ULTRA-HIGH ENERGY COSMIC RAYS
|
|
- Hilda Roberts
- 6 years ago
- Views:
Transcription
1 ULTRA-HIGH ENERGY COSMIC RAYS P. Tinyakov Université Libre de Bruxelles (ULB), Brussels Odense Winter School, October 2012
2 Outline 1 Introduction 2 Extensive airshowers 3 Detection methods Surface Detectors Fluorescence Telescopes UHECR experiments 4 Propagation Interaction with radiation backgrounds Deflections in magnetic fields 5 Production of UHECR 6 State of the art Spectrum Composition Anisotropy 7 Summary
3 Historical remarks 1912 On a ballon at an altitude of 5000 meters, Victor Hess discovered penetrating radiation coming form space Using a newly invent cloud chamber, Dimitry Skobelzyn observed the first ghostly tracks left by cosmic rays In his cloud chamber, Carl Anderson discovered antimatter in the form of the anti-electron, later called the positron Seth Neddermeyer and Carl Anderson discovered the the muon in cosmic rays. This gave birth to the science of elementary particle physics Pierre Auger, putting particle detectors far apart high in the Alps, discovered extensive air showers.
4 Historical remarks
5 All-particle CR spectrum = detector of 1 m2 has count rate 10 3 per second = detector of 1 m2 has count rate 2 per month Ultra-High Energy CR = detector of 1 km2 has count rate 1 per century
6 Why it is interesting to study ultra-high energy cosmic rays (UHECR)? These are the highest-energy particles ever observed. The energy range is inaccessible to colliders. Observations of UHECR give a possibility to test laws of Nature at extremely high energies. UHECR carry information about astrophysical processes capable of accelerating particles to extremely high energies. This, potentially, opens a new window into the Universe at highest energies ever. CHARGED PARTICLE ASTRONOMY?
7 Extensive airshowers Earth atmosphere is used as a calorimeter first interaction primary particle hadronic component air nucleus π + core Cherenkov light π o γ γ γ π e e + ν µ shower maximum γ γ µ ν electromagnetic cascade
8 Extensive airshowers first interaction hadronic component core Cherenkov light shower maximum electromagnetic cascade Probability of interaction 1 when σ n(x)dl 1 key quantity: depth X = m p n(x)dl First interaction: take σ (100MeV) 2 = m p n(x)dl 100 g/cm 2 Note: vertical atmosphere 1000 g/cm 2 = first interaction at h 10 km Depth of first interaction depends on primary particle: smaller for iron, larger for proton, even larger for photon. However, fluctuations are large. Width of the shower at maximum: a few km. Shower development in not sensitive to primary particle: details average away. Exception: number of muons (smaller for photon-initiated showers).
9 Extensive airshowers Main features: Most energy is carried by the EM component Shower front is curved; the curvature depends on age: younger showers are more curved = in principle, curvature may be used to measure the depth of the first interaction Very old (very inclined) showers consist of muons which are the most penetrating component (except undetectable neutrinos). These showers have a flat front. = Young very inclined showers = neutrino primary particles
10 Extensive airshowers Longitudinal shower profile is expressed in terms of atmospheric depth X = ρdl and is approximately given by the Gaisser-Hillas formula: ( ) X X max X 0 ( ) Xmax λ Xmax X N(X) = N max exp X max X 0 λ X max X 0 λ depth of the maximum depth of the first interaction a parameter number of charged particles, arbitrary units depth, g/cm2
11 Extensive airshowers Lateral distribution (density of charged particles as distance r from the core) is well fitted by the Linsley formula ( ) r α ( S(r) = const 1 + r ) (η α) R 0 R 0 R 0 Moliere radius m α, η two shape parameters 1e+10 1e+09 1e+08 1e+07 1e distance, m
12 Extensive airshowers Modeling of showers No accurate analytical model of shower exists Monte-Carlo code for simulation of showers: CORSIKA Even numerically, complete calculation is very difficult. A necessary approximation thinning Crucial ingredient of simulations hadronic models. They require extrapolation of hadronic interactions to high energies = source of systematic errors LHC data are useful (actually used) for the extrapolation
13 Summary I: extensive airshowers Shower development is a statistical process involving a few billion particles. First interaction that carries direct information about the primary particle is never observed. Shower modeling, especially at first stages, involves uncertainties resulting from extrapolation of particle cross sections to CM energies > 100 TeV However, there are indirect observables sensitive to the depth of the first interaction (= cross section), such as shower front curvature, depth of the shower maximum etc.
14 DETECTION Two basic detection methods: Detecting particles at the ground by an array of the detectors (SD) Detecting fluorescent light emitted (isotropically) by the shower core (FD) Possibility of radio detection is under investigation.
15 SURFACE DETECTORS
16 SURFACE DETECTORS Schematic detector design
17 SURFACE DETECTORS A typical SD event (Telescope Array)
18 SURFACE DETECTORS Geometry reconstruction: from detector counts & timing information
19 SURFACE DETECTORS Energy estimation: from full Monte-Carlo
20 SURFACE DETECTORS Typical parameters Detector spacing: km Systematic error in energy: 20% Energy resolution: 20% Angular resolution Energy-independent aperture above certain energy threshold, which is (a few) ev for TA
21
22 FD event example
23 FLUORESCENCE TELESCOPES Energy determination: back-of-envelope estimate E = length de dx E = 1 2 N max 1000g/cm 2 2 MeV g/cm 2 E = evn max Energy determination is robust. Based on center of shower, not tails. Easy to Monte Carlo.
24 FLUORESCENCE TELESCOPES Energy error 20% Energy determination is close to calorimetric Little dependence on Monte-Carlo Energy-dependent aperture Arrival direction error in monocular mode is very asymmetric, Possibility of stereo and hybrid observations = substantial improvement in angular resolution
25 HYBRID LAYOUT
26 Hybrid event example
27 UHECR EXPERIMENTS
28 UHECR EXPERIMENTS Parameters of some SD detectors exposure angular energy # of events (km 2 yr sr) resolution resolution at E > ev AGASA % 775 Auger % 7800 HiRes % 378 TA % 1809 Yakutsk % 364 at E = ev
29 PROPAGATION Uniform distribution of arrival directions suggests extragalactic origin Galactic magnetic field cannot confine protons with energy E > ev = almost certainly CRs with E > (a few) ev are of extragalactic origin = UHECR propagate over large (perhaps cosmological) distances. Issues to consider: scattering off matter deflections in magnetic fields (for charged particles)
30 Scattering Scattering off protons negligible: L = 1 σn 1031 cm 10 3 R U Scattering off CMB photons important (the Greizen-Zatsepin-Kuzmin, or GZK effect). Characteristic energy: E p m π(m p + m π /2) 2ω γ Greisen 1966; Zatsepin, Kuzmin 1966 (a few) ev
31 GZK processes Cross sections:
32 GZK processes Total pion photoproduction cross section: Cross section [mubarn] neutron proton E [GeV] lab
33 GZK processes Mean free path at ev: λ 1 σn 5 Mpc Typical energy loss in single collision: 20% As a function of energy: e + e pair production size of the Universe attenuation length interaction length
34 GZK processes Energy as a function of distance (protons)
35 The GZK cutoff For uniformly distributed sources one has flux R 0 1 r 2 r 2 dr R = there should be a cutoff by a factor R U /R GZK 100
36 What is observed? First measurements were controversial AGASA HiRes Now the controversy is resolved: there is a cutoff
37 What if UHECR are nuclei? If UHECR are nuclei, the picture remains qualitatively the same Relevant quantity is the γ-factor rather than the energy. For nuclei the γ-factor is smaller (by their atomic number) = pion production on CMB is no longer possible Light nuclei attenuate more than heavy ones (i.g., iron) The process relevant for energy attenuation is spallation, i.e., splitting off of nucleons. CM energies required are of order few MeV = dominated by IR photons The resulting attenuation length is similar to the case of protons (for iron) However, attenuation of nuclei depends on the IR background which is known less accurately than the CMB
38 Photon backgrounds Actual photon backgrounds: CMB radio IR
39 What if UHECR are photons? Photons attenuate due to e + e -production Photon Interaction and Attenuation Length [Mpc] E [ev]
40 What if UHECR are photons? At highest energies they propagate over tens of Mpc at most
41 Summary of UHECR attenuation Regardless of the UHECR composition (assuming SM particles), their propagation length shrinks from hundreds of Mpc a few tens of Mpc at energies around ev = There must be drop (cutoff) in the UHECR spectrum at E ev (the GZK cutoff in case of protons) = Sources of highest-energy CRs must be relatively close to us, within 100 Mpc or so
42 Deflections in magnetic fields Deflections are governed by the Lorentz force Ṗ = q v B In relativistic limit, deflections depend only on the ratio of charge to energy Regular field θ 0.52 q ( E ) 1 ( R ) ( B ) ev 1kpc 10 6 G Random field θ 1.8 q ( E ) 1 ( lc R ) 1/2 ( B ) ev 50Mpc G = Need to understand magnetic fields
43 Extragalactic fields Extragalactic magnetic fields are poorly known. Bounds from Faraday rotation measurements: B < 10 9 G but may be much smaller. From numerical simulations: Dolag, Grasso, Springel, Tkachev 2003; Sigl, Miniati, Enslin 2004 (contradict each other) E = ev
44 Extragalactic fields MFs in clusters are large, but this is irrelevant... Caveat: if we live in a filament, this may no longer be true: Earth Earth...because CRs must come from clusters anyway directions may get isotropized.
45 Galactic field Galactic magnetic field consists of regular and turbulent components It can be inferred from the Faraday rotation measures of extragalactic and Galactic radio sources (pulsars) Taylor, Stil and Sunstrum, 2009, ApJ, 702, 1230
46 Galactic field Another RM survey: Kronberg, Newton-McGee 2009
47 Galactic field The RM data can be well fitted by a model containing both disk and halo components Pshirkov, P.T ApJ NORTH HALO FIELD SUN DISK FIELD SOUTH HALO FIELD
48 Galactic field Model vs. observations
49 Galactic field Basic model parameters: Magnitude of disk field around the Earth: 2µG Pitch: 5 Thickness of the disk: 1 kpc Magnitude of the halo: 4µG Height of the halo above disk: 1.3 kpc Typical uncertainties: 30%
50 Deflections: magnitude E = ev, protons
51 Deflections: directions
52 Time delays A side effect of deflections in MF is time delays Delays occur for geometrical reasons δl L (δφ)2 Take δφ = 3, (δφ) 2 = L = 5 kpc t = 50 yr L = 50 Mpc t = yr L δl δφ = transient sources are seen as steady
53 Summary of deflections in MF Deflections in the extragalactic MF are likely to be negligible. Caveat: we may live inside a filament of the large-scale structure where fields can reach G with the correlation length O(Mpc). Then deflections may be large. Deflections of protons in GMF are dominated by the regular field and may be of the order 2 6 at energy E = ev depending on the direction = Charge-particle astronomy may be possible at highest energies, but only if UHECR are protons. In case of iron nuclei deflections are 26 times larger and arrival directions are isotropized.
54 Production of UHECR The production mechanisms can be generally divided into two types bottom-up (e.g., acceleration) top-down (e.g., decay of superheavy particles, topological defects, etc.) The top-down mechanisms are disfavored for two reasons: they are less motivated given that the cutoff in the spectrum is observed they are disfavored by the constraints on the photon fraction in UHECR (will be discussed below).
55 Acceleration Acceleration can be either stochastic or direct. The general idea behind stochastic acceleration (variations of Fermi mechanism): shock
56 Acceleration Operates in many astrophysical environments: supernova remnants, active galactic nuclei, GRB, colliding galaxies etc. Naturally gives power spectrum dn/de E γ Known to work at low energies However, unclear whether it can provide energies as high E ev
57 Acceleration There are two general constraints on maximum energy: Particle Larmor radius has to fit within the acceleration cite (Hillas condition) E < qbr Energy losses have to be smaller than energy gains qb > q4 m 4 E 2 B 2
58 Acceleration Hillas condition + constraints due to losses (proton, E = ev): Neutron stars Excluded by energy losses 10 White dwarfs 5 log(b ) G 0 5 AGN GRB Radio lobes Galaxy clusters Excluded by Hillas condition Galactic disk & halo log(r ) kpc
59 Acceleration An alternative direct acceleration by an electric field induced in the vicinity of compact objects (e.g., rapidly-rotating magnetized neutron stars; rotating black holes embedded in a magnetic field)
60 Acceleration The acceleration to E ev is much easier in case of iron than in case of protons Neronov et al, 2009 New J. Phys
61 Summary of acceleration Stochastic acceleration mechanism: better understood known to operate in various environments (supernova remnants, AGN,...) at lower energies maximum energy is constrained = unclear whether it can accelerate particles to sufficiently high energies, and where this can be achieved Direct acceleration: is less studied (idealized condition discussed before are unlikely in Nature, while realistic conditions are too complicated) but potentially more efficient
62 STATE OF THE ART New generation of experiments: Pierre Auger Observatory and Telescope Array. Advance: large area + hybrid type of detector. = Increase in statistics by a factor > 10 = Possibility to cross-calibrate the surface and fluorescent detectors
63 Spectrum The idea to build the hybrid detector originated from the contradiction between the AGASA (SD) and HiRes (FD) results. Hybrid detector allows to cross-calibrate the SD and FD by using the set of events common to both detectors. This program failed: both Auger and TA found that the energies measured by two detectors are systematically different (SD higher). It is not understood why. Note: it is still useful to have hybrid detector since SD has higher statistics, while FD has more straightforward energy determination. Current strategy is to calibrate SD on FD.
64 Spectrum TA energy calibration by FD
65 Spectrum The spectrum measured by the TA
66 Spectrum A mere rescaling brings spectra of different experiments to a good agreement:
67 Spectrum Remaining issues: The difference between SD and FD energy estimates The differences in energy determination by different experiments What is the absolute energy scale? This is important for the interpretation of the spectrum: What is the origin of the cutoff at around E = ev? Is it due to propagation or a mere cutoff in the source? What is the dip at E < ev a trace of e + e -pair production or Galactic-to-extragalactic transition?
68 Composition An observable sensitive to composition is the depth of the shower, X max Both mean value of X max and its variation differ for proton and iron: X max is larger for protons X max is larger for protons The measurement is difficult, because X max is measured by the FD only, and FD event selection is biased with respect to X max
69 Composition Protons or heavy Nuclei?
70 Composition Limits on flux of photons
71 Anisotropy Arrival directions is the most robust observable: independent of hadronic models free from systematic errors exposure angular energy # of events (km 2 yr sr) resolution resolution at E > 10 EeV Auger % 4727 HiRes % 378 TA % 854 Yakutsk % 364 at E = ev
72 Global sky distribution Global distribution of UHECR at E > ev is compatible with uniform. E>10 EeV E>10 EeV P =42% KS RA, degrees P = 37% KS E>10 EeV Equatorial coordinates, TA events with E > 10 EeV (May 2008 September 2010) data MC DEC, degrees
73 Global sky distribution The same, but at higher energies: E>57 EeV P KS = 30% RA, degrees Equatorial coordinates, TA events with E > 57 EeV (May 2008 September 2010) E>57 EeV P = 6% KS MC DEC, degrees data
74 Harmonic analysis: dipole amplitude Amplitude of the dipole as a function of energy: Auger, differential Auger, cumulative
75 Harmonic analysis: dipole phase TA preliminary Auger Yakutsk
76 Small-scale clustering AGASA E > 40 EeV δ TA Auger Auger
77 Search for point sources: correlations with AGN
78 Updated Auger analysis Auger collaboration, Astroparticle Phys. 34 (2010) 314 p data p = 0.21 iso Data 68% CL 95% CL 99.7% CL Total number of events (excluding exploratory scan) Updated analysis: 21 events correlate out of 55 total. With the whole set, isotropy is excluded at about 3σ.
79 Search for AGN signal in Telescope Array TA collaboration, 2011 Equatorial coordinates Original estimate of the correlating fraction is not supported Consistent with the updated estimate Consistent with no correlation 3 times the present statistics is needed for a conclusive test
80 AGNs or Cen A? Tensions within AGN interpretation: Virgo paucity Chemical composition (Fe or p?) Local AGNs are weak Cen A alternative explanation for the correlation signal? Gorbunov et al, , Fargion, Cen A is the closest radiogalaxy by chance projected on LSS Is outside of HiRes and TA 70 FOV Data % Isotropic 95% Isotropic 99.7% Isotropic Events Cen A
81 Correlations with BLL 11 correlate at 0.8 while 3 expected Gorbunov et al, JETP Lett. 80 (2004) 145 HiRes Collaboration, ApJ 636 (2006) 680 Not supported by the Auger data Pierre Auger Collaboration, ICRC 07
82 CORRELATIONS WITH MATTER DISTRIBUTION At highest energies the UHECR propagation distance becomes of order Mpc due to GZK suppression The matter distribution at these scales is inhomogeneous, being a network of galaxy clusters, filaments and voids = Anisotropy is expected, unless the deflections are very large = Composition is crucial Example: protons, E > 57 EeV, 6 Gaussian smearing: V Co UM C l=360 Hy N l=180 l=0 PP PI F E
83 Methods to test the correlations with the LSS: Pick a (complete) catalog of objects which are sufficiently numerous to trace well the matter distribution, and cross-correlate UHECR arrival directions with this catalog. Knowing matter distribution (e.g., from a complete catalogs of galaxies) calculate the predicted UHECR flux and compare to observations.
84 Correlation function Smoothed map (θ = 5 ) 2MRS catalog of galaxies with K mag < data collected after the exploratory scan = distribution following matter is favored over isotropy Results of the likelihood analysis
85 TA results Expected flux is calculated from the galaxy distribution (extended 2MRS catalog, galaxies with K mag < 12.5 within 250 Mpc), with Gaussian smoothing of the angular width θ. Protons are assumed. Compatibility with data is checked with the flux sampling test and presented as the probability as a function of θ Flux map smoothed at θ = 6, protons P-value showing compatibility with isotropy or LSS, as a function of θ 1 10 EeV, no MF % CL ISO p value STRUCT E > 10 EeV θ 15 20
86 The same plots, but at higher energies 1 40 EeV, no MF ISO p values % CL STRUCT E > 40 EeV θ 1 57 EeV, no MF. ISO p values % CL E > 57 EeV STRUCT θ
87 Summary No hints of new physics in the latest data. The existence of the cutoff in the spectrum is firmly established. However, it is not known whether this is a GZK cutoff, or merely maximum energy in the sources Composition is still unknown (but no large fraction of photons). Results are controversial. Key question for the future of the field: is charged-particle astronomy possible? No definite evidence for anisotropy (including point sources) is found so far. Various hints exist, but not yet sufficiently significant. O(3) O(10) increase in statistics will clear this up.
P. Tinyakov 1 TELESCOPE ARRAY: LATEST RESULTS. P. Tinyakov. for the Telescope Array Collaboration. Telescope Array detector. Spectrum.
1 1 Université Libre de Bruxelles, Bruxelles, Belgium Telescope Outline Telescope Global distributions Hot spot Correlation with LSS Other searches Telescope UHECR experiments Telescope ARRAY COLLABORATION
More informationRECENT RESULTS FROM THE PIERRE AUGER OBSERVATORY
RECENT RESULTS FROM THE PIERRE AUGER OBSERVATORY (Neutrino 2008, Christchurch, NZ) Esteban Roulet (Bariloche) the Auger Collaboration: 17 countries, ~100 Institutions, ~400 scientists Argentina, Australia,
More informationMass Composition Study at the Pierre Auger Observatory
OBSERVATORY Mass Composition Study at the Pierre Auger Observatory Laura Collica for the Auger Milano Group 4.04.2013, Astrosiesta INAF Milano 1 Outline The physics: The UHECR spectrum Extensive Air Showers
More informationExtensive Air Showers and Particle Physics Todor Stanev Bartol Research Institute Dept Physics and Astronomy University of Delaware
Extensive Air Showers and Particle Physics Todor Stanev Bartol Research Institute Dept Physics and Astronomy University of Delaware Extensive air showers are the cascades that develop in the atmosphere
More informationUltra- high energy cosmic rays
Ultra- high energy cosmic rays Tiina Suomijärvi Institut de Physique Nucléaire Université Paris Sud, Orsay, IN2P3/CNRS, France Atélier CTA, IAP, Paris, 30-31 June 2014 Outline Pierre Auger Observatory:
More informationUltra High Energy Cosmic Rays: Observations and Analysis
Ultra High Energy Cosmic Rays: Observations and Analysis NOT A NEW PROBLEM, STILL UNSOLVED John Linsley (PRL 10 (1963) 146) reports on the detection in Vulcano Ranch of an air shower of energy above 1020
More informationOverview: UHECR spectrum and composition Arrival directions and magnetic field Method for search for UHE nuclei sources Application to the Auger data
Overview: UHECR spectrum and composition Arrival directions and magnetic field Method for search for UHE nuclei sources Application to the Auger data Acceleration of UHECR A.G.N. GRB Radio Galaxy Lobe
More informationOVERVIEW OF THE RESULTS
VIIIth International Workshop on the Dark Side of the Universe, Buzios STUDY OF THE ULTRA HIGH ENERGY COSMIC RAYS WITH THE AUGER DATA OVERVIEW OF THE RESULTS H. Lyberis on behalf of the Pierre Auger Collaboration
More informationSTATUS OF ULTRA HIGH ENERGY COSMIC RAYS
STATUS OF ULTRA HIGH ENERGY COSMIC RAYS Esteban Roulet (Bariloche) COSMO / CosPA 2010, Tokyo Power law flux stochastic (Fermi) acceleration in shocks cosmic ray flux Small fractional energy gain after
More informationUltra-High Energy Cosmic Rays and Astrophysics. Hang Bae Kim Hanyang University Hangdang Workshop,
Ultra-High Energy Cosmic Rays and Astrophysics Hang Bae Kim Hanyang University Hangdang Workshop, 2012. 08. 22 Ultra High Energy Cosmic Rays Ultra High Energy Cosmic Ray (UHECR)» E 3 E & 10 18 ev Energy
More informationUHE Cosmic Rays and Neutrinos with the Pierre Auger Observatory
UHE Cosmic Rays and Neutrinos with the Pierre Auger Observatory Gonzalo Parente Bermúdez Universidade de Santiago de Compostela & IGFAE for the Pierre Auger Collaboration Particle Physics and Cosmology
More informationThe AUGER Experiment. D. Martello Department of Physics University of Salento & INFN Lecce. D. Martello Dep. of Physics Univ. of Salento & INFN LECCE
The AUGER Experiment D. Martello Department of Physics University of Salento & INFN Lecce The Pierre Auger Collaboration Argentina Australia Bolivia Brazil Croatia Czech Rep. France Germany Italy Mexico
More informationUltra High Energy Cosmic Rays What we have learnt from. HiRes and Auger. Andreas Zech Observatoire de Paris (Meudon) / LUTh
Ultra High Energy Cosmic Rays What we have learnt from HiRes and Auger Andreas Zech Observatoire de Paris (Meudon) / LUTh École de Chalonge, Paris, Outline The physics of Ultra-High Energy Cosmic Rays
More informationThe Pierre Auger Observatory Status - First Results - Plans
The Pierre Auger Observatory Status - First Results - Plans Andreas Haungs for the Pierre Auger Collaboration Forschungszentrum Karlsruhe Germany haungs@ik.fzk.de Andreas Haungs Pierre Auger Observatory
More informationUltra High Energy Cosmic Rays I
Ultra High Energy Cosmic Rays I John Linsley (PRL 10 (1963) 146) reports on the detection in Vulcano Ranch of an air shower of energy above 1020 ev. Problem: the microwave background radiation is discovered
More informationP. Tinyakov 1,2 TELESCOPE ARRAY: LATEST RESULTS. P. Tinyakov. for the Telescope Array Collaboration. Telescope Array detector.
1,2 1 Université Libre de Bruxelles, Bruxelles, Belgium 2 Institute for Nuclear Research, Moscow, Russia Telescope Outline Telescope Telescope UHECR ground-based experiments Telescope ARRAY DETECTOR Telescope
More informationStudy of the arrival directions of ultra-high-energy cosmic rays detected by the Pierre Auger Observatory
Study of the arrival directions of ultra-high-energy cosmic rays detected by the Pierre Auger Observatory Piera L. Ghia*, for the Pierre Auger Collaboration * IFSI/INAF Torino, Italy, & IPN/CNRS Orsay,
More informationCosmic Ray Astronomy. Qingling Ni
Cosmic Ray Astronomy Qingling Ni What is Cosmic Ray? Mainly charged particles: protons (hydrogen nuclei)+helium nuclei+heavier nuclei What s the origin of them? What happened during their propagation?
More informationParameters Sensitive to the Mass Composition of Cosmic Rays and Their Application at the Pierre Auger Observatory
WDS'12 Proceedings of Contributed Papers, Part III, 137 141, 2012. ISBN 978-80-7378-226-9 MATFYZPRESS Parameters Sensitive to the Mass Composition of Cosmic Rays and Their Application at the Pierre Auger
More informationAn Auger Observatory View of Centaurus A
An Auger Observatory View of Centaurus A Roger Clay, University of Adelaide based on work particularly done with: Bruce Dawson, Adelaide Jose Bellido, Adelaide Ben Whelan, Adelaide and the Auger Collaboration
More informationMulti-Messenger Astonomy with Cen A?
Multi-Messenger Astonomy with Cen A? Michael Kachelrieß NTNU, Trondheim [] Outline of the talk 1 Introduction 2 Dawn of charged particle astronomy? Expectations vs. Auger data Effects of cluster fields
More informationAnisotropy studies with the Pierre Auger Observatory
Anisotropy studies with the Pierre Auger Observatory Carla Macolino 1 for the Pierre Auger Collaboration 2 Full author list: http://www.auger.org/archive/authors_2011_05.html 1 Lab. de Physique Nucleaire
More informationResults from the Telescope Array Experiment
Results from the Telescope Array Experiment Hiroyuki Sagawa (ICRR, University of Tokyo) for the Telescope Array Collaboration @ AlbaNova University Center on 2011.08.1 2011/08/1 H. Sagawa @ 7th TeVPA in
More informationRecent results from the Pierre Auger Observatory
Recent results from the Pierre Auger Observatory Esteban Roulet, for the Pierre Auger Collaboration CONICET, Centro Atómico Bariloche, Bustillo 9500, Bariloche, 8400, Argentina E-mail: roulet@cab.cnea.gov.ar
More informationA few grams of matter in a bright world
A few grams of matter in a bright world Benjamin Rouillé d Orfeuil (LAL) Fellow Collaborators: D. Allard, C. Lachaud & E. Parizot (APC) A. V. Olinto (University of Chicago) February 12 th 2013 LAL All
More informationTHE PIERRE AUGER OBSERVATORY: STATUS AND RECENT RESULTS
SF2A 2006 D. Barret, F. Casoli, T. Contini, G. Lagache, A. Lecavelier, and L. Pagani (eds) THE PIERRE AUGER OBSERVATORY: STATUS AND RECENT RESULTS Serguei Vorobiov (for the Pierre Auger Collaboration)
More informationStudies of Ultra High Energy Cosmic Rays with the Pierre Auger Observatory
Studies of Ultra High Energy Cosmic Rays with the Pierre Auger Observatory Universidade Federal do Rio de Janeiro, Brazil E-mail: haris@if.ufrj.br Aquiring data continuously from 004, the Pierre Auger
More informationExperimental Constraints to high energy hadronic interaction models using the Pierre Auger Observatory part-i
Experimental Constraints to high energy hadronic interaction models using the Pierre Auger Observatory part-i (cosmic rays, the Auger detectors, event reconstruction, observations) Jose Bellido QCD @ Cosmic
More informationUHECR autocorrelation function after Auger
UHECR autocorrelation function after Auger Pasquale D. Serpico based on work in collaboration with A. Cuoco, S. Hannestad,, T. Haugbølle,, M. Kachelrieß (arxiv:0709.2712; arxiv:0809.4003 :0809.4003) SOCoR
More informationCosmic Rays. Discovered in 1912 by Viktor Hess using electroscopes to measure ionization at altitudes via balloon
Cosmic Rays Discovered in 1912 by Viktor Hess using electroscopes to measure ionization at altitudes via balloon Nobel Prize in 1936 Origin of high energy cosmic rays is still not completely understood
More informationUltrahigh Energy cosmic rays II
Ultrahigh Energy cosmic rays II Today we will discuss the new data on UHECR presented during the last couple of years by the Auger observatory in Argentina. These data do not match previous analyses and
More informationHadronic interactions of ultra-high energy cosmic rays
Hadronic interactions of ultra-high energy cosmic rays Pierre Auger Observatory Henryk Wilczyński Instytut Fizyki Jądrowej PAN, Kraków Kraków, 31 March 2017 Ultra-high energy cosmic rays Key questions:
More informationarxiv:astro-ph/ v1 28 Oct 2004
Highest Energy Cosmic Rays Angela V. Olinto arxiv:astro-ph/0410685v1 28 Oct 2004 Department of Astronomy & Astrophysics, Kavli Institute of Cosmological Physics The University of Chicago, 5640 S. Ellis
More informationNeutrino Oscillations and Astroparticle Physics (5) John Carr Centre de Physique des Particules de Marseille (IN2P3/CNRS) Pisa, 10 May 2002
Neutrino Oscillations and Astroparticle Physics (5) John Carr Centre de Physique des Particules de Marseille (IN2P3/CNRS) Pisa, 10 May 2002 n High Energy Astronomy Multi-Messanger Astronomy Cosmic Rays
More informationCOSMIC RAYS AND AGN's
COSMIC RAYS AND AGN's RAZELE COSMICE ŞI NUCLEELE GALACTICE ACTIVE (don't worry, it is in Romanian) Sorin Roman sroman@mpifr-bonn.mpg.de We'll try to talk about: -History -Composition -CR Spectrum -Detection
More informationRecent Results of the Telescope Array Experiment. Gordon Thomson University of Utah
Recent Results of the Telescope Array Experiment Gordon Thomson University of Utah 1 Outline Telescope Array Experiment TA Results Spectrum Anisotropy Future Plans Conclusions See John Belz talk for: TA
More informationUHE Cosmic Rays in the Auger Era
Vulcano Workshop 2010 - May, 23-29, 2010 UHE Cosmic Rays in the Auger Era Sergio Petrera, L'Aquila University email: sergio.petrera@aquila.infn.it Vulcano Workshop 2010 - May, 23-29, 2010 UHE Cosmic Rays
More informationThe Pierre Auger Project: Status and Recent Results. Pierre Auger Project. Astrophysical motivation
The Pierre Auger Project: Status and Recent Results Markus Roth Forschungszentrum Karlsruhe Markus.Roth@ik.fzk.de Astrophysical motivation Pierre Auger Project Experimental concept Status Results Summary
More informationRecent Results of the Observatory Pierre Auger. João R. T. de Mello Neto Instituto de Física Universidade Federal do Rio de Janeiro
Recent Results of the Observatory Pierre Auger João R. T. de Mello Neto Instituto de Física Universidade Federal do Rio de Janeiro S. Tomé e Príncipe, September 2009 Outline Cosmic ray detection and the
More informationUltra-High-Energy Cosmic Rays: A Tale of Two Observatories
Ultra-High-Energy Cosmic Rays: A Tale of Two Observatories RuoYu Shang Nicholas Sherer Fei Sun Bryce Thurston Measurement of the Depth of Maximumof Extensive Air Showers above 10 18 ev,"phys. Rev. Letters104(2010)
More informationThe Highest Energy Cosmic Rays
The Highest Energy Cosmic Rays Angela V. Olinto Department of Astronomy & Astrophysics, Kavli Institute of Cosmological Physics The University of Chicago, 5640 S. Ellis Ave, Chicago, IL 60637, USA olinto@oddjob.uchicago.edu
More informationHigher Statistics UHECR observatories: a new era for a challenging astronomy
CRIS 2010 100 years of Cosmic Ray Physics: from Pioneering Experiments to Physics in Space 1 Higher Statistics UHECR observatories: a new era for a challenging astronomy Etienne Parizot APC University
More informationCosmic Rays, Photons and Neutrinos
Cosmic Rays, Photons and Neutrinos Michael Kachelrieß NTNU, Trondheim [] Introduction Outline Plan of the lectures: Cosmic rays Galactic cosmic rays Basic observations Acceleration Supernova remnants Problems
More informationUltra High Energy Cosmic Rays. and
2011 BCVSPIN Advanced Study Institute in Particle Physics and Cosmology, Huê, Vietnam, 25-30 July 2011 Ultra High Energy Cosmic Rays and The Pierre Auger Observatory Paolo Privitera 1 Cosmic Rays are always
More informationUHECRs sources and the Auger data
UHECRs sources and the Auger data M. Kachelrieß Institutt for fysikk, NTNU Trondheim, Norway I review the evidence for a correlation of the arrival directions of UHECRs observed by the Pierre Auger Observatory
More informationSERCH FOR LARGE-SCALE
SERCH FOR LARGE-SCALE Université Libre de Bruxelles (ULB) Brussels SNOWPAC 23-28 March, 2010 Matter tracer model: generic model of CRs under the assumptions: nearly straight propagation typical deflections
More informationUltra-High Energy Cosmic Rays (III)
Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Ultra-High Energy Cosmic Rays (III) Ralph Engel Forschungszentrum Karlsruhe & Karlsruhe Institute of Technology Outline Brief overview (experimental
More informationCosmic Rays. M. Swartz. Tuesday, August 2, 2011
Cosmic Rays M. Swartz 1 History Cosmic rays were discovered in 1912 by Victor Hess: he discovered that a charged electroscope discharged more rapidly as he flew higher in a balloon hypothesized they were
More informationExperimental Constraints to High Energy Hadronic Interaction Models using the Pierre Auger Observatory Part II
Experimental Constraints to High Energy Hadronic Interaction Models using the Pierre Auger Observatory Part II Tanguy Pierog Karlsruhe Institute of Technology, Institut für Kernphysik, Karlsruhe, Germany
More informationFrontiers: Ultra High Energy Cosmic Rays
Frontiers: Ultra High Energy Cosmic Rays We now focus on cosmic rays with almost unimaginable energies: 10 19 ev and beyond. The very highest energy cosmic rays have energies in excess of 50 Joules(!),
More informationThe Pierre Auger Observatory
The Pierre Auger Observatory Hunting the Highest Energy Cosmic Rays I High Energy Cosmic Rays and Extensive Air Showers March 2007 E.Menichetti - Villa Gualino, March 2007 1 Discovery of Cosmic Rays Altitude
More informationUltra-High Energy Cosmic Rays & Neutrinos above the Terascale
Ultra-High Energy Cosmic Rays & Neutrinos above the Terascale Angela V. Olinto A&A, KICP, EFI The University of Chicago Nature sends 10 20 ev particles QuickTime and a YUV420 codec decompressor are needed
More informationSearch for clustering of ultra high energy cosmic rays from the Pierre Auger Observatory
Nuclear Physics B (Proc. Suppl.) 190 (2009) 198 203 www.elsevierphysics.com Search for clustering of ultra high energy cosmic rays from the Pierre Auger Observatory Silvia Mollerach, for the Pierre Auger
More informationDr. John Kelley Radboud Universiteit, Nijmegen
arly impressive. An ultrahighoton triggers a cascade of particles mulation of the Auger array. The Many Mysteries of Cosmic Rays Dr. John Kelley Radboud Universiteit, Nijmegen Questions What are cosmic
More informationResults from the Pierre Auger Observatory. Paul Sommers, Penn State August 7, 2008, SSI
Results from the Pierre Auger Observatory Paul Sommers, Penn State August 7, 2008, SSI The Cosmic Ray Energy Spectrum Non-thermal, approximate power law, up to about 3x10 20 ev (possibly higher) 1 EeV
More informationImplications of recent cosmic ray results for ultrahigh energy neutrinos
Implications of recent cosmic ray results for ultrahigh energy neutrinos Subir Sarkar Neutrino 2008, Christchurch 31 May 2008 Cosmic rays have energies upto ~10 11 GeV and so must cosmic neutrinos knee
More informationThe Secondary Universe
Secondary photons and neutrinos from distant blazars and the intergalactic magnetic fields UC Berkeley September 11, 2011 The talk will be based on A new interpretation of the gamma-ray observations of
More informationUltra High Energy Cosmic Rays. Malina Kirn March 1, 2007 Experimental Gravitation & Astrophysics
Ultra High Energy Cosmic Rays Malina Kirn March 1, 2007 Experimental Gravitation & Astrophysics Outline Cosmic Rays What are UHECR? GZK Effect Why study UHECR? Pillars of Research Energy Spectrum Composition
More informationIs the search for the origin of the Highest Energy Cosmic Rays over? Alan Watson University of Leeds, England
Colloquium, University of Virginia: 18 April 2008 Is the search for the origin of the Highest Energy Cosmic Rays over? Alan Watson University of Leeds, England a.a.watson@leeds.ac.uk 1 OVERVIEW Why there
More information> News < AMS-02 will be launched onboard the Shuttle Endeavour On May 2nd 2:33 P.M. from NASA Kennedy space center!
> News < Anti-matter, dark matter measurement By measuring the cosmic rays (Mainly electron, positron, proton, anti-proton and light nuclei) AMS-02 will be launched onboard the Shuttle Endeavour On May
More informationExtensive Air Shower and cosmic ray physics above ev. M. Bertaina Univ. Torino & INFN
Extensive Air Shower and cosmic ray physics above 10 17 ev M. Bertaina Univ. Torino & INFN ISMD 2015, Wildbad Kreuth 5-9 October 2015 Outline:» Part I: A general overview of cosmic ray science.» Part II:
More informationCosmic Rays in large air-shower detectors
Cosmic Rays in large air-shower detectors 2. The cosmic-ray spectrum from Galactic to Extra-galactic Seattle, July 2, 2009 Tom Gaisser 1 Cascade equations For hadronic cascades in the atmosphere X = depth
More informationWhat we (don t) know about UHECRs
What we (don t) know about UHECRs We know: their energies (up to 10 20 ev). their overall energy spectrum We don t know: where they are produced how they are produced what they are made off exact shape
More informationUltra-High Energy Cosmic Rays and the GeV-TeV Diffuse Gamma-Ray Flux
The 4th International Workshop on The Highest Energy Cosmic Rays and Their Sources INR, Moscow May 20-22, 2008 Ultra-High Energy Cosmic Rays and the GeV-TeV Diffuse Gamma-Ray Flux Oleg Kalashev* (INR RAS)
More informationUltrahigh Energy Cosmic Rays propagation II
Ultrahigh Energy Cosmic Rays propagation II The March 6th lecture discussed the energy loss processes of protons, nuclei and gamma rays in interactions with the microwave background. Today I will give
More informationSearches for cosmic ray anisotropies at ultra-high energies
Searches for cosmic ray anisotropies at ultra-high energies Haris Lyberis*, on behalf the Pierre Auger Collaboration * U n i v e r s i t é P a r i s V I I D e n i s d i d e r o t, P a r i s, F r a n c
More informationStatus and results from the Pierre Auger Observatory
April 15-19, 2007 Aspen, Colorado Status and results from the Pierre Auger Observatory Lorenzo Perrone for the Auger Collaboration Università del Salento and INFN Lecce Italy The Physics Case: highest
More informationUniversality (and its limitations) in Cosmic Ray shower development
Universality (and its limitations) in Cosmic Ray shower development Paolo Lipari, INFN Roma Sapienza Cosmic Ray International Seminar 2015 Gallipoli 14th september 2015 Definition of universality in the
More informationCosmic Rays: high/low energy connections
Lorentz Center Workshop Cosmic Ray Interactions: Bridging High and Low Energy Astrophysics 1 Cosmic Rays: high/low energy connections Etienne Parizot APC University of Paris 7 2 Cosmic rays: messages and
More informationCharged-particle and gamma-ray astronomy: deciphering charged messages from the world s most powerful
Charged-particle and gamma-ray astronomy: deciphering charged messages from the world s most powerful Charged-particle astronomy coming of age How it is done The sources The signals What we have learned
More informationIntergalactic Magnetic Field and Arrival Direction of Ultra-High-Energy Protons
Intergalactic Magnetic Field and Arrival Direction of Ultra-High-Energy Protons Dongsu Ryu (Chungnam National U, Korea) Hyesung Kang (Pusan National U, Korea) Santabrata Das (Indian Institute of Technology
More informationand small-x QCD Adrian Dumitru, ITP, Frankfurt University, 2005 CTEQ summer school Collaborators: H.J. Drescher and M. Strikman
Cosmic Ray Airshowers and small-x QCD Adrian Dumitru, ITP, Frankfurt University, 2005 CTEQ summer school Collaborators: H.J. Drescher and M. Strikman Cosmic Rays Airshowers QCD input, small x, high gluon
More informationHigh Energy Emission. Brenda Dingus, LANL HAWC
High Energy Emission from GRBs Brenda Dingus, LANL HAWC What are GRBs? Cosmological distance Typical observed z>1 Energy released is up to few times the rest mass of Sun (if isotropic) in a few seconds
More informationArrival directions of the highest-energy cosmic rays detected by the Pierre Auger Observatory
Arrival directions of the highest-energy cosmic rays detected by the Pierre Auger Observatory a for the Pierre Auger Collaboration b a Instituto de Física, Universidade Federal do Rio de Janeiro, Brazil
More informationInvestigation on mass composition of UHE cosmic rays using CRPropa 2.0
Investigation on mass composition of UHE cosmic rays using CRPropa. G Rastegarzade B Parvizi,, Physics Department, Semnan University, Semnan, P.O. Box 596-599, Iran Email: G_ rastegar@alum.sharif.edu Abstract
More informationSEARCHES OF VERY HIGH ENERGY NEUTRINOS. Esteban Roulet CONICET, Centro Atómico Bariloche
SEARCHES OF VERY HIGH ENERGY NEUTRINOS Esteban Roulet CONICET, Centro Atómico Bariloche THE NEUTRINO SKY THE ENERGETIC UNIVERSE multimessenger astronomy γ ν p γ rays (Fermi) ν (Amanda) UHE Cosmic rays
More informationThe Pierre Auger Observatory: on the arrival directions of the most energetic cosmic rays
The Pierre Auger Observatory: on the arrival directions of the most energetic cosmic rays Piera L. Ghia*, for the Pierre Auger Collaboration * IFSI/INAF Torino, Italy, & IPN/CNRS Orsay, France Outline
More informationThe Pierre Auger Observatory in 2007
The Pierre Auger Observatory in 2007 Henryk Wilczyński 1 for the Pierre Auger Collaboration 2 1 Institute of Nuclear Physics PAN, Kraków, Poland 2 Pierre Auger Observatory, Malargüe, Mendoza, Argentina
More informationNEW VIEWS OF THE UNIVERSE. Recent Studies of Ultra High Energy Cosmic Rays. Alan Watson University of Leeds, UK (regular KICP Visitor)
1 David Schramm Symposium: NEW VIEWS OF THE UNIVERSE Recent Studies of Ultra High Energy Cosmic Rays Alan Watson University of Leeds, UK (regular KICP Visitor) a.a.watson@leeds.ac.uk 2 Dave Schramm: 15
More informationTopic 7. Relevance to the course
Topic 7 Cosmic Rays Relevance to the course Need to go back to the elemental abundance curve Isotopes of certain low A elements such as Li, Be and B have larger abundances on Earth than you would expect
More informationExtremely High Energy Neutrinos
Extremely High Energy Neutrinos A. Ringwald http://www.desy.de/ ringwald DESY 6 th National Astroparticle Physics Symposium February 3, 2006, Vrije Universiteit, Amsterdam, Netherlands Extremely high energy
More informationThe Physics of Ultrahigh Energy Cosmic Rays. Example Poster Presentation Physics 5110 Spring 2009 Reminder: Posters are due Wed April 29 in class.
The Physics of Ultrahigh Energy Cosmic Rays Example Poster Presentation Physics 5110 Spring 2009 Reminder: Posters are due Wed April 29 in class. 1 Introduction to Cosmic Rays References: http://www.phy.bris.ac.uk/groups/particle/pus/affo
More informationULTRA HIGH ENERGY COSMIC RAYS WHERE DO WE STAND AFTER 10 YEARS AT THE PIERRE AUGER OBSERVATORY
Antoine Letessier Selvon (CNRS/UPMC) FRIF days Dourdan January 2014!1 ULTRA HIGH ENERGY COSMIC RAYS WHERE DO WE STAND AFTER YEARS AT THE PIERRE AUGER OBSERVATORY Antoine Letessier Selvon (CNRS/UPMC) FRIF
More informationOn the GCR/EGCR transition and UHECR origin
UHECR 2014 13 15 October 2014 / Springdale (Utah; USA) On the GCR/EGCR transition and UHECR origin Etienne Parizot 1, Noémie Globus 2 & Denis Allard 1 1. APC Université Paris Diderot France 2. Tel Aviv
More informationParticle Acceleration in the Universe
Particle Acceleration in the Universe Hiroyasu Tajima Stanford Linear Accelerator Center Kavli Institute for Particle Astrophysics and Cosmology on behalf of SLAC GLAST team June 7, 2006 SLAC DOE HEP Program
More informationULTRA-HIGH ENERGY COSMIC RAY COMPOSITION and MUON CONTENT vs. HADRONIC MODELS. Esteban Roulet Bariloche, Argentina
ULTRA-HIGH ENERGY COSMIC RAY COMPOSITION and MUON CONTENT vs. HADRONIC MODELS Esteban Roulet Bariloche, Argentina Many observables are sensitive to CR composition Shower maximum TA APP 64 (2014) Auger
More informationCosmogenic neutrinos II
Cosmogenic neutrinos II Dependence of fluxes on the cosmic ray injection spectra and the cosmological evolution of the cosmic ray sources Expectations from the cosmic ray spectrum measured by the Auger
More informationCosmic Rays: A Way to Introduce Modern Physics Concepts. Steve Schnetzer
Cosmic Rays: A Way to Introduce Modern Physics Concepts Steve Schnetzer Rutgers CR Workshop May 19, 2007 Concepts Astrophysics Particle Physics Radiation Relativity (time dilation) Solar Physics Particle
More information99 Years from Discovery : What is our current picture on Cosmic Rays? #6 How cosmic rays travel to Earth? Presented by Nahee Park
99 Years from Discovery : What is our current picture on Cosmic Rays? #6 How cosmic rays travel to Earth? Presented by Nahee Park #5 How do Cosmic Rays gain their energy? I. Acceleration mechanism of CR
More informationPEV NEUTRINOS FROM THE PROPAGATION OF ULTRA-HIGH ENERGY COSMIC RAYS. Esteban Roulet CONICET, Bariloche, Argentina
PEV NEUTRINOS FROM THE PROPAGATION OF ULTRA-HIGH ENERGY COSMIC RAYS Esteban Roulet CONICET, Bariloche, Argentina THE ENERGETIC UNIVERSE multi-messenger astronomy γ ν p γ rays neutrinos Fermi Amanda UHE
More informationCosmic Rays, their Energy Spectrum and Origin
Chapter 1 Cosmic Rays, their Energy Spectrum and Origin 1 The Problem of Cosmic Rays Most cosmic rays are not, as the name would suggest, a type of electromagnetic radiation, but are nucleonic particles
More informationA New View of the High-Energy γ-ray Sky with the Fermi Telescope
A New View of the High-Energy γ-ray Sky with the Fermi Telescope Aurelien Bouvier KIPAC/SLAC, Stanford University On behalf of the Fermi collaboration SNOWPAC, 2010 The Fermi observatory Launch: June 11
More informationThe Large Area Telescope on-board of the Fermi Gamma-Ray Space Telescope Mission
The Large Area Telescope on-board of the Fermi Gamma-Ray Space Telescope Mission 1 Outline Mainly from 2009 ApJ 697 1071 The Pair Conversion Telescope The Large Area Telescope Charged Background and Events
More informationULTRA HIGH ENERGY COSMIC RAYS
ULTRA HIGH ENERGY COSMIC RAYS Carla Bonifazi Instituto de Física Universidade Federal do Rio de Janeiro Dark Side Of The Universe 2012 Buzios Brazil Outline Introduction UHECRs Detection Recent Progress
More informationLessons 19 and 20. Detection of C.R. with energy > TeV Study of the C.R. isotropy/anisotropy Ground based detectors:
Lessons 19 and 20 Detection of C.R. with energy > TeV Study of the C.R. isotropy/anisotropy Ground based detectors: Detection at ground of extensive Air Showers: nature, direction and energy of the primary
More informationFirst Results from the Pierre Auger Project
First Results from the Pierre Auger Project A new cosmic ray observatory designed for a high statistics study of the the Highest Energy Cosmic Rays. Jim Beatty (Ohio State) for the Pierre Auger Collaboration
More informationUnderstanding High Energy Neutrinos
Understanding High Energy Neutrinos Paolo Lipari: INFN Roma Sapienza NOW-2014 Conca Specchiulla 12th september 2014 An old dream is becoming a reality : Observing the Universe with Neutrinos ( A new way
More informationIceCube: Ultra-high Energy Neutrinos
IceCube: Ultra-high Energy Neutrinos Aya Ishihara JSPS Research Fellow at Chiba University for the IceCube collaboration Neutrino2012 at Kyoto June 8 th 2012 1 Ultra-high Energy Neutrinos: PeV and above
More informationMeasurement of Anisotropy and Search for UHECR Sources
Prog. Theor. Exp. Phys. 2015, 00000 (29 pages) DOI: 10.1093/ptep/0000000000 Measurement of Anisotropy and Search for UHECR Sources O. Deligny 1, K. Kawata 2, and P. Tinyakov 3 arxiv:1702.07209v1 [astro-ph.he]
More informationThe Pierre Auger Observatory
The Pierre Auger Observatory astroparticle physics above ~1018 ev Jeff Brack Colorado State University Northern observatory Colorado, USA (R&D underway) Southern observatory Mendoza, Argentina (construction
More information