1. Angela V. Olinto The University of Chicago Anisotropies at the Highest Energies

2. CMB vs UHECR Anisotropies

3. 1.UHECRS are Charged, should ‘point’ above ~ 10 EeV Z Halo B? Extra-galactic B? B < nG  weak deflection R L = kpc Z -1 (E / EeV) (B /  G) -1 R L = Mpc Z -1 (E / EeV) (B / nG) -1 where EeV=10 18 eV kpc 10 kpc strong deflection Milky way B ~  G E > 10 19 eV E < 10 18 eV

4. 2. Cosmic Ray Spectrum is Power law Non-thermal Phenomena Extreme Accelerators E max > 10 20 eV E -2.7 E -3.1 12 orders of magnitude 32 orders of magnitude RHIC Tevatron LHC Ankle (1 particle /km 2 yr) E cm = PeV (E uhecr /ZeV) 1/2 (2A) 1/2 Swordy ‘02

5. 3. ‘Pointing” UHECRS E ~ 100s TeV CM ankle knee

6. E = Ze B L 10% efficiency 10 20 eV Protons 10 20 eV Iron Log B(G) Log L(cm) others GRBs LHC 4. No known mechanism acceleration nor clear Counterparts

7. Cosmologically Meaningful Termination GZK Cutoff Greisen, Zatsepin, Kuzmin 1966 p+  cmb   +  p +  0  n +  + Proton Horizon ~10 20 eV 5. Extragalactic propagation GZK imprint

8. Attenuation length e+e–e+e–  Interaction length Attenuation length

9. 6. GZK Effect  Anisotropies  Spectral Feature + LSS  Anisotropic Sky Distribution  Charged Particle Astronomy!!!

10. GZK Horizon - Protons Allard, AO, Parizot 08

11. Horizons: Gpc 10 19 eV ~ 1 Gpc 10 20 eV < 100 Mpc 100 Mpc

12. Inhomogeneous Galaxy Distribution 2MASS - Two Micron All Sky Survey

13. Horizons: Gpc 10 19 eV ~ 1 Gpc 10 20 eV < 100 Mpc 100 Mpc

14. The Pierre Auger Observatory of Ultra-High Energy Cosmic Rays Southern site 3 000 km 2 Northern site 20 000 km 2 Argentina Australia Brasil Bolivia* Croatia* Czech Rep. France Germany Italy Mexico Netherlands > 400 PhD scientists from > 70 Institutions and 18 countries Poland Portugal Slovenia Spain UK USA Vietnam* *Associate Countries

15. 18 Countries 70 Institutions, > 400 scientists

16. Many Candidates to win the World Cup 2010!!!

17. 1660 tanks = 3,000 km 2 Surface Array 4 Fluorescence Detector Sites Science Data since 2004 Completed in June 2008 Auger South

18. surface detector

19. tanks aligned seen from Los Leones

20. 4 Fluorescence Detector Sites

21. 1st - 4 Fold Hybrid Event 20 May 2007 E ~ 10 19 eV

22. Statistical 14% @ 50 EeV Systematic 22% Less than 1 degree @ 50 EeV > ~1 degree “astronomy” @ 50 EeV

23. Observed Spectrum showns GZK GZK

24. Unclear Trend in Observed Composition

25. Anisotropy Analysis

26. Auger Anisotropy Result 2007 Highest energy cosmic rays have an anisotropic distribution! Correlation with z < 0.018 AGNs in the 12 th Véron-Cetty/Véron catalogue The observed correlationdid not identify the CR sources but established anisotropy at 99% c.l. Data: 27 events above 57 EeV from 1/1/2004 to 31/8/2007 (exposure of 8890 km2 sr y)

27. Auger 2007 Anisotropy Result * - VCV AGN catalogue 3.2 o - 27 highest energy event Blue shades: equal integrated exposure

28. Challenges of the Analysis: 1. LOW STATISTICS!!!!! 2. Choice of catalogs Véron-Cetty / Véron, 12th Edition, 2006 “This catalogue should not be used for any statistical analysis as it is not complete in any sense, except that it is, we hope, a complete survey of the literature.”

29. Significance of the anisotropy result Not an “AGN correlation” result! 1st step: search for correlations between arrival directions of UHECR and various source catalogues Very large “raw significance” found w/ 12 th VCV catalogue of AGNs Did not seem to be fluctuation Auger collaboration set up a prescription for future data Even after generous penalty factors for a posteriori searches and scanning of parameter space (data from 2004/01/01 to 2006/05/27) 12 out of 15 events E > 56 EeV closer than 3.1° from an AGN in 12 th VCV with z ≤ 0.018 (D ≤ 75 Mpc) Most significant a posteriori “correlation signal”: 3.2 expected from isotropic distribution

30. Exploratory scan (Period I): 1 Jan 2004-27 May 2006 Integrated exposure: 4390 km2 sr y Scan in ψ(angular distance between CR and AGN), E th (CR energy), z max (AGN distance) Scan implemented to find the minimum of the binomial probability P that ≥ k out of N events correlate by chance Minimum value of P: E th = 56 EeV ψ = 3.1 o z max = 0.018 12/15 events correlate (3.2 expected by chance, p(z, ψ) = 0.21) Scan  proper penalization difficult to calculate  Prescription adopted p(z, ψ)= exposure-weighted chance probability for a CR to fall within ψ of the sources

31.  ≤ 3.1° z ≤ 0.018 (D ≤ 75 Mpc) E ≥ 56 EeV 3 Parameter Scan

32. correlation is most significant above E = 56 EeV where the CR flux drops… Energy Threshold makes sense

33. Significance of the anisotropy result 2nd step: predefine a region in the sky of excess CR flux & test if next UHECRs come from this region Independent data set, prescribed parameters, unambiguous significance 21% chance from isotropic distribution Nearby VCV AGN 21% sky

34. Independent data (Period II): 27/5/2006-31/8/2008 Integrated exposure: 4500 km2 sr y A-priori fixed parameters: E th = 56 EeV ψ = 3.1 o z max = 0.018 8/13 events correlate (2.7 expected by chance) Probability to happen by chance from an isotropic flux: P≈1.7 10 -3 Test built to have 1% probability to incorrectly reject isotropy. Test passed: 99% c.l. anisotropy Note: it does not show that VCV AGN are UHECR sources!

35. First 27 events Exploratory scan – 12/15 events correlated (3.2 expected) Prescription passed when 8/13 correlated (2.7 expected) NOTE: original set became 14 events when reconstructed with new energy analysis, 14+13 = 27

36. References Science 318 (2007), 939 “Correlation of the highest energy cosmic rays with nearby extragalactic objects” Astroparticle Physics 29 (2008), 188 “Correlation of the highest-energy cosmic rays with the positions of nearby active galactic nuclei” arXiv:0906.2347 31st International Cosmic Ray Conference, Lodz, Poland, July 2009 “Astrophysical Sources of Cosmic Rays and Related Measurements with the Pierre Auger Observatory” NEW Update to come soon...

37. ICRC Update 2009 ICRC new data (Period III): 27/5/2006-31/3/2009 after exploratory period (II+III) integrated exposure: 12650 km 2 sr y Updated event reconstruction: 56 EeV  55 EeV 31 new events E > 55 EeV: 44 post-prescription events A-priori fixed parameters: E th = 55 EeV ψ = 3.1º z max = 0.018 mask = cut out Galactic Plane

38. ICRC 2009 Likelihood ratio: binomial probability of correlation over binomial probability in isotropic case (p iso =0.21) 17/44 events in correlation (P=0.006) Isotropy still rejected at 99% c.l.

39. Time Ordered Degree of correlation (p=k/N) p data =17/44=0.38±0.07 Correlation degree decreased wrt our previous report but still more than 2 s.d. from isotropy

40. A Posteriori Analysis Point source searches Different methods & Catalogs (w/ ICRC 2009 Data) : I. Cross-correlation II. Log-likelihood III. 2-fold correlation Laura Watson: Bayesian Methods applied to 2007 data Fred Kuehn: Methos used in the collaboration

41. Centaurus A

42. KS test: 2% of isotropic realizations have a maximum departure from isotropy ≥ the maximum observed departure Integral number of events vs angular distance from Cen A Maximum excess @ 18 o radius: 12 observed events vs 2.7 expected

43. 1. X-ray AGNs in 22-months SWIFT-BAT catalogue (261 objects) 2. Galaxies in the HIPASS survey (3058 galaxies, radio, flux- limited, HI sources) 3. HIPASS-HL: sub-sample of HIPASS (the 765 most luminous galaxies) 4. Galaxies in the 2MRS compilation (|b|>10¡, 23000 most luminous galaxies from 2MASS, full-sky, IR) Other (Better) Catalogs

44. Cross Correlation e.g.: volume selected galaxies (D<200 Mpc) from 2MRS (1940 obj) Measures the excess of pairs within a given angular separation wrt isotropy (departures are larger if CRs correlate with denser regions of the catalogues) No weight by distance or luminosity (equal contribution to CR flux from every source)

45. Smoothed Maps from Catalogs For each catalogue: Smoothed probability maps of arrival directions Weight catalogue sources by flux x GZK attenuation 2 free parameters: smoothing angle σ and isotropic background (catalogue incompleteness + lower en. spill) F c (n) = density map value in the direction n Use data to find the best values of (σ, f iso ) by maximizing the LogLikelihood Parameters weakly constrained

46. Likelihood Test Simulate 10 4 samples with the same number of data as in the real set Draw events according to catalogue density map or isotropically Compare the likelihood distributions with the value obtained from data Better agreement with Catalog models vs Isotropy LL sensitive to data points “in or out” of high density catalogue regions Simulated data sets based on isotropy (I) and Catalog models (II) compared to data (black line/point).

47. Complementary method to test overall proportionality between models and data Based on the computation of two coefficients: correlation (test match between models and data) and concentration (test clustering properties of data) Data compatible with all the models The map based on SWIFT gives the most discriminant test against isotropy 2-fold correlation method

48. up to 3/31/2009, exposure 17,000 km 2 sr.y, 58 CRs w E>55 EeV Update on the correlation with VCV objects (a-priori analysis) Isotropy rejected at 99% c.l. Degree of correlation lower than in early data A-posteriori analysis: Excess of events close to Cen A (?) Distribution of arrival directions compatible with several catalogs that trace the distribution of nearby extra-galactic matter X-rays AGNs (e.g., SWIFT-BAT) interesting correlations More statistics needed to discriminate possible source scenarios “Only” collect ≈ 2 UHECR/month Only look in the Southern Sky Conclusions

49. Auger North 10 yr Black – 2MASS catalog z<0.02 Blue – Auger North simul Data – energy proportional to circle size Red – Auger South Data

50. 50CERN, 11 December 2007— Particle Physics Seminar: Auger results on UHECRs —