La nascita della astronomia dei raggi cosmici? Indicazioni dall' Osservatorio P. Auger

1. La nascita della astronomia dei raggi cosmici? Indicazioni dall' Osservatorio P. Auger Aurelio F. Grillo Teramo 8/05/08

2. Nuclear (p, He.... Fe) component

3. Knee Ankle Few/km sq per century ?

4. p Nuclei p?

6. for extragalactic protons On CMBR photons

8. The Auger hybrid concept

11. Almost completely operating, now 1 year full observatory !

12. Fluorescence light Fluorescence Detector FD Surface Detector SD

13. The Auger hybrid concept

14. The spectrum: most statistically significant from SD calibrated in energy by “hybrid” events - energy systematic error ~22 %, mostly from systematic of the FD detector (fluorescence yield, atmospheric transparency....) Surface Detector SD Fluorescence Detector FD

15. Ultra High Energy CR spectrum ICRC07

17. Evidence for GZK cutoff? Likely fit

18. Cosmic Ray astronomy? If UHECRs origin is astrophysical, astronomy may be possible above some x 1019 eV if particles are protons (and IG magnetic fields small)‏

19. Cosmic Ray astronomy? If UHECRs origin is astrophysical, astronomy may be possible above some x 1019 eV if particles are protons (and IG magnetic fields small)‏ Around ~1020 eV particles can only arrive from within ~ 100 Mpc (in case of GZK)

20. Cosmic Ray astronomy? If UHECRs origin is astrophysical, astronomy may be possible above some x 1019 eV if particles are protons (and IG magnetic fields small)‏ Around ~1020 eV particles can only arrive from within ~ 100 Mpc (in case of GZK) A statistically significant correlation with sources in the GZK spere would unambiguously prove the reality of the cutoff (and give hints on the nature of sources)‏

21. The “Telescope” - Angular resolution ~ 1 degree - Pointing Accuracy ~ 1 degree - Charged Messengers => deviation in mag. fields

22. Exposure of the experiment in Galactic coordinates

23. The (Aug. 2007) astronomy analyses ~9000 km2 sr yr, trigger efficiency ~100%

24. Search for point sources:the motivation Small magnetic deflection Only nearby sources if GZK feature ok Nearby Universe anisotropic Regular Gal. B field

25. Search for point sources:the motivation Small magnetic deflection Only nearby sources if GZK feature ok Nearby Universe anisotropic Regular Gal. B field Indication of GZK from spectrum Bounds on photons/neutrinos Acceleration favoured vs. top-down

26. Search for point sources:the method Need to search correlations of a selected sample of events with astrophysical objects.... how and where? Large parameter space: -- events -> Energy, angular aperture Sources -> what sources: type, distance (z)........

27. Search for point sources:the method Need to search correlations of a selected sample of events with astrophysical objects.... how and where? Large parameter space: -- events -> Energy, angular aperture Sources -> what sources: type, distance (z)........ Method: perform a scan in the parameters space, after having chosen sources of a given type from a catalogue Chosen Veron-Cetty, Veron Catalogue of AGNs

28. Search for point sources:the method Some definitions: p -- exposure-weighted fraction of the sky accessible to observation, covered by windows of radius ψ centred on the selected sources. P -- probability that k or more out of a total of N events from isotropic flux are correlated by chance with the selected objects at the chosen angular scale this probability needs 'penalization' i.e. Pfin = P/Nt (from MC)‏ z<0.018

29. Search for point sources:the strategy Performed an exploratory scan. Eth > 4 1019 eV z < 0.024 Of 15 events with Eth > 5.7 1019 eV, 12 correlated within with AGNs with z<0.019, while 3.2 expected with these parameters

30. Search for point sources:the strategy Performed an exploratory scan. Eth > 4 1019 eV z < 0.024 Of 15 events with Eth > 5.7 1019 eV, 12 correlated within with AGNs with z<0.018, while 3.2 expected with these parameters Further search performed with these a priori fixed parameters, ending when the probability to incorrectly reject hisotropy hypotesis < 1% Search started May 2006, ended May 2007 when 6/8 events found correlating. In sample May 2006 – Aug 2007 8/13 correlating P= 1.7 10-3

31. Search for point sources:the strategy Rescan whole dataset with improved reconstr. algorithm to fix parameters. 20 out of 27 events correlated (a posteriori) Pfin(iso)~10-5

40. Search for point sources:the PAO Sky Map Equatorial coordinates SuperGalactic plane Galactic plane South pole

41. Search for point sources:the PAO Sky Map PAO events

42. Search for point sources:the PAO Sky Map AGNs from VC-V catalogue (z<0.018)‏ PAO events

43. Search for point sources:the PAO Sky Map Virgo AGNs from VC-V catalogue CenA PAO events

44. Search for point sources:the PAO Sky Map Virgo AGNs from VC-V catalogue CenA PAO events

45. Search for point sources:the PAO Sky Map Virgo AGNs from VC-V catalogue CenA PAO events If region of Galactic plane excluded, 19 out of 21 events do correlate

46. Search for point sources:the PAO Sky Map Virgo AGNs from VC-V catalogue CenA PAO events Leiden – Argentine – Bonn Hydrogen Survey

47. Search for point sources:the PAO Sky Map

48. Search for point sources:the PAO Sky Map Both for real events and simulated sets of same size, either isotropic or source

49. Search for point sources:the PAO Sky Map CenA

50. Search for point sources:the PAO Sky Map AGNs: sources or tracers??