UHE Cosmic Rays in the Auger Era

Transcription

1 Vulcano Workshop May, 23-29, 2010 UHE Cosmic Rays in the Auger Era Sergio Petrera, L'Aquila University sergio.petrera@aquila.infn.it

2 Vulcano Workshop May, 23-29, 2010 UHE Cosmic Rays in the Auger Era Sergio Petrera, L'Aquila University sergio.petrera@aquila.infn.it Motivations Present status of the Pierre Auger Observatory The physics items: energy spectrum CR composition arrival directions Summary and outlook

3 The interest for UHECRs in three points E > ev transition galactic/extragalactic origin GZK effect pointing to the sources (particle astronomy!?)

4 The interest for UHECRs in three points E > ev transition galactic/extragalactic origin GZK effect pointing to the sources (particle astronomy!?)

5 The interest for UHECRs in three points E > ev transition galactic/extragalactic origin GZK effect pointing to the sources (particle astronomy!?)

6 The interest for UHECRs in three points E > ev transition galactic/extragalactic origin GZK effect pointing to the sources (particle astronomy!?)

7 The interest for UHECRs in three points E > ev transition galactic/extragalactic origin GZK effect pointing to the sources (particle astronomy!?) + GZK reduces the horizon

8 AGASA: stopped Jan HiRes: stopped Apr 2006 Auger: operating Telescope Array: starting the all-particle spectrum ankle UHE few/km sq per century GZK

9 AGASA: stopped Jan HiRes: stopped Apr 2006 Auger: operating Telescope Array: starting Exposures Exposures

10 The Pierre Auger Observatory

11 Auger South: the plan

12 3000 km 2 area Vulcano Workshop

13 Nitrogen fluorescence detected as shower develops Particles detected as they reach ground Auger detection techniques Fluorescence (50 W light c) nearly calorimetric direct view of shower evolution 10% duty cycle Acceptance depends on energy + atmosphere Surface (10 12 particles over 20 km 2 ) 100% duty cycle Flat acceptance above threshold Indirect measurements of primary energy and mass (relies on simulation) Hybrid = surface + fluorescence

14 Observables at Auger

15 Observables at Auger

16 Observables at Auger

17 SD energy calibration based on FD profiles golden hybrid events (independently detected) energy systematic error ~22 % mostly from systematics of the FD detector (fluorescence yield, atmospheric transparency...) Energy Calibration

18 Water Cherenkov tank Rotomolded polyethylene tank 10 m 2 x 1.2 m of ultrapure water in a light diffusing Tyvek liner, 3 PMTs Photonis (9 diameter); Autonomous unit: solar panel+battery, GPS timing, communication antenna, electronics Max 10 W power consumption the Surface Detector

19 Schmidt Telescope using 11 m 2 mirrors the Fluorescence Detector UV optical filter (also: provide protection from outside dust) Camera with 440 PMTs (Photonis XP 3062)

20 the Fluorescence Detector Schmidt Telescope using 11 m2 mirrors UV optical filter (also: provide protection from outside dust) Camera with 440 PMTs (Photonis XP 3062)

21 Auger 2010 Construction ended Apr Enhancements for Low Energies: HEAT (High Elevation Auger Telescopes) AMIGA (Auger Muon and Infill Array) + AERA array of radio detectors

22 Auger 2010 Construction ended Apr Enhancements for Low Energies: HEAT (High Elevation Auger Telescopes) AMIGA (Auger Muon and Infill Array) + AERA array of radio detectors New R&D: MW fluorescence detection [after Gorham et al., PR D 78 (2008) ] Towards an FD with 100% duty cycle?

23 ENERGY SPECTRUM

24 the Energy Spectrum PLB 685 (2010) 239 Cutoff at ~ ev significant with > 30

25 the Energy Spectrum PLB 685 (2010) 239 Cutoff at ~ ev significant with > 30

26 the Energy Spectrum Within the energy scale systematics

27 Comparison to Source Models

28 MASS COMPOSITION

29 Mass Composition: the principle X max photons protons Fe Energy

30 Mass Composition: the principle X max photons Data protons Fe X max Energy

31 Elongation Rate Measurement Auger and HiRes Xmax measurements are compatible within systematic uncertainties

32 Comparison with Hadronic Models PRL 104 (2010) Mass composition getting heavier HiRes PRL 2010 proton dominance above 1.6 EeV but... difficult to compare with HiRes due to different definitions of observables.

33 Comparison with Hadronic Models PRL 104 (2010) More about Mass Composition by Analisa Mariazzi

34 Photons: upper limits Top down models strongly constrained

35 Neutrinos: Earth skimming n t

36 ARRIVAL DIRECTIONS

37 Initial Anisotropy Searches Typical accuracy of reconstruction <1 No significant emission from Galactic Centre No broadband signals e.g. Dipole at any energy above 1 EeV e.g 1 < E < 3 EeV, Amplitude < 0.7% No clustering of the type claimed by AGASA No signal from BL Lacs as possibly seen by HiRes ICRC 2007 Summary: Previous reports have not been confirmed

38 Correlation with AGN's (2007) Based on a Prescribed Anisotropy Test: Correlation with Veron-Cetty-Veron AGN Catalog 20 out of 27 events E>57 EeV correlating within 3.1 degrees with z<0.017 AGN's Isotropy rejected with >99% C.L.

39 Correlation with AGN's (2010) Update of the Prescribed Anisotropy Test (correlation with VCV catalog of AGNs) 38% (21/55) correlate (post exploration) vs. 21% expected from isotropy correlation decreased but still incompatible with isotropy at 99% C.L.

40 More results on Correlations New paper in preparation: new catalogs, autocorrelation, CenA preliminary

41 Summary... High quality results on all the observables of UHECR's A comprehensive interpretation of the whole data still missing

42 Summary... High quality results on all the observables of UHECR's A comprehensive interpretation of the whole data still missing

43 Summary... High quality results on all the observables of UHECR's A comprehensive interpretation of the whole data still missing

44 Summary... High quality results on all the observables of UHECR's A comprehensive interpretation of the whole data still missing Much work to do... many more data...

45 and Outlook What's coming next?what's coming nex A new observatory: TA (Telescope Array) Auger South: low energy extension HEAT (3 high elevation telescopes) AMIGA (SD infill + muon detectors) +... Auger North: at Lamar (CO) undergoing evaluation Go to space!

46 and Outlook What's coming next?what's coming nex A new observatory: TA (Telescope Array) Auger South: low energy extension 576 scintillator HEAT detectors (3 high elevation telescopes) AMIGA (SD infill + muon detectors) km Auger interval North: at Lamar (CO) undergoing evaluation Go to space! ~2.5 hours from SLC 3 (+2) Communication Towers 3 FD stations (atmospheric fluorescence telescopes) 30 km

47 and Outlook What's coming next?what's coming nex A new observatory: TA (Telescope Array) Auger South: low energy extension HEAT (3 high elevation telescopes) AMIGA (SD infill + muon detectors) +... Auger North: at Lamar (CO) undergoing evaluation Go to space!

48 and Outlook What's coming next?what's coming nex A new observatory: TA (Telescope Array) Auger South: low energy extension HEAT (3 high elevation telescopes) AMIGA (SD infill + muon detectors) +... Auger North: at Lamar (CO) undergoing evaluation Go to space!

49 Auger North

50 Auger North: comparison with other expts

51 Auger North: correlations above 60 EeV

52 Photon search

53 Auger North: Photon search

54 and Outlook What's coming next?what's coming nex A new observatory: TA (Telescope Array) Auger South: low energy extension HEAT (3 high elevation telescopes) AMIGA (SD infill + muon detectors) +... Auger North: at Lamar (CO) undergoing evaluation Go to space!

55 and Outlook What's coming next?what's coming nex A new observatory: TA (Telescope Array) Auger South: low energy extension HEAT (3 high elevation telescopes) AMIGA (SD infill + muon detectors) +... Auger North: at Lamar (CO) undergoing evaluation Go to space! Thanks