Auger results and the sources of UHECRs Michael Kachelrie NTNU, - - PowerPoint PPT Presentation

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Jan 06, 2023 227 likes •635 views

Auger results and the sources of UHECRs Michael Kachelrie NTNU, Trondheim [] Outline of the talk 1 Motivation & expectations for UHECR astronomy 2 Auger data and their interpretation 3 Auto-correlation analysis 4 Cen A as UHECR source

SLIDE 1

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Auger results and the sources of UHECRs

Michael Kachelrieß NTNU, Trondheim

SLIDE 2

Outline of the talk

1 Motivation & expectations for UHECR astronomy 2 Auger data and their interpretation 3 Auto-correlation analysis 4 Cen A as UHECR source Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 3

What is the bonus of UHECR astronomy?

astronomy with VHE photons restricted to few Mpc:

10 12 14 16 18 20 22 Gpc 100Mpc 10Mpc Mpc 100kpc 10kpc kpc log10(E/eV)

photon horizon γγ → e+e− CMB IR radio Virgo ⇓ GC ⇓

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 4

What is the bonus of UHECR astronomy?

astronomy with VHE photons restricted to few Mpc: astronomy with HE neutrinos:

large λν, but also large uncertainty δϑ > ∼ 1◦

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 5

What is the bonus of UHECR astronomy?

astronomy with VHE photons restricted to few Mpc: astronomy with HE neutrinos:

large λν, but also large uncertainty δϑ > ∼ 1◦ small event numbers: < ∼ few/yr for PAO or ICECUBE identification of steady sources challenging

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 6

What is the bonus of UHECR astronomy?

10 12 14 16 18 20 22 Gpc 100Mpc 10Mpc Mpc 100kpc 10kpc kpc log10(E/eV)

proton horizon photon horizon γγ → e+e− CMB IR Virgo ⇓ GC ⇓

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 7

What is the bonus of UHECR astronomy?

10 12 14 16 18 20 22 Gpc 100Mpc 10Mpc Mpc 100kpc 10kpc kpc log10(E/eV)

proton horizon photon horizon γγ → e+e− CMB IR Virgo ⇓ GC ⇓ use larger statistics of UHECRs well-suited horizon scale small enough deflections in magnetic fields?

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 8

Possible anisotropies of extragalactic CRs:

1 Dipole anisotropy – cosmol. Compton-Getting effect

induced by motion of Sun relative to cosmological rest frame requires λCR(E) > ∼ λLSS

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 9

Possible anisotropies of extragalactic CRs:

1 Dipole anisotropy – cosmol. Compton-Getting effect

induced by motion of Sun relative to cosmological rest frame requires λCR(E) > ∼ λLSS

2 Anisotropies on medium scales

z ≤ 0.2: spots with ℓ ∼ 20–40 degrees reflects LSS of matter, modified by B requires λCR(E) < ∼ few×λLSS

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 10

Possible anisotropies of extragalactic CRs:

1 Dipole anisotropy – cosmol. Compton-Getting effect

induced by motion of Sun relative to cosmological rest frame requires λCR(E) > ∼ λLSS

2 Anisotropies on medium scales

z ≤ 0.2: spots with ℓ ∼ 20–40 degrees reflects LSS of matter, modified by B requires λCR(E) < ∼ few×λLSS

3 Small-scale clustering

Small-scale ∼ exp. angular resolution/deflections in B ⇒ CR from the “same” point sources requires small qB/E and small Ns

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 11

Possible anisotropies of extragalactic CRs:

1 Dipole anisotropy – cosmol. Compton-Getting effect

induced by motion of Sun relative to cosmological rest frame requires λCR(E) > ∼ λLSS

2 Anisotropies on medium scales

z ≤ 0.2: spots with ℓ ∼ 20–40 degrees reflects LSS of matter, modified by B requires λCR(E) < ∼ few×λLSS

3 Small-scale clustering

Small-scale ∼ exp. angular resolution/deflections in B ⇒ CR from the “same” point sources requires small qB/E and small Ns

4 Correlations with specific sources

requires small qB/E and small Ns good source catalogue

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 12

Correlations with AGNs: Auger analysis

AGN from VCC catalogue:

mainly Seyfert galaxies expectation: Emax ≪ 1020eV for most AGN in VCC

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 13

Correlations with AGNs: Auger analysis

first data set with data < May 2006 to fix cuts: Eth = 56EeV, ℓ0 = 3.1◦ and d ≤ 75Mpc. second data set May 2006–August 2007: 13 events, 8 correlated, 2.7 expected ⇒ pch ≈ 2×10−3

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 14

Correlations with AGNs: Auger analysis

first data set with data < May 2006 to fix cuts: Eth = 56EeV, ℓ0 = 3.1◦ and d ≤ 75Mpc. second data set May 2006–August 2007: 13 events, 8 correlated, 2.7 expected ⇒ pch ≈ 2×10−3 just a “3 σ effect”, test against isotropy, no propagation not confirmed by HiRes AGN or something with similar distribution?

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 15

Correlations with AGNs: PAO analysis

27 CRs (⊙) and 472 AGN (∗):

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 16

Correlations with AGNs: PAO analysis

27 CRs (⊙) and 472 AGN (∗):

correlated AGN are not promising UHECR sources

[Moskalenko et al. ’08, Hardcaste et al. ’08, Rachen ’08, . . . ] Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 17

Deflections for eE/Q = 4×1019eV in regular GMF:

2 4 6 8 10

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 18

Energy threshold consistent with GZK horizon?

8 out of 13 CRs (E ≥ 57EeV) correlated within 75 Mpc:

1 10 100 1000 1e+19 1e+20 1e+21 R [Mpc] E [eV] 10 % 30 % 50 % 70 % 90 %

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 19

Energy threshold consistent with GZK horizon?

8 out of 13 CRs (E ≥ 57EeV) correlated within 75 Mpc:

1 10 100 1000 1e+19 1e+20 1e+21 R [Mpc] E [eV] 10 % 30 % 50 % 70 % 90 %

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 20

Energy threshold consistent with GZK horizon?

8 out of 13 CRs (E ≥ 57EeV) correlated within 75 Mpc:

1 10 100 1000 1e+19 1e+20 1e+21 R [Mpc] E [eV] 10 % 30 % 50 % 70 % 90 %

under-estimation of energy scale? or only LSS?

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 21

Energy threshold consistent with GZK horizon?

8 out of 13 CRs (E ≥ 57EeV) correlated within 75 Mpc:

1 10 100 1000 1e+19 1e+20 1e+21 R [Mpc] E [eV] 10 % 30 % 50 % 70 % 90 %

under-estimation of energy scale? or only LSS? safer method?

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 22

Comparing with sources:

[A. Cuoco et al. ’07, ’08 ]

Use the auto-correlation function, w(ϑ) = DD(ϑ) RR(ϑ) −1, where

DD: number of pairs in catalogue RR: number of pairs in random sets

for most popular sources of UHECRs:

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 23

Comparing with sources:

[A. Cuoco et al. ’07, ’08 ]

Use the auto-correlation function, w(ϑ) = DD(ϑ) RR(ϑ) −1, for most popular sources of UHECRs: AGN

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 24

Comparing with sources:

[A. Cuoco et al. ’07, ’08 ]

Use the auto-correlation function, w(ϑ) = DD(ϑ) RR(ϑ) −1, for most popular sources of UHECRs: AGN and GRB [ ]

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 25

Auto-correlation function of different sources:

[A. Cuoco et al. ’07 ] Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 26

Auto-correlation function of different sources:

[A. Cuoco et al. ’07 ] Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 27

Auto-correlation function of different sources:

[A. Cuoco et al. ’07 ] Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 28

Auto-correlation function of different sources:

[A. Cuoco et al. ’07 ]

reduced statistical error differences on all angular scales reduced dependence on B:

global comparison on all angular scales

nly relative deflections enter

possible to constrain B

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 29

Auto-correlation function of different sources:

[A. Cuoco et al. ’07 ]

reduced statistical error differences on all angular scales reduced dependence on B:

global comparison on all angular scales

nly relative deflections enter

possible to constrain B

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 30

Auto-correlation function of different sources:

[A. Cuoco et al. ’07 ]

reduced statistical error differences on all angular scales reduced dependence on B:

global comparison on all angular scales

nly relative deflections enter

possible to constrain B

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 31

Auto-correlation function of different sources:

[A. Cuoco et al. ’07 ]

reduced statistical error differences on all angular scales reduced dependence on B:

global comparison on all angular scales

nly relative deflections enter

possible to constrain B

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 32

Clustering signal for the PAO–Science data

[A. Cuoco et al. ’08 ] Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 33

Cen A as UHECR source?

[Romero et al. ’96, Farrar, Piran ’00, Rachen ’08, . . . ] Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 34

Cen A as UHECR source?

[MK, S. Ostapchenko, R. Tom` as ’08 ]

initial protons final protons total neutrinos γ γ

HESS CGRO FERMI PAO

8 10 12 14 16 18 20 14 15 16 17 18 19

log10(E/eV) log10 (E2Φ/eV km-2 yr-1)

acceleration close to AGN core secondaries by pγ interactions γ spectrum from cascading

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 35

Summary

tension between horizon and fraction of correlated PAO events

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 36

Summary

tension between horizon and fraction of correlated PAO events tension between chemical composition and correlation data from PAO

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 37

Summary

tension between horizon and fraction of correlated PAO events tension between chemical composition and correlation data from PAO ⇒ nuclei with admixture of protons?

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 38

Summary

tension between horizon and fraction of correlated PAO events tension between chemical composition and correlation data from PAO ⇒ nuclei with admixture of protons? auto-correlation more robust method than cross-correlation

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 39

Summary

tension between horizon and fraction of correlated PAO events tension between chemical composition and correlation data from PAO ⇒ nuclei with admixture of protons? auto-correlation more robust method than cross-correlation deflections and lensing in cluster and Galactic fields important

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs

SLIDE 40

Summary

tension between horizon and fraction of correlated PAO events tension between chemical composition and correlation data from PAO ⇒ nuclei with admixture of protons? auto-correlation more robust method than cross-correlation deflections and lensing in cluster and Galactic fields important Cen A may be first source observed in TeV γ-rays and UHECRs

Moriond ’09 Michael Kachelrieß Auger results and the sources of UHECRs