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The next 10 years in Particle Astrophysics

The next 10 years in Particle Astrophysics. Workshop summary Some personal observations Tribute to Alan. Solar flare shock acceleration . Coronal mass ejection 09 Mar 2000. SOHO/ LASCO CME of 06-Nov 1997. Lessons from the heliosphere. ACE energetic particle fluences:

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The next 10 years in Particle Astrophysics

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  1. The next 10 years in Particle Astrophysics Workshop summary Some personal observations Tribute to Alan in honor of Alan Watson

  2. Solar flare shock acceleration Coronal mass ejection 09 Mar 2000 in honor of Alan Watson

  3. SOHO/ LASCO CME of 06-Nov 1997 in honor of Alan Watson

  4. Lessons from the heliosphere • ACE energetic particle fluences: • Smooth spectrum • composed of several distinct components: • Most shock accelerated • Many events with different shapes contribute at low energy (< 1 MeV) • Few events produce ~10 MeV • Knee ~ Emax of a few events • Ankle at transition from heliospheric to galactic cosmic rays R.A. Mewaldtet al., A.I.P. Conf. Proc. 598 (2001) 165 in honor of Alan Watson

  5. Heliospheric cosmic rays • ACE--Integrated fluences: • Many events contribute to low-energy heliospheric cosmic rays; • fewer as energy increases. • Highest energy (75 MeV/nuc) is dominated by low-energy galactic cosmic rays, and this component is again smooth • Beginning of a pattern? R.A. Mewaldtet al., A.I.P. Conf. Proc. 598 (2001) 165 in honor of Alan Watson

  6. Knee galactic Ankle Highest energy cosmic rays • Emax ~ bshock Ze x B x Rshock for SNR •  Emax ~ Z x 100 TeV • Many potential sources • Knee region: • Differential spectral index changes at ~ 3 x 1015eV, a = 2.7  a = 3.0 • Some SNR can accelerate protons to ~1015 eV (Berezhko & Völk) • 1016 to 1018 eV: a few special sources? Reacceleration? • Ankle at ~ 3 x 1018 eV: • Flatter spectrum • Suggestion of change in composition • New population of particles, possibly extragalactic? • Look for composition signatures of “knee” and “ankle” Extragalactic? in honor of Alan Watson

  7. 30 Rigidity-dependence • Acceleration, propagation • depend on B: rgyro = R/B • Rigidity, R = E/Ze • Ec(Z) ~ Z Rc • rSNR ~ parsec •  Emax ~ Z * 1015 eV • 1 < Z < 30 (p to Fe) • Slope change should occur within factor of 30 in energy • Characteristic pattern of increasing A with energy in honor of Alan Watson

  8. Direct measurements to 100 TeV:No major composition change RUNJOB: thanks to T. Shibata ATIC (preliminary): thanks to E-S Seo & J. Wefel in honor of Alan Watson

  9. K-H Kampert et al., astro-ph/0204205 ICRC 2001 (Hamburg) Recent Kascade data show increasing fraction of heavy nuclei 1015-3x1016 eV M. Roth et al., Proc ICRC 2003 (Tsukuba) vol 1, p 139 Note anomalous He / proton ratio in recent Kascade analyses in honor of Alan Watson

  10. Völk & Zirakashvili, 28th ICRC p. 2031 Erlykin & Wolfendale, J Phys G27 (2001) 1005 Galactic models of knee & beyond: conspiracy or accident? • Axford: • continuity of spectrum over factor 300 of energy implies relation between acceleration mechanisms • reacceleration by multiple SNR • Völk: • reacceleration by shocks in galactic wind (analogous to CIRs in heliosphere) • Erlykin & Wolfendale: • Local source at knee on top of smooth galactic spectrum • (bending of “background” could reflect change in diffusion @ ~1 pc) • What happens for E > 3x1016 eV? in honor of Alan Watson

  11. Chem. Composition Iron 1 km Proton AMANDA (number of muons) log(E/PeV) 2 km Spase (number of electrons) Chemical Composition SPASE (Bartol-Leeds) SPASE-AMANDA Astropart. Phys. (2004) AMANDA in honor of Alan Watson

  12. Rates of contained, coincident events in IceCube Area--solid-angle ~ 1/3 km2sr (including angular dependence of EAS trigger) 3000 x aperture of SPASE-AMANDA in honor of Alan Watson

  13. IceTop station • Two Ice Tanks 3 m2 x 0.9 m deep (scaled down from Haverah, Auger) • Integrated with IceCube: same hardware, software • Coincidence between tanks = potential air shower • Signal in single tank = potential muon • Significant area for horizontal muons • Low Gain/High Gain operation to achieve dynamic range • Two DOMs/tank gives redundancy against failure of any single DOM because only 1 low-gain detector is needed per station in honor of Alan Watson

  14. Large showers with E ~ 100-1000 PeV will clarify transition from galactic to extra-galactic cosmic rays. Showers triggering 4 stations give ~300 TeV threshold for EAS array Small showers (2-10 TeV) associated with the dominant m background in the deep detector are detected as 2-tank coincidences at a station. Detection efficiency ~ 5% provides large sample to study this background in honor of Alan Watson

  15. Test station deployed at South Pole November, 2003 in honor of Alan Watson

  16. Filling 03/04 test tanks • Tank10 (1 m deep) • Filled Nov 22, 2003 • 20 minutes to fill • < 10 RPSC man hours for transport and filling • Tank09 ( 0.9 m ) • Filled Nov 26, 2003 • Freeze time 60+ days • 40 days planned • Plan revised to finish freeze after closing tank in honor of Alan Watson

  17. Tanks closed Jan 23-26 Tank10 during freeze and after closing b) Jan 23 after closing, tent used as outer cover over black vinyl sheeting a) Dec 6 during freeze (cover used as extra sun shade) in honor of Alan Watson

  18. Feb 10/11, 2004 Tank 9 with m telescope Tank 10 • Remote operation since February • pre-pre-production DAQ and main board • monitoring temperatures during austral winter • limited muon data in honor of Alan Watson

  19. Primary composition with IceCube • Nm from deep IceCube; Ne from IceTop • High altitude allows good energy resolution • Good mass separation from Nm/Ne • 1/3 km2 sr (2000 x SPASE-AMANDA) • Covers sub-PeV to EeV energies Simulations of R. Engel in honor of Alan Watson

  20. Transition from Galactic to Extra-galactic origin? • Where is the transition? (Hillas’ talk) • Composition signature: • From mostly heavy primaries at end of galactic origin to large fraction of protons • Continuous coverage over a large energy range would be helpful (G Thomson’s talk) in honor of Alan Watson

  21. <ln(A)> = 0, E > 3 1016 eV Protons <ln(A)> = 4 ±2, E ~ 1015 eV Elongation rate, Xmax & composition(Linsley & Watson 1981) Xmax = l ln(E0/A) + B Analysis of fluctuations in rise-time, 1973: “…departure of individual showers from the mean behaviour … most readily understood if some of the primary particles of energy E ~ 1018 eV are light, probably protons…” ---A.A. Watson & J.G. Wilson, 1974 in honor of Alan Watson

  22. HiRes new composition result: transition occurs before ankle Original Fly’s Eye (1993): transition coincides with ankle G. Archbold, P. Sokolsky, et al., Proc. 28th ICRC, Tsukuba, 2003 Change of composition at the ankle? Stereo in honor of Alan Watson

  23. Exposure of giant arrays (as of ICRC-2003, thanks to M.Teshima) 1018-1019 eV threshold regime in honor of Alan Watson

  24. More questions about UHECR • What are the sources: – GRB? (Waxman), AGN? (Berezinsky), Top-down? (Sigl) • Does spectrum continue past GZK limit? • What is the distribution of sources? – Medina-Tanco, Olinto, Sommers • Clustering? – How many sources? • Point sources? • Galactic halo distribution? • Importance of magnetic fields? • Need all-sky coverage for full picture in honor of Alan Watson

  25. Energy content of extra-galactic component depends on location of transition • Normalize @ 1019 eV: • rCR = 2 x 10-19 erg/cm3 • Power ~ rCR / 1010 yrs • ~ 1045 erg/Mpc3/yr • Uncertainties: • Normalization point: • 1018 to 1019.5 used • Factor 10 / decade • Spectral slope • a=2.3 for rel. shock • = 2.0 non-rel. • Emin ~ mp (gshock)2

  26. GRB model Bahcall & Waxman, hep-ph/0206217 Waxman, astro-ph/0210638 • Assume E-2 spectrum at source, normalize @ 1019.5 • 1045 erg/Mpc3/yr • ~ 1053 erg/GRB • Evolution like star-formation rate • GZK losses included • Galactic extragalactic transition ~ 1019 eV in honor of Alan Watson

  27. Berezinsky et al. AGN • Assuming a cosmological distribution of sources with: • dN/dE ~ E-2, E < 1018 eV • dN/dE ~ E-g, 1018< E < 1021 • g = 2.7 (no evolution) • g = 2.5 (with evolution) • Need L0 ~ 3 ×1046 erg/Mpc3 yr • They interpret dip at 1019 as • p + g2.7 p + e+ + e- Berezinsky, Gazizov, Grigorieva astro-ph/0210095 in honor of Alan Watson

  28. Plot from HiRes, astro-ph/0208301 Does spectrum exceed GZK? • AGASA now finished • No sign of cutoff • Clusters10-5 sources/Mpc3 • HiRes • Consistent with GZK cutoff • No clustering observed • Auger South • Should answer the question within a year or so in honor of Alan Watson

  29. Haverah Park Edge et al., 1973 UHECR Spectrum 1 event per km2 per century with E > 1020 eV in honor of Alan Watson

  30. Connection to g-rays and n • Talks of Völk, Hinton, Weekes, Mirzoyan • Is there more than electron acceleration in GRB and AGN ? • Zas: p/n as a probe of top-down vs acceleration models of UHECR • Also probes evolution of sources in honor of Alan Watson

  31. New experiments • Telescope array • Auger North • EUSO • Neutrino telescopes • AMANDA, Baikal continue in short term • ANTARES (& Nestor) in 2005, 2006? • IceCube • Km3 in Mediterranean • Radio detection for UHEn in honor of Alan Watson

  32. Matter Distribution 7 Mpc < D < 21 Mpc Cronin astro-ph/0402487 [Kravtsov]

  33. Closing remarks • Thanks to • Johannes, Jeremy and colleagues • to Carol Ward and Maria • to Mansukh Patel • Thanks to Auger Collaboration for a great experiment • Best wishes to Alan for future science in honor of Alan Watson

  34. Power needed for extragalactic cosmic rays assuming transition at 1019 eV • Energy density in UHECR, CR ~ 2 x 10-19 erg/cm3 • Such an estimate requires extrapolation of UHECR to low energy • CR = (4/c)  E(E) dE = (4/c){E2(E)}E=1019eV x ln{Emax/Emin} • This gives CR ~ 2 x 10-19 erg/cm3 for differential index  = 2, (E) ~ E-2 • Power required ~ CR/1010 yr ~ 1045 erg/Mpc3/yr • Estimates depend on cosmology and extragalactic magnetic fields: • 3 x 10-3 galaxies/Mpc3 5 x 1039 erg/s/Galaxy • 3 x 10-6 clusters/Mpc3 4 x 1042 erg/s/Galaxy Cluster • 10-7 AGN/Mpc3 1044 erg/s/AGN • ~1000 GRB/yr 3 x 1052 erg/GRB • Assume E-2 spectrum. Then n signal ~ 10 to 100/km2yr • ~20% have E>50 TeV (greater than atmospheric background) in honor of Alan Watson

  35. Remote operation of DOMs • Pre-production main boards; pre-production DAQ • Use SPASE GPS clock for time stamp • Slow readout (large dead-time) • No local coincidence • Study main board temperatures during austral winter in honor of Alan Watson

  36. Remote operation of DOMs in honor of Alan Watson

  37. Energy-dependence of secondary/primary cosmic-ray nuclei • B/C ~ E-0.6 • Observed spectrum: • f(E) = dN/dE ~ K E-2.7 • Interpretation: • Propagation depends on E • t(E) ~ E-0.6 • f(E) ~ Q(E) x t(E) x (c/4p) • Implication: • Source spectrum Q(E) ~ E-2.1 in honor of Alan Watson

  38. Expected shape of spectrum: Differential index a ~ 2.1 for diffusive shock acceleration aobserved ~ 2.7; asource ~2.1; Da~ 0.6 tesc(E) ~ E-0.6 c tesc Tdisk ~100 TeV Isotropy problem Emax ~ bshock Ze x B x Rshock  Emax ~ Z x 100 TeV with exponential cutoff of each component But spectrum continues to higher energy:  Emax problem Expect p + gas  g (TeV) for certain SNR Need nearby target as shown in picture from Nature (April 02) Interpretation uncertain; see Enomoto et al., Aharonian (Nature); Reimer et al., astro-ph/0205256  Problem of elusive p0g-rays Problems of simplest SNR shock model in honor of Alan Watson

  39. Total protons Fe helium CNO Mg… 3 components a=2.7 a=2.4 K-H Kampert et al., astro-ph/0204205 Speculation on the knee in honor of Alan Watson

  40. Haverah Park, Edge et al., 1973 UHECR spectrum in honor of Alan Watson

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