μ- Capture, Energy Rotation, Cooling and High-pressure Cavities
Physics of High-Energy Cosmic Raysweb.phys.ntnu.no/~mika/oslo.pdf · 2006-03-01 · High-Energy...
Transcript of Physics of High-Energy Cosmic Raysweb.phys.ntnu.no/~mika/oslo.pdf · 2006-03-01 · High-Energy...
Physics of High-Energy Cosmic Rays
Michael Kachelrieß
NTNU Trondheim
CR spectrum
Michael Kachelrieß High-Energy Cosmic Rays
CR spectrum
for practically all energies only two informations:
exponent α of dN/dE ∝ 1/Eα
chemical composition
Michael Kachelrieß High-Energy Cosmic Rays
Why UHECR astronomy:
astronomy with HE photons restricted to few Mpc:
10−5 10−4 10−3 10−2 10−1 100 101 102 103
redshift z
7
8
9
10
11
12
13
14
15
16
log
10[E
/eV
]
10−5 10−4 10−3 10−2 10−1 100 101 102 103
7
8
9
10
11
12
13
14
15
16
Eew~ (GF)−1/2
Gal
acti
c C
ente
r
Mrk
501
star
fo
rmat
ion
pea
ks
star
fo
rmat
ion
beg
ins
γe γe
γp e+e
−p
γγ e+e
−
3K
IR
VIS
UV
ν−domain
Michael Kachelrieß High-Energy Cosmic Rays
Why UHECR astronomy:
astronomy with HE photons restricted to few Mpc:very small neutrino event numbers: <
∼few/yr for AUGER
103
102
10
1
10-1
1022102110201019101810171016
j(E)
E2 [e
V c
m-2
s-1
sr-1
]
E [eV]
WB
max
0.2
CR flux
Michael Kachelrieß High-Energy Cosmic Rays
AUGER experiment:
Michael Kachelrieß High-Energy Cosmic Rays
AUGER experiment:
Michael Kachelrieß High-Energy Cosmic Rays
AUGER: Pampa + Detector
Michael Kachelrieß High-Energy Cosmic Rays
Standard picture
Galactic SNR produce observed CRs up to E ∼ 1017 eV
Michael Kachelrieß High-Energy Cosmic Rays
Standard picture
Galactic SNR produce observed CRs up to E ∼ 1017 eV
Fermi shock acceleration explains power-law 1/E2.2
Michael Kachelrieß High-Energy Cosmic Rays
Standard picture
Galactic SNR produce observed CRs up to E ∼ 1017 eV
Fermi shock acceleration explains power-law 1/E2.2
modified by energy dependent diffusion
Michael Kachelrieß High-Energy Cosmic Rays
Standard picture
Galactic SNR produce observed CRs up to E ∼ 1017 eV
Fermi shock acceleration explains power-law 1/E2.2
modified by energy dependent diffusion
extragalactic sources only above E ∼ 1019 eV
Michael Kachelrieß High-Energy Cosmic Rays
Three outstanding questions:
Is the standard picture correct?
Michael Kachelrieß High-Energy Cosmic Rays
Three outstanding questions:
Is the standard picture correct?
Is astronomy with UHECRs possible?
role of magnetic fieldsprotons vs nuclei as primaries
Michael Kachelrieß High-Energy Cosmic Rays
Three outstanding questions:
Is the standard picture correct?
Is astronomy with UHECRs possible?
role of magnetic fieldsprotons vs nuclei as primaries
Is physics beyond the SM needed to explain UHECR events?
energy spectrum consistent with GZK suppression?
suppression depends on number of sources, their minimal
distances, magnetic fields, . . .
correlations with sources at cosmological distances?
Michael Kachelrieß High-Energy Cosmic Rays
Energy losses, the dip and the GZK cutoff
1e-11
1e-10
1e-09
1e-08
1e-07
18 18.5 19 19.5 20 20.5 21 21.5
(1/E
)*d
E/d
t [1
/yr]
log10(E/eV)
pion production
pair production
redshift
at E ∼ 4×1019 eV:N + γ3K → ∆→ N +πstarts and reduces freemean path to∼ 20 Mpc
pair production leedsto a dip at ∼ 1019 eV
Michael Kachelrieß High-Energy Cosmic Rays
Cosmic ray spectrum: the dip at 1019 eV [Berezinsky, Grigorieva, Hnatyk ’04 ]
Michael Kachelrieß High-Energy Cosmic Rays
Transition to extragalactic protons
[Bere
zin
sky,
Grigorieva,H
naty
k’0
4]
Michael Kachelrieß High-Energy Cosmic Rays
Transition to extragalactic protons
[Bere
zin
sky,
Grigorieva,H
naty
k’0
4]
dip suggests: primaries above 1018 eV are extragalactic protons
Michael Kachelrieß High-Energy Cosmic Rays
Contradiction between shock acceleration and observed
spectrum?
1e+19
1e+20
1e+21
1e+18 1e+19 1e+20
E3 *F
(E)
[eV
2 cm
-2 s
-1 s
r-1]
E [eV]
HiRes I
HiRes II
n=10-5/Mpc3; β=1.7; 1/E2.0
n=10-5/Mpc3; same sources; 1/E2.7
n=inf; same sources; 1/E2.7
n=inf; same sources; 1/E2.0
Michael Kachelrieß High-Energy Cosmic Rays
Contradiction between shock acceleration and observed
spectrum?
good fit with just 2 free parameters, compatible with th.models
strong evidence for extragalactic protons above 1018 eV
is astronomy possible?
proton as primary necessary but not sufficient conditionstill depends on magnetic fields...
Michael Kachelrieß High-Energy Cosmic Rays
Deflections for eE/Q = 4×1019eV in the GMF:
0 2 4 6 8 10
Michael Kachelrieß High-Energy Cosmic Rays
Extragalactic magnetic field – simulation DGST:
Pavo
+
+
+
Centaurus
Virgo
10 2 3 4 5
+Coma
++
+ PerseusA3627
Hydra
0 [Degrees]
[Dolag, Grasso, Springel, Tkachev ’03 ]
Michael Kachelrieß High-Energy Cosmic Rays
Extragalactic magnetic field – simulation DGST:
DGST: astronomy with UHE protons possible in large part of sky!
Michael Kachelrieß High-Energy Cosmic Rays
Examples for astronomical studies:
finding point sources:
h12
+60
−60
−30
+30
0
o
o
o
o
h h24
GC
AGASA
C
Michael Kachelrieß High-Energy Cosmic Rays
Examples for astronomical studies:
finding point sources:
Michael Kachelrieß High-Energy Cosmic Rays
Examples for astronomical studies:
finding point sources:correlation with certain source classes
(100 EeV)
(1 ZeV)
Neutronstar
Whitedwarf
SNR
Crab
E ~ ZBLmax
AGN
Protons
Collidinggalaxies
GRB
VirgoGalactic disk
halo
Clusters
RG lobes
1 au 1 pc 1 kpc 1 Mpc
-9
-3
3
9
15
3 6 9 12 15 18 21
x
log(Magnetic field, gauss)
β
log(size, km)
Fe (100 EeV)
Protons
x
Michael Kachelrieß High-Energy Cosmic Rays
Examples for astronomical studies:
finding point sources:correlation with certain source classes
Michael Kachelrieß High-Energy Cosmic Rays
Examples for astronomical studies:
finding point sources:correlation with certain source classes
estimation of general source properties (ns, L)
Michael Kachelrieß High-Energy Cosmic Rays
Examples for astronomical studies:
finding point sources:correlation with certain source classes
estimation of general source properties (ns, L)identification of acceleration mechanism
Michael Kachelrieß High-Energy Cosmic Rays
Examples for astronomical studies:
finding point sources:correlation with certain source classes
estimation of general source properties (ns, L)identification of acceleration mechanism
correlation with large-scale structure of sources
Michael Kachelrieß High-Energy Cosmic Rays
Example: Number density ns of sources
As ns decreases, sources become brighter for fixed flux ⇒probability for clustering increases [Waxman, Fisher, Piran ’96 ]
Michael Kachelrieß High-Energy Cosmic Rays
Example: Number density ns of sources
As ns decreases, sources become brighter for fixed flux ⇒probability for clustering increases. [Waxman, Fisher, Piran ’96 ]
Since NtotÀ Ncl, most sources are not seen:
0
50
100
150
200
250
300
350
0 1 2 3 4 5 6
P_n(k
)
k-plets
Michael Kachelrieß High-Energy Cosmic Rays
Example: Number density ns of sources
As ns decreases, sources become brighter for fixed flux ⇒probability for clustering increases. [Waxman, Fisher, Piran ’96 ]
Since NtotÀ Ncl, most sources are not seen:
0
50
100
150
200
250
300
350
0 1 2 3 4 5 6
P_n
(k)
k-plets
allows to estimate ns
Michael Kachelrieß High-Energy Cosmic Rays
Small-scale clusters and density of sources:
0.001
0.01
0.1
1
1e-07 1e-06 1e-05 1e-04 0.001 0.01
P
ns/Mpc3
➜ HiRes 68%
➜ HiRes 90%
➜ HiRes 99%
X-ray selected AGN⇐ ⇒
Michael Kachelrieß High-Energy Cosmic Rays
Medium-scale anisotropies in UHECRs:
1e-05
0.0001
0.001
0.01
0.1
1
0 20 40 60 80 100 120 140 160 180
P(δ
)
δ [degrees]
H 40 EeV 27A+ H 57
A+H+Y+S 101A+H+Y+S+HP+VR 106
all public + unpub
Michael Kachelrieß High-Energy Cosmic Rays
Multi-messenger astronomy:
HE photons and neutrinos are secondaries of CR interactions
Michael Kachelrieß High-Energy Cosmic Rays
Multi-messenger astronomy:
HE photons and neutrinos are secondaries of CR interactions
all three fluxes are related: e.g. CR flux bounds neutrino flux
Michael Kachelrieß High-Energy Cosmic Rays
Multi-messenger astronomy:
HE photons and neutrinos are secondaries of CR interactions
all three fluxes are related: e.g. CR flux bounds neutrino flux
all energy in γ and e± cascades down to MeV–GeV range,bounded by observations:
10-2
1
102
104
106
108 1010 1012 1014 1016 1018 1020 1022 1024
j(E)
E2 [e
V c
m-2
s-1
sr-1
]
E [eV]
EGRET
FORTE
GLUE
MACROBaikal
AMANDA II
RICE
AGASA
Fly’s Eyeatm ν
γ
νi
p
[Semikoz, Sigl ’03 ]
Michael Kachelrieß High-Energy Cosmic Rays
Sensitivity of neutrino detectors
1
10
102
103
1012 1014 1016 1018 1020 1022
j(E)
E2 [e
V c
m-2
s-1
sr-1
]
E [eV]
γ-ray bound
MPR bound
WB bound
atm ν
ICECUBE
NUTEL
EUSO
ANITA 30 days
TA
RICE
AUGER
AMANDA-II, ANTARES
BAIKAL
atm ν
Michael Kachelrieß High-Energy Cosmic Rays
Summary I:
UHECR data will provide soon unique information about
structure of galactic magnetic field
magnitude of extragalactic magnetic fields
if both are “small”, astronomy with UHECRs will be possible
determination of source density ns
determination of source classes
acceleration mechanism?
if primary type is established, QCD studies with UHECRs will test
inelastic cross section, elasticity
QCD color-glas condensate
Michael Kachelrieß High-Energy Cosmic Rays
Summary II
Z bursts and topological defects can be only subdominantsources of UHECR
no positive evidence for superheavy dark matter from its twokey signatures:
photonsgalactic anisotropy
open questions for AUGER, Anita, . . . :
clustering due to point sources?
correlations with BL Lacs?
existence of GZK suppression?
photons as primaries?
detection of UHE neutrinos: opens a new window to theUniverse
Michael Kachelrieß High-Energy Cosmic Rays