3D 21cm power spectrum Error-bars: sample variance of (607 Mpc) 3 sim volume 20% Black dots: artificially homogeneous reionization (nonlinear velocity caused distortion) Red dots: actual ionization fluctuations (nonlinear velocity+ ionization patchiness caused distortion)

54 Q: Will nonlinear peculiar velocity and inhomogeneous reionization spoil 21cm Cosmology from the EoR? Shapiro, Mao, Iliev, Mellema, Datta, Ahn, Koda 2013 PRL, in press; arxiv: Curve: matter overdensity power spectrum Dots: best-fit 4 th -moment of 3D 21cm power spectrum Error-bars: sample variance of (607 Mpc) 3 sim volume 30% Black dots: artificially homogeneous reionization (nonlinear velocity caused distortion) Red dots: actual ionization fluctuations (nonlinear velocity+ ionization patchiness caused distortion)

2036 Curve: matter overdensity power spectrum Dots: best-fit 4 th -moment of 3D 21cm power spectrum Error-bars: sample variance of

55 Q: Will nonlinear peculiar velocity and inhomogeneous reionization spoil 21cm Cosmology from the EoR? Shapiro, Mao, Iliev, Mellema, Datta, Ahn, Koda 2013 PRL, in press; arxiv: Curve: matter overdensity power spectrum Dots: best-fit 4 th -moment of 3D 21cm power spectrum Error-bars: sample variance of (607 Mpc) 3 sim volume 60% Black dots: artificially homogeneous reionization (nonlinear velocity caused distortion) Red dots: actual ionization fluctuations (nonlinear velocity+ ionization patchiness caused distortion)

56 Q: Will nonlinear peculiar velocity and inhomogeneous reionization spoil 21cm Cosmology from the EoR? Shapiro, Mao, Iliev, Mellema, Datta, Ahn, Koda 2013 PRL, in press; arxiv: Curve: matter overdensity power spectrum Dots: best-fit 4 th -moment of 3D 21cm power spectrum Error-bars: sample variance of (607 Mpc) 3 sim volume % Black dots: artificially homogeneous reionization (nonlinear velocity caused distortion) Red dots: actual ionization fluctuations (nonlinear velocity+ ionization patchiness caused distortion)

57 Q: Will nonlinear peculiar velocity and inhomogeneous reionization spoil 21cm Cosmology from the EoR? Shapiro, Mao, Iliev, Mellema, Datta, Ahn, Koda 2013 PRL, in press; arxiv:

58 Q: Will nonlinear peculiar velocity and inhomogeneous reionization spoil 21cm Cosmology from the EoR? Shapiro, Mao, Iliev, Mellema, Datta, Ahn, Koda 2013 PRL, in press; arxiv: A: Ionization patchiness and its nonlinear coupling to peculiar velocity can: Spoil the µ 4 decomposition scheme by underestimating the matter power spectrum P δδ (k) by ~ 30% (60%) when the cosmic mean ionized fraction is x i = 0.2 (0.5), respectively, for k = h/mpc, with larger errors at later times during reionization; Cause a systematic error of ~30% in the spherically-averaged 21cm power spectrum predicted by linear theory, and of ~10% by quasi-linear theory, when x i = 0.5, for the wavenumber range k = h/mpc. The scheme works reasonably well early in reionization (~< 40% ionized), but not late (~> 80% ionized)

59 Probing reionization with LOFAR using 21cm redshift space distortions Jensen, Datta, Mellema, Chapman, Abdalla, Iliev, Mao, Santos, Shapiro, Zaroubi, etal 2013, MNRAS, submitted; arxiv:

60 Probing reionization with LOFAR using 21cm redshift space distortions Jensen, Datta, Mellema, Chapman, Abdalla, Iliev, Mao, Santos, Shapiro, Zaroubi, etal 2013, MNRAS, submitted; arxiv: Without peculiar velocity With peculiar velocity

61 Probing reionization with LOFAR using 21cm redshift space distortions Jensen, Datta, Mellema, Chapman, Abdalla, Iliev, Mao, Santos, Shapiro, Zaroubi, etal 2013, MNRAS, submitted; arxiv: Angle-averaged P(k) s of the density fluctuations that contribute to the µ-decomposition of the 21cm δt b 3D P(k,µ) Quasi-linear approximation for the angle-averaged 21cm power spectrum :

Probing reionization with LOFAR using 21cm redshift space distortions Jensen, Datta, Mellema, Chapman, Abdalla, Iliev, Mao, Santos, Shapiro, Zaroubi, etal

62 Probing reionization with LOFAR using 21cm redshift space distortions Jensen, Datta, Mellema, Chapman, Abdalla, Iliev, Mao, Santos, Shapiro, Zaroubi, etal 2013, MNRAS, submitted; arxiv: Evolution of the 3D 21cm Power Spectrum from the 607 Mpc box Reionization Simulation at wavevector k = 0.21 Mpc -1

63 Probing reionization with LOFAR using 21cm redshift space distortions Jensen, Datta, Mellema, Chapman, Abdalla, Iliev, Mao, Santos, Shapiro, Zaroubi, etal 2013, MNRAS, submitted; arxiv: Extracted anisotropy terms (P µ 2 + P µ 4 ) from mock observations by LOFAR including noise, using the 3D 21cm Power Spectrum from the 607 Mpc box Reionization Simulation at z = 9.5 where <x> m = 0.1 Anisotropy can be observed with LOFAR after ~> 1000 hours of observation

64 Probing reionization with LOFAR using 21cm redshift space distortions Jensen, Datta, Mellema, Chapman, Abdalla, Iliev, Mao, Santos, Shapiro, Zaroubi, etal 2013, MNRAS, submitted; arxiv: Extracted anisotropy terms (P µ 2 + P µ 4 ) from mock observation by LOFAR including noise, using the 3D 21cm Power Spectrum from the 607 Mpc box Reionization Simulation for wavevector k = 0.21 Mpc hrs per redshift Anisotropy observed with LOFAR after ~> 1000 hours of observation can distinguish Inside-out from Outside-in reionization

Light-cone effect on the 21cm power spectrum Datta, Mellema, Mao, Iliev, Shapiro, Ahn 2012, MNRAS, 424, 1877; arxiv:1109.

65 Light-cone effect on the 21cm power spectrum Datta, Mellema, Mao, Iliev, Shapiro, Ahn 2012, MNRAS, 424, 1877; arxiv: Observed 21cm signal from the EoR will be anisotropic even without peculiar velocity, since light reaching the earth from more distant points along the LOS was emitted further back in cosmic time, from less evolved universe light-cone distortion

Reionization of the Universe

Reionization of the Universe Paul Shapiro The University of Texas at Austin Collaborators in the new work described today include: Pierre Ocvirk 3, Dominique Aubert 3, Nicolas Gillet 3, Ilian Iliev 2,