[PPT] - Measurement of the UHECRs flux and composition with Pierre Auger PowerPoint Presentation

SLIDE 1

OBSERVATORY

Measurement of the UHECRs flux and composition with Pierre Auger Observatory

Ioana C. Mari¸ s for the Pierre Auger Collaboration

SLIDE 2

Outline

Ultra high energy cosmic rays
Pierre Auger Observatory
Energy spectrum

(calibration, combined spectrum)

Composition

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 2

SLIDE 3

Introduction: Cosmic rays energy spectrum

Energy [eV]

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20

10 ]

1

sr

1

sec

2

E J(E) [m

16

10

14

10

12

10

10

10

8

10

6

10

4

10

2

10 1

2

10 (GeV)

pp

s Equivalent c.m. energy

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2

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10

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10 ATIC PROTON RUNJOB KASCADE Fly’s Eye Stereo MSU Akeno HiRes I HiRes II AGASA Auger 2007

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 3

SLIDE 4

Introduction: Cosmic rays energy spectrum

Energy [eV]

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10

16

10

17

10

18

10

19

10

20

10 ]

1.5

eV

1

sr

1

sec

2

J(E) [m

2.5

Scaled flux E

14

10

15

10

16

10

17

10 (GeV)

pp

s Equivalent c.m. energy

3

10

4

10

5

10

6

10

Tevatron (p-p) LHC (p-p) PROTON RUNJOB KASCADE Fly’s Eye Stereo Akeno

HiRes I HiRes II AGASA Auger 2007- combined

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 3

SLIDE 5

Introduction: Cosmic rays energy spectrum

Energy [eV]

15

10

16

10

17

10

18

10

19

10

20

10 ]

1.5

eV

1

sr

1

sec

2

J(E) [m

2.5

Scaled flux E

14

10

15

10

16

10

17

10 (GeV)

pp

s Equivalent c.m. energy

3

10

4

10

5

10

6

10

Tevatron (p-p) LHC (p-p) PROTON RUNJOB KASCADE Fly’s Eye Stereo Akeno

HiRes I HiRes II AGASA Auger 2007- combined

spectral features: change in composition nature of the sources transition from galactic to extragalactic origin

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 3

SLIDE 6

Introduction: Cosmic rays energy spectrum

Energy [eV]

15

10

16

10

17

10

18

10

19

10

20

10 ]

1.5

eV

1

sr

1

sec

2

J(E) [m

2.5

Scaled flux E

14

10

15

10

16

10

17

10 (GeV)

pp

s Equivalent c.m. energy

3

10

4

10

5

10

6

10

Tevatron (p-p) LHC (p-p) PROTON RUNJOB KASCADE Fly’s Eye Stereo Akeno

HiRes I HiRes II AGASA Auger 2007- combined

Greisen Zatsepin Kuzmin effect

p + γCMB → ∆+(1232)

→ p + π0 → pγγ → n + π+ → pe+ν 15% energy loss / interaction ⇒ only nearby universe visible

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 3

SLIDE 7

Introduction: Cosmic rays energy spectrum

Energy [eV]

15

10

16

10

17

10

18

10

19

10

20

10 ]

1.5

eV

1

sr

1

sec

2

J(E) [m

2.5

Scaled flux E

14

10

15

10

16

10

17

10 (GeV)

pp

s Equivalent c.m. energy

3

10

4

10

5

10

6

10

Tevatron (p-p) LHC (p-p) PROTON RUNJOB KASCADE Fly’s Eye Stereo Akeno

HiRes I HiRes II AGASA Auger 2007- combined

UHECRs Challenges

energy spectrum
reduce stat. and syst.

uncertainties

composition
arrival directions

Pierre Auger Observatory

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 3

SLIDE 8

Introduction: Measurement Techniques

Surface detector(SD)

acceptance geometric
energy scale from air shower

simulations

duty cycle ≈ 100%

Fluorescence detector(FD)

energies from longitudinal energy

deposit, nearly calorimetric

acceptance from detector and

atmosphere simulation

duty cycle ≈ 10%

Pierre Auger Observatory: acceptance and energy from data !

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 4

SLIDE 9

Pierre Auger Observatory: hybrid detector

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

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SLIDE 10

Surface detector (SD)

3000 km2, 1612 tanks deployed, 1584 with water, 1526 working

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 5

SLIDE 11

Surface detector (SD)

three 9 inch PMTs 12 tons of water electronics battery solar panel GPS antenna communications antenna XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 5

SLIDE 12

Fluorescence detector (FD)

Atmosphere monitoring

radio soundings (h, T, P), LED for end to end

calibration, LASER shots, horizontal attenuation, IR cloud cameras, star light monitor XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 5

SLIDE 13

Pierre Auger Observatory: event example

azimuth [deg] 150 155 160 165 170 175 180 elevation [deg] 5 10 15 20 25 30

t [25 ns] 150 200 250 300 350 400 450 S [VEM peak] 100 200 300 400 500 t [25 ns] 150 200 250 300 350 400 450 S [VEM peak] 2 4 6 8 10 12 14 t [25 ns] 150 200 250 300 350 400 450 S [VEM peak] 2 4 6 8 10 t [25 ns] 150 200 250 300 350 400 450 S [VEM peak] 0.5 1 1.5 2 2.5 3 3.5 4 t [25 ns] 150 200 250 300 350 400 450 S [VEM peak] 0.5 1 1.5 2 2.5 3 3.5 t [25 ns] 150 200 250 300 350 400 450 S [VEM peak] 1 2 3 4 5 t [25 ns] 150 200 250 300 350 400 450 S [VEM peak] 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 t [25 ns] 150 200 250 300 350 400 450 S [VEM peak] 0.5 1 1.5 2 2.5 3 3.5 4 t [25 ns] 150 200 250 300 350 400 450 S [VEM peak] 0.5 1 1.5 2 2.5 3 3.5 t [25 ns] 150 200 250 300 350 400 450 S [VEM peak] 0.2 0.4 0.6 0.8 1 1.2

x [km] 63.5 63.6 63.7 63.8 63.9 y [km] 47.1 47.2 47.3 47.4 47.5

FADC traces (25 ns) Detector signal (VEM) vs time Golden hybrid events: SD and FD Footprint on the camera

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 6

SLIDE 14

Pierre Auger Observatory: event example

r [m] 500 1000 1500 2000 2500 3000 Signal [VEM] 1 10

2

10

3

10

4

10 / NDoF: 6.833/ 7

2

χ

S(1000 m) ]

2

slant depth [g/cm

400 600 800

)]

2

dE/dX [PeV/(g/cm

10 20 30 40 50

/Ndf= 167.37/217

2

χ

Lateral distribution: S(1000 m) Longitudinal profile: energy

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 6

SLIDE 15

Pierre Auger Observatory: event example

r [m] 500 1000 1500 2000 2500 3000 Signal [VEM] 1 10

2

10

3

10

4

10 / NDoF: 6.833/ 7

2

χ

S(1000 m) ]

2

slant depth [g/cm

400 600 800

)]

2

dE/dX [PeV/(g/cm

10 20 30 40 50

/Ndf= 167.37/217

2

χ

Xmax⇒ composition Transfer the FD energy to the SD high statistics data! (no simulations needed) Lateral distribution: S(1000 m) Longitudinal profile: energy

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 6

SLIDE 16

S(1000 m) to Energy

From ’Golden Hybrids’ (FD+SD) lateral particle distribution ↓ S(1000m) ↓ zenith angle correction (constant intensity cut method) ↓ S38 ↓ FD energy ↓ ESD

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 7

SLIDE 17

S(1000 m)- Attenuation in the atmosphere

ground level inclined shower vertical shower

inclined S(1000m) < vertical S(1000m)

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 8

SLIDE 18

Zenith angle correction: S(1000m) ⇒ S38

θ

2

cos

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 S(1000 m) [VEM] 25 30 35 40 45 50 55 60

polynomial exponential

S38 S38(1000 m) = S(1000 m)/f(θ)

f(θ) = 1 + a · x + b · x2 , x = cos2 θ − cos2 38◦

correct all shower sizes to the same angle 38◦

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 9

SLIDE 19

Energy Calibration

Stat. uncertainties:

S38◦ (≈ 16%)

shower to shower

fluctuations

reconstruction

EFD(≈ 8%)

reconstruction
atmosphere

E = A · SB

38◦

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 10

SLIDE 20

Energy Scale Systematics

Absolute Fluorescence Yield 14% Pressure dependence of Fluorescence Yield 1% Humidity dependence of Fluorescence Yield 1% Temperature dependence of Fluorescence Yield 5% FD absolute calibration 11% FD wavelength dependence response 3% Rayleigh scattering in atmosphere 1% Wavelength dependence of aerosol scattering 1% FD reconstruction method 10% Invisible energy 5% Total: 22% experimental uncertainties to be improved

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 11

SLIDE 21

Vertical Energy Spectrum

lg(E/eV) 18.5 19 19.5 20 20.5 ))

1

sr

1

s

2

J /(m lg( E

17
16
15
14
13

E[eV]

18

10 × 3

19

10

19

10 × 2

20

10

20

10 × 2

4128 2450 1631 1185

761 560 367 284 178 125 79 54 25 14 5 5 1 1

Auger ICRC 2007, vertical

5165 km2 sr year until ICRC 2007

0.8 × one year complete observatory

Events (observed/expected) above 4 · 1019 eV: 51/(132 ± 9) above 1020 eV: 2/(30 ± 2.5)

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

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SLIDE 22

Horizontal and Hybrid Energy Spectra

lg(E/eV) 18 18.5 19 19.5 20 20.5 ))

2

eV

1

sr

1

s

2

J /(m

3

lg( E 23.5 24 24.5

E[eV]

18

10 × 2

19

10

19

10 × 2

20

10

20

10 × 2

Auger ICRC 2007, horizontal

lg(E/eV) 18 18.5 19 19.5 20 20.5 ))

2

eV

1

sr

1

s

2

J /(m

3

lg( E 23.5 24 24.5

E[eV]

18

10 × 2

19

10

19

10 × 2

20

10

20

10 × 2

Auger ICRC 2007, hybrid

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 13

SLIDE 23

Auger Energy Spectrum

lg(E/eV) 18 18.5 19 19.5 20 20.5 ))

2

eV

1

sr

1

s

2

J /(m

3

lg( E 23.5 24 24.5

E[eV]

18

10 × 2

19

10

19

10 × 2

20

10

20

10 × 2

vertical hybrid horizontal combined

Very good agreement between the three spectra (< 3%)

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 14

SLIDE 24

Auger Energy Spectrum: Spectral features

lg(E/eV) 18 18.5 19 19.5 20 20.5

1

2.62

E × J/ A

1
0.5

0.5 1 1.5 2

E[eV]

18

10

18

10 × 2

19

10

19

10 × 2

20

10

20

10 × 2 Auger ICRC 2007, combined

γ1 = 3.30 ± 0.06 γ2 = 2.62 ± 0.03 γ3 = 4.14 ± 0.42

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 15

SLIDE 25

Auger Energy Spectrum: Spectral features

lg(E/eV) 18 18.5 19 19.5 20 20.5

1

2.62

E × J/ A

1
0.5

0.5 1 1.5 2

E[eV]

18

10

18

10 × 2

19

10

19

10 × 2

20

10

20

10 × 2 Auger ICRC 2007, combined

ankle: (4.46 ± 0.4) · 1018 eV flux suppression: (56 ± 8) · 1018 eV

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 15

SLIDE 26

Anisotropies- energy spectrum

lg(E/eV) 18 18.5 19 19.5 20 20.5

1

2.62

E × J/ A

1
0.5

0.5 1 1.5 2

E[eV]

18

10

18

10 × 2

19

10

19

10 × 2

20

10

20

10 × 2 Auger ICRC 2007, combined

the energy and redshift that maximise the signal are compatible

with the GZK horizon

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 16

SLIDE 27

Anisotropies- energy spectrum

lg(E/eV) 18 18.5 19 19.5 20 20.5

1

2.62

E × J/ A

1
0.5

0.5 1 1.5 2

E[eV]

18

10

18

10 × 2

19

10

19

10 × 2

20

10

20

10 × 2 Auger ICRC 2007, combined

Next talk by Raffaella Bonino

the energy and redshift that maximise the signal are compatible

with the GZK horizon

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 16

SLIDE 28

Mass composition- energy spectrum

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 17

SLIDE 29

Mass composition- energy spectrum

)

2

Slant depth (g/cm 200 300 400 500 600 700 800 900 1000 )

9

Number of charged particles (x10 1 2 3 4 5 6 7 8 Height a.s.l. (km) 2 4 6 8 10 12 eV

19

proton, E=10 Auger shower )

2

Slant depth (g/cm 200 300 400 500 600 700 800 900 1000 )

9

Number of charged particles (x10 1 2 3 4 5 6 7 8 Height a.s.l. (m) 2000 4000 6000 8000 10000 12000 eV

19

iron, E=10 Auger shower )

2

Slant depth (g/cm 200 300 400 500 600 700 800 900 1000 )

9

Number of charged particles (x10 1 2 3 4 5 6 7 8 Height a.s.l. (km) 2 4 6 8 10 12 eV

19

ray, E=10

γ Auger shower

Xmax

⇒ FD composition

shower front properties

⇒ SD composition

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 18

SLIDE 30

Mass composition- energy spectrum

E [eV]

18

10

19

10

]

2

> [g/cm

max

<X

650 700 750 800 850

QGSJETII-03 QGSJET01 SIBYLL2.1 EPOS1.6

p r

t
n

i r

n

A

A: Allard et al. B: Berezinsky et al.

B

PAO-Hybrid HiRes-Stereo

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 19

SLIDE 31

Conclusions

Auger energy spectrum

vertical SD spectrum acceptance: 5165 km2 sr year (02.2007)
good agreement between the three energy spectra
6σ evidence for flux suppression at high energies
combined with the anisotropies studies ⇒ GZK effect

Composition

mean Xmax ⇒ mixed composition
(strong photon limits from SD+ independent FD: TD & SHDM

excluded)

(neutrino limits)
....

Outlook

(soon) updated energy spectrum: 8000 km2 sr year
high statistics above 1019.8 eV needed to constrain models

⇒ Auger North

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 20

SLIDE 32

Extra slides

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 21

SLIDE 33

Neutrino limit

Neutrino Energy [eV]

14

10

16

10

18

10

20

10

22

10

24

10

26

10 ]

1

sr

1

s

2

f(E) [GeV cm

2

E

8

10

7

10

6

10

5

10

4

10

3

10 AMANDA II HiRes HiRes HiRes Baikal RICE’06 GLUE’04 ANITA-lite FORTE’04 GZK neutrinos

Auger differential Auger integrated TD (Kal. 02) XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 22

SLIDE 34

Auger Energy Spectrum: Extra slide 1

23 23.4 23.8 24.2 24.6 25 18 18.5 19 19.5 20 20.5 log(E/eV) log(J(E)*E3 (/m2 s sr eV-2)

HR-I (mono) HR-II (mono) AGASA Auger (2007)

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

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SLIDE 35

Auger Energy Spectrum: Extra slide 1

23 23.4 23.8 24.2 24.6 25 18 18.5 19 19.5 20 20.5 log(E/eV) log(J(E)*E3 (/m2 s sr eV-2)

Auger (2007, +17%) HR-I (mono) HR-II (mono) AGASA (-25%)

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

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SLIDE 36

Method of Constant Intensity

Hypothesis: cosmic ray flux is isotropic (at least in local coordinates) Φ = dN dΩdEdAeffdt SD data: projection on flat array geometry Aeff = A · cos θ intensity: events above a certain energy dI d cos2 θ = const

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

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SLIDE 37

Method of Constant Intensity

aim: find S(θ) from I = const, ∆ cos2 θ = const

lg( S(1000 m) /VEM) 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 # 1 10

2

10

3

10

4

10

° < 0 θ < ° 25 ° < 25 θ < ° 37 ° < 37 θ < ° 47 ° < 47 θ < ° 59

/VEM)

38

lg( S 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 # 1 10

2

10

3

10

4

10

° < 0 θ < ° 25 ° < 25 θ < ° 37 ° < 37 θ < ° 47 ° < 47 θ < ° 59

’correct’ all shower sizes to same zenith angle 38◦

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

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SLIDE 38

Acceptance

iron

θ

2

cos 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 lg(E/eV) 17.6 17.8 18 18.2 18.4 18.6 18.8 19 19.2 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

proton

θ

2

cos 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 lg(E/eV) 17.6 17.8 18 18.2 18.4 18.6 18.8 19 19.2 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

trigger efficiency= 1 for E>4 EeV

(independent of primary mass, core position , etc)

cross-checked with hybrid events!
reconstruct any T5 event
aperture is sum of elementary hexagons

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

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SLIDE 39

Acceptance

trigger efficiency= 1 for E>4 EeV

(independent of primary mass, core position , etc)

cross-checked with hybrid events!
reconstruct any T5 event
aperture is sum of elementary hexagons

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 26

SLIDE 40

Energy Calibration

Stat. uncertainties:

S38◦ (≈ 16%)

shower to shower

fluctuations

reconstruction

EFD(≈ 8%)

reconstruction
atmosphere

E = A · SB

38◦

XLIII nd Rencontres de Moriond- EW, 2008

I. C. Mari¸

s for the Pierre Auger Collaboration 27

SLIDE 41

Photon limit

[eV] E

19

10

20

10 [%] Photon Fraction for E>E 1 10 100

SHDM SHDM’ TD Z Burst GZK Photons) Limit (E>E

A A A2 HP HP AY Y Y FD

limits at 95% CL

SHDM & TD: astro-ph/0506128 SHDM’: C.T. Hill Nucl.Phys. B224, 469(1983), T.W.B.Kibble, Rep. Prog.Phys. 58, 477(1995)

XLIII nd Rencontres de Moriond- EW, 2008

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SLIDE 42

Photon limit

[eV] E

19

10

20

10 ]

1

yr

1

sr

2

[km Photon Flux for E>E

3

10

2

10

1

10

SHDM SHDM’ TD Z Burst GZK Photons ) Limit (E>E

A

limits at 95% CL

SHDM & TD: astro-ph/0506128 SHDM’: C.T. Hill Nucl.Phys. B224, 469(1983), T.W.B.Kibble, Rep. Prog.Phys. 58, 477(1995)

XLIII nd Rencontres de Moriond- EW, 2008

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