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Bologna, 27 Aprile 2006 WMAP – 3-year results Fabio Finelli INAF/OAB & INAF/IASF-BO Lauro Moscardini Dip. Astronomia UniBo.

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Presentazione sul tema: "Bologna, 27 Aprile 2006 WMAP – 3-year results Fabio Finelli INAF/OAB & INAF/IASF-BO Lauro Moscardini Dip. Astronomia UniBo."— Transcript della presentazione:

1 Bologna, 27 Aprile 2006 WMAP – 3-year results Fabio Finelli INAF/OAB & INAF/IASF-BO Lauro Moscardini Dip. Astronomia UniBo

2 Bologna, 27 Aprile WMAP 1st year papers 2. WMAP 3rd papers 3. A. Lewis, astro-ph/ Planck Bluebook, astro-ph/ Wayne Hus webpage: SOURCES

3 Bologna, 27 Aprile 2006 WMAP WMAP: spinning (~0.5 rpm), precessing satellite orbiting L2 dual Gregorian (1.4×1.6m) mirror system passively cooled to <95K radiometers measuring phase and amplitude of incoming waves Proposed in 1995; selected in 1996; launched in june 2001; possibly 8-years mission 13 papers in 2003, 7311 citations up today 4 new papers in march 2006, 160 citations up today

4 Bologna, 27 Aprile 2006 Channels frequencies: 22, 30, 40, 60, 90 GHz (3.3 to 13.6 mm wavelength) resolution: degrees sensitivity: ~35µK per 0.3×0.3 degree pixel

5 Bologna, 27 Aprile 2006 Channels frequencies: 22, 30, 40, 60, 90 GHz (3.3 to 13.6 mm wavelength) resolution: degrees sensitivity: ~35µK per 0.3×0.3 degree pixel

6 Bologna, 27 Aprile 2006 Sky Maps foregrounds: synchrotron, dust, free-free emission

7 Bologna, 27 Aprile 2006 Temperature Map foreground subtraction: spectra differ from the CMB's Planck spectrum comparison of signals from different channels fitting of foreground templates

8 Bologna, 27 Aprile 2006 Power-Spectrum Analysis subtraction of mean temperature; relative temperature fluctuations coefficients a lmexpansion into spherical harmonics; coefficients a lm power spectrum C l = power spectrum C l =, related to the matter power spectrum P(k) principal effects: –Sachs-Wolfe effect –acoustic oscillations –Silk damping

9 Bologna, 27 Aprile 2006 Courtesy by W. Hu

10 Bologna, 27 Aprile 2006

11 Mechanisms for anisotropies density: density: adiabatic process compression increases T, while expansion decreases T gravity: gravity: gravitational red- or blue-shift velocity: velocity: Doppler effect Different contributions must be summed up Primary anisotropies: Primary anisotropies: produced on the last scattering surface Secondary anisotropies: Secondary anisotropies: produced along the trajectory to the observer

12 Bologna, 27 Aprile 2006 On scales larger than the horizon (i.e. large angles, small l) Velocity can be neglected (dipole), microphysics too, gravity wins against density! Temperature fluctuations are directly proportional to Sachs-Wolfe effect the gravitational potential: Sachs-Wolfe effect Notice: overdensity are colder than average! Already observed by COBE in 1991! Good estimates for amplitude and slope of P(k), but problems of cosmic variance

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19 The cosmological parameters (I): the density parameters i Matter: m Dark energy: DE (w P/ c 2 =-1 is the cosmological constant ; w -1 is the quintessence) Baryons: b Curvature: K =1 - i Total: 0 =1- K

20 Bologna, 27 Aprile 2006 The cosmological parameters (II): the spectral parameters Standard inflationary models predict that primordial fluctuations are Gaussian Adiabatic Scale invariant, i.e. with logarithmic slope of the power spectrum n=1: P(k)=A k n The amplitude A is usually expressed in terms of the variance computed on a scale of 8 Mpc/h: 8

21 Bologna, 27 Aprile 2006 The cosmological parameters (III): the other ones Hubble constant H 0The Hubble constant H 0 and its redshift evolution: measures the expansion rate of the universe and enters the distance definitions The optical depthThe optical depth : it is related to the probability that a CMB photon with an electron along the trajectory: dP=n e T c dt=-d If there is re-ionization at a given redshift z re, photons are diffuse there is a suppression of fluctuations on scales smaller than the horizon scale at z re (warning: degeneracy with spectral index n). The higher is z re, the smaller is the angular scale involved by diffusion.

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23 Power Spectra and Cosmological Parameters Varying the baryonic density

24 Bologna, 27 Aprile 2006 Power Spectra and Cosmological Parameters Varying the Hubble constant

25 Bologna, 27 Aprile 2006 Power Spectra and Cosmological Parameters Varying the matter density

26 Bologna, 27 Aprile 2006 Power Spectra and Cosmological Parameters Varying the total density

27 Bologna, 27 Aprile 2006 CMB Polarisation CMB photons have last been Thomson scattered directional dependence of Thomson cross section imprints polarisation polarisation pattern has similar, but shifted power spectrum

28 Bologna, 27 Aprile 2006 Polarisation and Reionisation Universe recombined when CMB formed hydrogen was later reionised ionised hydrogen damps primordial fluctuations creates secondary polarisation constraints on reionisation from temperature- polarisation and polarisation power spectra

29 Bologna, 27 Aprile 2006 Where were we? WMAP 1st year results (Feb.03): TT & TE EE detection by DASI (02), CBI (04), CAPMAP (05), Boomerang (05) 2dF: Percival et al. (02), Cole et al. (05). CMB anisotropies Galaxy surveys SDSS: Tegmark et al. (04), Seljak et al. (05). Ly used heavily in WMAP1, but not in WMAP3: … further study is needed if the new values are consistent with Ly data. See however Viel et al. (06), Seljak et al. (06) for WMAP3 + Ly

30 Bologna, 27 Aprile 2006 Issues after WMAP 1st year Low amplitude for low multipoles of the C l pattern Weird alignment of the l=2,3 of a lm Sticky points out of the CDM fit High value for Evidence of running of the spectral index ?

31 Bologna, 27 Aprile 2006 Will these waves in 1st year data persist?

32 Bologna, 27 Aprile 2006 Temperature WMAP3 plus small scale CMB data The spectrum is cosmic variance limited to l=400 (354 1 st year)and S/N>1 up to l=850 (658 1st year)

33 Bologna, 27 Aprile 2006 Red: WMAP1 Black: WMAP3 Points: ratio of WMAP3 over WMAP1 value Red line: ratio of window function WMAP1 over WMAP3 Red: WMAP1 with 06 analysis and 06 windows function Black: WMAP3

34 Bologna, 27 Aprile 2006 WMAP1 WMAP3 Anomaly on the octupole alleviated; quadrupole remains low TE in better agreement with CDM; is almost half of 1st yr value Some (but not all) of the sticky points remain

35 Bologna, 27 Aprile 2006 Lines: Red: WMAP1 Orange: WMAP1 + CBI +ACBAR Black: WMAP3 Points: Grey: WMAP1 Black: WMAP3

36 Bologna, 27 Aprile 2006 courtesy from Spergel et al., 2006 CDM plus constraints

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38 courtesy from Hinshaw et al., 2006 CDM plus is a good fit to WMAP

39 Bologna, 27 Aprile 2006 Polarization only useful for measuring tau for near future Polarization probably best way to detect tensors CMB Polarization

40 Bologna, 27 Aprile 2006 Cosmological Parameters: Main WMAP3 parameter results rely on polarization courtesy from A. Lewis, 2006

41 Bologna, 27 Aprile 2006 WMAP3 TT with tau = 0.10 ± 0.03 prior (equiv to WMAP EE) Black: TT+prior Red: full WMAP courtesy from A. Lewis, 2006

42 Bologna, 27 Aprile 2006 Implications for Nucleosynthesis

43 Bologna, 27 Aprile 2006 courtesy from Page et al., 2006 From = (1st year) To = (3 years)

44 Bologna, 27 Aprile 2006 courtesy from Spergel et al., e 2 contours: Light Blue: WMAP1 Red: WMAP1 + CBI +ACBAR Blue: WMAP3

45 Bologna, 27 Aprile 2006 n s < 1 or tau is high or there are tensors or the model is wrong or we are quite unlucky n s =1 So: Is Harrison-Zeldovich Ruled out?

46 Bologna, 27 Aprile 2006 Dark Energy: w DE w = -1 for CMB anisotropies we need DE perturbations w DE constant in time c DE =1 ( p DE =c 2 DE DE+…).

47 Bologna, 27 Aprile 2006 WMAP 3 years results without DE perturbations are flawed Effect known since Caldwell,Dave, Steinhardt PRL 1998 Abramo, Finelli, Pereira PRD 2004

48 Bologna, 27 Aprile 2006 Massive Neutrinos courtesy from Spergel et al., 2006

49 Bologna, 27 Aprile 2006 Curvature K 0 courtesy from Spergel et al., 2006

50 Bologna, 27 Aprile 2006 Curvature K 0 plus Dark Energy courtesy from Spergel et al., 2006

51 Bologna, 27 Aprile 2006 Gravity Waves Baldi,Finelli,Matarrese, PRD72 (2005) r < 0.55 (2 ) WMAP3 only r < 0.28 (2 ) WMAP3 plus SDSS r k* = P T (k * )/P S (k * ) r < 1.28 (2 ) WMAP1 only r < 1.14 (2 ) WMAP1 plus 2dFGRS

52 Bologna, 27 Aprile 2006 LCDM+ Tensors No evidence from tensor modes -is not going to get much better from TT! courtesy from A. Lewis, 2006 Finelli et al., in preparation (2006) Leach & Liddle, PRD (2003) Single standard scalar field inflation: r = - 8 n T

53 Bologna, 27 Aprile 2006 Black: SZ marge; Red: no SZSlightly LOWERS n s SZ Marginalization Spergel et al. WMAP-3 yr twist: SZ

54 Bologna, 27 Aprile 2006 CMB lensing and WMAP3 Black: with red: without - increases n s not included in Spergel et al analysis opposite effect to SZ marginalization

55 Bologna, 27 Aprile 2006 And Planck? to be launched in 2008 improved frequency coverage ( GHz) for improved foreground subtraction improved resolution (>5') and sensitivity (~µK) more accurate polarisation measurement foregrounds!

56 Bologna, 27 Aprile 2006 Planck vs WMAP:1 courtesy from C. Burigana

57 Bologna, 27 Aprile 2006 Planck vs WMAP:2 courtesy from C. Burigana

58 Bologna, 27 Aprile 2006 Planck vs WMAP:3 courtesy from Planck Bluebook, astro-ph/

59 Bologna, 27 Aprile 2006 Planck vs WMAP:4 courtesy from Spergel et al., 2006

60 Bologna, 27 Aprile 2006 courtesy from Planck Bluebook, astro-ph/ Planck vs WMAP:5


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