charged cosmic rays and neutrinosweb.phys.ntnu.no/~mika/now12.pdf · 2012-09-14 · (resonant)...

[]

Charged Cosmic Rays and Neutrinos

Michael Kachelrieß

NTNU, Trondheim

Introduction

Outline of the talk1 Introduction ⇒ talk by F. Halzen

2 SNRs as Galactic CR sources

3 Extragalactic CRs

◮ transition

◮ anisotropies

◮ composition measurements

4 Astrophysical source models ⇒ talks of S. Ando & F. Halzen

5 Cosmogenic neutrinos

6 Summary

Michael Kachelrieß (NTNU Trondheim) Cosmic Rays and Neutrinos NOW 2012 2 / 25

Introduction

The CR–γ–ν connection:

HE neutrinos and HE photons are unavoidable byproducts of HECRs

astrophysical models, direct flux:◮ strongly model dependent fluxes


Introduction




astrophysical models, cosmogenic flux:◮ ratio Iν/IN determined by nuclear composition and source evolution


Introduction





top-down models:◮ large fluxes with Iν ≫ Ip

◮ ratio Iν/Ip fixed by fragmentation


Introduction





top-down models:◮ large fluxes with Iν ≫ Ip

◮ ratio Iν/Ip fixed by fragmentation

prizes to win:◮ astronomy above 100 TeV◮ identification of CR sources◮ determine galactic–extragalactic transition of CRs◮ test/discover new particle physics


[]

Diffusive shock acceleration in test particle picture:

energy spectrum dN/dE ∝ 1/E2

escape flux dN/dr ∝ exp(−(r − Rsh)/x0) for r > Rsh

SNRs as CR sources

SNR: Leptonic versus hadronic models [⇒ Giordano ]

Test the SNR CR acceleration paradigm through SNR’s particle radiation:


SNRs as CR sources

SNR: Leptonic versus hadronic models [⇒ Giordano ]

Test the SNR CR acceleration paradigm through SNR’s particle radiation:

combining Fermi and IACT contrains models tightly


SNRs as CR sources

Maximal energy of SNR: Lagage-Cesarsky limit

acceleration rate

βacc =dE

dt

∣

∣

∣

∣

acc

=3Ev2

sh

ζD(E), ζ ∼ 8 − 20


SNRs as CR sources


acceleration rate

βacc =dE

dt

∣

∣

∣

∣

acc

=3Ev2

sh

ζD(E), ζ ∼ 8 − 20

assume Bohm diffusion D(E) = cRL/3 ∝ E and B ∼ µG


SNRs as CR sources


acceleration rate

βacc =dE

dt

∣

∣

∣

∣

acc

=3Ev2

sh

ζD(E), ζ ∼ 8 − 20

assume Bohm diffusion D(E) = cRL/3 ∝ E and B ∼ µG

⇒ Emax ∼ 1013—1014 eV


SNRs as CR sources

Maximal energy of SNR: [Bell, Luzcek ’02, Bell ’04 ]

(resonant) coupling CR ↔ Alfven waves


SNRs as CR sources



non-linear non-resonant magnetic field amplification


SNRs as CR sources



non-linear non-resonant magnetic field amplification

observational evidence for B ∼ 0.1 − 1 mG in young SNR rims


SNRs as CR sources

SNR RX J1713.7-3946

/%��#��;��"

� �7��!��;��"

changes on δt ∼ 1 yr imply B ∼ 1mG⇒ Emax ∼ 1016 eV for protons


SNRs as CR sources

Tycho observations by VERITAS

Γ = 1.95 ± 0.51stat ± 0.30sys


SNRs as CR sources



SNRs as CR sources


CRs escape before Sedov phase


SNRs as CR sources


CRs escape before Sedov phaseEγ,max >10 TeV requires:

◮ protons with E > 100 TeV


SNRs as CR sources



◮ protons with E > 100 TeV◮ electrons, ICS on CMB

Eγ =4

3

εγE2

e

m2e

≈ 3 GeV

(

Ee

1TeV

)2


SNRs as CR sources



◮ protons with E > 100 TeV◮ electrons, ICS on CMB

Eγ =4

3

εγE2

e

m2e

≈ 3 GeV

(

Ee

1TeV

)2

electrons with E > 50 TeV


SNRs as CR sources

Tycho: Leptonic versus hadronic models [Morlino, Capriolo ’11 ]

Radio

Suzaku

FermiLAT

VERITAS

10 15 20 259.5

10.0

10.5

11.0

11.5

12.0

12.5

13.0

13.5

LogHΝL @HzD

LogHΝ

FΝL@J

yH

zD


SNRs as CR sources

Why is there a universal CR spectrum?age-limited

◮ CRs are advected down-stream, released at end of Sedov phase– adiabatic losses, reduced Emax, no B amplification


SNRs as CR sources

Why is there a universal CR spectrum?

age-limitedCRs escape up-stream:

◮ standard approach: homogeneous field & free escape boundary


SNRs as CR sources



◮ standard approach: homogeneous field & free escape boundary◮ filamentation instability: [Reville, Bell ’11 ]


SNRs as CR sources



◮ standard approach: homogeneous field & free escape boundary◮ filamentation instability: [Reville, Bell ’11

]


Transition from Galactic to extragalactic CRs Nuclear composition

Transition – KASCADE Grande data

energy (eV/particle)

1410 1510 1610 1710 1810 1910 2010

]1.

5 e

V-1

sr

-1 s

-2 [

m2.

5 E·

dI/d

E

1310

1410

1510

1610

1710

Grande QGSJETII, all-particle (this work)Grande QGSJETII, hydrogen (this work)Grande QGSJETII, He+C+Si (this work)Grande QGSJETII, iron (this work)KASCADE QGSJETII, all-particle (this work)KASCADE QGSJETII, hydrogen (this work)KASCADE QGSJETII, He+C+Si (this work)KASCADE QGSJETII, iron (this work)


EAS-TOP, all-particleAkeno, all-particleHiRes II, all-particleGAMMA, all-particleTibet, all-particle


Transition from Galactic to extragalactic CRs Nuclear composition

Transition – KASCADE Grande data

energy (eV/particle)

1410 1510 1610 1710 1810 1910 2010

]1.

5 e

V-1

sr

-1 s

-2 [

m2.

5 E·

dI/d

E

1310

1410

1510

1610

1710



EAS-TOP, all-particleAkeno, all-particleHiRes II, all-particleGAMMA, all-particleTibet, all-particle

rising proton fraction E >∼

1017 eV?


Transition from Galactic to extragalactic CRs Anisotropies

PAO result on dipole anisotropy:

[EeV] E0.3 1 2 3 4 5 10 20

Am

plitu

de

-310

-210

-110

1

Rayleigh AnalysisEast/West Analysis



PAO result on dipole anisotropy:

[EeV] E0.3 1 2 3 4 5 10 20

]°P

hase

[

180

270

0

90

180

East/West analysisRayleigh analysis



Anisotropy of protons at E = 1018 eV [Giacinti et al. ’11 ]

10

15

20

25

30

35

40

2 3 4 5 6 7 8

Dip

ole

ampl

itude

(pe

rcen

t)

B0 (µG)

Profile 2, 200 pcProfile 1, 200 pcProfile 2, 500 pcProfile 1, 500 pc

protons excluded for all reasonable parameters

⇒ measuring protons at E = 1018 eV means fixing transition energy


Nuclear composition

Energy spectrum

PAO confirmed the “GZK-suppression” seen first by HiRes


Nuclear composition

Energy spectrum

PAO confirmed the “GZK-suppression” seen first by HiRes

interpretation:◮ Emax of sources?◮ does not fix composition: proton GZK, Fe photo disintegration


Nuclear composition

Determining nuclear composition: Xmax and RMS(Xmax)Bethe-Heitler model: Nmax ∝ E0 and Xmax ∝ ln(E0)


Nuclear composition


superposition model: nuclei = A shower with E = E0/A

⇒ Xmax ∝ − ln(A) and RMS(Xmax) reduced


Nuclear composition


superposition model: nuclei = A shower with E = E0/A

⇒ Xmax ∝ − ln(A) and RMS(Xmax) reduced

RMS(Xmax) has smaller theoretical error than Xmax


Nuclear composition

Nuclear composition via Xmax:

/decade] 18 19

]2>

[g/c

mm

ax<X

650

700

750

800

850

proton

iron

QGSJET01QGSJETIISibyll2.1EPOSv1.99

Auger 2009

HiRes ApJ 2005


Nuclear composition

Nuclear composition via RMS(Xmax) from Auger:

E [eV]

1810 1910

E [eV]

1810 1910

]2)

[g/c

mm

axR

MS

(X

10

20

30

40

50

60

70 proton

iron


Nuclear composition

Mixed composition:

Mean 744.8RMS 62.02

]2 [g/cmmaxX600 650 700 750 800 850 900 9500

0.02

0.04

0.06

0.08

0.1

0.12

Mean 744.8RMS 62.02

70% proton

30% iron

sum

σ2 =∑

i

fiσ2i +

∑

i<j

fifj(Xmax,i − Xmax,j)2


Nuclear composition

What goes wrong?internal discrepancy in PAO:

◮ AGN correlations favor protons

◮ RMS(Xmax) favors heavy

◮ energy spectrum, Xmax and RMS(Xmax) difficult to fit

experimental discrepancy: HiRes/TA ⇔ Auger

◮ Xmax

◮ RMS(Xmax)

discrepancy experiment ⇔ theory:

◮ energy ground array/fluoresence ∼ 1.2

◮ muon number exp/MC ∼ 1.2 − 2


Nuclear composition

Comparison of MCs to LHC data: Energy flow

'()*'+),-)./00/1)+234/)05/6)7/1/)891024:;91;6)

./0PYTHIA as typical HEP model Cosmic ray interaction models


Cosmogenic neutrinos Limit from EGRB

Fermi-LAT limit for cosmogenic neutrinos: [Berezinsky et al. ’10,. . . ]

106 108 1010 1012 1014 1016 1018 1020 102210-2

100

102

104

E2 J(

E), e

V cm

-2s-1

sr-1

E, eV

Fermi LAT

p

zmax=2, Emax=1021eVHiRes




E, eV1810 1910 2010 2110

-1st

er-1

sec

-2m2

J(E

) eV

3E

2310

2410

2510eV; m=021=10

max=2; Emaxz

HiRes II HiRes I

p

iνΣ

2.7

2.0

2.7

2.0

2.0

2.7




0 1 2 3 4 5 610-8

10-7

10-6

10-5

10-4

cas(m

), eV

/cm

3 5

5

6

6

4

4

2

m

5.8x10-7

Emax=1021eV

2

g=2.6g=2.0




1016 1017 1018 1019 1020 1021 102210-1

100

101

102

103

104

105

106

1021

1020

IceCube 5yr tilted

2.0

RICE

Auger diff.

E-2 cascade

ANITA

E2 J(

E), e

Vcm

-2s-1

sr-1

E, eV

ANITA-liteAuger

2.6

nadirJEM-EUSOBAIKAL

e =

1022

m=3




108 1010 1012 101410-2

100

m=0, g=2.0, z

max=2, E

max=1021eV

1 nG

E

2 J(E

), eV

cm

-2s-1

sr-1

E, eV

0.01 nG


Cosmogenic neutrinos Dependence on composition

Cosmogenic neutrinos: proton vs. Fe

[Anchordoqui et al. ’07 ]


Summary

Summary

Galactic CRs: Tycho: room left for leptonic models marginal

UHECRs:

◮ understanding differences PAO vs. TA and MC vs. experiment

◮ extensions (HEAT, Amiga, infill array) allow cross checks

◮ test of MC models against LHC data

◮ proton dominance at 1018 eV fixes transition energy

cosmogenic neutrino flux is low, because of Fermi limit

2 Icecube events: start of neutrino astronomy?


New TA data for Xmax:


Zenith angle dependence, TA scintillator:


Icecube events

Icecube events

2 cascade events close to Emin = 1015 eV, bg = 0.14

•

•

•

energy distributions of neutrinos reaching to the IceCube


Icecube events

Icecube events


Glashow resonance◮ very narrow

◮ if W− → q̄q, detected energy too low


Icecube events

Icecube events


Glashow resonance

cosmogenic neutrinos: <∼

1 events/yr

[Anchordoqui et al. ’07 ]


Icecube events

Icecube events


Glashow resonance


1 events/yr

extragalactic sources: extension to higher energies?if yes, then diffuse flux


Icecube events

Icecube events


Glashow resonance


1 events/yr

extragalactic sources: extension to higher energies?if yes, then diffuse flux

Galactic point sources: SNR with d ∼ 50 pc


charged cosmic rays and neutrinosweb.phys.ntnu.no/~mika/now12.pdf · 2012-09-14 · (resonant)...

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