Planck’s constraints on the missing baryons (PIP-105) Carlos Hernández-Monteagudo Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Teruel, Spain On behalf of the Planck collaboration

Outline  The kinetic Sunyaev-Zel’dovich effect (kSZ)  The central galaxy catalogue (CGC)  Measuring the kSZ pairwise momentum  Correlating with a reconstruction of the peculiar velocity field  Constraints on the missing baryons 2Hernández-Monteagudo, "Planck's Constraints on the missing baryons"

The kinetic Sunyaev-Zel’dovich effect Hernández-Monteagudo, "Planck's Constraints on the missing baryons"3 The kSZ effect expresses the Doppler kick experienced by CMB photons when scattering off rapidly moving electrons The kSZ temperature anisotropies is independent of frequency (just like primary CMB anisotropies) When looking at the direction of hot gas clouds, it is likely to be contaminated by the (dominant) thermal Sunyaev-Zel’dovich (tSZ) effect, which flips from negative to positive at the cross-over frequency of 217 GHz. To avoid the tSZ and other contamination, we use different channels and foreground-cleaned maps, like SEVEM, SMICA and NILC.

The Central Galaxy Catalogue (CGC) Hernández-Monteagudo, "Planck's Constraints on the missing baryons"4 Based upon SDSS DR7 NYUAV galaxy catalogue after isolating brightest galaxies in 1 Mpc (transversal direction) and 1000 km/s (LOS) It consists of galaxies placed at z~0.12, of which ~83% should be true central galaxies. When placing them in a grid, we retain only the 150,000 most nearby ones Fraction of brightest galaxies that are actually central galaxies in the Millenium simulation (Guo et al. 2011, Planck PIP-XI)

Measuring the kSZ pairwise momentum Hernández-Monteagudo, "Planck's Constraints on the missing baryons"5 The peculliar kSZ parwise momentum (pkSZ) is built upon quantities evaluated along the line of sight, It expresses the gravitational infall/collapse of structure The estimates of the kSZ temperature anisotropies are obtained after applying aperture photometry (AP, T AP ) on the CGs, with varying aperture We subtract the average T AP within a thin redshift shell of width σ z ~0.01 (as in Hand et al. 2012, although results do not depend critically on this choice)

Measuring the kSZ pairwise momentum Hernández-Monteagudo, "Planck's Constraints on the missing baryons"6 We found a colour-free decrement that becomes more significant (up to 4 σ) for the cleaned SEVEM map and for apertures of 8 – 12 arcmin. For 8 arcmin, a fit to the output of numerical simulations yields S/N ~ 4.5

Error computation Hernández-Monteagudo, "Planck's Constraints on the missing baryons"7 … [1] [2] … N cg AP est.# [0] [1] [2] [3] … [50] We rotate/displace the entire CGC over the CMB maps with no known sources

Measuring the kSZ pairwise momentum Hernández-Monteagudo, "Planck's Constraints on the missing baryons"8  The behaviour of the kSZ signal wrt aperture is different to what is found in simulated clusters: this constitutes evidence for signal outside halos.  The impact of tSZ seems to be negligible Hand et al Simulated clusters of Dolag & Sunyaev. 2013

Inverting galaxy density into velocity Hernández-Monteagudo, "Planck's Constraints on the missing baryons"9 Three approaches: LINEAR, LOG-LINEAR, LOG- 2LPT Impact of mask: LINEAR method most promising after all We invert the linear continuity equation to estimate the peculiar velocity field from the CG density field Correlation coefficient Without mask With mask Logarithmic linearisation

Inverting galaxy density into velocity Hernández-Monteagudo, "Planck's Constraints on the missing baryons"10 Linear reconstruction performs best, S/N ~ 4.6 We normalise recovered velocities to unit RMS Adopting the velocity amplitude form the numerical sims, we can infer a value of τ T (Thomson optical depth) : correlation between kSZ temperature anisotropies and recovered velocities (with RMS=1)

Consistency tests Hernández-Monteagudo, "Planck's Constraints on the missing baryons"11 We compute correlation after shuffling the recovered velocities among the CGs: the correlation is only recovered for the correct configuration The coupling of intrinsic CMB large modes with large spatial modes of the recovered velocities constitutes the largest contribution to the variance: the low-k modes of the recovered velocities are suppressed after shuffling these

Consistency tests Hernández-Monteagudo, "Planck's Constraints on the missing baryons"12 As for the peculiar kSZ pairwise momentum, we find more kSZ signal at apertures close to 8 arcmin (~0.8 Mpc at z~0.12) than at 5 arcmin, and it extends up to ~12 arcmin. The typical CG virial radius is below 200 Kpc: gas outside halos? χ2χ2 Aperture [arcmin]

Measuring the amoung of gas Hernández-Monteagudo, "Planck's Constraints on the missing baryons"13 From the correlation, from the LINEAR approach, we obtain τ T = x From the kSZ pairwise momentum, we obtain τ T = 2.5 +/- 0.6 x For a typical CG halo we expect τ T = 4 x 10 -5

Implications for the missing baryons Hernández-Monteagudo, "Planck's Constraints on the missing baryons"14 τ T = σ T n e Δ g L eff The Thomson optical depth (τ T ) is proportional/degenerate to the product of density and length L eff = 0.8 Mpc L eff = 38 Mpc L eff = 105 Mpc τ T = x 10 -4

Implications for the missing baryons Hernández-Monteagudo, "Planck's Constraints on the missing baryons"15 In this plot, solid lines provide the Δ g (gas overdensity in volumes around CGs) required to reach cosmic density limit in all structures below d obs,max τ T = σ T n e Δ g L eff L eff = 2x0.8 Mpc (spheres) L eff = 38 Mpc (cylinders) L eff = 105 Mpc (cylinders) τ T = x 10 -4

Implications for the missing baryons Hernández-Monteagudo, "Planck's Constraints on the missing baryons"16 In this plot, solid lines provide the Δ g (gas overdensity in volumes around CGs) required to reach cosmic density limit in all structures below d obs,max τ T = σ T n e Δ g L eff L eff = 2x0.8 Mpc (spheres) L eff = 38 Mpc (cylinders) L eff = 105 Mpc (cylinders) τ T = x Cylinders centred upon CGs within d=300 Mpc/h occupy a volume fraction f vol = π r p 2 L eff and contain a fraction of the cosmic baryon budget f b : ≠ f(L eff )

Implications for the missing baryons Hernández-Monteagudo, "Planck's Constraints on the missing baryons"17 L eff = 2x0.8 Mpc (spheres) L eff = 38 Mpc (cylinders) L eff = 105 Mpc (cylinders) τ T = x According to Planck, cylinders centred upon CGs up to a distance d=300 Mpc/h contain a fraction of % of all baryons. That is, Planck’s observations are compatible to having detected all missing baryons at z~ 0.12

Conclusions Hernández-Monteagudo, "Planck's Constraints on the missing baryons"18 Planck has measured a pairwise momentum in the direction of central galaxies (CGs) at z=0.12 that is independent of frequency and shows a form very close to expectations from numerical simulations and previous measurements of Hand et al The signficance level for frequency maps lies at the level of 3σ, increasing to > 4σ for foreground-cleaned maps. The value of the Thomson optical depth from this pairwise momentum is τ T = 2.5 +/- 0.6 x After inverting the CG density field into an estimate of the peculiar velocity field, and cross-correlating it to Planck kSZ temperature estimates, we find evidence for bulk flows extending up to ~ 100 Mpc/h with S/N> 4.5. The inferred value for the Thomson optical depth is τ T = x In both cases, we find evidence for kSZ signal arising outside halos. Accounting for the CG number density, we find that structures contributing to the kSZ around all CGs up to 300 Mpc/h contain % of all baryons.

The scientific results that we present today are a product of the Planck Collaboration, including individuals from more than 100 scientific institutes in Europe, the USA and Canada Planck is a project of the European Space Agency, with instruments provided by two scientific Consortia funded by ESA member states (in particular the lead countries: France and Italy) with contributions from NASA (USA), and telescope reflectors provided in a collaboration between ESA and a scientific Consortium led and funded by Denmark. Hernández-Monteagudo, "Planck's Constraints on the missing baryons"19