Pierre%20Auger%20Observatory%20for%20UHE%20Cosmic%20Rays

1
Pierre Auger Observatory for UHE Cosmic Rays
Gianni Navarra (INFN-University of Torino) for
the Pierre Auger Collaboration
Science Case the need for Auger Principles
and Advantages of a Hybrid Detector Present
Status of the Observatory First preliminary
Data Perspectives
XXXXth Rencontres de Moriond ElectroWeak
Interactions and Unified Theories La Thuile
5-12th March 2005
2
Pierre Auger Collaboration
16 Countries 50 Institutions 350 Scientists
Italy Argentina Czech Republic Australia
France Brazil Germany Bolivia
Greece Mexico Poland USA Slovenia
Vietnam Spain United Kingdom
Associate Countries
Spokesperson Alan Watson
3
UHE Cosmic Rays
Surface particle detectors
Eo gt1020 eV 1 part / (km2 century sr) ? 102
103 km2 collecting areas
4
UHE Cosmic Rays
atmospheric fluorescence detectors
Atmospheric fluorescence detectors
Eo gt1020 eV 1 part / (km2 century sr) ? 102
103 km2 collecting areas
5
HiRes vs AGASA
Surface particle detectors
30 Syst. Error
AGASA
HiReS
??
Atmospheric fluorescence detectors
D. Bergmann
6
GZK?
Astrophysics?
Cosmic ray sources are close by (lt100 Mpc)
Dq degree ? Sources !!!
7
Relic Particles in Galactic Halo ?
Fundamental Physics ?
2
Sakar Toldrà, Nucl.Phys.B621495-520,2002 Toldrà
, astro-ph/0201151
8
16
Composition (p,Fe,g,n) Astronomy (point
sources)
Mrelic 1022 eV SUSY evolution, n-body decay
8
Required to solve EHECR-Puzzle
Better understanding of Syst. Errors Better
Resolution in Energy and Direction Much
more Statistics

• Hybrid Approach
• Independent EAS-observation techniques
  Shower-by-Shower in one Experiment
• ? Much larger Experiment

9
Atmospheric fluorescence detectors Atmospheric
fluorescence detectors
UHE Cosmic Rays with Auger
Surface particle detectors
Atmospheric fluorescence detectors
Eo gt1020 eV 1 part / (km2 century sr) ? 102
103 km2 collecting areas
10
Southern Site
Pampa Amarilla Province of Mendoza 3000 km2, 875
g/cm2, 1400 m
Surface Array 1600 Water Tanks 1.5 km
spacing 3000 km2
Lat. 35.5 south
Fluorescence Detectors 4 Sites 6 Telescopes per
site (180 x 30) 24 Telescopes total
70 km
11
View of Los LeonesFluorescence Site
12
Six Telescopes viewing 30x30 each
13
Schmidt Telescope using 11 m2 mirrors
14
Los Leones (fully operational)
Coihueco (fully operational)
15
Aligned Water Tanksas seen from Los Leones
16
Water Tank in the Pampa
17
Installation Chain
18
Southern Site as of Febr. 2005
650 Water Tanks (out of 1600) 12 Telescopes
19
Calibration
20
SD Calibration by Single Muon Triggers
Agreement with GEANT4 Simulation up to 10 ? VEM
(Vertical Equivalent Muons). VEM 100 PE
/PMT Huge Statistics! Systematic error 5
Sum
PMT 1
VEM Peak
Local EM Shower
PMT 2
PMT 3
21
SD calibration monitoring
Base-Temperature vs Time
Single tank response
single muons
Noise
Signal-Height vs Time
Signal-Height vs Base-Temp
3
Huge Statistics! Systematic error 5
22
FD Calibration
Absolute End to End Calibration
N Photons at diaphragm ? FADC counts
A Drum device installed at the aperture uniformly
illuminates the camera with light from a
calibrated source (1/month)
Mirror
Calibrated light source
Camera
Diffusely reflective drum
Drum from outside telescope building
Relative UV LED optical fibers (1/night)

• Alternative techniques for cross checks
• Scattered light from laser beam
• Calibr. light source flown on balloon

All agreed within 10 for the EA
23
Atmospheric Monitoring

• LIDAR at each eye
• cloud monitors at each eye
• central laser facility
• regular balloon flights

steerable LIDAR facilities located at each FD
eye
Central laser facility (fibre linked to tank)
LIDAR at each FD building

• light attenuation length
• Aerosol concentration

Balloon probes ? (T,p)-profiles
24
PerformancedemonstratedbyFirst Preliminary Data
25
Vertical (q35o) Inclined (q72o)
35 tanks
14 tanks
14 km
13 km
Energy (6-7) 10 19 eV
7 km
26
Young Old Shower
young shower
old shower
27
Vertical vs Horizontal Showers
0.2 µs
young showers Wide time distribution
Strong curvature Steep lateral distribution
old showers Narrow time distribution Weak
curvature Flat lateral distribution
28
A Big One 1020 eV, q 60
34 tanks
60
8 km
(m)
14 km
propagation time of 40 µs
Lateral Distribution Function
1020eV
1?1020eV
29
EAS as seen by FD-cameras
EAS as seen by FD-cameras
Two-Mirror event
Only pixels with 40 pe/100 ns are shown (10 MHz
FADC ? 4 g/cm2 12 bit resol., 15 bit dynamic
range) Pixel-size 1.5 light spot 0.65
(90) 1019 eV events trigger up to 30 km
30
Energy Reconstruction
Integral of Longitudinal Shower Profile ? Energy
4.8 Photons / m / electron ( 0.5 of dE/dx)
preliminary
31
A Stereo Hybrid q 70
70
Coihueco Fluores. Telescope
global view
37 km
Lateral Distribution Function
81019eV
24km
Los Leones Fluores. Telescope
32
A stereo hybrid q 70
37 km
24km
33
A stereo hybrid q 70
Shower Profile
71019eV
(SD 81019eV)
34
The Power of Hybrid Observations
35
The Power of Hybrid Observations
y
36

Some numbers data taking from Jan. 2004 SD
number of tanks in operation 650 fully
efficient above 3.1018 eV number of events
120,000 reconstructed ( gt 3fold, gt1018 eV)
16,500 at present 600 events/day FD number of
sites in operation 2 SDFD number of hybrids
1750 350 golden
37
Preliminary Sky Plot
no energy cut applied
Auger-S gt85o
Auger-S gt60o
38
Distribution of Nearby Matter
7-21 Mpc
Auger-S gt60o
Auger-N gt60o
Jim Cronin, astro-ph/0402487
39
Two Candidate Sites
AUGER NORTH
40
CONCLUSIONS

• Auger construction in rapid progress in south
  Physics data taking since January 2004
• Stable operation, excellent performance
• Hybrid approach is a great advantage!
• Neutrino sensitivity
• First physics results by summer 2005
• Energy spectrum
• Sky map
• Auger North proposal in progress

41
Pampa Amarilla
42
Hybrid Reconstruction Quality
E(eV) Ddir (o) DCore (m) DE/E () DXmaxg/cm2
1018 0.7 60 13 38
1019 0.5 50 7 25
1020 0.5 50 6 24
statisticalerrors only
zenith angles lt 60O
68 error bounds given detector is optimized for
1019eV, but good Hybrid reconstruction quality at
lower energy
43
High-Energy Neutrinos in Auger
? ns expected from distant AGN a/o decay of TDs ?
X-section _at_ 1020 eV 10-32 cm2 (Earth
opaque for En ?1015 eV) ? detection by
horizontal EAS ? If nm ? nt Oscillations ?
advantageous for observation of nt induced
Showers
n
TD
Tests of many AGN TD Models in range
AGN
44
LDF in Hybrid Events
lt EFD gt 1.2?1018 eV
Data points scaled from SD
LDF for 1018 eV Showers (Energy from FD)
good agreement of SD and FD good agreement
of SD and MC
45
Neutrino Sensitivities (per site)
Expected no. per year
?e and ?? Sensitivity
?? Sensitivity
High
DIS
None
?? Limit (E-2) for 5 years
X. Bertou et. al. Astropart. Phys. 17 (2002) 183
46
Integrated Sensitivity of Various Experiments
47
High-Energy Neutrinos in Auger
? ns expected from distant AGN a/o decay of TDs ?
X-section _at_ 1020 eV 10-32 cm2 (Earth
opaque for En ?1015 eV) ? detection by
horizontal EAS ? If nm ? nt Oscillations ?
advantageous for observation of nt induced
Showers
n
Neutrino Sensitivity (per flavor)