ArgentinaAustralia

Bolivia*

BrasilCroatia

Czech RepublicFrance

GermanyItaly

Poland Mexico

NetherlandsPortugal

Romania*Slovenia

Spain United Kingdom

USAVietnam*

~ 500 Scientists 19 Countries

1

~ E-2.7

~ E-3.1 Above 1020 eV (50 Joules!):Φ ≈ 1 per km2 per century

Very low flux …

Very big detectors

2

Up to the “knee” – observe nuclei from H to Fe and beyond

3

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

4

5

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

7

Emax = β B L ZeB

L

βc shock speed

Ze particle charge

8

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

9

AGN

10

38° South, Argentina, Mendoza, Malargue

11

Surface Array 1650 detector stations 1.5 Km spacing 3000 km2

Fluorescence Detectors 4 Telescope enclosures 6 Telescopes per

enclosure 24 Telescopes total

12

13

View of Los Leones Fluorescence Site

14

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

15

Energy reconstructed from measured maximum size --- calorimetric (minimal MC) 16

telescope calibration includes the atmosphere

Mike Sutherland

17

18

19

μe

21

22

23

“GZK”

First pointed out in 1966 in two papers, one by Greisen and one by Zatsepin & Kuz’min

p + (2.7oK) p 0

n +

24

Nuclei photo-disintegrate at similar thresholds, distances

25

Improved!

26

“Tail” dominated by protons

Proton-Air Cross Section from the Depth of Shower Maximum

27Phys. Rev. Lett. 109 (2012) 062002

28

(Only about 10% of all events can have Xmax measured directly)

2013 update of Physical Review Letters 104 (2010) 091101

29

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

30

31

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 ...

32

2 Events

33

34

35

Cumulative total within Ψ (degrees)

36

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

37

Amir Shadkam, LSU

38

39

40

41

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

43

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

44

40 MHz

120 MHz

Electronics UpgradeIncrease the speed of the FADC by a factor of three;Increase dynamic range

45

Reconstructed Muons and Muon LDF

46

Scintillators near or under (or over) SD tanks

47

Segmented Tank

48

Muon Detection: RPCs

49

• 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

50

Muon signals : tank vs RPCproton, 1019.5 eV q=40o

Hits in RPC

51

Photons

Muons

Muon signals : tank vs RPCproton, 1019.5 eV q=40o