1 / 48

Krzysztof M. Górski Jet Propulsion Laboratory/Caltech (Warsaw University Observatory)

Exploiting the CMB Observations from Space - Looking Forward to Planck and Beyond. Krzysztof M. Górski Jet Propulsion Laboratory/Caltech (Warsaw University Observatory). Another look at comparison to COBE-DMR. V-Band WMAP data. IRAS/DIRBE. CMB Life after WMAP and its Predecessors.

moesha
Download Presentation

Krzysztof M. Górski Jet Propulsion Laboratory/Caltech (Warsaw University Observatory)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Exploiting the CMB Observations from Space - Looking Forward to Planck and Beyond Krzysztof M. Górski Jet Propulsion Laboratory/Caltech (Warsaw University Observatory)

  2. Another look at comparison to COBE-DMR

  3. V-Band WMAP data IRAS/DIRBE

  4. CMB Life after WMAP and its Predecessors • The cosmological model has already been fairly tightly constrained • It is, therefore, possible that what is left to be done is “just” • Refinement, refinement, refinement - • For example, Planck polarization measurements, etc. • But, perhaps, • Not all loose ends have been tied up yet - • Does the data already collected tell us something that has not been deciphered yet?

  5. Comparison of low-l spectra from COBE-DMR and WMAP

  6. Is the Universe Probed by the CMB at Large Angular ScalesInteresting“after” WMAP? Are we at “the End?”, “the Beginning of the End?”, or “the End of the Beginning?” of our approach to understanding the universe through the measurements and interpretation of the CMB anisotropy?

  7. “Simplicity, simplicity - you can already see everything…” • Are these two views of the CMB sky “equivalent” • Is the universe as isotropic as it “should” be, or as we would like it to be? • Are there novel ways to address such questions with the data now at hand, e.g. WMAP sky maps?

  8. How Can we Test the Isotropy of the Universe? • Eriksen, H.K., Hansen, F.K., Banday, A.J., Lilje, P.B., & Gorski, K.M., 2003, astro-ph/037507 • “Asymmetries in the CMB Anisotropy Field” • Eriksen, H.K., Lilje, P.B., Banday, A.J., & Gorski, K.M., 2003, astro-ph/0310831 • “Estimating N-Point Correlation Functions from Pixelized Sky Maps” • Hansen, F.K. & Gorski, K.M., 2003, MNRAS 344, p.544 • “Fast Cosmic Microwave Background Power Spectrum Estimation of Temperature and Polarization with Gabor Transforms” • Hansen, F.K., Gorski, K.M., & Hivon, E., 2002, MNRAS, 336, p.1304 • “Gabor Transforms on the Sphere with Applications to CMB Power Spectrum Estimation” • Eriksen, H.K., Banday, A.J., & Gorski, K.M., 2002, A&A, 395, p.409 • “The N-Point Correlation Functions of the COBE-DMR Maps Revisited” • Hivon, E., Gorski, K.M., Netterfield, C.B., Crill, B.P., Prunet, S., & Hansen, F., 2002, Ap.J., 567, p.2 • “MASTER of the CMB Anisotropy Power Spectrum: A Fast Method for Statistical Analysis of Large and Complex CMB Data Sets” • Wandelt, B.D, Hivon, E.H., & Gorski, K.M., 2001, PhR D, 64, p.3003, • “CMB Power Spectrum Statistics for High Precision Cosmology”

  9. Two Options for Analysis of the High Resolution Whole Sky Map of the CMB Anisotropy • Extract pseudo-alms and pseudo-Cls on the whole sky less the galactic and foreground source cut - care needs to be taken of the cut geometry effect on the coupling of the harmonic and spectral coefficients • Extract pseudo-alms and pseudo-Cls on the small disk (less the foreground source cut, if sources present) - given simple geometry of the boundary of the disk, the coupling of the harmonic and spectral coefficients can be accounted for exactly

  10. Average Power SpectraDerived on the Whole Sky (red), and on the9.5 deg Disk (green) • “Integrals” of both spectra are equal - the variances of the anisotropy power per pixel on the sky are equal

  11. Analysis of WMAP Sky Maps Cut up into 9.5 deg Disks • 164 disks of 9.5 deg radius are placed outside the WMAP Kp2 sky cut • First, Gabor pseudo-spectra derived on those small disks are used to test the isotropy of the CMB power spectrum • Second, 82 disk center directions are used to define North poles of the reference frames in which pseudo-spectra are derived from the north and south hemispheres • Coadded V+W WMAP data are used with the Kp2 sky cut • 6144 Monte-Carlo simulations of the best fitting running spectrum model and WMAP noise are used for statistical calibration of the results

  12. And the results are … • Blue/green dots: total 9.5 degree disk pseudo-power between l=2, and l=63 compared to the theoretical distribution of the best fitting model; >90% events - green, <10% events - blue • Large disks: color coded ratio of north/south hemisphere l=2-63 pseudo-power; low values - yellow, large values - dark red

  13. Localised 3-point correlation function analysis • Intermediate scale three point analysis of the co-added Q+V+W WMAP sky maps (filtered to remove the power at l<18); Kp0 sky cut was applied • 3-point functions computed in 460 isocles configurations smaller than 5 deg on a set of 81 disks • C2

  14. WMAP vs. COBE-DMR and Dust Emission of the Galaxy

  15. Usual suspects Systematic effect Foreground effect Galactic? Extra-galactic? The least likely to be accepted: intrinsic CMB effect Refutation? What about the WMAP - DMR consistency: No common mode systematic effects Difficult to explain power deficit in a region of low foreground emission; consistent results across frequencies Conclusions There is growing evidence that interesting effects exist, unexpectedly, at rather large angular scales in the WMAP data. Other than this work, Park (astro-ph/0307469, genus asymmetry), Naselsky et al.(astro-ph/0310235, phase correlations), Coles et al.(astro-ph/0310252, phase correlations), Vielva et al.(astro-ph/0310273 wavelets), and Copi et al.(astro-ph/0310511, multipole vectors) claim finding various forms of non-gaussianity and north-south asymmetry in the WMAP sky maps. Some of those claims are statistically stronger than ours. Clearly, there is also a growing need for explanations.

  16. Large-scale anomalies in the WMAP data Large-scale anomalies in the first-year WMAP data: • Low-l multipole alignments and symmetries (l = 2, 3, 5, 6) • Large-scale power asymmetry (l < 40) • Non-Gaussianity in the northern galactic hemisphere at ~ 3 degree scales • Unusually cold spot spanning 10° on the sky at (l,b) = (207°, -59°)

  17. 1) Low-l alignments and symmetries l = 2 l = 3 First reports: De Oliveira-Costa et al. 2004, Phys. Rev. D. 69, 063516Bennett et al. 2003, ApJS, 148, 1 End-to-end Monte-Carlo analysis: Eriksen et al. 2004, ApJ, 612, 633 Multipole vector approach: Copi et al. 2004, Phys. Rev. D 70, 043515Schwartz et al. 2004, Phys. Rev. D 93, 221301Katz and Weeks, 2004, Phys. Rev. D. 70, 063527Weeks, 2004, preprint, astro-ph/0412231 l = 6 l = 5 Claimed anomalies: Low quadrupole amplitudeInitially claimed at few percent level; exact calculations show 10% significance Alignment between l = 2 and l = 3 planes Significance about 98%, independent of method Planar l = 3 and 6 modes; spherically symmetric l = 5 modeSignificance of 1.5, 3 and 2 for l = 3, 5 and 6, respectively Problem:All results are obtained from full-sky “foreground corrected” maps, which are known to contain residual foregrounds. Cosmological significance remains unclear.

  18. 2) Large-scale power asymmetry, l < 40 Power spectra in reference frame of maximal asymmetry Computed power spectrum from complementary hemispheres in one hundred reference frames Asymmetry significant at 2.5-3, independent of frequency, galactic cut, and statistic. Eriksen et al. 2004, ApJ, 605, 14Eriksen et al. 2004, ApJ, 612, 64Eriksen et al. 2004, astro-ph/0407271Hansen et al. 2004, MNRAS, 354, 641Hansen et al. 2004, MNRAS, 354, 905Larson and Wandelt, 2004, ApJ, 613, L85Donoghue and Donoghue, 2004, astro-ph/0411237Etc.

  19. Quantitative description -- the genus 3) Hot and cold spot anomaly in the northern galactic hemisphere at ~ 3° scales Threshold atTlim = -40 K Many small spots; few big spots Many big spots; few small spots Threshold atTlim = +40 K No large cold spots on the northern hemisphere; another manifestation of the power asymmetry Nhot(40 K)  Ncold(-40 K); indication of an intrinsically non-Gaussian distribution Uniform distribution Eriksen et al. 2004, ApJ, 612, 64; Hansen et al. 2004, ApJ, 607, 67Park, 2004, 2004, MNRAS, 349, 313, etc.

  20. 4) Cold spot at (l,b) = (207°, -59°) First detection:Vielva et al. 2004, ApJ, 609, 22Confirmations:Cruz et al. 2004, MNRAS, 509, XMukherjee and Wang, 2004, ApJ, 613, 59 • Large, very cold spot was detected using wavelets by Vielva et al. • Anomalous at the 3 confidence level, compared to Monte Carlo simulations • Independent of frequency and foreground correction method

  21. Conclusions • The large-scale features of the WMAP data are currently not properly understood • Foregrounds do not seem as a probable explanation for any of the l > 6 effects. Situation still unresolved for the l < 6 alignment and symmetry anomalies • Assuming the WMAP data are free of systematics, these detections could possibly point towards new physics.

  22. Sensitivity comparison of WMAP and Planck

  23. What (we hope) Planck will add In addition to wider frequency coverage and better sensitivity than WMAP, Planck has the resolution needed to see into the damping tail. No other experiment can cover enough sky to make a cosmic variance limited measurement of the scales around the 3rd and 4th peaks. (4yr) (1yr)

  24. What (we hope) Planck will add A precise measurement of the E-mode polarization power spectrum.

  25. US Planck Algorithm Development Group • First Meeting - March 11, 2004 • Weekly Telecons, 1/2 day • Monthly Face-to-face Meetings, all-day, regularly at JPL, to be held (occasionally) at other locations • Presently attended by team members from Pasadena, Berkeley, Davis (CA), Urbana/Champaign (IL) • Coordination: KMG • Active Participants: • Pasadena: • E. Hivon, H.-K. Eriksen, G. Prezeau, J. Jewell, S. Levin, E. Pierpaoli, K.M. Gorski, C. Lawrence, K. Ganga • Berkeley: • J. Borrill, R. Stompor, C. Cantalupo, G. Chon, A. Amblard • Davis: • L. Knox, M. Chu, O. Holm • Urbana-Champaign: • B. Wandelt, C. Armitage, I. O’Dwyer, D. Larson • ADG activity is conducted on the level of effort basis

  26. Map Making from HFI 217 GHz TQU TODs • Input Data Generated by Level S Simulation Pipeline: • 217 GHz: 5’ circular beam, 200 Hz sampling • 4 polarized detectors, 1 year mission: 24 Gsamples of measurements • Individual detector pointing (double precision) • TOD = 1 TB of data • TOD = ~550 GB if pointing reformatted • Stationary Noise 1 / f 2, knee = 30 mHz • Pointing jitter • 2 scanning strategies • Nominal (i.e., no modulation - misses Ecliptic poles) • Cycloidal modulation of spin axis pointing to cover the whole sky (6 months precession period) • Computing: • Seaborg (NERSC, LBL, Berkeley) • 2048 CPUs and 2 TB of RAM used • ~5 hrs execution time • Output: • TQU HEALPix maps, 1.7 arcmin pixels (50 Mpixel/map)

  27. Parameters: Computing: Simulation Parameters and Computational Resources

  28. The Planck satellite will gather an unprecedented volume of Cosmic Microwave Background (CMB) temperature and polarization data whose analysis will present a major computational challenge. Christopher Cantalupo, Julian Borrill & Radek Stompor, Computational Research Division, Lawrence Berkeley National Laboratory & Spaces Sciences Laboratory, UC Berkeley Temporal correlations in the detector noise mean that maximum likelihood (generalized least squares) methods must be used to obtain the highest fidelity CMB sky maps. Here we have used MADmap - a massively parallel implementation of the preconditioned conjugate gradient solution to maximum likelihood map-making - to make the first optimal, full-resolution, I, Q & U maps from 1 year of simulated data from all of the Planck detectors at a single frequency. (but - Mapcumba …) This calculation (mapping 75 billion observations to 150 million pixels) used 6000 processors of NERSC's Seaborg supercomputer for 2 hours, demonstrating the practicality of processing such data volumes by these methods. Scaling to this concurrency did involve breaking significant MPI and I/O bottlenecks, but the results here show that continued access to state-of-the-art supercomputers, and the development of codes that can exploit their full capabilities, will be of great benefit to Planck science. Computing Full Resolution Maximum Likelihood Maps of Complete Single Frequency Planck Data

  29. Planck Scanning strategy

  30. The input CMB signals for these simulations were generated by matching spherical harmonics up to l = 3000 to the WMAP-extended data.

  31. Full WMAP resolution (Nside 512) Single Frequency (94 GHz) 1st Year CMB Intensity Data

  32. Full Planck Resolution Single Frequency 1 Year CMB Intensity Map

  33. The Same 100 Square Degree Patch Cut From Full-Sky WMAP and Planck Maps

  34. TT Power Spectrum from 12 HFI Detectors at 217GHz

  35. NASA “Beyond Einstein” Strategic Plan

  36. NASA’s Beyond Einstein Timeline Concept studies (funded) Announcement of Opportunity? Dark Energy Probe (aka SNAP): 5 Inflation Probe (aka CMBPOL): 3 Black Hole Finder: 2 “…The Einstein Probes are currently planned to be fully competed, scientist-led mission opportunities with the goal to launch one such mission every three years, starting about 2010. The order in which the Einstein Probes are flown will be determined by both science priority and technological readiness. An Einstein Probe is envisioned as costing between $350M to $500M (real year$) ...”

  37. Challenges for a Future Space Mission • Instrument Parameters • All-sky coverage:optimal for GW search • Complete frequency coverage • Control systematic errors • Sensitivity: ~1 mKs, 30x better than Planck • Angular resolution: • 2-5 arcmin to clean lensing signal; known lensing and SZ science • Science Goals: • Definitively search for IGB signal • Use lensing signal to measure P(k) • Map scalar signal to cosmic variance Experimental Probe of Inflationary Cosmology (EPIC) Consortium: Charles Beichman Robert Caldwell John Carlstrom Sarah Church Asantha Cooray Peter Day Scott Dodelson Darren Dowell Mark Dragovan Todd Gaier Ken Ganga Walter Gear Jason Glenn Alexey Goldin Krzysztof Gorski Shaul Hanany Carl Heiles Eric Hivon William Holzapfel Kent Irwin Jeff Jewell Marc Kamionkowski Manoj Kaplinghat Brian Keating Lloyd Knox Andrew Lange Charles Lawrence Rick LeDuc Adrian Lee Erik Leitch Steven Levin Hien Nguyen Gary Parks Tim Pearson Jeffrey Peterson Clem Pryke Jean-Loup Puget Anthony Readhead Paul Richards Ron Ross Mike Seiffert Helmuth Spieler Thomas Spilker Martin White Jonas Zmuidzinas Current Team Leader: James Bock (JPL)

  38. The Not-So Distant Future WMAP Scalar DASI QUAD IGB (T/S = 0.05) Lensing BICEP Hivon & Kamionkowski, 2002 We’re soon to learn a great deal more about: • Scalar and lensing signals • Foregrounds • Methodology • Technology Planck

  39. Cosmic Microwave Background Polarization CMB Polarization Power Spectrum Scalars = Polarization from physics at decoupling Cosmic Shear = Gravitational lensing of CMB by matter IGB = Signal from Inflationary Gravity-wave Background EPIC = Experimental Probe of Inflationary Cosmology

  40. Future Focal Plane Sensitivities • Planck bolos near photon noise limit • Need arrays for improved sensitivity • ~104 detectors for NET = 1 mKs • polarization sensitivity • collimated beams • physically large • no mixed technology focal planes Current and future focal planes HEMTsBolometers TA = 3hn/k hopt = 50 % Dn/n = 30 % Dn/n = 30 % Q&U / feed Qmax/Q0 = 5 & telescope with T = 60 K, e = 1% Vs.

  41. HEALPix • Hierarchical, Equal Area, iso-Latitude Pixelization of the sphere - a novel data structure and a software package for discretization, and fast global (and local) synthesis and analysis of functions and data on a sphere • KMG, E. Hivon (IPAC/Caltech), B.D. Wandelt (UIUC), A.J. Banday (MPA Garching), et al. • Used by WMAP, Boomerang, Planck; >300 individual users worldwide • Available at http://www.eso.org/science/healpix

More Related