argentina australia bolivia * brasil croatia czech republic france germany italy poland mexico
DESCRIPTION
Argentina Australia Bolivia * Brasil Croatia Czech Republic France Germany Italy Poland Mexico Netherlands Portugal Romania* Slovenia Spain United Kingdom USA Vietnam *. ~ 500 Scientists 19 Countries. Up to the “knee” – observe nuclei from H to Fe and beyond. - PowerPoint PPT PresentationTRANSCRIPT
ArgentinaAustralia
Bolivia*
BrasilCroatia
Czech RepublicFrance
GermanyItaly
Poland Mexico
NetherlandsPortugal
Romania*Slovenia
Spain United Kingdom
USAVietnam*
~ 500 Scientists 19 Countries
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~ E-2.7
~ E-3.1 Above 1020 eV (50 Joules!):Φ ≈ 1 per km2 per century
Very low flux …
Very big detectors
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Up to the “knee” – observe nuclei from H to Fe and beyond
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Extensive Air Showers
(1019 eV) N ~ 1010 particles
90% e+/- 10% μ +/- (primary proton)
e+/- ~ 5 MeV μ +/- ~ 5 GeV
(cosmic ray proton)
Reconstructed longitudinal profiles
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E=1019eV
E=1020eV
E=1018eV
Trajectories of Cosmic Ray Protons in the Galaxy
• Protons are trapped in our Galaxy up to ~1018eV
• Protons can travel straight above ~1020eV
• Charged-Particle Astronomy
How to get particles to extreme energy
• Fermi Acceleration (Bottom-Up) - repeated encounters with strong plasma shocks - naturally produces power-law with correct index - maximum energy can be extremely large - observed in nature
• “Exotic” (Top-Down) - decay of massive relic particles - interaction of nu’s w/cosmic background neutrinos (-> Z) - topological defects, other things ? - Signature: photons, neutrinos
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Emax = β B L ZeB
L
βc shock speed
Ze particle charge
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VLA image of Cygnus AAn active galaxy
M. Urry, astro-ph/0312545
Acceleration can occur both at remote termination shocks and at shocks near the central engine
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AGN
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38° South, Argentina, Mendoza, Malargue
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Surface Array 1650 detector stations 1.5 Km spacing 3000 km2
Fluorescence Detectors 4 Telescope enclosures 6 Telescopes per
enclosure 24 Telescopes total
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View of Los Leones Fluorescence Site
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The Fluorescence Detector
3.4 m spherical mirror
PMT cameraSpherical surface
camera440 PMT with light
collectorsLarge 300x300 field of
view1.5º pixel fov
(spot 1/3 of pixel)
FADC trace
100 s
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Energy reconstructed from measured maximum size --- calorimetric (minimal MC) 16
telescope calibration includes the atmosphere
Mike Sutherland
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μe
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“GZK”
First pointed out in 1966 in two papers, one by Greisen and one by Zatsepin & Kuz’min
p + (2.7oK) p 0
n +
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Nuclei photo-disintegrate at similar thresholds, distances
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Improved!
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“Tail” dominated by protons
Proton-Air Cross Section from the Depth of Shower Maximum
27Phys. Rev. Lett. 109 (2012) 062002
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(Only about 10% of all events can have Xmax measured directly)
2013 update of Physical Review Letters 104 (2010) 091101
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SD: Development of Muons in Shower
SD: Asymmetry of Shower front thickness
FD: Mean depth of Shower Max
FD: Fluctuations of Shower Max
Spectral “Ankle”
Update: Correlation with nearby AGNE > 55 EeV, within 3.1o of VCV catalog AGN, d < 75 Mpc, Cover of Science!
Through summer 2007:
20 of 27 events correlate
5.7 expected if isotropic (21%)
Probability ~ 10-3
Science 318 (2007) p.939
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Cumulative event total
Frac
tion
corr
elat
ing
Update: Correlation with nearby AGN
Bah, Humbug!
Status in 2013
Full Moon
Closest (4 Mpc) powerful radio galaxy with characteristics jets and lobes, candidate for UHECR acceleration.
Cen A ...
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2 Events
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Cumulative total within Ψ (degrees)
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R = “Rigidity” = E/Z (rL = E/qB = R/B )
e.g.: R = 10 EV for 10 EeV proton, 260 EeV iron
R ~ 100 EV
R ~ 20 EV
R ~ 10 EV
Azadeh Keivani
Some fun: double bumps
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Amir Shadkam, LSU
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http://bit.ly/augerstorm
http://www.youtube.com/watch?v=E0h36hPpeJE
Summary
• Energy spectrum exhibits ankle and GZK suppression
• The sources are extragalactic, within the “GZK sphere”: (weak) anisotropy persists above ~60 EeV
• The composition is baryonic, appearing to become iron-dominated (or new particle physics … models do not give enough muons)
• p-Air, p-p cross sections beyond the LHC energy
• Few/no photons or neutrinos (disfavors exotic “top down” models) • Photons/neutrinos nearing GZK regime 42
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What’s Next?
Auger has been “operating” since 2004, fully deployed since 2008. The international agreement runs for ~2 more years (end of 2015)
We hope to continue after that, are exploring new technologies in use now or can be started very soon …
-- Auger Engineering Radio Array - AERA
-- Microwave, GHz, ... prototypes operating
-- Focus on better composition determination through new muon detectors, new fluorescence techniques, … R&D
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40 MHz
120 MHz
Electronics UpgradeIncrease the speed of the FADC by a factor of three;Increase dynamic range
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Reconstructed Muons and Muon LDF
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Scintillators near or under (or over) SD tanks
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Segmented Tank
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Muon Detection: RPCs
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• First Lab Prototype• 0.5 x 1 m2
• 0.3 mm gaps• Original RPC design for timing (st~200ps)
• Main goal: test low gas flux
• Second Lab Prototype• 0.5 x 1 m2
• 2 x 1 mm gap• Main Goal:
• Optimize efficiency• Optimize signal
RPC prototypes
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Muon signals : tank vs RPCproton, 1019.5 eV q=40o
Hits in RPC
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Photons
Muons
Muon signals : tank vs RPCproton, 1019.5 eV q=40o