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What can we learn from the GZK feature?. Angela V. Olinto Astronomy & Astrophysics Kavli Institute Cosmol.Phys. Enrico Fermi Institute University of Chicago. Huge Amounts!. If the GZK feature is accurately measured... we can learn the 1. composition of the primaries
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What can we learn from the GZK feature? Angela V. Olinto Astronomy & Astrophysics Kavli Institute Cosmol.Phys. Enrico Fermi Institute University of Chicago
Huge Amounts! • If the GZK feature is accurately measured... we can learn the • 1. composition of the primaries • average characteristics of the sources of (UHE) Cosmic Rays • 2. injection spectral index (Berezinsky, Waxman, Sigl...) • 3. Emax 4. cosmological evolution of sources 5. transition between galactic & extragalactic CRs (Berezinsky) 6. structure & magnitude of galactic magnetic fields (MedinaTanco) 7. structure & magnitude of extra-galactic magnetic fields (MedinaTanco, Sigl)
GZK & Magnetic Fields Deligny, Parizot, Letessier-Selvon ‘04
Huge Amounts! • If the GZK feature is accurately measured... we can learn the • 1. composition of the primaries • average characteristics of the sources of (UHE) Cosmic Rays • 2. injection spectral index (Berezinsky, Waxman, Sigl...) • 3. Emax 4. cosmological evolution of sources 5. transition between galactic & extragalactic CRs (Berezinsky) 6. structure & magnitude of galactic magnetic fields (MedinaTanco) 7. structure & magnitude of extra-galactic magnetic fields (MedinaTanco, Sigl) 8. cosmogenic neutrino flux 9. hadronic interactions at larger energies than terrestrial accelerators. ... (Engels)
And if we can identify anisotropies... And if we can identify point sources... 10. correlation studies with possible source distribution (Sommers) search for sources test acceleration models vs. decay models propagation, magnetic fields, multi-wavelength studies, etc... 11. individual source studies - acceleration models, propagation from different directions, magnetic fields, multi-wavelength studies, etc...
Accurately=Statistics+... Auger South (3 yr) Auger South + North EUSO DeMarco, Blasi, AO’03
GZK Images 3, 4, 5, 6 ...?
Analytical vs. Monte-CarloGZK modification factor (2 x 106 realizations) injection E-2.1 DeMarco, Blasi, AO’03
Fluctuations about GZK feature are large for AGASA & HiRes 400 realizations of GZK feature for low statistics DeMarco, Blasi, & A.O. ‘03
systematic errors by hand… AGASA AGASA-15% HiRes +15% no GZK @ 2.5 HiRes 1.5 Emax=1021.5 eV DeMarco, Blasi, AO ‘03
And if we don’t see the GZK feature? Anyone willing to relax the CMB part of the equation? • Extragalactic Proton Sources + CMB GZK feature What about the Extragalactic assumption? Galactic Protons - extreme Bgal Galactic Iron - fast spinning young neutron stars?
Crab Nebula Young Neutron Star Winds: a Galactic Fe option Local Source - New Component Rgyro = 1.4 kpc E20/Z26B3G E-1 Neutron Stars: 10 km 1.4 Msolar can rotate 3000/sec at birth!! Blasi, Epstein, AO ‘00
Allowed Regions of B-Wi for producing >1020 eV Iron Cosmic Rays • For B13 =B/1013G > 60, star spins down • before SNR is “transparent” to UHECR Blasi, Epstein, AO ‘00
And if we don’t see the GZK feature? Anyone willing to relax the CMB part of the equation? • Extragalactic Proton Sources + CMB GZK feature What about the Extragalactic assumption? Galactic Protons - extreme Bgal Galactic Iron - fast spinning young neutron stars? Galactic Halo Photons - Super Heavy DM / Z bursts What about the Proton Assumption? Iron has its own GZK feature
Nuclei GZK Feature Greisen ‘66, Zatsepin-Kuzmin ‘66, Puget, Stecker, Bredekamp’78; Epele, Roulet ‘98; Stecker, Salamon’98; Anchordoqui, Dova,et al ‘98, Bertone et al 02; Yamamoto et al ‘04, Allard, Khan, Parizot ‘04, ... Allard, Khan & Parizot ‘04
And if we don’t see the GZK feature? Anyone willing to relax the CMB part of the equation? • Extragalactic Proton Sources + CMB GZK feature What about the Extragalactic assumption? Galactic Protons - extreme Bgal Galactic Iron - fast spinning young neutron stars? Galactic Halo Photons - Super Heavy DM / Z bursts What about the Proton Assumption? Iron will have its own GZK feature Photons evidence for Top-Down models Strongly interacting ?? (neutrinos, uhecrons,...)
No GZK feature + Photons New Physics Options: • Super-Heavy Particle Relics • (in Galactic halo) • no GZK feature for Protons • Photons at all Energies • New component • Galactic Halo Siganture • Topological Defects = extragalactic • GZK feature for Protons • Photons at the Highest Energies New Neutrino Sources + Z bursts
The GZK feature brought us here? No, luv!
Do we know the composition? No information near GZK region E > 1019.3 eV HiRes
Huge Amounts! • If the GZK feature is accurately measured... we can learn the • 1. composition of the primaries • average characteristics of the sources of (UHE) Cosmic Rays • 2. injection spectral index (Berezinsky, Waxman, Sigl...) • 3. Emax 4. cosmological evolution of sources 5. transition between galactic & extragalactic CRs (Berezinsky) 6. structure & magnitude of galactic magnetic fields (MedinaTanco) 7. structure & magnitude of extra-galactic magnetic fields (MedinaTanco, Sigl) 8. cosmogenic neutrino flux 9. hadronic interactions at larger energies than terrestrial accelerators. ... (Engels)
Certainty of Cosmogenic Neutrinos? New Physics: Flux ≥ Flux Extragalactic Protons: Cosmogenic, p, or GZK guaranteed ’s (Galactic Protons - hard to hide anisotropies) Galactic Iron - not much of a flux Extragalactic Iron?
Certainty of Cosmogenic Neutrinos? New Physics: Flux ≥ Flux Extragalactic Protons: Cosmogenic, p, or GZK guaranteed ’s (Galactic Protons - hard to hide anisotropies) Galactic Iron - not much of a flux Extragalactic Iron? - “guaranteed” ’s also!
Neutrinos’s fromExtragalactic Iron Ave, Busca, AO, WATSON, Yamamoto ‘04 Advantages: easier to accelerate to UHEs & easier to isotropize Start with pure Iron source E-2 up to Emax, MC up to d=100, 300, 500 Mpc with: Photo-dissociation (IRB, CMB) to secondaries; Pair production losses; Photo-pion production of secondaries; Neutron decay; Use Yield for cosmological distances (CDM model) a la Engel, Seckel, Stanev ‘01
Energy Losses Ave, Busca, AO, Watson, Yamamoto ‘04 2.5 Gpc 2 Mpc
Example of iron propagation Allard, Khan & Parizot ‘04 High energy nuclei are photo-disintegrated and loose their energy rapidly, at 1020 eV, the energy loss length is shorter than the mass loss length.
N/A IRON PROTON n-decay Ave, Busca, AO, Watson, Yamamoto ‘04
dN/dNA dlogE IRON PROTON en e e Fe narrower p from 1st interaction N’s similar E Ave, Busca, AO, Watson, Yamamoto ‘04
Neutrino flux IRON PROTON W&B Ringwald en e e Ave, Busca, AO, Watson, Yamamoto ‘04
flux & Emax Emax > 10 21.5 eV Ave, Busca, AO, Watson, Yamamoto ‘04
flux & evolution IRON PROTON (1+z)4 stronger (z=1.9, flat 2.7, decay) (1+z)3 weaker Ave, Busca, AO, Watson, Yamamoto ‘04
Certainty of Neutrinos? New Physics: Flux ≥ Flux Extragalactic Protons: Cosmogenic, p, or GZK guaranteed ’s (Galactic Protons - hard to hide anisotropies) Galactic Iron - not much of a flux Extragalactic Iron? - “guaranteed” ’s also! flux depends on Emax (>1021.5 eV) & evolution
Earth Skimming Auger exposure to tau Neutrinos zenith angle > 90o
Pierre Auger Project North and South - 6000 km2 ( future enlarge to > > 6000 km2 ) to learn the origin of UHECRs + UHE Neutrinos!
Pierre Auger Project North and South - 6000 km2 ( future enlarge to > > 6000 km2 ) to learn the origin of UHECRs + UHE Neutrinos! Cheers, Alan!
Large Extra DimensionsTeV Gravity - BH formation Ahn, Ave, Cavaglia, AO ‘03
Large Extra DimensionsTeV Gravity - BH formation Ahn, Ave, Cavaglia, AO ‘03
TeV gravity & EHE Tau Neutrinos nice to be next to a Mountain range TeV Gravity Standard Model Ahn, Ave, Cavaglia, AO’03
Super Heavy Relics in the Dark Halo of our Galaxy photons protons Dark Matter = 23% Universe (83 % matter in U) baryons only 4% extragal protons problems w/composition at lower energy Berezinsly, Blasi, Vilenkin `99
Topological Defects Cosmic Necklaces protons photons Berezinsly, Blasi, Vilenkin `99
Tanks in Inclined Showers Old showers - muons