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1

High Energy Cosmic Rays  

E-print Network

Cloud chambers emulsion #12;T.Hebbeker Neutrino Oscillations Super- Kamiokande CerenkovA + Atmosphere ? Influence on climate ? Charged particles = seeds for condensation cloud chamber Cosmics Leaving OUtdoor 011 012 013 014 015 016 017 018 019 020 02 02 017 018 019 020 CMS muon chamber Aachen 2002 4 cm #12

Hebbeker, Thomas

2

High-energy Cosmic Rays  

E-print Network

After a brief review of galactic cosmic rays in the GeV to TeV energy range, we describe some current problems of interest for particles of very high energy. Particularly interesting are two features of the spectrum, the `knee' above $10^{15}$ eV and the `ankle' above $10^{18}$ eV. An important question is whether the highest energy particles are of extra-galactic origin and, if so, at what energy the transition occurs. A theme common to all energy ranges is use of nuclear abundances as a tool for understanding the origin of the cosmic radiation.

Thomas K. Gaisser; Todor Stanev

2005-10-11

3

Ultra High Energy Cosmic Rays  

E-print Network

The origin of the particles in the highest energy end of the cosmic ray spectrum is discussed in the context of the wider problem of the origin of the whole cosmic radiation as observed at the Earth. In particular we focus our attention on the acceleration problem and on the transition from galactic to extragalactic cosmic rays.

Pasquale Blasi

2006-09-29

4

Lecture notes on high energy cosmic rays  

E-print Network

I give a concise introduction into high energy cosmic ray physics, including also few related aspects of high energy gamma-ray and neutrino astrophysics. The main emphasis is placed on astrophysical questions, and the level of the presentation is kept basic.

M. Kachelriess

2008-01-29

5

High energy cosmic rays: sources and fluxes  

NASA Astrophysics Data System (ADS)

We discuss the production of a unique energy spectrum of the high energy cosmic rays detected with air showers by shifting the energy estimates of different detectors. After such a spectrum is generated we fit the spectrum with three or four populations of cosmic rays that might be accelerated at different cosmic ray sources. We also present the chemical composition that the fits of the spectrum generates and discuss some new data sets presented this summer at the ICRC in Rio de Janeiro that may require new global fits.

Stanev, Todor; Gaisser, Thomas K.; Tilav, Serap

2014-04-01

6

Cosmic Rays High Energy Particles  

E-print Network

1937 Anderson, Neddermeyer Muon 1937 Powell Positron ! Antimatter ! 1932 Anderson Pion Cloud chambers ? Charged particles = seeds for condensation cloud chamber / bubble chamber Cosmics Leaving OUtdoor Droplets for condensation cloud chamber / bubble chamber Cosmics Leaving OUtdoor Droplets CERN #12;T.Hebbeker Lightnings

Hebbeker, Thomas

7

Cosmic Rays High Energy Particles  

E-print Network

, Neddermeyer Muon 1937 Powell Positron ! Antimatter ! 1932 Anderson Pion Cloud chambers emulsion #12;T for condensation cloud chamber / bubble chamber Cosmics Leaving OUtdoor Droplets CERN #12;T.Hebbeker Lightnings 02 02 017 018 019 020 CMS muon chamber Aachen 2002 4 cm #12;T.Hebbeker Polar Light (Aurea Borealis

Hebbeker, Thomas

8

Testing fundamental principles with high-energy cosmic rays  

E-print Network

Testing fundamental principles with high-energy cosmic rays Luis Gonzalez-Mestres LAPP, Université_sci@yahoo.fr It is not yet clear [1] whether the observed flux suppression for ultra-high energy cosmic rays (UHECR to violations of standard special relativity modifying cosmic- ray propagation or acceleration at very high

9

High Energy Cosmic Rays from Local GRBs  

E-print Network

We have developed a model that explains cosmic rays with energies E between \\~0.3 PeV and the energy of the second knee at E_2 ~ 3*10^{17} eV as originating from a recent Galactic gamma-ray burst (GRB) that occurred ~1 Myr ago within 1 kpc from Earth. Relativistic shocks from GRBs are assumed to inject power-law distributions of cosmic rays (CRs) to the highest energies. Diffusive propagation of CRs from the local GRB explains the CR spectrum near and above the first knee at E_1 ~ 3*10^{15} eV. The first and the second knees are explained as being directly connected with the injection of plasma turbulence in the interstellar medium on a ~1 pc and ~100 pc scales, respectively. Transition to CRs from extragalactic GRBs occurs at E > E_2. The origin of the ankle in the CR spectrum at E ~ 4*10^{18} eV is due to photopair energy losses of UHECRs on cosmological timescales, as also suggested by Berezinsky and collaborators. Any significant excess flux of extremely high energy CRs deviating from the exponential cutoff behavior at E> E_{GZK} = 6*10^{19} eV would imply a significant contribution due to recent GRB activity on timescales t < 10^8 yrs from local extragalactic sources within ~10 Mpc.

A. Atoyan; C. D. Dermer

2005-08-23

10

Terrestrial Effects of High Energy Cosmic Rays  

NASA Astrophysics Data System (ADS)

On geological timescales, the Earth is likely to be exposed to an increased flux of high energy cosmic rays (HECRs) from astrophysical sources such as nearby supernovae, gamma ray bursts or by galactic shocks. These high-energy particles strike the Earth's atmosphere initiating an extensive air shower. As the air shower propagates deeper, it ionizes the atmosphere by producing charged secondary particles. Increased ionization could lead to changes in atmospheric chemistry, resulting in ozone depletion. This could increase the flux of solar UVB radiation at the surface, which is potentially harmful to living organisms. Increased ionization affects the global electrical circuit can could possibly enhance the low-altitude cloud formation rate. Secondary particles such as muons and thermal neutrons produced as a result of nuclear interactions are able to reach the ground, enhancing the biological radiation dose. The muon flux dominates radiation dose from cosmic rays causing DNA damage and increase in the mutation rates, which can have serious biological implications for terrestrial and sub-terrestrial life. This radiation dose is an important constraint on the habitability of a planet. Using CORSIKA, we perform massive computer simulations and construct lookup tables from 10 GeV - 1 PeV primaries (1 PeV - 0.1 ZeV in progress), which can be used to quantify these effects. These tables are freely available to the community and can be used for other studies, not necessarily relevant to Astrobiology. We use these tables to study the terrestrial implications of galactic shock generated by the infall of our galaxy toward the Virgo cluster. This could be a possible mechanism explaining the observed periodicity in biodiversity in paleobiology databases.

Atri, Dimitra

2011-01-01

11

30TH INTERNATIONAL COSMIC RAY CONFERENCE Radio Detection of UltraHigh Energy Cosmic Rays  

E-print Network

30TH INTERNATIONAL COSMIC RAY CONFERENCE Radio Detection of Ultra­High Energy Cosmic Rays HEINO from cosmic rays, confirmed the geosynchrotron effect for extensive air showers, and provided a good rays and the usage of the LOFAR radio telescope (and later the SKA) as a cosmic ray detector. Here

Falcke, Heino

12

High energy cosmic rays, gamma rays and neutrinos from AGN  

E-print Network

The author reviews a model for the emission of high energy cosmic rays, gamma-rays and neutrinos from AGN (Active Galactic Nuclei) that he has proposed since 1985. Further discussion of the knee energy phenomenon of the cosmic ray energy spectrum requires the existence of a heavy particle with mass in the knee energy range. A possible method of detecting such a particle in the Pierre Auger Project is suggested. Also presented is a relation between the spectra of neutrinos and gamma-rays emitted from AGN. This relation can be tested by high energy neutrino detectors such as ICECUBE, the Mediterranean Sea Detector and possibly by the Pierre Auger Project.

Yukio Tomozawa

2008-02-03

13

High energy physics in cosmic rays  

SciTech Connect

In the first half-century of cosmic ray physics, the primary research focus was on elementary particles; the positron, pi-mesons, mu-mesons, and hyperons were discovered in cosmic rays. Much of this research was carried out at mountain elevations; Pic du Midi in the Pyrenees, Mt. Chacaltaya in Bolivia, and Mt. Evans/Echo Lake in Colorado, among other sites. In the 1960s, claims of the observation of free quarks, and satellite measurements of a significant rise in p-p cross sections, plus the delay in initiating accelerator construction programs for energies above 100 GeV, motivated the Michigan-Wisconsin group to undertake a serious cosmic ray program at Echo Lake. Subsequently, with the succession of higher energy accelerators and colliders at CERN and Fermilab, cosmic ray research has increasingly focused on cosmology and astrophysics, although some groups continue to study cosmic ray particle interactions in emulsion chambers.

Jones, Lawrence W. [University of Michigan, Ann Arbor, Michigan (United States)

2013-02-07

14

Testing Fundamental Physics with High-Energy Cosmic Rays  

E-print Network

Cosmic rays may provide opportunities for probing fundamental physics. For example, ultra-high-energy cosmic rays might originate from the decays of metastable heavy particles, and astrophysical gamma rays can be used to test models of quantum gravity. Both scenarios offer ways to avoid the GZK cut-off.

John Ellis

2000-10-24

15

Clusters in Very High Energy Cosmic Rays  

E-print Network

Arrival directions of cosmic rays with the energy E>4.10^{19} eV are analyzed by using data of the Yakutsk and AGASA (Japan) extensive air showers (EAS) arrays. It is supposed that the clusters can be formed as a result of decay of superheavy particles. The consequences of this supposition compare with experimental data.

A. A. Mikhailov

2004-03-19

16

Ultra High Energy Cosmic Rays: present status and future prospects  

E-print Network

Reasons for the current interest in cosmic rays above 10^19 eV are described. The latest results on the energy spectrum, arrival direction distribution and mass composition of cosmic rays are reviewed, including data that were reported after the meeting in Blois in June 2001. The enigma set by the existence of ultra high-energy cosmic rays remains. Ideas proposed to explain it are discussed and progress with the construction of the Pierre Auger Observatory is outlined.

A. A. Watson

2001-12-20

17

THE COMPOSITION OF ULTRA HIGH ENERGY COSMIC RAYS THROUGH HYBRID  

E-print Network

THE COMPOSITION OF ULTRA HIGH ENERGY COSMIC RAYS THROUGH HYBRID ANALYSIS AT TELESCOPE ARRAY fulfillment of the requirements for the degree of Doctor of Philosophy in Physics Department of Physics Kieda Physics and Astronomy #12;ABSTRACT The chemical composition of cosmic rays is critically important

18

High energy cosmic rays from AGN and the GZK cutoff  

E-print Network

Based on a model for the emission of high energy cosmic rays from AGN (Active Galactic Nuclei) that has been proposed by the author, he reviews the status of the GZK cutoff and the correlation of high energy cosmic ray sources with AGN locations in the existing data. The determination of mass for the incident particles seems to be a key factor, and a suggestion for doing that has been made in this article.

Yukio Tomozawa

2008-02-20

19

High energy cosmic ray iron spectrum experiment  

NASA Technical Reports Server (NTRS)

An instrument containing a gas Cerenkov counter and an iron ionization spectrometer was constructed in order to measure the cosmic-ray iron spectrum to 300 GeV/nucleon. Trajectories of particles were determined by entopistic or position-determining scintillator systems. The geometric factors with and without the gas Cerenkov counter were 0.3 and 0.6 sq m-ster, respectively. The instrument was successfully flown in June 1976 without the spectrometer and in October 1976 with the spectrometer from Palestine, Texas. The June flight yielded 14.5 h of data; the October flight, 25 h.

Arens, J. F.; Balasubrahmanyan, V. K.; Ormes, J. F.; Schmidt, W. K. H.; Simon, M.; Spiegelhauer, H.

1978-01-01

20

Observing Ultra-High Energy Cosmic Rays with Smartphones  

E-print Network

We propose a novel approach for observing cosmic rays at ultra-high energy ($>10^{18}$~eV) by repurposing the existing network of smartphones as a ground detector array. Extensive air showers generated by cosmic rays produce muons and high-energy photons, which can be detected by the CMOS sensors of smartphone cameras. The small size and low efficiency of each sensor is compensated by the large number of active phones. We show that if user adoption targets are met, such a network will have significant observing power at the highest energies.

Whiteson, Daniel; Shimmin, Chase; Brodie, Kyle; Burns, Dustin

2014-01-01

21

Observing Ultra-High Energy Cosmic Rays with Smartphones  

E-print Network

We propose a novel approach for observing cosmic rays at ultra-high energy ($>10^{18}$~eV) by repurposing the existing network of smartphones as a ground detector array. Extensive air showers generated by cosmic rays produce muons and high-energy photons, which can be detected by the CMOS sensors of smartphone cameras. The small size and low efficiency of each sensor is compensated by the large number of active phones. We show that if user adoption targets are met, such a network will have significant observing power at the highest energies.

Daniel Whiteson; Michael Mulhearn; Chase Shimmin; Kyle Brodie; Dustin Burns

2014-10-10

22

Ultra High Energy Cosmic Rays: The theoretical challenge  

E-print Network

The origin of the highest-energy cosmic rays remains a mystery. The lack of a high energy cutoff in the cosmic ray spectrum together with an apparently isotropic distribution of arrival directions have strongly constrained most models proposed for the generation of these particles. An overview of the present state of theoretical proposals is presented. Astrophysical accelerators as well as top-down scenarios are reviewed along with their most general signatures. The origin and nature of these ultra-high energy particles will be tested by future observations and may indicate as well as constrain physics beyond the standard model of particle physics.

A. V. Olinto

2000-02-01

23

High Energy Neutrino Astronomy - the cosmic-ray connection  

E-print Network

Several of the models for origin of the highest energy cosmic rays also predict significant neutrino fluxes. A common factor of the models is that they must provide sufficient power to supply the observed energy in the extragalactic component of the cosmic radiation. The assumption that a comparable amount of energy goes into high-energy neutrinos allows a model-independent estimate of the neutrino signal that may be expected.

Thomas K. Gaisser

2000-11-28

24

Ionization of High Energy Cosmic-Ray Electrons  

Microsoft Academic Search

The ionization produced by high energy cosmic-ray electrons has been measured in a cloud chamber in order to determine whether the probable ionization produced by a high velocity particle continues to rise logarithmically with the energy, or whether it takes on a constant value as has been predicted theoretically. A lateral clearing field was arranged so that the ionization could

Evans Hayward

1947-01-01

25

Ultra High Energy Comic Rays in the Cosmic Microwave Background  

E-print Network

We consider the propagation of ultra high energy cosmic rays (UHECR), for energies greater than E > 10^{14} eV but less than E < 10^{26} eV, in the cosmic medium of the Cosmic Microwave Background (CMB). We find that the CMB plays a pivot role in this energy range. As example, the observed "knee(s)" and the "ankle" could be understood in reasonable terms. What we may observe at energy near 10^{25} eV (W^\\pm bursts or Z^0 bursts) is also briefly discussed.

Hwang, W-Y Pauchy

2011-01-01

26

Ultra High Energy Comic Rays in the Cosmic Microwave Background  

E-print Network

We consider the propagation of ultra high energy cosmic rays (UHECR), for energies greater than E > 10^{14} eV but less than E < 10^{26} eV, in the cosmic medium of the Cosmic Microwave Background (CMB). We find that the CMB plays a pivot role in this energy range. As example, the observed "knee(s)" and the "ankle" could be understood in reasonable terms. What we may observe at energy near 10^{25} eV (W^\\pm bursts or Z^0 bursts) is also briefly discussed.

W-Y. Pauchy Hwang; Bo-Qiang Ma

2011-07-22

27

Cosmic strings and ultra-high energy cosmic rays  

NASA Technical Reports Server (NTRS)

The flux is calculated of ultrahigh energy protons due to the process of cusp evaporation from cosmic string loops. For the standard value of the dimensionless cosmic string parameter epsilon is identical to G(sub mu) approx. = 10(exp -6), the flux is several orders of magnitude below the observed cosmic ray flux of ultrahigh energy protons. However, the flux at any energy initially increases as the value of epsilon is decreased. This at first suggests that there may be a lower limit on the value of epsilon, which would imply a lower limit on the temperature of a cosmic string forming phase transition in the early universe. However, the calculation shows that this is not the case -- the particle flux at any energy reaches its highest value at epsilon approx. = 10(exp -15) and it then decreases for further decrease of the value of epsilon. This is due to the fact that for too small values of epsilon (less than 10(exp -15)), the energy loss of the loops through the cusp evaporation process itself (rather than gravitational energy loss of the loops) becomes the dominant factor that controls the behavior of the number density of the loops at the relevant times of emission of the particles. The highest flux at any energy remains at least four orders of magnitude below the observed flux. There is thus no lower limit on epsilon.

Bhattacharjee, Pijushpani

1989-01-01

28

Anomalous transport of high energy cosmic rays in galactic superbubbles  

NASA Astrophysics Data System (ADS)

High-energy cosmic rays may exhibit anomalous transport as they traverse and are accelerated by a collection of supernovae explosions in a galactic superbubble. Signatures of this anomalous transport can show up in the particles' evolution and their spectra. In a continuous-time-random-walk (CTRW) model assuming standard diffusive shock acceleration theory (DSA) for each shock encounter, and where the superbubble (an OB stars association) is idealized as a heterogeneous region of particle sources and sinks, acceleration and transport in the superbubble can be shown to be sub-diffusive. While the sub-diffusive transport can be attributed to the stochastic nature of the acceleration time according to DSA theory, the spectral break appears to be an artifact of transport in a finite medium. These CTRW simulations point to a new and intriguing phenomenon associated with the statistical nature of collective acceleration of high energy cosmic rays in galactic superbubbles.

Barghouty, Nasser

29

Anomalous Transport of High Energy Cosmic Rays in Galactic Superbubbles  

NASA Technical Reports Server (NTRS)

High-energy cosmic rays may exhibit anomalous transport as they traverse and are accelerated by a collection of supernovae explosions in a galactic superbubble. Signatures of this anomalous transport can show up in the particles' evolution and their spectra. In a continuous-time-random- walk (CTRW) model assuming standard diffusive shock acceleration theory (DSA) for each shock encounter, and where the superbubble (an OB stars association) is idealized as a heterogeneous region of particle sources and sinks, acceleration and transport in the superbubble can be shown to be sub-diffusive. While the sub-diffusive transport can be attributed to the stochastic nature of the acceleration time according to DSA theory, the spectral break appears to be an artifact of transport in a finite medium. These CTRW simulations point to a new and intriguing phenomenon associated with the statistical nature of collective acceleration of high energy cosmic rays in galactic superbubbles.

Barghouty, Nasser F.

2014-01-01

30

pp interaction at very high energies in cosmic ray experiments  

NASA Astrophysics Data System (ADS)

An analysis of p-air cross section data from extensive air shower measurements is presented, based on an analytical representation of the pp scattering amplitudes that describes with high precision all available accelerator data at ISR, SPS and LHC energies. The theoretical basis of the representation, together with the very smooth energy dependence of parameters controlled by unitarity and dispersion relations, permits reliable extrapolation to high energy cosmic ray (CR) and asymptotic energy ranges. Calculations of ? p-airprod based on Glauber formalism are made using the input values of the quantities ? , ? , BI and BR at high energies, with attention given to the independence of the slope parameters, with {{B}R}\

Kendi Kohara, A.; Ferreira, Erasmo; Kodama, Takeshi

2014-11-01

31

Testing Brane World Models with Ultra High Energy Cosmic Rays  

E-print Network

The arrival time coherence of particles in the Ultra High Energy Air Showers where the center of mass energy of the interaction is of the order of $10^{15} eV$, puts strict constraint on the propagation of particles in a hypothetical extra-dimension. We first argue that at such high energies bulk modes and massive KK-modes can be produced abundantly and in many models their phase space volume is larger than confined modes. Then, we study the minimum propagation time in one and two-brane models and show that a large part of the parameter space of these models are ruled out unless the confinement of fields is proteced by symmetries up to energies not accessible even to the high energy tail of Ultar High Energy Cosmic Rays (UHECRs). As a by-product we confirm the result obtained in some previous works about the close relation between a small Cosmological Constant and the hierarchy problem.

Houri Ziaeepour

2002-12-03

32

High-Energy Cosmic Rays from Gamma-Ray Bursts  

E-print Network

A model is proposed for the origin of cosmic rays (CRs) from ~10^14 eV to the highest energies, >10^20 eV. Gamma-Ray Bursts (GRBs) are assumed to inject CR protons and ions into the interstellar medium of star-forming galaxies--including the Milky Way--with a power law spectrum extending to a maximum energy ~10^20 eV. The CR spectrum near the knee is fit with CRs trapped in the Galactic halo that were accelerated and injected by an earlier Galactic GRB. These CRs diffuse in the disk and halo of the Galaxy due to gyroresonant pitch-angle scattering with MHD turbulence in the Galaxy's magnetic field. The preliminary (2001) KASCADE data through the knee of the CR spectrum are fit by a model with energy-dependent propagation of CR ions from a single Galactic GRB. Ultra-high energy CRs (UHECRs), with energies above the ankle are assumed to propagate rectilinearly with their spectrum modified by photo-pion, photo-pair, and expansion losses. We fit the measured UHECR spectrum assuming comoving luminosity densities of GRB sources consitent with possible star formation rate histories of the universe. For power-law CR proton injection p>2 this model implies that the nonthermal content in the GRB blast waves is hadronically dominated by a factor ~60-200. Calculations show that 100 TeV-100 PeV neutrinos could be detected several times per year from all GRBs in kilometer-scale neutrino detectors such as IceCube, for GRB blast-wave Doppler factors <~200. GLAST measurements of gamma-ray components and cutoffs will constrain the product of nonthermal baryon loading and radiative efficiency, limit the Doppler factor, and test this senario.

Stuart D. Wick; Charles D. Dermer; Armen Atoyan

2004-01-13

33

Ultra High Energy Cosmic Rays from Decaying Superheavy Particles  

E-print Network

Decaying superheavy particles can be produced by Topological Defects or, in case they are quasi-stable, as relics from the early Universe. The decays of these particles can be the sources of observed Ultra High Energy Cosmic Rays ($E \\sim 10^{10} - 10^{12} GeV$). The Topological Defects as the UHE CR sources are critically reviewed and cosmic necklaces and monopole-antiminopole pairs are identified as most plausible sources. The relic superheavy particles are shown to be clustering in the halo and their decays produce UHE CR without GZK cutoff. The Lightest Supersymmetric Particles with Ultra High Energies are naturally produced in the cascades accompanying the decays of superheavy particles. These particles are discussed as UHE carriers in the Universe.

V. Berezinsky

1998-01-08

34

Ultra-high energy cosmic rays from Quark Novae  

E-print Network

We explore acceleration of ions in the Quark Nova (QN) scenario, where a neutron star experiences an explosive phase transition into a quark star (born in the propeller regime). In this picture, two cosmic ray components are isolated: one related to the randomized pulsar wind and the other to the propelled wind, both boosted by the ultra-relativistic Quark Nova shock. The latter component acquires energies $10^{15} {\\rm eV} 10^{18.6}$ eV. The composition is dominated by ions present in the pulsar wind in the energy range above $10^{18.6}$ eV, while at energies below $10^{18}$ eV the propelled ejecta, consisting of the fall-back neutron star crust material from the explosion, is the dominant one. Added to these two components, the propeller injects relativistic particles with Lorentz factors $\\Gamma_{\\rm prop.} \\sim 1-1000$, later to be accelerated by galactic supernova shocks. The QN model appears to be able to account for the extragalactic cosmic rays above the ankle and to contribute a few percent of the galactic cosmic rays below the ankle. We predict few hundred ultra-high energy cosmic ray events above $10^{19}$ eV for the Pierre Auger detector per distant QN, while some thousands are predicted for the proposed EUSO and OWL detectors.

R. Ouyed; P. Kernen; J. Maalampi

2005-03-10

35

The composition of cosmic rays at high energies  

NASA Technical Reports Server (NTRS)

Measurements of the composition of the cosmic rays at high energies, and of the energy spectra of the individual components provide the basis for the understanding of the sources, of the acceleration mechanism, and of the galactic containment of these particles. A brief review of the presently available information and a recent measurement performed on the Space Shuttle to substantially extend the range of energies in which the elemental composition is known are described. Results, and recent data on the electron component of cosmic rays are discussed and summarized. The body of data now available contains several features that are difficult to explain within current models of galactic shock acceleration and 'leakly box' containment. The need for further measurements is emphasized and possible opportunities for future work are briefly discussed.

Muller, Dietrich

1989-01-01

36

Astroparticle Theory: Some New Insights into High Energy Cosmic Rays  

E-print Network

Some new developments obtained in the last few years concerning the propagation of high energy cosmic rays are discussed. In particular, it is shown how the inclusion of drift effects in the transport diffusion equations leads naturally to an explanation for the knee, for the second knee and for the observed behavior of the composition and anisotropies between the knee and the ankle. It is shown that the trend towards a heavier composition above the knee has significant impact on the predicted neutrino fluxes above $10^{14}$ eV. The effects of magnetic lensing on the cosmic rays with energies above the ankle are also discussed, analyzing the main features of the different regimes that appear between the diffusive behavior that takes place at lower energies and the regime of small deflections present at the highest ones.

Esteban Roulet

2003-10-14

37

On the Origin of Ultra High Energy Cosmic Rays II  

SciTech Connect

We show that accretion disks around Active Galactic Nuclei (AGNs) could account for the enormous power in observed ultra high energy cosmic rays {approx}10{sup 20} eV (UHEs). In our model, cosmic rays are produced by quasi-steady acceleration of ions in magnetic structures previously proposed to explain jets around Active Galactic Nuclei with supermassive black holes. Steady acceleration requires that an AGN accretion disk act as a dynamo, which we show to follow from a modified Standard Model in which the magnetic torque of the dynamo replaces viscosity as the dominant mechanism accounting for angular momentum conservation during accretion. A black hole of mass M{sub BH} produces a steady dynamo voltage V {proportional_to} {radical}M{sub BH} giving V {approx} 10{sup 20} volts for M{sub BH} {approx} 10{sup 8} solar masses. The voltage V reappears as an inductive electric field at the advancing nose of a dynamo-driven jet, where plasma instability inherent in collisionless runaway acceleration allows ions to be steadily accelerated to energies {approx} V, finally ejected as cosmic rays. Transient events can produce much higher energies. The predicted disk radiation is similar to the Standard Model. Unique predictions concern the remarkable collimation of jets and emissions from the jet/radiolobe structure. Given MBH and the accretion rate, the model makes 7 predictions roughly consistent with data: (1) the jet length; (2) the jet radius; (3) the steady-state cosmic ray energy spectrum; (4) the maximum energy in this spectrum; (5) the UHE cosmic ray intensity on Earth; (6) electron synchrotron wavelengths; and (7) the power in synchrotron radiation. These qualitative successes motivate new computer simulations, experiments and data analysis to provide a quantitative verification of the model.

Fowler, T K; Colgate, S; Li, H; Bulmer, R H; Pino, J

2011-03-08

38

Active Galactic Nuclei with Starbursts: Sources for Ultra High Energy Cosmic Rays  

E-print Network

Ultra high energy cosmic ray events presently show a spectrum, which we interpret here as galactic cosmic rays due to a starburst in the radio galaxy Cen A pushed up in energy by the shock of a relativistic jet. The knee feature and the particles with energy immediately higher in galactic cosmic rays then turn into the bulk of ultra high energy cosmic rays. This entails that all ultra high energy cosmic rays are heavy nuclei. This picture is viable if the majority of the observed ultra high energy events come from the radio galaxy Cen A, and are scattered by intergalactic magnetic fields across most of the sky.

P. L. Biermann; J. K. Becker; L. Caramete; L. A. Gergely; I. C. Maris; A. Meli; V. de Souza; T. Stanev

2009-04-10

39

Ultra high energy cosmic rays from cosmological relics  

E-print Network

Ultra High Energy Cosmic Rays (UHECR) can be a signal from very early (post-inflationary) Universe. At this cosmological epoch Topological Defects (TD) and long-lived suprheavy (SH) particles are expected to be naturally and effectively produced. Both of these relics can produce now the particles, such as protons and photons, with energies in a great excess of what is observed in UHECR, $E \\sim 10^{10} - 10^{11} GeV$. The Topological Defects as the UHECR sources are critically reviewed and cosmic necklaces and monopolonia are identified as most plausible sources. The relic superheavy particles and monopolonia are shown to be clustering in the halo of our Galaxy and their decays produce UHECR without the GZK cutoff. The observational signature of both models are discussed.

V. Berezinsky

1998-11-17

40

Composition of Primary Cosmic-Ray Nuclei at High Energies  

E-print Network

The TRACER instrument (``Transition Radiation Array for Cosmic Energetic Radiation'') has been developed for direct measurements of the heavier primary cosmic-ray nuclei at high energies. The instrument had a successful long-duration balloon flight in Antarctica in 2003. The detector system and measurement process are described, details of the data analysis are discussed, and the individual energy spectra of the elements O, Ne, Mg, Si, S, Ar, Ca, and Fe (nuclear charge Z=8 to 26) are presented. The large geometric factor of TRACER and the use of a transition radiation detector make it possible to determine the spectra up to energies in excess of 10$^{14}$ eV per particle. A power-law fit to the individual energy spectra above 20 GeV per amu exhibits nearly the same spectral index ($\\sim$ 2.65 $\\pm$ 0.05) for all elements, without noticeable dependence on the elemental charge Z.

M. Ave; P. J. Boyle; F. Gahbauer; C. Hoppner; J. R. Horandel; M. Ichimura; D. Muller; A. Romero-Wolf

2008-01-03

41

High-Energy Cosmic Ray Event Data from the Pierre Auger Cosmic Ray Observatory  

DOE Data Explorer

The Pierre Auger Cosmic Ray Observatory in Mendoza, Argentina is the result of an international collaboration funded by 15 countries and many different organizations. Its mission is to capture high-energy cosmic ray events or air showers for research into their origin and nature. The Pierre Auger Collaboration agreed to make 1% of its data available to the public. The Public Event Explorer is a search tool that allows users to browse or search for and display figures and data plots of events collected since 2004. The repository is updated daily, and, as of June, 2014, makes more than 35,000 events publicly available. The energy of a cosmic ray is measured in Exa electron volts or EeV. These event displays can be browsed in order of their energy level from 0.1 to 41.1 EeV. Each event has an individual identification number.

The event displays provide station data, cosmic ray incoming direction, various energy measurements, plots, vector-based images, and an ASCII data file.

42

High-Energy Cosmic Rays and Neutrinos from Gamma-Ray Bursts  

E-print Network

A complete model for the origin of high-energy >~10^{14} eV) cosmic rays from gamma-ray bursts (GRBs) and implications of this hypothesis are described. Detection of high-energy neutrinos from GRBs provide an unambiguous test of the model. Evidence for cosmic-ray acceleration in GRBs is suggested by the detection of anomalous gamma-ray components such as that observed from GRB 941017. Neutron beta-decay halos around star-forming galaxies such as the Milky Way are formed as a consequence of this model. Cosmic rays from GRBs in the Galaxy are unlikely to account for the ~10^{18} eV cosmic-ray excess reported by the Sydney University Giant Air Shower Recorder (SUGAR), but could contribute to past extinction events.

C. Dermer

2005-06-16

43

Predictions of the Gamma-Ray Burst Model of Ultra High Energy Cosmic Rays  

E-print Network

The cosmological gamma-ray burst (GRB) model for the production of ultra- high energy cosmic rays is described, and the current observational evidence which support it discussed. Several predictions of the model are presented, which would allow it to be tested by future high energy cosmic ray and gamma- ray experiments. If the predicted signatures of the GRB model are observed, they will not only corroborate the model, but will also provide information about the source population, and will allow to investigate the unknown structure of the inter-galactic magnetic field.

Eli Waxman

1996-12-06

44

Observations of Ultra-High Energy Cosmic Rays  

E-print Network

The status of measurements of the arrival directions, mass composition and energy spectrum of cosmic rays above 3 x 10^18 eV (3 EeV) is reviewed using reports presented at the 29th International Cosmic Ray Conference held in Pune, India, in August 2005. The paper is based on a plenary talk given at the TAUP2005 meeting in Zaragoza, 10 - 14 September 2005.

A A Watson

2005-11-29

45

Propagation and Chemical Composition of Ultra High Energy Cosmic Rays  

E-print Network

Extragalactic cosmic ray protons with an injection spectrum of the type $E^{-2.7}$ show a spectrum on earth with a dip due to the Bethe-Heitler pair production against the photons of the cosmic microwave background. The dip is produced in the energy region $10^{18} - 4\\times 10^{19}$ eV with position and shape that reproduce with high accuracy the spectrum observed experimentally. This interpretation of the observed data predicts the existence of an energy scale that signals a possible transition from galactic to extragalactic cosmic rays. In fact, at energies lower than a characteristic value $E_c\\approx 1\\times 10^{18}$ eV, determined by the equality between the rate of energy losses due to pair production and adiabatic losses, the spectrum of cosmic rays flattens in all cases of interest. In this model, the transition from galactic to extragalactic cosmic rays occurs at some energy below $E_c$, corresponding to the position of the so-called second knee. Another viable explanation of the observed data is based on a completely different approach assuming a mixed composition with protons and nuclei at energies $E\\ge 10^{19}$ eV. This scenario implies a transition from galactic to extragalactic cosmic rays at the ankle energies ($\\sim 10^{19}$ eV). In the present paper we will review the main features of the dip model comparing it with the model of transition at the ankle.

Roberto Aloisio

2007-01-22

46

A Lookup Table to Compute High Energy Cosmic Ray Effects on Terrestrial Atmospheric Chemistry  

E-print Network

A variety of events such as gamma-ray bursts and supernovae may expose the Earth to an increased flux of high-energy cosmic rays, with potentially important effects on the biosphere. Existing atmospheric chemistry software ...

Atri, Dimitra

2009-04-27

47

Ultra-high energy cosmic rays threshold in Randers-Finsler space  

E-print Network

Kinematics in Finsler space is used to study the propagation of ultra high energy cosmic rays particles through the cosmic microwave background radiation. We find that the GZK threshold is lifted dramatically in Randers-Finsler space. A tiny deformation of spacetime from Minkowskian to Finslerian allows more ultra-high energy cosmic rays particles arrive at the earth. It is suggested that the lower bound of particle mass is related with the negative second invariant speed in Randers-Finsler space.

Zhe Chang; Xin Li

2008-09-27

48

Are gamma-ray bursts the sources of ultra-high energy cosmic rays?  

NASA Astrophysics Data System (ADS)

We reconsider the possibility that gamma-ray bursts (GRBs) are the sources of the ultra-high energy cosmic rays (UHECRs) within the internal shock model, assuming a pure proton composition of the UHECRs. For the first time, we combine the information from gamma-rays, cosmic rays, prompt neutrinos, and cosmogenic neutrinos quantitatively in a joint cosmic ray production and propagation model, and we show that the information on the cosmic energy budget can be obtained as a consequence. In addition to the neutron model, we consider alternative scenarios for the cosmic ray escape from the GRBs, i.e., that cosmic rays can leak from the sources. We find that the dip model, which describes the ankle in UHECR observations by the pair production dip, is strongly disfavored in combination with the internal shock model because (a) unrealistically high baryonic loadings (energy in protons versus energy in electrons/gamma-rays) are needed for the individual GRBs and (b) the prompt neutrino flux easily overshoots the corresponding neutrino bound. On the other hand, GRBs may account for the UHECRs in the ankle transition model if cosmic rays leak out from the source at the highest energies. In that case, we demonstrate that future neutrino observations can efficiently test most of the parameter space - unless the baryonic loading is much larger than previously anticipated.

Baerwald, Philipp; Bustamante, Mauricio; Winter, Walter

2015-03-01

49

On astrophysical solution to ultra high energy cosmic rays  

E-print Network

We argue that an astrophysical solution to UHECR problem is viable. The pectral features of extragalactic protons interacting with CMB are calculated in model-independent way. Using the power-law generation spectrum $\\propto E^{-\\gamma_g}$ as the only assumption, we analyze four features of the proton spectrum: the GZK cutoff, dip, bump and the second dip. We found the dip, induced by electron-positron production on CMB, as the most robust feature, existing in energy range $1\\times 10^{18} - 4\\times 10^{19}$ eV. Its shape is stable relative to various phenomena included in calculations. The dip is well confirmed by observations of AGASA, HiRes, Fly's Eye and Yakutsk detectors. The best fit is reached at $\\gamma_g =2.7$, with the allowed range 2.55 - 2.75. The dip is used for energy calibration of the detectors. After the energy calibration the fluxes and spectra of all three detectors agree perfectly, with discrepancy between AGASA and HiRes at $E> 1\\times 10^{20}$ eV being not statistically significant. The agreement of the dip with observations should be considered as confirmation of UHE proton interaction with CMB. The dip has two flattenings. The high energy flattening at $E \\approx 1\\times 10^{19}$ eV automatically explains ankle. The low-energy flattening at $E \\approx 1\\times 10^{18}$ eV provides the transition to galactic cosmic rays. This transition is studied quantitatively. The UHECR sources, AGN and GRBs, are studied in a model-dependent way, and acceleration is discussed. Based on the agreement of the dip with existing data, we make the robust prediction for the spectrum at $1\\times 10^{18} - 1\\times 10^{20}$ eV to be measured in the nearest future by Auger detector.

V. Berezinsky; A. Z. Gazizov; S. I. Grigorieva

2007-02-01

50

Energy spectrum of ultra high energy cosmic rays  

E-print Network

The construction of the southern site of the Pierre Auger Observatory is almost completed. Three independent measurements of the flux of the cosmic rays with energies larger than 1 EeV have been performed during the construction phase. The surface detector data collected until August 2007 have been used to establish a flux suppression at the highest energies with a 6 sigma significance. The observations of cosmic rays by the fluorescence detector allowed the extension of the energy spectrum to lower energies, where the efficiency of the surface detector is less than 100% and a change in the spectral index is expected.

Ioana C. Maris; for the Pierre Auger Collaboration

2008-08-12

51

Study of the Shadow of the Moon in Very High Energy Cosmic Rays with the Milagrito Water Cherenkov Detector  

E-print Network

Study of the Shadow of the Moon in Very High Energy Cosmic Rays with the Milagrito Water Cherenkov of the Moon in Very High Energy Cosmic Rays with the Milagrito Water Cherenkov Detector by Morgan O of California at Riverside 2001 #12; Study of the Shadow of the Moon in Very High Energy Cosmic Rays

California at Santa Cruz, University of

52

Curvature Oscillations in Modified Gravity and High Energy Cosmic Rays  

E-print Network

It is shown that F(R)-modified gravitational theories lead to curvature oscillations in astrophysical systems with rising energy density. The frequency and the amplitude of such oscillations could be very high and would lead to noticeable production of energetic cosmic ray particles.

E. V. Arbuzova; A. D. Dolgov; L. Reverberi

2012-11-24

53

The Fly's Eye Extremely High Energy Cosmic Ray Spectrum D.J. Bird,1  

E-print Network

The Fly's Eye Extremely High Energy Cosmic Ray Spectrum D.J. Bird,1 S.C. Corbato,3 H.Y. Dai,3 B present our latest results on the cosmic ray energy spectrum above 1017 eV observed by Fly's Eye. Tracks detected by both eyes can be well reconstructed and therefore have very good energy resolution

54

EPOS Model and Ultra High Energy Cosmic Rays  

E-print Network

Interpretation of extensive air showers (EAS) experiments results is strongly based on air shower simulations. The latter being based on hadronic interaction models, any new model can help for the understanding of the nature of cosmic rays. The EPOS model reproducing all major results of existing accelerator data (including detailed data of RHIC experiments) has been introduced in air shower simulation programs CORSIKA and CONEX few years ago. The new EPOS 1.99 has recently been updated taking into account the problem seen in EAS development using EPOS 1.61. We will show in details the relationship between some EPOS hadronic properties and EAS development, as well as the consequences on the model and finally on cosmic ray analysis.

T. Pierog; K. Werner

2009-05-08

55

SimProp: a simulation code for ultra high energy cosmic ray propagation  

SciTech Connect

A new Monte Carlo simulation code for the propagation of Ultra High Energy Cosmic Rays is presented. The results of this simulation scheme are tested by comparison with results of another Monte Carlo computation as well as with the results obtained by directly solving the kinetic equation for the propagation of Ultra High Energy Cosmic Rays. A short comparison with the latest flux published by the Pierre Auger collaboration is also presented.

Aloisio, R.; Grillo, A.F. [INAF Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze (Italy); Boncioli, D. [INFN and Physics Department, University of Roma Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma (Italy); Petrera, S.; Salamida, F., E-mail: aloisio@arcetri.astro.it, E-mail: denise.boncioli@roma2.infn.it, E-mail: grillo@lngs.infn.it, E-mail: petrera@aquila.infn.it, E-mail: salamida@ipno.in2p3.fr [INFN and Physics Department, University of L'Aquila, L'Aquila (Italy)

2012-10-01

56

Electron calibration of a high energy cosmic ray detector  

NASA Technical Reports Server (NTRS)

The spectrum of cosmic ray electrons above 10 GeV was studied extensively. The spectrum is predicted to steepen at an energy which is related to the lifetime of electrons in the interstellar medium against losses due to inverse Compton collisions with photons and to synchrotron radiation in galactic magnetic fields. The experimental results diverge widely; the lack of agreement between the various measurements is due to a variety of experimental problems.

Simnett, G. M.; Silverberg, R. F.; Crannell, C. J.; Gearhart, R. A.; Hagen, F. A.; Jones, W. V.; Kurz, R. J.; Ormes, J. F.; Price, R. D.

1972-01-01

57

CALET: High energy cosmic ray observatory on International Space Station  

NASA Astrophysics Data System (ADS)

The CALorimeteric Electron Telescope (CALET) is a Japanese-led international mission being developed as part of the utilization plan for the International Space Station (ISS). CALET will be launched by an H-II B rocket utilizing the Japanese developed HTV (H-II Transfer Vehicle) in 2014. The instrument will be robotically emplaced upon the Exposed Facility attached to the Japanese Experiment Module (JEM-EF). CALET is a calorimeter based instrument which will have superior energy resolution and excellent separation between hadrons and electrons and between charged particles and gamma rays in the GeV to trans-TeV energy range. CALET will address many questions in high energy astrophysics, including (1) the nature of the sources of high energy particles and photons, through the high energy electron spectrum, (2) signatures of dark matter, in either the high energy electron or gamma ray spectrum, (3) the details of particle propagation in the Galaxy, by a combination of energy spectrum measurements of electrons, protons and highercharged nuclei. In this paper the outline and current status of CALET are summarized.

Mori, Masaki; CALET Collaboration

2012-12-01

58

The Acceleration of Ultra--High-Energy Cosmic Rays in Gamma-Ray Bursts  

Microsoft Academic Search

Ultra-high-energy cosmic rays (UHECRs) are roughly isotropic and attain very large energies, E ≳ 3 1020 eV. Conventional models fail to explain both facts. I show here that acceleration of UHECRs in gamma-ray bursts (GRBs) satisfies both observational constraints. Using the Mszros & Rees model (see their recent work) of GRBs as due to hyperrelativistic shocks, I show that

Mario Vietri

1995-01-01

59

Ultra High Energy Cosmic Rays and Gamma Ray Bursts from Axion Stars  

E-print Network

We propose a model in which ultra high energy cosmic rays and gamma ray bursts are produced by collisions between neutron stars and axion stars. The acceleration of such a cosmic ray is made by the electric field, $\\sim 10^{15} (B/10^{12} {G}) {eV} {cm}^{-1}$, which is induced in an axion star by relatively strong magnetic field $B>10^{12}$ G of a neutron star. On the other hand, similar collisions generate gamma ray bursts when magnetic field is relatively small, e.g. $\\leq 10^{10}$ G. Assuming that the axion mass is $\\sim 10^{-9}$ eV, we can explain huge energies of the gamma ray bursts $\\sim 10^{54}$ erg as well as the ultra high energies of the cosmic rays $\\sim 10^{20}$ eV. We estimate rate of energy release in the collisions and we find that the rate roughly agrees with observations. In addition, we show that these axion stars are plausible candidates for MACHOs. Since the axion star induces oscillating electric current under the magnetic field, observable monochromatic radiations are emitted.

Aiichi Iwazaki

2000-08-29

60

Extragalactic Sources for Ultra High Energy Cosmic Ray Nuclei  

E-print Network

In this article we examine the hypothesis that the highest energy cosmic rays are complex nuclei from extragalactic sources. Under reasonable physical assumptions, we show that the nearby metally rich starburst galaxies (M82 and NGC 253) can produce all the events observed above the ankle. This requires diffusion of particles below $10^{20}$ eV in extragalactic magnetic fields $B \\approx 15$ nG. Above $10^{19}$ eV, the model predicts the presence of significant fluxes of medium mass and heavy nuclei with small rate of change of composition. Notwithstanding, the most salient feature of the starburst-hypothesis is a slight anisotropy induced by iron debris just before the spectrum-cutoff.

Luis Anchordoqui; Haim Goldberg; Stephen Reucroft; John Swain

2001-09-20

61

High-energy cosmic rays and neutrinos from semirelativistic hypernovae  

SciTech Connect

The origin of the ultrahigh-energy (UHE) cosmic rays (CRs) from the second knee ({approx}6x10{sup 17} eV) above in the CR spectrum is still unknown. Recently, there has been growing evidence that a peculiar type of supernovae, called hypernovae, are associated with subenergetic gamma-ray bursts, such as SN1998bw/GRB980425 and SN2003lw/GRB031203. Such hypernovae appear to have high (up to mildly relativistic) velocity ejecta, which may be linked to the subenergetic gamma-ray bursts. Assuming a continuous distribution of the kinetic energy of the hypernova ejecta as a function of its velocity E{sub k}{proportional_to}({gamma}{beta}){sup -{alpha}} with {alpha}{approx}2, we find that (1) the external shock wave produced by the high-velocity ejecta of a hypernova can accelerate protons up to energies as high as 10{sup 19} eV; (2) the cosmological hypernova rate is sufficient to account for the energy flux above the second knee; and (3) the steeper spectrum of CRs at these energies can arise in these sources. In addition, hypernovae would also give rise to a faint diffuse UHE neutrino flux, due to p{gamma} interactions of the UHE CRs with hypernova optical-UV photons.

Wang Xiangyu [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Department of Astronomy, Nanjing University, Nanjing 210093 (China); Razzaque, Soebur; Meszaros, Peter [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Dai Zigao [Department of Astronomy, Nanjing University, Nanjing 210093 (China)

2007-10-15

62

Contribution from individual nearby sources to the spectrum of high-energy cosmic-ray electrons  

NASA Astrophysics Data System (ADS)

In the last few years, very important data on high-energy cosmic-ray electrons and positrons from high-precision space-born and ground-based experiments have attracted a great deal of interest. These particles represent a unique probe for studying local comic-ray accelerators because they lose energy very rapidly. These energy losses reduce the lifetime so drastically that high-energy cosmic-ray electrons can attain the Earth only from rather local astrophysical sources. This work aims at calculating, by means of Monte Carlo simulation, the contribution from some known nearby astrophysical sources to the cosmic-ray electron/positron spectra at high energy (?10 GeV). The background to the electron energy spectrum from distant sources is determined with the help of the GALPROP code. The obtained numerical results are compared with a set of experimental data.

Sedrati, R.; Attallah, R.

2014-04-01

63

Origin of very high- and ultra-high-energy cosmic rays  

NASA Astrophysics Data System (ADS)

While there is some level of consensus on a Galactic origin of cosmic rays up to the knee (Ek31015 eV) and on an extragalactic origin of cosmic rays with energy above 1019 eV, the debate on the genesis of cosmic rays in the intermediate energy region has received much less attention, mainly because of the ambiguity intrinsic in defining such a region. The energy range between 1017 eV and 1019 eV is likely to be the place where the transition from Galactic to extragalactic cosmic rays takes place. Hence the origin of these particles, though being of the highest importance from the physics point of view, it is also one of the most difficult aspects to investigate. Here I will illustrate some ideas concerning the sites of acceleration of these particles and the questions that their investigation may help answer, including the origin of ultra-high-energy cosmic rays.

Blasi, Pasquale

2014-04-01

64

Inverse problem for extragalactic transport of ultra-high energy cosmic rays  

NASA Astrophysics Data System (ADS)

The energy spectra and composition of ultra-high energy cosmic rays are changing in a course of propagation in the expanding Universe filled with background radiation. We developed a numerical code for solution of inverse problem for cosmic-ray transport equations that allows the determination of average source spectra of different nuclei from the cosmic ray spectra observed at the Earth. Employing this approach, the injection spectra of protons and Iron nuclei in extragalactic sources are found assuming that only these species are accelerated at the source. The data from the Auger experiment and the combined data from the Telescope Array + HiRes experiments are used to illustrate the method.

Ptuskin, V. S.; Rogovaya, S. I.; Zirakashvili, V. N.

2015-03-01

65

Ultra high energy cosmic rays and the large scale structure of the galactic magnetic field  

E-print Network

We study the deflection of ultra high energy cosmic ray protons in different models of the regular galactic magnetic field. Such particles have gyroradii well in excess of 1 kpc and their propagation in the galaxy reflects only the large scale structure of the galactic magnetic field. A future large experimental statistics of cosmic rays of energy above 10$^{19}$ eV could be used for a study of the large scale structure of the galactic magnetic field if such cosmic rays are indeed charged nuclei accelerated at powerful astrophysical objects and if the distribution of their sources is not fully isotropic.

Todor Stanev

1996-07-17

66

High-energy cosmic ray muons in the Earth's atmosphere  

SciTech Connect

We present the calculations of the atmospheric muon fluxes at energies 10-10{sup 7} GeV based on a numerical-analytical method for solving the hadron-nucleus cascade equations. It allows the non-power-law behavior of the primary cosmic ray (PCR) spectrum, the violation of Feynman scaling, and the growth of the total inelastic cross sections for hadron-nucleus collisions with increasing energy to be taken into account. The calculations have been performed for a wide class of hadron-nucleus interaction models using directly the PCR measurements made in the ATIC-2 and GAMMA experiments and the parameterizations of the primary spectrum based on a set of experiments. We study the dependence of atmospheric muon flux characteristics on the hadronic interaction model and the influence of uncertainties in the PCR spectrum and composition on the muon flux at sea level. Comparison of the calculated muon energy spectra at sea level with the data from a large number of experiments shows that the cross sections for hadron-nucleus interactions introduce the greatest uncertainty in the energy region that does not include the knee in the primary spectrum.

Kochanov, A. A., E-mail: kochanov@iszf.irk.ru [Russian Academy of Sciences, Siberian Branch, Institute of Solar-Terrestrial Physics (Russian Federation); Sinegovskaya, T. S. [Irkutsk State Railway University (Russian Federation)] [Irkutsk State Railway University (Russian Federation); Sinegovsky, S. I., E-mail: sinegovsky@api.isu.ru [Irkutsk State University (Russian Federation)

2013-03-15

67

Anisotropy of Ultra High Energy Cosmic Rays in the Dark Matter Halo Model  

E-print Network

The harmonic analysis of anisotropy of Ultra High Energy Cosmic Rays is performed for the Dark Matter halo model. In this model the relic superheavy particles comprise part of the Dark Matter and are concentrated in the Galactic halo. The Ultra High Energy Cosmic Rays are produced by the decays of these particles. Anisotropy is caused by the non-central position of the Sun in the Galactic halo. The calculated anisotropy is in reasonable agreement with the AGASA data. For more precise test of the model a comparison of fluxes in the directions of the Galactic Center and Anticenter is needed.

V. Berezinsky; A. Mikhailov

1999-01-14

68

Lookup tables to compute high energy cosmic ray induced atmospheric ionization and changes in atmospheric chemistry  

SciTech Connect

A variety of events such as gamma-ray bursts and supernovae may expose the Earth to an increased flux of high-energy cosmic rays, with potentially important effects on the biosphere. Existing atmospheric chemistry software does not have the capability of incorporating the effects of substantial cosmic ray flux above 10 GeV. An atmospheric code, the NASA-Goddard Space Flight Center two-dimensional (latitude, altitude) time-dependent atmospheric model (NGSFC), is used to study atmospheric chemistry changes. Using CORSIKA, we have created tables that can be used to compute high energy cosmic ray (10 GeV1 PeV) induced atmospheric ionization and also, with the use of the NGSFC code, can be used to simulate the resulting atmospheric chemistry changes. We discuss the tables, their uses, weaknesses, and strengths.

Atri, Dimitra; Melott, Adrian L. [Department of Physics and Astronomy, University of Kansas, 1251 Wescoe Dr. 1082, Lawrence, KS 66045-7582 (United States); Thomas, Brian C., E-mail: dimitra@ku.edu, E-mail: melott@ku.edu, E-mail: brian.thomas@washburn.edu [Department of Physics and Astronomy, Washburn University, 1700 SW College Ave., Topeka, KS 66621 (United States)

2010-05-01

69

Neutrinos as a Probe of Ultra-High Energy Cosmic Rays  

NASA Astrophysics Data System (ADS)

The search for astrophysical high-energy neutrinos is one of the pillars of multi-messenger astronomy. Neutrino production in extragalactic sources or the cosmic environment is intimately related to (and limited by) the observed emission of ?-rays and cosmic rays. We will review the various indirect neutrino limits that arise from this cosmic connection. So far, no high-energy neutrino source could be unambiguously identified. However, the strong limits on TeV to PeV neutrino emission set by this non-observation serve as an indirect constraint of candidate sources of cosmic rays. At the EeV energy scale the diffuse flux of cosmogenic neutrinos associated with the propagation of ultra-high energy cosmic rays in the cosmic radiation background seems to be the most promising candidate for a future detection. We will discuss its model dependence w.r.t. nuclear composition and evolution of the sources and provide simple bolometric scaling relations and lower limits.

Ahlers, Markus

2013-02-01

70

Constraining sources of ultra high energy cosmic rays using high energy observations with the Fermi satellite  

SciTech Connect

We analyze the conditions that enable acceleration of particles to ultra-high energies, ? 10{sup 20} eV (UHECRs). We show that broad band photon data recently provided by WMAP, ISOCAM, Swift and Fermi satellites, yield constraints on the ability of active galactic nuclei (AGN) to produce UHECRs. The high energy (MeVGeV) photons are produced by Compton scattering of the emitted low energy photons and the cosmic microwave background or extra-galactic background light. The ratio of the luminosities at high and low photon energies can therefore be used as a probe of the physical conditions in the acceleration site. We find that existing data excludes core regions of nearby radio-loud AGN as possible acceleration sites of UHECR protons. However, we show that giant radio lobes are not excluded. We apply our method to Cen A, and show that acceleration of protons to ? 10{sup 20} eV can only occur at distances ?>100 kpc from the core.

Pe'er, Asaf; Loeb, Abraham, E-mail: apeer@cfa.harvard.edu, E-mail: aloeb@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, MS-51, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-03-01

71

Coronal Gamma Ray Bursts as the sources of Ultra High Energy Cosmic Rays?  

E-print Network

I consider the possibility that Ultra High Energy Cosmic Rays are accelerated in Gamma Ray Bursts located in the Galactic corona, thus circumventing the problem raised by Greisen--Zatsepin--Kuz'min cutoff. The acceleration of UHECRs could occur in the pulsars which, in the coronal GRB model, produce them: the same parameters that permit fitting GRBs' observations in the model of Podsiadlowski, Rees and Ruderman (1995) lead to an estimate of the highest achievable energies corresponding to that of the Bird et al (1994) event, and to very low luminosities in cosmic rays. I show that, if the observations of Milgrom and Usov (1995a) are confirmed, the extragalactic GRBs' model for the acceleration of UHECRs is untenable, but the same constraint does not apply to the coronal model. Also, I show that the efficiency of particle acceleration needs be much smaller (and less demanding) than in cosmological models of GRBs. Uncertainties remain about the ensuing cosmic ray spectral distribution. I also briefly discuss observational strategies to distinguish between the two possibilities.

Mario Vietri

1995-10-30

72

A Method for Constraining Cosmic Magnetic Field Models Using Ultra-High Energy Cosmic Rays: The Field Scan Method  

E-print Network

The Galactic magnetic field, locally observed to be on the order of a few $\\mu$G, is sufficiently strong to induce deflections in the arrival directions of ultra-high energy cosmic rays. We present a method that establishes measures of self-consistency for hypothesis sets comprised of cosmic magnetic field models and ultra-high energy cosmic ray composition and source distributions. The method uses two independent procedures to compare the backtracked velocity vectors outside the magnetic field model to the distribution of backtracked velocity directions of many isotropic observations with the same primary energies. This allows for an estimate of the statistical consistency between the observed data and simulated isotropic observations. Inconsistency with the isotropic expectation of source correlation in both procedures is interpreted as the hypothesis set providing a self-consistent description of GMF and UHECR properties for the cosmic ray observations.

Michael S. Sutherland; Brian M. Baughman; James J. Beatty

2012-07-06

73

Gravitational radiation from ultra high energy cosmic rays in models with large extra dimensions  

Microsoft Academic Search

The effects of classical gravitational radiation in models with large extra dimensions are investigated for ultra high energy cosmic rays (CRs). The cross sections are implemented into a simulation package (SENECA) for high energy hadron induced CR air showers. We predict that gravitational radiation from quasi-elastic scattering could be observed at incident CR energies above 109GeV for a setting with

Ben Koch; Hans-Joachim Drescher; Marcus Bleicher

2006-01-01

74

The Most Likely Sources of High-Energy Cosmic-Ray Electrons in Supernova Remnants  

Microsoft Academic Search

Evidence of nonthermal X-ray emission and TeV gamma rays from supernova remnants (SNRs) have strengthened the hypothesis that primary Galactic cosmic-ray electrons are accelerated in SNRs. High-energy electrons lose energy via synchrotron and inverse Compton processes during propagation in the Galaxy. Because of these radiative losses, TeV electrons liberated from SNRs at distances larger than ~1 kpc, or times older

T. Kobayashi; Y. Komori; K. Yoshida; J. Nishimura

2004-01-01

75

Ultra High Energy Cosmic Rays: the present position and the need for mass composition measurements  

E-print Network

The present situation with regard to experimental data on ultra high-energy cosmic rays is briefly reviewed. Whilst detailed knowledge of the shape of the energy spectrum is still lacking, it is clear that events above 10^20 eV do exist. Evidence for clustering of the directions of some of the highest energy events remains controversial. Clearly, more data are needed and these will come from the southern branch of the Pierre Auger Observatory in the next few years. What is evident is that our knowledge of the mass composition of cosmic rays is deficient at all energies above 10^18 eV. It must be improved if we are to discover the origin of the highest energy cosmic rays. The major part of the paper is concerned with this problem: it is argued that there is no compelling evidence to support the common assumption that cosmic rays of the highest energies are protons.

A. A. Watson

2003-12-18

76

Relations Between High Energy Astroparticle Physics, Cosmic Ray Physics and Space Situational Awareness  

Microsoft Academic Search

The paper overviews high energy galactic and solar cosmic ray data respectively models, which contributes to the physics behind space situational awareness (SSA) activities. The European SSA programme was signed during the ESA Ministerial Conference in November 2008. SSA activities related to Near Earth Objects (NEOs) and space weather (SW) will be explained in detail. Technological, societal economic impacts due

Frank Jansen; Jrg Behrens

2010-01-01

77

LAT Perspectives in Detection of High Energy Cosmic Ray Electrons  

NASA Technical Reports Server (NTRS)

The GLAST Large Area Telescope (LAT) science objectives and capabilities in the detection of high energy electrons in the energy range from 20 GeV to approx. 1 TeV are presented. LAT simulations are used to establish the event selections. It is found that maintaining the efficiency of electron detection at the level of 30% the residual hadron contamination does not exceed 2-3% of the electron flux. LAT should collect approx. ten million of electrons with the energy above 20 GeV for each year of observation. Precise spectral reconstruction with high statistics presents us with a unique opportunity to investigate several important problems such as studying galactic models of IC radiation, revealing the signatures of nearby sources such as high energy cutoff in the electron spectrum, testing the propagation model, and searching for KKDM particles decay through their contribution to the electron spectrum.

Moiseev, Alexander; Ormes, J. F.; Funk, Stefan

2007-01-01

78

High Energy Neutrinos and Cosmic-Rays From Low-Luminosity Gamma-Ray Bursts?  

SciTech Connect

The recently discovered gamma-ray burst (GRB) 060218/SN 2006aj is classified as an X-ray Flash with very long duration driven possibly by a neutron star. Since GRB 060218 is very near {approx} 140 Mpc and very dim, one-year observation by Swift suggests that the true rate of GRB 060218-like events might be very high so that such low luminosity GRBs (LL-GRBs) might form a different population of GRBs from the cosmological high luminosity GRBs (HL-GRBs). We found that the high energy neutrino background from such LL-GRBs could be comparable with or larger than that from HL-GRBs. If each neutrino event is detected by IceCube, later optical-infrared follow-up observations such as by Subaru could identify a Type Ibc supernova associated with LL-GRBs, even if gamma- and X-rays are not observed by Swift. This is in a sense a new window from neutrino astronomy, which might enable us to confirm the existence of LL-GRBs and to obtain information about their rate and origin. We also argue LL-GRBs as high energy gamma-ray and cosmic-ray sources.

Murase, Kohta; /Kyoto U., Yukawa Inst., Kyoto; Ioka, Kunihito; /Kyoto U.; Nagataki, Shigehiro; /Kyoto U., Yukawa Inst., Kyoto /KIPAC, Menlo Park; Nakamura, Takashi; /Kyoto

2006-07-10

79

Could Dense Quark Matter be a Source of Super High Energy Cosmic Rays?  

E-print Network

We propose that the dense quark matter could be a source of the high-energy secondary hadrons. These particles can be created from hadronization of the parton(s), which possess the energy of grouped partons from coherent interactions as a result of their collective behav- ior in high dense medium. The medium might be formed in the centre of some massive stars, and it could be a source of the super high-energy cosmic rays. In this work we consider some experimental results as an evidence on collective phenomenon, that can lead to coherent interactions in high dense medium and production of the high-energy secondary hadrons.

Mais Suleymanov

2011-10-10

80

Cosmic Ray Origin: Lessons from Ultra-High-Energy Cosmic Rays and the Galactic/Extragalactic Transition  

NASA Astrophysics Data System (ADS)

We examine the question of the origin of the Galactic cosmic-rays (GCRs) in the light of the data available at the highest energy end of the spectrum. We argue that the data of the Pierre Auger Observatory and of the KASCADE-Grande experiment suggest that the transition between the Galactic and the extragalactic components takes place at the energy of the ankle in the all-particle cosmic-ray spectrum, and at an energy of the order of 1017 eV for protons. Such a high energy for Galactic protons appears difficult to reconcile with the general view that GCRs are accelerated by the standard diffusive shock acceleration process at the forward shock of individual supernova remnants (SNRs). We also review various difficulties of the standard SNR-GCR connection, related to the evolution of the light element abundances and to significant isotopic anomalies. We point out that most of the power injected by the supernov in the Galaxy is actually released inside superbubbles, which may thus play an important role in the origin of cosmic-rays, and could solve some persistent problems of the standard SNR-GCR scenario in a rather natural way.

Parizot, Etienne

2014-11-01

81

A ring imaging Cherenkov telescope for observations of high energy cosmic rays  

NASA Astrophysics Data System (ADS)

We describe a ring imaging Cherenkov counter for high altitude balloon flights designed to measure the energy spectra of cosmic ray nuclei above 40 GeV/amu. The instrument has a 3 m long nitrogen gas radiator at 1 atm, a spherical and planar mirror system, and ~ 2.2 m2 of TMAE/ethane photon detecting drift chambers with fused silica windows in the focal plane. The mirror system is designed such that cosmic ray particles which trigger the instrument cannot pass through the photon detectors. Cosmic ray trajectories through the instrument are determined by eight low mass drift chambers, each of 2.2 m2 area, which predict the ring image center to +/- 0.76 mm. Ground tests with cosmic ray muons prior to the flight show that the detectors see about two photoelectrons from a high energy singly charged particle. Special efforts were made to ensure stable operation and constant temperatures and pressures under remote control during the balloon flight. In September 1991, this instrument flew for 31 h at an altitude of ~ 37 km and collected cosmic ray events which were transmitted to a ground station for recording. Now at the University of Utah, Salt Lake City, UT 84112, USA.

Buckley, J.; Dwyer, J.; Mller, D.; Swordy, S.; Tang, K. K.

1992-12-01

82

The Need for Direct High-Energy Cosmic-Ray Measurements  

NASA Technical Reports Server (NTRS)

Measuring the chemical composition of the cosmic rays in the energy region of greater than or equal to 10(exp 12)eV would be highly useful in settling several nagging questions concerning the propagation of cosmic rays in the galaxy. In particular an accurate measurement of secondary to primary ratios such as Boron to Carbon would gibe clear evidence as to whether the propagation of cosmic rays is determined by a diffusion coefficient that varies with the particle's energy as E(sup 0.5) or E(sup 0.3). This would go a long ways in helping us to understand the anistropy (or lack thereof) of the highest energy cosmic rays and the power requirements for producing those particles at approximately equal to 10(exp 18) eV which are believed to be highest energy particles produced in the Galaxy. This would be only one of the benefits of a mission such as ACCESS to perform direct particle measurements on very high energy cosmic rays.

Jones, Frank C.; Streitmatter, Robert

2004-01-01

83

A C++ Code to Solve the DGLAP Equations Applied to Ultra High Energy Cosmic Rays  

E-print Network

We solve numerically the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) equations for the evolution of fragmentation functions using the Laguerre method. We extend this method to include supersymmetric evolution. The solution to the DGLAP equations is particularly interesting to calculate the expected spectra of Ultra High Energy Cosmic Rays in models where they are produced by the decay of a massive particle X, M_X > 10^{12} GeV.

Ramon Toldra

2002-01-10

84

Gravitational Radiation from Ultra High Energy Cosmic Rays in Models with Large Extra Dimensions  

E-print Network

The effects of classical gravitational radiation in models with large extra dimensions are investigated for ultra high energy cosmic rays (CRs). The cross sections are implemented into a simulation package (SENECA) for high energy hadron induced CR air showers. We predict that gravitational radiation from quasi-elastic scattering could be observed at incident CR energies above $10^9$ GeV for a setting with more than two extra dimensions. It is further shown that this gravitational energy loss can alter the energy reconstruction for CR energies $E_{\\rm CR}\\ge 5\\cdot 10^9$ GeV.

Ben Koch; Hans-Joachim Drescher; Marcus Bleicher

2006-02-07

85

Observations of High Energy Cosmic Ray Electrons by the ATIC Balloon Experiment  

NASA Technical Reports Server (NTRS)

Recently the Advanced Thin Ionization Calorimeter (ATIC) balloon experiment reported observations of high energy cosmic ray electrons over the energy range 300 to 800 GeV, indicating a feature or "bump" in the otherwise smoothly decreasing energy spectrum. The severe energy losses that occur as these high energy particles traverse the galaxy render the cosmic ray electron spectrum sensitive to local (a few kiloparsecs) sources and hence very interesting. The ATIC results are the first time that such a cosmic ray spectrum anomaly has been observed at high energy. Potential sources of this electron excess include pulsars, microquasars, supernovae remnants as well as the annihilation of exotic dark matter candidate particles. ATIC has had three successful high altitude flights over the continent of Antarctica 2000-2001, 2002-2003 and 2007-2008. Only results from the first two flights have been reported so far. During this talk we will discuss the ATIC experiment, the electron observations (including preliminary results from the most recent ATIC flight), examine the merits of the various source models and compare the ATIC observations with other recent measurements.

Guzik, T. G.; Chang, J.; Adams, J. H., Jr.; Ahn, H. S.; Bashindzhagyan, G. L.; Christl, M.; Isbert, J.; Kim, K. C.; Kuznetsov, E. N.; Panasyuk, M. I.; Panov, A. D.; Schmidt, W. K. H.; Seo, E. S.; Sokolskaya N. V.; Watts, J. W.; Wefel, J. P.; Wu, J.; Zatsepin, V. I.

2009-01-01

86

GeV Photons from Ultra High Energy Cosmic Rays accelerated in Gamma Ray Bursts  

E-print Network

Gamma-ray bursts are produced by the dissipation of the kinetic energy of a highly relativistic fireball, via the formation of a collisionless shock. When this happens, Ultra High Energy Cosmic Rays up to 10^20 eV are produced. I show in this paper that these particles produce, via synchrotron emission as they cross the acceleration region, photons up to 300 GeV which carry away a small, ~0.01, but non-negligible fraction of the total burst energy. I show that, when the shock occurs with the interstellar medium, the optical depth to photon-photon scattering, which might cause energy degradation of the photons, is small. The burst thusly produced would be detected at Earth simultaneoulsy with the parent gamma-ray burst, although its duration may differ significantly from that of the lower energy photons. The expected fluences, ~10^{-5}-10^{-6} erg/cm^2 are well within the range of planned detectors. A new explanation for the exceptional burst GRB 940217 is discussed.

Mario Vietri

1997-05-09

87

High energy neutrinos from primary cosmic rays accelerated in the cores of active galaxies  

NASA Technical Reports Server (NTRS)

The spectra and high-energy neutrino fluxes are calculated from photomeson production in active galactic nuclei (AGN) such as quasars and Seyfert galaxies using recent UV and X-ray observations to define the photon fields and an accretion-disk shock-acceleration model for producing ultrahigh-energy cosmic rays in the AGN. Collectively AGN should produce the dominant isotropic neutrino background between 10 exp 4 and 10 exp 10 GeV. Measurement of this background could be critical in determining the energy-generation mechanism, evolution, and distribution of AGN. High-energy background spectra and spectra from bright AGN such as NGC4151 and 3C273 are predicted which should be observable with present detectors. High energy AGN nus should produce a sphere of stellar disruption around their cores which could explain their observed broad-line emission regions.

Stecker, F. W.; Done, C.; Salamon, M. H.; Sommers, P.

1991-01-01

88

High Energy Emission and Cosmic Rays from Gamma-Ray Bursts  

E-print Network

The paper is devoted to the analysis of particle acceleration in Gamma-Ray Bursts and its radiative consequences. Therefore we get on one hand constraints on the physics and on the other hand possible signatures of particle acceleration that could be recorded by the new gamma ray instruments. We have previously shown that UHECRs can be generated in GRBs even with conservative assumptions on the magnetic field and the scattering capability of its perturbations, provided that a suitable relativistic Fermi process is at work during the so-called "internal shock" phase. We extend here the analysis of the consequences of these assumptions to the whole prompt emission of both electrons and protons. Indeed, assuming that the magnetic field decays in $1/r^2$ and that the scattering time of particles is longer than the Bohm's assumption, in particular with a rule derived from Kolmogorov scaling, we show with no other parameter adaptation that the intensity of the subequipartition magnetic field, that: i) UHECRs can be generated with a sufficient flux within the GZK-sphere to account for the CR-spectrum at the ankle. ii) The peak energy of the gamma spectrum around 100 keV, namely the so-called $E_{peak}$, is conveniently explained. iii) A thermal component below the $E_{peak}$ is often unavoidable. iv) The cosmic rays could radiate gamma rays around 67 MeV (in the co-moving frame, which implies $\\simeq 20$ GeV for the observer) due to $\\pi^0$-decay and a low energy neutrino emission (around 0.2 GeV) associated to neutron decay and also neutrinos of energy between 5 and 150 GeV from muon decay. v) The UHECRs radiate high energy gamma rays between a few tens of MeV and 10 GeV (taking the pair creation process into account) due to their synchrotron emission with a sufficient flux to be observable.

Denis Gialis; Guy Pelletier

2004-11-05

89

Ultra-high energy cosmic-rays: A fresh look at an old problem  

NASA Astrophysics Data System (ADS)

The nature of the ultra-high energy cosmic-rays (UHECR) is an old problem with many important issues still unresolved. The body of experimental evidence has increased significantly in recent years. Much of this new knowledge has come from the Pierre Auger Observatory and the Telescope Array Project, both are cosmic-ray observatories, but there are also interesting clues from gamma-ray and neutrino observatories. In this talk I will briefly outline the current experimental evidence. Then I will discuss several distinctly different pictures with regard to the nature of the UHECR. I will argue that there is no simple picture of the UHECR that is without difficulty. I will describe some possible ways forward on both the experimental and phenomenological fronts.

Younk, Patrick

2013-04-01

90

Physics from the Very-High Energy Cosmic-Ray Shadows of the Moon and Sun with Milagro  

E-print Network

Physics from the Very-High Energy Cosmic-Ray Shadows of the Moon and Sun with Milagro by Grant E. I'd also like to thank Jonathan Roberts for helpful comments on the Sun. After moving into a new of the Moon and Sun in TeV cosmic rays are unique probes of the character of these particles and the magnetic

California at Santa Cruz, University of

91

Ultra-high-energy cosmic rays in a galactic wind and its termination shock  

NASA Technical Reports Server (NTRS)

Results are reported from numerical modeling of the acceleration and transport of ultra-high-energy cosmic rays in a galactic wind and its termination shock. A two-dimensional (azimuthally symmetric) wind and spiral magnetic field, with a spherical termination shock, where the velocity drops suddenly, is assumed. The time-dependent cosmic-ray transport equation, including all major transport effects is solved using an implicit finite-difference scheme. Particles are injected as the shock of low energy, and the subsequent evolution of the distribution function is followed. Iron nuclei are readily accelerated at the shock to energies up to 100 billion GeV, and protons to 10 billion GeV. A major effect aiding the acceleration of these particles is the spiral of the magnetic field carried out by the wind, caused by the rotation of the Galaxy, with the result that the shock is nearly normal over most of its area. Increasing the magnetic field or rotation rate increases the maximum energy attainable. Anisotropies and energy densities of the particles are also discussed. It is concluded that the process is consistent with observations of ultra-high-energy cosmic rays.

Jokipii, J. R.; Morfill, G.

1987-01-01

92

Ultra-high energy cosmic ray investigations by means of EAS muon density measurements  

E-print Network

A new approach to investigations of ultra-high energy cosmic rays based on the ground-level measurements of the spectra of local density of EAS muons at various zenith angles is considered. Basic features of the local muon density phenomenology are illustrated using a simple semi-analytical model. It is shown that muon density spectra are sensitive to the spectrum slope, primary composition, and to the features of hadronic interaction. New experimental data on muon bundles at zenith angles from 30 degrees to horizon obtained with the coordinate detector DECOR are compared with CORSIKA-based simulations. It is found that measurements of muon density spectra in inclined EAS give possibility to study characteristics of primary cosmic ray flux in a very wide energy range from 10^15 to 10^19 eV.

Barbashina, N S; Chernov, D V; Dmitrieva, A N; Gromushkin, D M; Kindin, V V; Kokoulin, R P; Kompaniets, K G; Mannocchi, G; Petrukhin, A A; Saavedra, O; Shutenko, V V; Timashkov, D A; Trinchero, G; Yashin, I I; 10.1016/j.nuclphysbps.2006.11.043

2008-01-01

93

Ultra-high energy cosmic ray investigations by means of EAS muon density measurements  

E-print Network

A new approach to investigations of ultra-high energy cosmic rays based on the ground-level measurements of the spectra of local density of EAS muons at various zenith angles is considered. Basic features of the local muon density phenomenology are illustrated using a simple semi-analytical model. It is shown that muon density spectra are sensitive to the spectrum slope, primary composition, and to the features of hadronic interaction. New experimental data on muon bundles at zenith angles from 30 degrees to horizon obtained with the coordinate detector DECOR are compared with CORSIKA-based simulations. It is found that measurements of muon density spectra in inclined EAS give possibility to study characteristics of primary cosmic ray flux in a very wide energy range from 10^15 to 10^19 eV.

N. S. Barbashina; A. G. Bogdanov; D. V. Chernov; A. N. Dmitrieva; D. M. Gromushkin; V. V. Kindin; R. P. Kokoulin; K. G. Kompaniets; G. Mannocchi; A. A. Petrukhin; O. Saavedra; V. V. Shutenko; D. A. Timashkov; G. Trinchero; I. I. Yashin

2007-01-11

94

Telescope Array Radar (TARA) Observatory for Ultra-High Energy Cosmic Rays  

DOE PAGESBeta

Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest conventional cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs. In this report, we describe the design and performance of the TARA transmitter and receiver systems.

Abbasi, R. [Univ. of Utah, Salt Lake City, UT (United States); Takai, H. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Allen, C. [Univ. of Kansas, Lawrence, KS (United States); Beard, L. [Purdue Univ., West Lafayette, IN (United States); Belz, J. [Univ. of Utah, Salt Lake City, UT (United States); Besson, D. [Univ. of Kansas, Lawrence, KS (United States). Moscow Engineering and Physics Inst. (Russian Federation); Byrne, M. [Univ. of Utah, Salt Lake City, UT (United States); Abou Bakr Othman, M. [Univ. of Utah, Salt Lake City, UT (United States); Farhang-Boroujeny, B. [Univ. of Utah, Salt Lake City, UT (United States); Gardner, A. [Univ. of Utah, Salt Lake City, UT (United States); Gillman, W.H. [Gillman and Associates, Salt Lake City, UT (United States); Hanlon, W. [Univ. of Utah, Salt Lake City, UT (United States); Hanson, J. [Univ. of Kansas, Lawrence, KS (United States); Jayanthmurthy, C. [Univ. of Utah, Salt Lake City, UT (United States); Kunwar, S. [Univ. of Kansas, Lawrence, KS (United States); Larson, S. L. [Utah State Univ., Logan, UT (United States); Myers, I. [Univ. of Utah, Salt Lake City, UT (United States); Prohira, S. [Univ. of Kansas, Lawrence, KS (United States); Ratzlaff, K. [Univ. of Kansas, Lawrence, KS (United States); Sokolsky, P. [Univ. of Utah, Salt Lake City, UT (United States); Thomson, G. B. [Univ. of Utah, Salt Lake City, UT (United States); Von Maluski, D. [Univ. of Utah, Salt Lake City, UT (United States)

2014-12-01

95

Diffusive Propagation of High Energy Cosmic Rays in Galaxy:. Effect of Hall Drift  

NASA Astrophysics Data System (ADS)

We phenomenologically developed a propagation model of high energy galactic cosmic rays. We derived the analytical solutions by adopting the semi-empirical diffusion equation, proposed by Berezinskii et al. (1990) and the diffusion tensor proposed by Ptuskin et al. (1993). This model takes into account both the symmetric diffusion and the antisymmetric diffusion due to the particle Hall drift. Our solutions are an extension of the model developed by Ptuskin et al. to a two-dimensional two-layer (galactic disk and halo) model, and they coincide completely with the solution derived by Berezinskii et al. in the absence of antisymmetric diffusion due to Hall drift. We showed that this relatively simple toy model can be used to explain the variation in the exponent of the cosmic ray energy spectrum, ?, around the knee E ?1015 eV.

Arakida, Hideyoshi; Kuramata, Shuichi

96

"Explosive regime" should dominate collisions of ultra-high energy cosmic rays  

E-print Network

Since the launch of LHC experiments it has been discovered that the high multiplicity trigger in pp, pA collisions finds events behaving differently from the typical (minimally biased) ones. In central pPb case it has been proven that those possess collective phenomena known as the radial, elliptic and triangular flows, similar to what is known in heavy ion (AA) collisions. In this paper we argue that at the ultra-high energies, E_lab ~ 10^{20} eV, of the observed cosmic rays this regime changes from a small-probability fluctuation to a dominant one. We estimate velocity of the transverse collective expansion for the light-light and heavy-light collisions, and find it comparable to what is observed at LHC for the central PbPb case. We argue that significant changes of spectra of various secondaries associated with this phenomenon should be important for the development of the cosmic ray cascades.

Tigran Kalaydzhyan; Edward Shuryak

2014-07-11

97

PARSEC: A parametrized simulation engine for ultra-high energy cosmic ray protons  

NASA Astrophysics Data System (ADS)

We present a new simulation engine for fast generation of ultra-high energy cosmic ray data based on parametrizations of common assumptions of UHECR origin and propagation. Implemented are deflections in unstructured turbulent extragalactic fields, energy losses for protons due to photo-pion production and electron-pair production, as well as effects from the expansion of the universe. Additionally, a simple model to estimate propagation effects from iron nuclei is included. Deflections in the Galactic magnetic field are included using a matrix approach with precalculated lenses generated from backtracked cosmic rays. The PARSEC program is based on object oriented programming paradigms enabling users to extend the implemented models and is steerable with a graphical user interface.

Bretz, Hans-Peter; Erdmann, Martin; Schiffer, Peter; Walz, David; Winchen, Tobias

2014-02-01

98

Ultra-High-Energy Cosmic Rays from Young Neutron Star Winds.  

PubMed

The long-held notion that the highest energy cosmic rays are of distant extragalactic origin is challenged by observations that events above approximately 1020 eV do not exhibit the expected high-energy cutoff from photopion production off the cosmic microwave background. We suggest that these unexpected ultra-high-energy events are due to iron nuclei accelerated from young strongly magnetized neutron stars through relativistic MHD winds. We find that neutron stars whose initial spin periods are shorter than approximately 10 ms and whose surface magnetic fields are in the 1012-1014 G range can accelerate iron cosmic rays to greater than approximately 1020 eV. These ions can pass through the remnant of the supernova explosion that produced the neutron star without suffering significant spallation reactions or energy loss. For plausible models of the Galactic magnetic field, the trajectories of the iron ions curve sufficiently to be consistent with the observed, largely isotropic arrival directions of the highest energy events. PMID:10770705

Blasi; Epstein; Olinto

2000-04-20

99

Effects of Cosmic Infrared Background on High Energy Delayed Gamma-Rays From Gamma-Ray Bursts  

SciTech Connect

Regenerated high energy emissions from gamma-ray bursts (GRBs) are studied in detail. If the primary emission spectrum extends to TeV range, these very high energy photons will be absorbed by the cosmic infrared background (CIB). The created high energy electron-positron pairs up-scatter not only cosmic microwave background (CMB) photons but also CIB photons, and secondary photons are generated in the GeV-TeV range. These secondary delayed photons may be observed in the near future, and useful for a consistency check for the primary spectra and GRB physical parameters. The up-scattered CIB photons cannot be neglected for low redshift bursts and/or GRBs with a relatively low maximum photon energy. The secondary gamma-rays also give us additional information on the CIB, which is uncertain in observations so far.

Murase, Kohta; /Kyoto U., Yukawa Inst., Kyoto; Asano, Katsuaki; /Natl. Astron. Observ. of Japan; Nagataki, Shigehiro; /Kyoto U., Yukawa Inst., Kyoto /KIPAC, Menlo Park

2007-04-06

100

Lorentz Violation for Photons and Ultra-High Energy Cosmic Rays  

E-print Network

Lorentz symmetry breaking at very high energies may lead to photon dispersion relations of the form omega^2=k^2+xi_n k^2(k/M_Pl)^n with new terms suppressed by a power n of the Planck mass M_Pl. We show that first and second order terms of size xi_1 > 10^(-14) and xi_2 cosmic rays above 10^(19) eV that should already have been detected, if corresponding terms for electrons and positrons are significantly smaller. This suggests that Lorentz invariance breakings suppressed up to second order in the Planck scale are unlikely to be phenomenologically viable for photons.

Matteo Galaverni; Guenter Sigl

2008-07-02

101

Numerical Simulation of the Anomalous Transport of High-Energy Cosmic Rays in Galactic Superbubble  

NASA Technical Reports Server (NTRS)

A continuous-time random-walk (CTRW) model to simulate the transport and acceleration of high-energy cosmic rays in galactic superbubbles has recently been put forward (Barghouty & Schnee 2102). The new model has been developed to simulate and highlight signatures of anomalous transport on particles' evolution and their spectra in a multi-shock, collective acceleration context. The superbubble is idealized as a heterogeneous region of particle sources and sinks bounded by a random surface. This work concentrates on the effects of the bubble's assumed astrophysical characteristics (cf. geometry and roughness) on the particles' spectra.

Barghouty, A. F.; Price, E. M.; MeWaldt, R. A.

2013-01-01

102

HOW MANY ULTRA-HIGH ENERGY COSMIC RAYS COULD WE EXPECT FROM CENTAURUS A?  

SciTech Connect

The Pierre Auger Observatory has associated a few ultra-high energy cosmic rays (UHECRs) with the direction of Centaurus A. This source has been deeply studied in radio, infrared, X-ray, and {gamma}-rays (MeV-TeV) because it is the nearest radio-loud active galactic nucleus. Its spectral energy distribution or spectrum shows two main peaks, the low-energy peak, at an energy of 10{sup -2} eV, and the high-energy peak, at about 150 keV. There is also a faint very high energy (VHE; E {>=} 100 GeV) {gamma}-ray emission fully detected by the High Energy Stereoscopic System experiment. In this work, we describe the entire spectrum: the two main peaks with a synchrotron/synchrotron self-Compton model, and the VHE emission with a hadronic model. We consider p{gamma} and pp interactions. For the p{gamma} interaction, we assume that the target photons are those produced at 150 keV in leptonic processes. On the other hand, for the pp interaction we consider as targets the thermal particle densities in the lobes. Requiring a satisfactory description of the spectra at very high energies with p{gamma} interaction, we obtain an excessive luminosity in UHECRs (even exceeding the Eddington luminosity). However, when considering the pp interaction to describe the {gamma}-spectrum, the number of UHECRs obtained is in agreement with Pierre Auger observations. We also calculate the possible neutrino signal from pp interactions on a Km{sup 3} neutrino telescope using Monte Carlo simulations.

Fraija, N.; Gonzalez, M. M.; Perez, M. [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Circuito Exterior, C.U., A. Postal 70-264, 04510 Mexico D.F. (Mexico); Marinelli, A., E-mail: nifraija@astro.unam.mx, E-mail: magda@astro.unam.mx, E-mail: jguillen@astro.unam.mx, E-mail: antonio.marinelli@fisica.unam.mx [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Circuito Exterior, C.U., A. Postal 70-264, 04510 Mexico D.F. (Mexico)

2012-07-01

103

High energy cosmic rays experiments inspired by noncommutative quantum field theory  

E-print Network

Phenomenological analysis of the covariant theta-exact noncommutative (NC) gauge field theory (GFT), inspired by high energy cosmic rays experiments, is performed in the framework of the inelastic neutrino-nucleon scatterings, plasmon and $Z$-boson decays into neutrino pair, the Big Bang Nucleosynthesis (BBN) and the Reheating Phase After Inflation (RPAI), respectively. Next we have have found neutrino two-point function and shows a closed form decoupling of the hard ultraviolet (UV) divergent term from softened ultraviolet/infrared (UV/IR) mixing term and from the finite terms as well. For a certain choice of the noncommutative parameter theta which preserves unitarity, problematic UV divergent and UV/IR mixing terms vanish. Non-perturbative modifications of the neutrino dispersion relations are assymptotically independent of the scale of noncommutativity in both the low and high energy limits and may allow superluminal propagation.

Josip Trampetic

2012-10-19

104

GZK Photons in the Minimal Ultra High Energy Cosmic Rays Model  

E-print Network

In a recently proposed model the cosmic rays spectrum at energies above 10^{18} eV can be fitted with a minimal number of unknown parameters assuming that the extragalactic cosmic rays are only protons with a power law source spectrum ~E^{-alpha} and alpha~2.6. Within this minimal model, after fitting the observed HiRes spectrum with four parameters (proton injection spectrum power law index and maximum energy, minimum distance to sources and evolution parameter) we compute the flux of ultra-high energy photons due to photon-pion production, the GZK photons, for several radio background models and average extragalactic magnetic fields with amplitude between 10^{-11} G and 10^{-9} G. We find the photon fraction to be between 10^{-4} and 10^{-3} in cosmic rays at energies above 10^{19} eV. These small fluxes could only be detected in future experiments like Auger North plus South and EUSO.

Graciela Gelmini; Oleg Kalashev; Dmitry V. Semikoz

2007-02-18

105

Ultra-high-energy cosmic ray acceleration in engine-driven relativistic supernovae.  

PubMed

The origin of ultra-high-energy cosmic rays (UHECRs) remains an enigma. They offer a window to new physics, including tests of physical laws at energies unattainable by terrestrial accelerators. They must be accelerated locally, otherwise, background radiations would severely suppress the flux of protons and nuclei, at energies above the Greisen-Zatsepin-Kuzmin (GZK) limit. Nearby, gamma ray bursts (GRBs), hypernovae, active galactic nuclei and their flares have all been suggested and debated as possible sources. A local sub-population of type Ibc supernovae (SNe) with mildly relativistic outflows have been detected as sub-energetic GRBs, X-ray flashes and recently as radio afterglows without detected GRB counterparts. Here, we measure the size-magnetic field evolution, baryon loading and energetics, using the observed radio spectra of SN 2009bb. We place such engine-driven SNe above the Hillas line and establish that they can readily explain the post-GZK UHECRs. PMID:21285953

Chakraborti, S; Ray, A; Soderberg, A M; Loeb, A; Chandra, P

2011-01-01

106

CONSTRAINTS ON THE SOURCE OF ULTRA-HIGH-ENERGY COSMIC RAYS USING ANISOTROPY VERSUS CHEMICAL COMPOSITION  

SciTech Connect

The joint analysis of anisotropy signals and chemical composition of ultra-high-energy cosmic rays offers strong potential for shedding light on the sources of these particles. Following up on an earlier idea, this paper studies the anisotropies produced by protons of energy >E/Z, assuming that anisotropies at energy >E have been produced by nuclei of charge Z, which share the same magnetic rigidity. We calculate the number of secondary protons produced through photodisintegration of the primary heavy nuclei. Making the extreme assumption that the source does not inject any proton, we find that the source(s) responsible for anisotropies such as reported by the Pierre Auger Observatory should lie closer than ?20-30, 80-100, and 180-200 Mpc if the anisotropy signal is mainly composed of oxygen, silicon, and iron nuclei, respectively. A violation of this constraint would otherwise result in the secondary protons forming a more significant anisotropy signal at lower energies. Even if the source were located closer than this distance, it would require an extraordinary metallicity ?> 120, 1600, and 1100 times solar metallicity in the acceleration zone of the source, for oxygen, silicon, and iron, respectively, to ensure that the concomitantly injected protons do not produce a more significant low-energy anisotropy. This offers interesting prospects for constraining the nature and the source of ultra-high-energy cosmic rays with the increase in statistics expected from next-generation detectors.

Liu, Ruo-Yu; Wang, Xiang-Yu [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Taylor, Andrew M. [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland); Lemoine, Martin [Institut d'Astrophysique de Paris, CNRS, UPMC, 98 bis Boulevard Arago, F-75014 Paris (France); Waxman, Eli, E-mail: lemoine@iap.fr [Physics Faculty, Weizmann Institute, P.O. Box 26, Rehovot 7600 (Israel)

2013-10-20

107

Ultra high energy cosmic ray energy spectrum and composition using hybrid analysis with telescope array  

NASA Astrophysics Data System (ADS)

Cosmic radiation was discovered in 1912. This year, the 100 th anniversary of the discovery, marks not only the major progress that has been made in understanding these particles, but also the remaining questions about them. Questions about their sources, acceleration mechanisms, propagation and composition are still unanswered. There are only two experiments currently running that have the ability to study cosmic rays in the Ultra High Energy (E > 1018.0 eV) regime. The Telescope Array studies Ultra High Energy Cosmic Rays (UHECRs) using a hybrid detector. Fluorescence telescopes measure the longitudinal development of the extensive air shower generated by a primary cosmic ray particle, while scintillator detectors measure the lateral distribution of secondary particles that hit the ground. The Middle Drum (MD) fluorescence telescope consists of 14 refurbished telescopes from the High Resolution Fly's Eye (HiRes) experiment, providing a direct link back to the HiRes experiment and data. The surface array is comprised of 507 Scintillator Detectors (SD) of a similar design as was used by the Akeno Giant Air Shower Array (AGASA), providing a link to that experiment as well. Studying TA hybrid events (events observed by both the FD and SD), makes the analysis presented in this work the lynchpin that connects the HiRes experiment to the AGASA experiment. This uniquely allows for a direct comparison between the two detection types and allows us to answer questions about the differences in the energy spectrum measurements shown by the two previous experiments. Furthermore, the hybrid analysis improves the geometrical reconstruction of the showers significantly. This provides a more accurate measurement of the energy of the primary particle and makes it possible to make an accurate prediction regarding the chemical composition of the cosmic ray particle. Historically, only the HiRes experiment and the Pierre Auger Observatory (PAO) have made significant composition measurements of UHECRs, and they report conflicting measurements. The hybrid composition measurement done in this work can be directly compared to the hybrid PAO result.

Allen, Monica Gene

108

ULTRA-HIGH-ENERGY COSMIC RAYS FROM CENTAURUS A: JET INTERACTION WITH GASEOUS SHELLS  

SciTech Connect

Ultra-high-energy cosmic rays (UHECRs), with energies above {approx}6 x 10{sup 19} eV, seem to show a weak correlation with the distribution of matter relatively near to us in the universe. It has earlier been proposed that UHECRs could be accelerated in either the nucleus or the outer lobes of the nearby radio galaxy Cen A. We show that UHECR production at a spatially intermediate location about 15 kpc northeast from the nucleus, where the jet emerging from the nucleus is observed to strike a large star-forming shell of gas, is a plausible alternative. A relativistic jet is capable of accelerating lower energy heavy seed cosmic rays (CRs) to UHECRs on timescales comparable to the time it takes the jet to pierce the large gaseous cloud. In this model, many CRs arising from a starburst, with a composition enhanced in heavy elements near the knee region around PeV, are boosted to ultra-high energies by the relativistic shock of a newly oriented jet. This model matches the overall spectrum shown by the Auger data and also makes a prediction for the chemical composition as a function of particle energy. We thus predict an observable anisotropy in the composition at high energy in the sense that lighter nuclei should preferentially be seen toward the general direction of Cen A. Taking into consideration the magnetic field models for the Galactic disk and a Galactic magnetic wind, this scenario may resolve the discrepancy between HiRes and Auger results concerning the chemical composition of UHECRs.

Gopal-Krishna [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune, 411 007 (India); Biermann, Peter L. [Max-Planck-Institute for Radioastronomy, Auf dem Huegel 69, 53121 Bonn (Germany); De Souza, Vitor [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Av. Trabalhador Sao-carlense 400, Centro, CEP 13566-590, Sao Carlos (Brazil); Wiita, Paul J., E-mail: krishna@ncra.tifr.res.i [Department of Physics, The College of New Jersey, P.O. Box 7718, Ewing, NJ 08628 (United States)

2010-09-10

109

Fast Neutron - Mirror Neutron Oscillation and Ultra High Energy Cosmic Rays  

E-print Network

If there exists the mirror world, a parallel hidden sector of particles with exactly the same microphysics as that of the observable particles, then the primordial nucleosynthesis constraints require that the temperature of the cosmic background of mirror relic photons should be smaller than that of the ordinary relic photons, T'/T neutron - mirror neutron oscillation in vacuum, with an oscillation time $\\tau \\sim 1$ s, much smaller than the neutron lifetime. We show that this could provide a very efficient mechanism for transporting ultra high energy protons at large cosmological distances. The mechanism operates as follows: a super-GZK energy proton scatters a relic photon producing a neutron that oscillates into a mirror neutron which then decays into a mirror proton. The latter undergoes a symmetric process, scattering a mirror relic photon and producing back an ordinary nucleon, but only after traveling a distance $(T/T')^{3}$ times larger than ordinary protons. This may relax or completely remove the GZK-cutoff in the cosmic ray spectrum and also explain the correlation between the observed ultra high energy protons and far distant sources as are the BL Lacs.

Zurab Berezhiani; Luis Bento

2006-02-24

110

A Study of the Composition of Ultra-High-Energy Cosmic Rays Using the High-Resolution Fly's Eye  

Microsoft Academic Search

The composition of ultra-high-energy cosmic rays is measured with the High Resolution Fly's Eye cosmic-ray observatory data using the Xmax technique. Data were collected in stereo between 1999 November and 2001 September. The data are reconstructed with well-determined geometry. Measurements of the atmospheric transmission are incorporated in the reconstruction. The detector resolution is found to be 30 g cm-2 in

R. U. Abbasi; T. Abu-Zayyad; G. Archbold; R. Atkins; J. Bellido; K. Belov; J. W. Belz; S. BenZvi; D. R. Bergman; J. Boyer; G. W. Burt; Z. Cao; R. Clay; B. M. Connolly; B. Dawson; W. Deng; Y. Fedorova; J. Findlay; C. B. Finley; W. F. Hanlon; G. A. Hughes; P. Huntemeyer; C. C. H. Jui; K. Kim; M. A. Kirn; B. Knapp; E. C. Loh; M. M. Maetas; K. Martens; G. Martin; N. Manago; E. J. Mannel; J. A. J. Matthews; J. N. Matthews; A. O'Neill; L. Perera; K. Reil; R. Riehle; M. D. Roberts; M. Sasaki; M. Seman; S. R. Schnetzer; K. Simpson; J. D. Smith; R. Snow; P. Sokolsky; C. Song; R. W. Springer; B. T. Stokes; J. R. Thomas; S. B. Thomas; G. B. Thomson; S. Westerhoff; L. R. Wiencke; A. Zech

2005-01-01

111

Gamma ray signatures of ultra high energy cosmic ray accelerators: electromagnetic cascade versus synchrotron radiation of secondary electrons  

E-print Network

We discuss the possibility of observing ultra high energy cosmic ray sources inhigh energy gamma rays. Protons propagating away from their accelerators produce secondary electrons during interactions with cosmic microwave background photons. These electrons start an electromagnetic cascade that results in a broad band gamma ray emission. We show that in a magnetized Universe ($B \\gtrsim 10^{-12}$ G) such emission is likely to be too extended to be detected above the diffusebackground. A more promising possibility comes from the detection of synchrotron photons from the extremely energetic secondary electrons. Although this emission is produced in a rather extended region of size $\\sim 10Mpc$, it is expected to be point-like and detectable at GeV energies if the intergalactic magnetic field is at the nanogauss level.

Stefano Gabici; Felix A. Aharonian

2006-10-12

112

The UCSD high energy X-ray timing experiment cosmic ray particle anticoincidence detector  

NASA Technical Reports Server (NTRS)

The HEXTE, part of the X-Ray Timing Explorer (XTE), is designed to make high sensitivity temporal and spectral measurements of X-rays with energies between 15 and 250 keV using NaI/CsI phoswich scintillation counters. To achieve the required sensitivity it is necessary to provide anticoincidence of charged cosmic ray particles incident upon the instrument, some of which interact to produce background X-rays. The proposed cosmic ray particle anticoincidence shield detector for HEXTE uses a novel design based on plastic scintillators and wavelength-shifter bars. It consists of five segments, each with a 7 mm thick plastic scintillator, roughly 50 cm x 50 cm in size, coupled to two wavelength-shifter bars viewed by 1/2 inch photomultiplier tubes. These segments are configured into a five-sided, box-like structure around the main detector system. Results of laboratory testing of a model segment, and calculations of the expected performance of the flight segments and particle anticoincidence detector system are presented to demonstrate that the above anticoincidence detector system satisfies its scientific requirements.

Hink, P. L.; Rothschild, R. E.; Pelling, M. R.; Macdonald, D. R.; Gruber, D. E.

1991-01-01

113

Using Fractal Dimensionality in the Search for Source Models of Ultra-High Energy Cosmic Rays  

E-print Network

Although the existence of cosmic rays with energies extending well above $10^{19}$ eV has been confirmed, their origin remains one of the most important questions in astro-particle physics today. Several source models have been proposed for the observed set of Ultra High Energy Cosmic Rays (UHECRs). Yet none of these models have been conclusively identified as corresponding with all of the available data. One possible way of achieving a global test of anisotropy is through the measurement of the information dimension, $D_{\\rm I}$, of the arrival directions of a sample of events. $D_{\\rm I}$ is a measure of the intrinsic heterogeneity of a data sample. We will show how this method can be used to take into account the extreme asymmetric angular resolution and the highly irregular aperture of a monocular air-fluorescence detector. We will then use a simulated, isotropic event sample to show how this method can be used to place upper limits on any number of source models with no statistical penalty.

B. T. Stokes; C. C. H. Jui; J. N. Matthews

2003-11-10

114

Observing ultra high energy cosmic rays with the Pierre Auger Observatory  

NASA Astrophysics Data System (ADS)

The Pierre Auger Observatory was designed to measure ultra-high energy cosmic rays above 1018eV with high accuracy using a hybrid air shower detection technique. A Surface Detector (SD) with 1600 water-Cherenkov stations on a 1500 m triangular grid covers an area of 3000 km2. The atmosphere above the array is viewed by a Fluorescence Detector (FD) with 24 telescopes at 4 sites in the periphery of the SD. As an enhancement to this baseline design, in order to reach a lower energy threshold below 1017eV, the Collaboration has implemented extensions to the Observatory. The SD extension is AMIGA (Auger Muons and Infill for the Ground Array), an infilled area with detectors at a smaller spacing than in the main array and with buried scintillator counters. The FD is complemented by HEAT (High Elevation Auger Telescopes), with 3 additional telescopes that are tilted upwards to extend the elevation range. A review of the status and the main results from the observatory is presented with the emphasis given to the measurement of energy spectrum above 1018 eV where we observe a suppression for energies larger than 31019 eV, chemical composition, arrival directions, the search for photons and neutrinos as primary particles and finally the importance of the extensions of the Auger Observatory due that they allow to study the energy range where the transition from a Galactic to an extra-Galactic origin of cosmic rays may occur.

Salazar, I. Humberto; Varela, C. Enrique; Pierre Auger Collaboration

2013-06-01

115

Constraints on the Production of Ultra-High-Energy Cosmic Rays by Isolated Neutron Stars  

E-print Network

The energetics, spectrum, and composition of cosmic rays with energies below about $10^{15}$ eV are fairly well explained by models involving supernova shocks. In contrast, no widely accepted theory exists for the origin of ultra-high energy cosmic rays (UHECRs), which have energies above $10^{15}$ eV. Instead of proposing a specific model, here we place strong constraints on any model of UHECRs involving isolated neutron stars (no companions). We consider the total power requirements and show that the only viable power source associated with isolated neutron stars is rotation. Mechanisms based on accretion from the interstellar medium fall short of the necessary power despite the most optimistic assumptions. Power considerations also demonstrate that not enough rotational energy is tapped by a "propeller"-like acceleration of interstellar matter. The most promising source of energy is rotational spindown via magnetic braking. We examine microphysical energy loss processes near magnetized neutron stars and conclude that the most likely site for yielding UHECRs from isolated neutron stars is near or beyond the light cylinder.

Aparna Venkatesan; M. Coleman Miller; Angela V. Olinto

1997-08-04

116

Magnetic diffusion effects on the ultra-high energy cosmic ray spectrum and composition  

SciTech Connect

We discuss the effects of diffusion of high energy cosmic rays in turbulent extra-galactic magnetic fields. We find an approximate expression for the low energy suppression of the spectrum of the different mass components (with charge Z) in the case in which this suppression happens at energies below ? Z EeV, so that energy losses are dominated by the adiabatic ones. The low energy suppression appears when cosmic rays from the closest sources take a time comparable to the age of the Universe to reach the Earth. This occurs for energies E < Z EeV (B/nG)?(l{sub c}/Mpc)(d{sub s}/70Mpc) in terms of the magnetic field RMS strength B, its coherence length l{sub c} and the typical separation between sources d{sub s}. We apply this to scenarios in which the sources produce a mixed composition and have a relatively low maximum rigidity (E{sub max} ? (210)Z EeV), finding that diffusion has a significant effect on the resulting spectrum, the average mass and on its spread, in particular reducing this last one. For reasonable values of B and l{sub c} these effects can help to reproduce the composition trends observed by the Auger Collaboration for source spectra compatible with Fermi acceleration.

Mollerach, Silvia; Roulet, Esteban, E-mail: mollerach@cab.cnea.gov.ar, E-mail: roulet@cab.cnea.gov.ar [CONICET, Centro Atmico Bariloche, Av. Bustillo 9500 (8400) (Argentina)

2013-10-01

117

Lorentz Invariance Violation and Chemical Composition of Ultra High Energy Cosmic Rays  

E-print Network

Motivated by experimental indications of a significant presence of heavy nuclei in the cosmic ray flux at ultra high energies ($\\gtrsim 10^{19} \\eV$), we consider the effects of Planck scale suppressed Lorentz Invariance Violation (LIV) on the propagation of cosmic ray nuclei. In particular we focus on LIV effects on the photodisintegration of nuclei onto the background radiation fields. After a general discussion of the behavior of the relevant quantities, we apply our formalism to a simplified model where the LIV parameters of the various nuclei are assumed to kinematically result from a single LIV parameter for the constituent nucleons, $\\eta$, and we derive constraints on $\\eta$. Assuming a nucleus of a particular species to be actually present at $10^{20}$ eV the following constraints can be placed: $-3\\times10^{-2} \\lesssim \\eta \\lesssim 4$ for $^{56}$Fe, $-2\\times10^{-3} \\lesssim \\eta \\lesssim 3\\times10^{-2}$ for $^{16}$O and $-7\\times10^{-5} \\lesssim \\eta \\lesssim 1\\times10^{-4}$ for $^{4}$He, respectively.

Andrey Saveliev; Luca Maccione; Guenter Sigl

2011-03-22

118

Magnetic deflections of ultra-high energy cosmic rays from Centaurus A  

NASA Astrophysics Data System (ADS)

We present the results of a study that simulates trajectories of ultra-high energy cosmic rays from Centaurus A to Earth, for particle rigidities from E/Z=2 EV to 100 EV, i.e., covering the possibility of primary particles as heavy as Fe nuclei with energies exceeding 50 EeV. The Galactic magnetic field is modeled using the recent work of Jansson and Farrar (JF12) which fitted its parameters to match extragalactic Faraday rotation measures and WMAP7 synchrotron emission maps. We include the random component of the GMF using the JF12 3D model for Brand(r?) and explore the impact of different random realizations, coherence length and other features on cosmic ray deflections. Gross aspects of the arrival direction distribution such as mean deflection and the RMS dispersion depend mainly on rigidity and differ relatively little from one realization to another. However different realizations exhibit non-trivial substructure whose specific features vary considerably from one realization to another, especially for lower rigidities. At the lowest rigidity of 2 EV, the distribution is broad enough that it might be compatible with a scenario in which Cen A is the principle source of all UHECRs. No attempt is made here to formulate a robust test of this possibility, although some challenges to such a scenario are noted.

Keivani, Azadeh; Farrar, Glennys R.; Sutherland, Michael

2015-02-01

119

A search for high-energy cosmic gamma-ray bursts  

NASA Astrophysics Data System (ADS)

The results of a search for cosmic gamma-ray bursts of primary energies E01 greater than 5 GeV and E04 greater than 20 TeV over time scales t = 1-100 ms, performed using the four-liquid-scintillation-counter EAS array (Morello and Navarra, 1981) at Plateau Rosa (elevation 3500 m) on 215 days during 1979-1982, are presented in tables and graphs and discussed. No counting-rate excess significantly above the statistical fluctuation is observed, although satellite detectors report at least 10 observable bursts during the operating period. Upper limits for the high-energy burst flux are established as phi1(E greater than E01) less than 0.00004 times t to the 0.36 erg/sq cm and phi4(E greater than E04) less than 0.000016 erg/sq cm for t less than 100 ms.

Morello, C.; Periale, L.; Navarra, G.

1984-12-01

120

The mass composition of ultra-high energy cosmic rays with the Pierre Auger Observatory  

NASA Astrophysics Data System (ADS)

Ultra-high energy cosmic rays are the most energetic particles known in nature. The Pierre Auger Observatory was built to study these amazing particles to determine their origin. The study of their mass composition can help to constrain the models concerning their origins and their production mechanisms in the astrophysical sources. To this aim, several methods have been developed to infer the composition using the Auger surface detector array data. The main difficulty is to isolate the muonic component in the signal measured by the surface detector. We present the results of the composition parameters derived from the ground level component and compare them to the predictions for different nuclear masses of the primary particles and hadronic interaction models.

Martraire, D.

2014-12-01

121

Characteristics of cesium iodide for use as a particle discriminator for high energy cosmic rays  

NASA Technical Reports Server (NTRS)

The possible use of CsI to discriminate between high energy cosmic ray electrons and interacting protons has been investigated. The pulse-shape properties as a function of ionization density, temperature, and spectral response are presented for thallium-activated CsI and as a function of ionization density for sodium-activated CsI. The results are based on previously published data and on corroborative measurements from the present work. Experimental results on the response of CsI to electron-induced electromagnetic cascades and to interacting hadrons are described. Bibliographies of publications dealing with the properties of CsI and with pulse-shape discrimination techniques are presented.

Crannell, C. J.; Kurz, R. J.; Viehmann, W.

1973-01-01

122

Japanese-American Cooperative Emulsion Experiment /JACEE/. [high energy cosmic ray studies  

NASA Technical Reports Server (NTRS)

The instrumentation and results of long duration balloon flights carried out jointly by U.S. and Japan researchers to examine high energy cosmic rays are reported. Basic detector geometries are 2.5 sq m sr with operation at altitudes with 3-4 g/sq cm pressure, with observations thus far of over 100 hr. Energies from 2-100 TeV are recorded for nucleus-nucleus and hadron-nucleus interactions, and searches are made for new particle or interactions. The detector is an emulsion chamber which comprises doubly-coated nuclear emulsions on 800 micron thick methacryl substrates, X-ray films, etchable detectors, low density spacers, and lead sheets. Segmentation of the instrument into a primary charge module, a target section, a spacer section, and a lead-emulsion calorimeter allows accurate charge measurement for primary nuclei, reliable energy resolution, and a large geometrical factor for collecting high energy events. A primary Ca nucleus of 300 TeV has been observed.

Huggett, R. W.; Hunter, S. D.; Jones, W. V.; Takahashi, Y.; Ogata, T.; Saito, T.; Holynski, R.; Jurak, A.; Wolter, W.; Parnell, T. A.

1981-01-01

123

Ultra-High-Energy Cosmic Rays from a Magnetized Strange Star Central Engine for Gamma-Ray Bursts  

E-print Network

Ultra-high-energy cosmic rays (UHECRs) have been tried to be related to the most varied and powerful sources known in the universe. Gamma-ray bursts (GRBs) are natural candidates. Here, we argue that cosmic rays can be accelerated by large amplitude electromagnetic waves (LAEMWs) when the MHD approximation of the field in the wind generated by the GRB's magnetized central engine breaks down. The central engine considered here is a strange star born with differential rotation from the accretion induced conversion of a neutron star into a strange star in a low-mass X-ray binary system. The LAEMWs generated this way accelerate light ions to the highest energies $E = q\\eta\\Delta\\Phi_{max}$ with an efficiency $\\eta \\sim 10^{-1}$ that accounts for all plausible energy losses. Alternatively, we also consider the possibility that, once formed, the LAEMWs are unstable to creation of a relativistically strong electromagnetic turbulence due to an overturn instability. Under this assumption, a lower limit to the efficiency of acceleration is estimated to be about $\\eta \\sim 10^{-2.5}$. Due to their age, low mass X-ray binary systems can be located in regions of low interstellar medium density as, e.g., globular clusters or even intergalactic medium in case of high proper motion systems, and cosmic ray energy losses due to proton collisions with photons at the decelerating region are avoided, thus opening the possibility for particles to exploit the full voltage available, well beyond that currently observed.

O. Esquivel; D. Page

2008-04-04

124

High energy irradiations simulating cosmic-ray-induced planetary gamma ray production. I - Fe target  

NASA Technical Reports Server (NTRS)

Two thick Fe targets were bombarded by a series of 6 GeV proton irradiations for the purpose of simulating the cosmic ray bombardment of planetary objects in space. Gamma ray energy spectra were obtained with a germanium solid state detector during the bombardment, and 46 of the gamma ray lines were ascribed to the Fe targets. A comparison between observed and predicted values showed good agreement for Fe lines from neutron inelastic scattering and spallation reactions, and less satisfactory agreement for neutron capture reactions, the latter attributed to the difference in composition between the Fe target and the mean lunar abundance used in the modeling. Through an analysis of the irradiation results together with continuum data obtained in lunar orbit, it was found that 100 hours of measurement with a current instrument should generate a spectrum containing approximately 20 lines due to Fe alone, with a 2-sigma sensitivity for detection of about 0.2 percent.

Metzger, A. E.; Parker, R. H.; Yellin, J.

1986-01-01

125

A possible correlation between the high-energy electron spectrum and the cosmic ray secondary-to-primary ratios  

NASA Astrophysics Data System (ADS)

Recent observations of high-energy cosmic ray electrons by the Fermi-Large Area Telescope (LAT) and the High Energy Stereoscopic System (HESS) experiments between 20 GeV and 5 TeV have found that the energy spectrum closely follows a broken power law with a break at around 1 TeV. On the other hand, measurements of cosmic ray secondary-to-primary ratios like the boron-to-carbon ratio seem to indicate a possible change in the slope at energies around 100 GeV n-1. In this paper, we discuss one possible explanation for the observed break in the electron spectrum and its possible correlation with the flattening in the secondary-to-primary ratios at higher energies. In our model, we assume that cosmic rays after acceleration by supernova remnant shock waves, escape downstream of the shock and remain confined within the remnant until the shock slows down. During this time, the high-energy electrons suffer from radiative energy losses and the cosmic ray nuclei undergo nuclear fragmentations due to their interactions with the matter. Once the cosmic rays are released from the supernova remnants, they follow diffusive propagation in the Galaxy where they further suffer from radiative or fragmentation losses.

Thoudam, Satyendra; Hrandel, Jrg R.

2011-06-01

126

Energy reconstruction of hadron-initiated showers of ultra-high energy cosmic rays  

E-print Network

The current methods to determine the primary energy of ultra-high energy cosmic rays (UHECRs) are different when dealing with hadron or photon primaries. The current experiments combine two different techniques, an array of surface detectors and fluorescence telescopes. The latter allow an almost calorimetric measurement of the primary energy. Thus, hadron-initiated showers detected by both type of detectors are used to calibrate the energy estimator from the surface array (usually the interpolated signal at a certain distance from the shower core S(r0)) with the primary energy. On the other hand, this calibration is not feasible when searching for photon primaries since no high energy photon has been unambiguously detected so far. Therefore, pure Monte Carlo parametrizations are used instead. In this work, we present a new method to determine the primary energy of hadron-induced showers in a hybrid experiment based on a technique previously developed for photon primaries. It consists on a set of calibration ...

Ros, G; Supanitsky, A D; del Peral, L; Rodrguez-Fras, M D

2015-01-01

127

Perturbations to aquatic photosynthesis due to high-energy cosmic ray induced muon flux in the extragalactic shock model  

E-print Network

We modify a mathematical model of photosynthesis to quantify the perturbations that high energy muons could make on aquatic primary productivity. Then we apply this in the context of the extragalactic shock model, according to which Earth receives an enhanced dose of high-energy cosmic rays when it is at the galactic north. We obtain considerable reduction in the photosynthesis rates, consistent with potential drops in biodiversity.

Rodriguez, Lien; Rodriguez, Oscar

2013-01-01

128

ULTRA-HIGH ENERGY COSMIC-RAY ACCELERATION IN THE JET OF CENTAURUS A  

SciTech Connect

We evaluate the achievable maximum energy of nuclei diffusively accelerated by shock wave in the jet of Cen A, based on an updated model involving the stochastic magnetic fields that are responsible for recent synchrotron X-ray measurements. For the maximum energy analysis, conceivable energy constraints from spatiotemporal scales are systematically considered for the jet-wide including discrete X-ray knots. We find that in the inner region within approx1 arcmin from galactic core, which includes knots AX and BX, proton and iron nucleus can be accelerated to 10{sup 19}-10{sup 20} and 10{sup 21} eV (10-100 EeV and ZeV) ranges, respectively. The upper cutoff energy of the very energetic neutrinos produced via photopion interaction is also provided. These are essential for identifying the acceleration site of the ultra-high energy cosmic ray detected in the Pierre Auger Observatory, which signifies the arrival from nearby galaxies including Cen A.

Honda, Mitsuru [Plasma Astrophysics Laboratory, Institute for Global Science, Mie (Japan)

2009-12-01

129

High-energy cosmic-ray fluxes in the Earth atmosphere: Calculations vs experiments  

NASA Astrophysics Data System (ADS)

A new calculation of the atmospheric fluxes of cosmic-ray hadrons and muons in the energy range 10-105 GeV has been performed for the set of hadron production models, EPOS 1.6, QGSJET II-03, SIBYLL 2.1, and others that are of interest to cosmic-ray physicists. The fluxes of secondary cosmic rays at several levels in the atmosphere are computed using directly data of the ATIC-2, GAMMA experiments, and the model proposed recently by Zatsepin and Sokolskaya as well as the parameterization of the primary cosmic-ray spectrum by Gaisser and Honda. The calculated energy spectra of the hadrons and muon flux as a function of zenith angle are compared with measurements as well as other calculations. The effect of uncertainties both in the primary cosmic-ray flux and hadronic model predictions on the spectra of atmospheric hadrons and muons is considered.

Kochanov, A. A.; Sinegovskaya, T. S.; Sinegovsky, S. I.

2008-12-01

130

Future use of silicon photomultipliers for the fluorescence detection of ultra-high-energy cosmic rays  

NASA Astrophysics Data System (ADS)

A sophisticated technique to measure extensive air showers initiated by ultra-high-energy cosmic rays is by means of fluorescence telescopes. Secondary particles of the air shower excite nitrogen molecules of the atmosphere, which emit fluorescence light when they de-excite. Due to their high photon detection efficiency (PDE) silicon photomultipliers (SiPMs) promise to increase the sensitivity of todays fluorescence telescopes which use photomultiplier tubes - for example the fluorescence detector of the Pierre Auger Observatory. On the other hand drawbacks like a small sensitive area, a strong temperature dependency and a high noise rate have to be managed. We present plans for a prototype fluorescence telescope using SiPMs and a special light collecting optical system of Winston cones to increase the sensitive area. In this context we made measurements of the relative PDE of SiPMs depending on the incident angle of light. The results agree with calculations based on the Fresnel equations. Furthermore, measurements of the brightness of the night sky are presented since this photon flux is the main background to the fluorescence signals of the extensive air showers. To compensate the temperature dependency of the SiPM, frontend electronics make use of temperature sensors and microcontrollers to directly adjust the bias-voltage according to the thermal conditions. To reduce the noise rate we study the coincidence of several SiPMs signals triggered by cosmic ray events. By summing up these signals the SiPMs will constitute a single pixel of the fluorescence telescope.

Stephan, Maurice; Hebbeker, Thomas; Lauscher, Markus; Meurer, Christine; Niggemann, Tim; Schumacher, Johannes

2011-10-01

131

Ultra-high-energy cosmic ray acceleration by relativistic blast waves  

E-print Network

We consider the acceleration of charged particles at the ultra-relativistic shocks, with Lorentz factors \\Gamma_s >> 1 relative to the upstream medium, arising in relativistic fireball models of gamma-ray bursts (GRBs). We show that for Fermi-type shock acceleration, particles initially isotropic in the upstream medium can gain a factor of order \\Gamma_s^2 in energy in the first shock crossing cycle, but that the energy gain factor for subsequent shock crossing cycles is only of order 2, because for realistic deflection processes particles do not have time to re-isotropise upstream before recrossing the shock. We evaluate the maximum energy attainable and the efficiency of this process, and show that for a GRB fireball expanding into a typical interstellar medium, these exclude the production of ultra-high-energy cosmic rays (UHECRs), with energies in the range 10^{18.5} - 10^{20.5} eV, by the blast wave. We propose, however, that in the context of neutron star binaries as the progenitors of GRBs, relativistic ions from the pulsar wind bubbles produced by these systems could be accelerated by the blast wave. We show that if the known binary pulsars are typical, the maximum energy, efficiency, and spectrum in this case can account for the observed population of UHECRs.

Yves A. Gallant; Abraham Achterberg

1999-03-01

132

HIGH-ENERGY COSMIC-RAY DIFFUSION IN MOLECULAR CLOUDS: A NUMERICAL APPROACH  

SciTech Connect

The propagation of high-energy cosmic rays (CRs) through giant molecular clouds constitutes a fundamental process in astronomy and astrophysics. The diffusion of CRs through these magnetically turbulent environments is often studied through the use of energy-dependent diffusion coefficients, although these are not always well motivated theoretically. Now, however, it is feasible to perform detailed numerical simulations of the diffusion process computationally. While the general problem depends upon both the field structure and particle energy, the analysis may be greatly simplified by dimensionless analysis. That is, for a specified purely turbulent field, the analysis depends almost exclusively on a single parameter-the ratio of the maximum wavelength of the turbulent field cells to the particle gyration radius. For turbulent magnetic fluctuations superimposed over an underlying uniform magnetic field, particle diffusion depends on a second dimensionless parameter that characterizes the ratio of the turbulent to uniform magnetic field energy densities. We consider both of these possibilities and parametrize our results to provide simple quantitative expressions that suitably characterize the diffusion process within molecular cloud environments. Doing so, we find that the simple scaling laws often invoked by the high-energy astrophysics community to model CR diffusion through such regions appear to be fairly robust for the case of a uniform magnetic field with a strong turbulent component, but are only valid up to {approx}50 TeV particle energies for a purely turbulent field. These results have important consequences for the analysis of CR processes based on TeV emission spectra associated with dense molecular clouds.

Fatuzzo, M. [Physics Department, Xavier University, Cincinnati, OH 45207 (United States); Melia, F. [Department of Physics, Applied Math Program, and Steward Observatory, University of Arizona, AZ 85721 (United States); Todd, E. [Physics Department, University of Arizona, AZ 85721 (United States); Adams, F. C., E-mail: fatuzzo@xavier.ed, E-mail: melia@physics.arizona.ed, E-mail: etodd@physics.arizona.ed, E-mail: fca@umich.ed [Michigan Center for Theoretical Physics, University of Michigan Physics Department, Ann Arbor, MI 48109 (United States)

2010-12-10

133

GZK photons in the minimal ultra-high energy cosmic rays model  

Microsoft Academic Search

In a recently proposed model the cosmic rays spectrum at energies above 1018eV can be fitted with a minimal number of unknown parameters assuming that the extragalactic cosmic rays are only protons with a power law source spectrum ?E?? and ??2.6. Within this minimal model, after fitting the observed HiRes spectrum with four parameters (proton injection spectrum power law index

Graciela Gelmini; Oleg Kalashev; Dmitry V. Semikoz

2007-01-01

134

On the Possible Association of Ultra High Energy Cosmic Rays with Nearby Active Galaxies  

SciTech Connect

Data collected by the Pierre Auger Observatory provide evidence for anisotropy in the arrival directions of cosmic rays (CRs) with energies >57 EeV that suggests a correlation with the positions of active galactic nuclei (AGN) located within {approx}75 Mpc. However, this analysis does not take into account AGN morphology. A detailed study of the sample of AGN whose positions correlate with the CR events shows that most of them are classified as Seyfert 2 and low-ionization nuclear emission-line region (LINER) galaxies which do not differ from other local AGN of the same types. Therefore, the claimed correlation between the CR events observed by the Pierre Auger Observatory and local active galaxies should be considered as resulting from a chance coincidence, if the production of the highest energy CRs is not episodic in nature, but operates in a single object on long ({ge} Myr) timescales. Additionally, most of the selected sources do not show significant jet activity, and hence--in the framework of the jet paradigm--there are no reasons for expecting them to accelerate CRs up to the highest energies, {approx}10{sup 20} eV, at all. If the extragalactic magnetic fields and the sources of these CRs are coupled with matter, it is possible that the deflection angle is larger than expected in the case of a uniform source distribution due to effectively larger fields. A future analysis has to take into account AGN morphology and may yield a correlation with a larger deflection angle and/or more distant sources. We further argue that Cen A alone could be associated with at least 4 events due to its large radio extent, and Cen B can be associated with more than 1 event due to its proximity to the Galactic plane and, correspondingly, the stronger Galactic magnetic field the ultra high energy CRs (UHECRs) encounter during propagation. If the UHECRs associated with these events are indeed accelerated by Cen A and Cen B, their deflection angles may provide information on the structure of the magnetic field in the direction of these putative sources. Future -ray observations (by, e.g., Gamma-Ray Large Area Space Telescope [GLAST], High Energy Stereoscopic System [HESS]) may provide additional clues to the nature of the accelerators of the UHECRs in the local Universe.

Moskalenko, Igor V.; Stawarz, Lukasz; Porter, Troy A.; Cheung, Chi C.

2008-05-14

135

BLAZARS AS ULTRA-HIGH-ENERGY COSMIC-RAY SOURCES: IMPLICATIONS FOR TeV GAMMA-RAY OBSERVATIONS  

SciTech Connect

The spectra of BL Lac objects and Fanaroff-Riley I radio galaxies are commonly explained by the one-zone leptonic synchrotron self-Compton (SSC) model. Spectral modeling of correlated multiwavelength data gives the comoving magnetic field strength, the bulk outflow Lorentz factor, and the emission region size. Assuming the validity of the SSC model, the Hillas condition shows that only in rare cases such sources accelerate protons to much above 10{sup 19} eV, so {approx}> 10{sup 20} eV ultra-high-energy cosmic rays (UHECRs) are likely to be heavy ions if powered by this type of radio-loud active galactic nuclei (AGNs). Survival of nuclei is shown to be possible in TeV BL Lacs and misaligned counterparts with weak photohadronic emissions. Another signature of hadronic production is intergalactic UHECR-induced cascade emission, which is an alternative explanation of the TeV spectra of some extreme non-variable blazars such as 1ES 0229+200 or 1ES 1101-232. We study this kind of cascade signal, taking into account effects of the structured extragalactic magnetic fields in which the sources should be embedded. We demonstrate the importance of cosmic-ray deflections on the {gamma}-ray flux, and show that required absolute cosmic-ray luminosities are larger than the average UHECR luminosity inferred from UHECR observations and can even be comparable to the Eddington luminosity of supermassive black holes. Future TeV {gamma}-ray observations using the Cerenkov Telescope Array and the High Altitude Water Cerenkov detector array can test for UHECR acceleration by observing >25 TeV photons from relatively low redshift sources such as 1ES 0229+200, and {approx}>TeV photons from more distant radio-loud AGNs.

Murase, Kohta [Department of Physics, Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210 (United States); Dermer, Charles D. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Takami, Hajime [Max Planck Institute for Physics, Foehringer Ring 6, 80805 Munich (Germany); Migliori, Giulia [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-04-10

136

Blazars as Ultra-high-energy Cosmic-ray Sources: Implications for TeV Gamma-Ray Observations  

NASA Astrophysics Data System (ADS)

The spectra of BL Lac objects and Fanaroff-Riley I radio galaxies are commonly explained by the one-zone leptonic synchrotron self-Compton (SSC) model. Spectral modeling of correlated multiwavelength data gives the comoving magnetic field strength, the bulk outflow Lorentz factor, and the emission region size. Assuming the validity of the SSC model, the Hillas condition shows that only in rare cases such sources accelerate protons to much above 1019 eV, so >~ 1020 eV ultra-high-energy cosmic rays (UHECRs) are likely to be heavy ions if powered by this type of radio-loud active galactic nuclei (AGNs). Survival of nuclei is shown to be possible in TeV BL Lacs and misaligned counterparts with weak photohadronic emissions. Another signature of hadronic production is intergalactic UHECR-induced cascade emission, which is an alternative explanation of the TeV spectra of some extreme non-variable blazars such as 1ES 0229+200 or 1ES 1101-232. We study this kind of cascade signal, taking into account effects of the structured extragalactic magnetic fields in which the sources should be embedded. We demonstrate the importance of cosmic-ray deflections on the ?-ray flux, and show that required absolute cosmic-ray luminosities are larger than the average UHECR luminosity inferred from UHECR observations and can even be comparable to the Eddington luminosity of supermassive black holes. Future TeV ?-ray observations using the Cerenkov Telescope Array and the High Altitude Water Cerenkov detector array can test for UHECR acceleration by observing >25 TeV photons from relatively low redshift sources such as 1ES 0229+200, and gsimTeV photons from more distant radio-loud AGNs.

Murase, Kohta; Dermer, Charles D.; Takami, Hajime; Migliori, Giulia

2012-04-01

137

Diffuse fluxes of cosmic high energy neutrinos  

NASA Technical Reports Server (NTRS)

Production spectra of high-energy neutrinos from galactic cosmic ray interactions with interstellar gas and extragalactic ultrahigh energy cosmic-ray interactions with microwave black-body photons are presented and discussed. These production processes involve the decay of charged pions and are thus related to the production of cosmic gamma-rays from the decay of neutral pions. Estimates of the neutrino fluxes from various diffuse cosmic sources are then made and the reasons fro significant differences with previous estimates are discussed. Predicted event rates for a DUMAND type detection system are significantly lower than early estimates indicated.

Stecker, F. W.

1978-01-01

138

A new limit on the Ultra-High-Energy Cosmic-Ray flux with the Westerbork Synthesis Radio Telescope  

E-print Network

A particle cascade (shower) in a dielectric, for example as initiated by an ultra-high energy cosmic ray, will have an excess of electrons which will emit coherent \\v{C}erenkov radiation, known as the Askaryan effect. In this work we study the case in which such a particle shower occurs in a medium just below its surface. We show, for the first time, that the radiation transmitted through the surface is independent of the depth of the shower below the surface when observed from far away, apart from trivial absorption effects. As a direct application we use the recent results of the NuMoon project, where a limit on the neutrino flux for energies above $10^{22}$\\,eV was set using the Westerbork Synthesis Radio Telescope by measuring pulsed radio emission from the Moon, to set a limit on the flux of ultra-high-energy cosmic rays.

S. ter Veen; S. Buitink; H. Falcke; C. W. James; M. Mevius; O. Scholten; K. Singh; B. Stappers; K. D. de Vries

2010-10-28

139

Measurement of the chemical composition of the ultra-high-energy cosmic rays with the Pierre Auger Observatory  

E-print Network

The Pierre Auger Observatory infers the chemical composition of ultra-high-energy cosmic rays through two independent detection techniques. The Fluorescence Detector (FD) measures the longitudinal profile of high energy air showers and can determine the depth of the shower maximum $X_{max}$, which is sensitive to the chemical composition of the primary cosmic rays. Additionally, measurements by the Surface Detector (SD) provide independent experimental observables based on the muonic shower component to analyze the chemical composition. We present the results for the $X_{max}$ distributions and the mass composition results measured by the FD and the SD for the energies $E \\geq 10^{18}$\\,eV. The data will be compared with the expectations for proton and iron primaries according to different hadronic interaction models.

Plum, Matthias

2015-01-01

140

Cosmic Rays Above the Second Knee from Clusters of Galaxies and Associated High-Energy Neutrino Emission  

E-print Network

Accretion and merger shocks in clusters of galaxies are potential accelerators of high-energy protons, which can give rise to high-energy neutrinos through pp interactions with the intracluster gas. We discuss the possibility that protons from cluster shocks make a significant contribution to the observed cosmic rays in the energy range between the second knee around 10^17.5 eV and the ankle around 10^18.5 eV. The accompanying cumulative neutrino background above PeV may be detectable by upcoming neutrino telescopes such as IceCube or KM3NeT, providing a test of this scenario as well as a probe of cosmic-ray confinement properties in clusters.

Kohta Murase; Susumu Inoue; Shigehiro Nagataki

2008-10-28

141

On the interpretation of the cosmic-ray anisotropy at ultra-high energies  

E-print Network

A natural interpretation of the correlation between nearby Active Galactic Nuclei (AGN) and the highest-energy cosmic rays observed recently by the Pierre Auger Collaboration is that the sources of the cosmic rays are either AGN or other objects with a similar spatial distribution (the ``AGN hypothesis''). We question this interpretation. We calculate the expected distribution of the arrival directions of cosmic rays under the AGN hypothesis and argue that it is not supported by the data, one of manifestations of the discrepancy being the deficit of events from the direction of the Virgo supercluster. We briefly discuss possible alternative explanations including the origin of a significant part of the observed events from Cen A.

D. S. Gorbunov; P. G. Tinyakov; I. I. Tkachev; S. V. Troitsky

2008-04-07

142

Magnetic lensing of extremely high energy cosmic rays in a galactic wind  

E-print Network

We show that in the model of Galactic magnetic wind recently proposed to explain the extremely high energy (EHE) cosmic rays so far observed as originating from a single source (M87 in the Virgo cluster), the magnetic field strongly magnifies the fluxes and produces multiple images of the source. The apparent position on Earth of the principal image moves, for decreasing energies, towards the galactic south. It is typically amplified by an order of magnitude at $E/Z\\sim 2\\times 10^{20}$ eV, but becomes strongly demagnified below $10^{20}$ eV. At energies below $E/Z\\sim 1.3\\times 10^{20}$ eV, all events in the northern galactic hemisphere are due to secondary images, which have huge amplifications ($>10^2$). This model would imply strong asymmetries between the north and south galactic hemispheres, such as a (latitude dependent) upper cut-off value below $2\\times 10^{20}$ eV for CR protons arriving to the south and lower fluxes in the south than in the north above $10^{20}$ eV. The large resulting magnifications reduce the power requirements on the source, but the model needs a significant tunning between the direction to the source and the symmetry axis of the wind. If more modest magnetic field strengths were assumed, a scenario in which the observed EHE events are heavier nuclei whose flux is strongly lensed becomes also plausible and would predict that a transition from a light composition to a heavier one could take place at the highest energies.

Diego Harari; Silvia Mollerach; Esteban Roulet

2000-05-24

143

LHCf: calibration of hadron interaction models for high energy cosmic-ray physics at the LHC energy  

NASA Astrophysics Data System (ADS)

LHCf measures the energy and transverse momentum of neutral particles produced in the forward region of the LHC interaction point. In high energy cosmic ray measurements, the results strongly depend on the hadron interaction model which is used in the air shower simulation. LHCf will take data at s = 0.9, 2.4, 7, 10 and 14 TeV collisions at LHC and provide crucial calibration points for the hadron interaction models.

Mase, T.; Adriani, O.; Bonechi, L.; Bongi, M.; Castellini, G.; D'Alessandro, R.; Faus, A.; Grandi, M.; Haguenauer, M.; Itow, Y.; Kasahara, K.; Kawade, K.; Macina, D.; Masuda, K.; Matsubara, Y.; Menjo, H.; Mitsuka, G.; Muraki, Y.; Nakai, M.; Papini, P.; Perrot, A.-L.; Ricciarini, S.; Sako, T.; Shimizu, Y.; Taki, K.; Tamura, T.; Torii, S.; Tricomi, A.; Turner, W. C.; Velasco, J.; Viciani, A.; Yoshida, K.

2010-06-01

144

Probing Very High Energy Prompt Muon and Neutrino fluxes and the cosmic ray knee via Underground Muons  

E-print Network

We calculate event rate and demonstrate the observational feasibility of very high energy muons (1-1000 TeV) in a large mass underground detector operating as a pair-meter. This energy range corresponds to surface muon energies of $\\sim$(5 TeV - 5000 TeV) and primary cosmic ray energies of $\\sim$ (50 TeV - 5 $\\times 10^4$ TeV). Such measurements would significantly assist in an improved understanding of the prompt contribution to $\

Raj Gandhi; Sukanta Panda

2006-08-31

145

Bounds on Direct Couplings of Superheavy Metastable Particles to the Inflaton Field from Ultra High Energy Cosmic Ray Events  

E-print Network

Top-down models for the origin of ultra high energy cosmic rays (UHECR's) propose that these events are the decay products of relic superheavy metastable particles, usually called $X$ particles. These particles can be produced in the reheating period following the inflationary epoch of the early Universe. We obtain constraints on some parameters such as the lifetime and direct couplings of the $X$-particle to the inflaton field from the requirement that they are responsible for the observed UHECR flux.

A. H. Campos; L. L. Lengruber; H. C. Reis; R. Rosenfeld; R. Sato

2001-08-24

146

Layered water Cherenkov detector for the study of ultra high energy cosmic rays  

NASA Astrophysics Data System (ADS)

We present a new design for the water Cherenkov detectors that are in use in various cosmic ray observatories. This novel design can provide a significant improvement in the independent measurement of the muonic and electromagnetic component of extensive air showers. From such multi-component data an event by event classification of the primary cosmic ray mass becomes possible. According to popular hadronic interaction models, such as EPOS-LHC or QGSJetII-04, the discriminating power between iron and hydrogen primaries reaches Fisher values of ~ 2 or above for energies in excess of 1019 eV with a detector array layout similar to that of the Pierre Auger Observatory.

Letessier-Selvon, Antoine; Billoir, Pierre; Blanco, Miguel; Mari?, Ioana C.; Settimo, Mariangela

2014-12-01

147

High-energy cosmic-ray electrons - A new measurement using transition-radiation detectors  

NASA Technical Reports Server (NTRS)

A new detector for cosmic-ray electrons, consisting of a combination of a transition-radiation detector and a shower detector, has been constructed, calibrated at accelerator beams, and exposed in a balloon flight under 5 g/sq cm of atmosphere. The design of this instrument and the methods of data analysis are described. Preliminary results in the energy range 9-300 GeV are presented. The energy spectrum of electrons is found to be significantly steeper than that of protons, consistent with a long escape lifetime of cosmic rays in the galaxy.

Hartmann, G.; Mueller, D.; Prince, T.

1977-01-01

148

Workshop on Cosmic Ray and High Energy Gamma Ray Experiments for the Space Station Era, Louisiana State University, Baton Rouge, October 17-20, 1984, Proceedings  

NASA Technical Reports Server (NTRS)

The potential of the Space Station as a platform for cosmic-ray and high-energy gamma-ray astronomy is discussed in reviews, reports, and specific proposals. Topics examined include antiparticles and electrons, science facilities and new technology, high-energy nuclear interactions, nuclear composition and energy spectra, Space Shuttle experiments, Space Station facilities and detectors, high-energy gamma rays, and gamma-ray facilities and techniques. Consideration is given to universal-baryon-symmetry testing on the scale of galactic clusters, particle studies in a high-inclination orbit, balloon-borne emulsion-chamber results on ultrarelativistic nucleus-nucleus interactions, ionization states of low-energy cosmic rays, a large gamma-ray telescope for point-source studies above 1 GeV, and the possible existence of stable quark matter.

Jones, W. V. (editor); Wefel, J. P. (editor)

1985-01-01

149

Strangelets in Cosmic Rays  

E-print Network

The properties of strangelets are reviewed and two experiments searching for them in cosmic rays are described. The prospects for strangelets as ultra-high energy cosmic rays beyond the classical GZK-cutoff are discussed.

Jes Madsen

2006-12-29

150

Magnetars in the Metagalaxy: The Origin of Ultra-High Energy Cosmic Rays  

NASA Astrophysics Data System (ADS)

I describe a model of UHE Cosmic Ray origins. These ``cosmic basballs'' are ascribed to maximally rotating magnetars - neutron stars with 1015 Gauss magnetic fields rotating near breakup - born in all the galaxies within the GZK volume, each emitting a Goldreich-Julian current of ions. I show that the particle spectrum at earth agrees well with the cosmic ray spectrum above 1018 eV, that the spctrum would extend to 1022 eV (perhaps higher, if neutron stars with stronger fields exist), and that gravity wave emission may modify the predicted particle spectrum at the higher energies. I use constraints from superbubbles in the interstellar medium to constrain the amount of gravity wave emission required, and also relate the results to bursts of anomalous atmospheric chemistry observed in ice cores from the Greenland ice cap.

Arons, J.

2001-12-01

151

New Results on High Energy Cosmic Ray Electrons Observed with Fermi LAT and Their Implications on the Origin of Cosmic Rays  

NASA Technical Reports Server (NTRS)

The Large Area Telescope on-board the Fermi Gamma-Ray Space Telescope has collected more than 10 million cosmic ray electrons with energy above 7 GeV since its science operation on orbit. High energy electrons rapidly lose their energy by synchrotron radiation on Galactic magnetic fields and by inverse Compton scattering on the interstellar radiation field. The typical distance over which a 1 TeV electron loses half its total energy is estimated to be 300-400 pc.This makes them a unique tool for probing nearby Galactic space. Observed spectrum has a harder spectral index than was previously reported and suggests the presence of nearby sources of high energy electrons. One of viable candidates are nearby pulsars, possibly some of recently discovered by Fermi. At the same time the dark matter origin of such sources cannot be ruled out. I will also report our current upper limits on cosmic ray electrons anisotropy which helps to set constraints on their local sources.

Moiseev, Alexander

2010-01-01

152

High-energy cosmic rays and the Greisen-Zatsepin-Kuz'min effect.  

PubMed

Although cosmic rays were discovered over 100 years ago their origin remains uncertain. They have an energy spectrum that extends from ?1GeV to beyond 10(20)eV, where the rate is less than 1 particle perkm(2) per century. Shortly after the discovery of the cosmic microwave background in 1965, it was pointed out that the spectrum of cosmic rays should steepen fairly abruptly above about 4נ10(19)eV, provided the sources are distributed uniformly throughout the Universe. This prediction, by Greisen and by Zatsepin and Kuz'min, has become known as the GZK effect and in this article I discuss the current position with regard to experimental data on the energy spectrum of the highest cosmic-ray energies that have been accumulated in a search that has lasted nearly 50 years. Although there is now little doubt that a suppression of the spectrum exists near the energy predicted, it is by no means certain that this is a manifestation of the GZK effect as it might be that this energy is also close to the maximum to which sources can accelerate particles, with the highest energy beam containing a large fraction of nuclei heavier than protons. The way forward is briefly mentioned. PMID:24552650

Watson, A A

2014-03-01

153

Galaxy clusters as reservoirs of heavy dark matter and high-energy cosmic rays: constraints from neutrino observations  

SciTech Connect

Galaxy Clusters (GCs) are the largest reservoirs of both dark matter and cosmic rays (CRs). Dark matter self-annihilation can lead to a high luminosity in gamma rays and neutrinos, enhanced by a strong degree of clustering in dark matter substructures. Hadronic CR interactions can also lead to a high luminosity in gamma rays and neutrinos, enhanced by the confinement of CRs from cluster accretion/merger shocks and active galactic nuclei. We show that IceCube/KM3Net observations of high-energy neutrinos can probe the nature of GCs and the separate dark matter and CR emission processes, taking into account how the results depend on the still-substantial uncertainties. Neutrino observations are relevant at high energies, especially at ?>10 TeV. Our results should be useful for improving experimental searches for high-energy neutrino emission. Neutrino telescopes are sensitive to extended sources formed by dark matter substructures and CRs distributed over large scales. Recent observations by Fermi and imaging atmospheric Cherenkov telescopes have placed interesting constraints on the gamma-ray emission from GCs. We also provide calculations of the gamma-ray fluxes, taking into account electromagnetic cascades inside GCs, which can be important for injections at sufficiently high energies. This also allows us to extend previous gamma-ray constraints to very high dark matter masses and significant CR injections at very high energies. Using both neutrinos and gamma rays, which can lead to comparable constraints, will allow more complete understandings of GCs. Neutrinos are essential for dark matter annihilation channels like ????{sup +}?{sup ?}, where the neutrino signals are larger than the gamma-ray signals, and for hadronic instead of electronic CRs, because only the first leads to neutrinos. Our results suggest that the multi-messenger observations of GCs will be able to give useful constraints on specific models of dark matter and CRs.

Murase, Kohta; Beacom, John F., E-mail: murase@ias.edu, E-mail: beacom.7@osu.edu [CCAPP, OSU, 191 W. Woodruff Ave., Columbus, Ohio 43210 (United States)

2013-02-01

154

High-energy cosmic rays and tests of basic principles of Physics. Looking at the Planck scale and beyond  

NASA Astrophysics Data System (ADS)

With the present understanding of data, the observed flux suppression for ultra-high energy cosmic rays (UHECR) at energies above 4.1019 eV can be a signature of the Greisen-Zatsepin-Kuzmin (GZK) cutoff or be related to a similar mechanism. But it may also correspond, for instance, to the maximum energies available at the relevant sources. In both cases, violations of special relativity modifying cosmic-ray propagation or acceleration at very high energy can potentially play a role. Other violations of fundamental principles of standard particle physics (quantum mechanics, energy and momentum conservation, vacuum homogeneity and "static" properties, effective space dimensions, quark confinement) can also be relevant at these energies. In particular, UHECR data would in principle allow to set bounds on Lorentz symmetry violation (LSV) in patterns incorporating a privileged local reference frame (the "vacuum rest frame", VRF). But the precise analysis is far from trivial, and other effects can also be present. The effective parameters can be related to Planckscale physics, or even to physics beyond Planck scale, as well as to the dynamics and effective symmetries of LSV for nucleons, quarks, leptons and the photon. LSV can also be at the origin of GZK-like effects. In the presence of a VRF, and contrary to a "grand unification" view, LSV and other violations of standard principles can modify the internal structure of particles at very high energy and conventional symmetries may cease to be valid at energies close to the Planck scale. We present an updated discussion of these topics, including experimental prospects, new potentialities for high-energy cosmic ray phenomenology and the possible link with unconventional pre-Big Bang scenarios, superbradyon (superluminal preon) patterns The subject of a possible superluminal propagation of neutrinos at accelerator energies is also dealt with.

Gonzalez-Mestres, L.

2014-04-01

155

Probing the origin of cosmic-rays with extremely high energy neutrinos using the IceCube Observatory  

E-print Network

We have searched for extremely high energy neutrinos using data taken with the IceCube detector between May 2010 and May 2012. Two neutrino induced particle shower events with energies around 1 PeV were observed, as reported previously. In this work, we investigate whether these events could originate from cosmogenic neutrinos produced in the interactions of ultra-high energy cosmic-rays with ambient photons while propagating through intergalactic space. Exploiting IceCube's large exposure for extremely high energy neutrinos and the lack of observed events above 100 PeV, we can rule out the corresponding models at more than 90% confidence level. The model independent quasi-differential 90% CL upper limit, which amounts to $E^2 \\phi_{\

IceCube Collaboration; M. G. Aartsen; R. Abbasi; M. Ackermann; J. Adams; J. A. Aguilar; M. Ahlers; D. Altmann; C. Arguelles; J. Auffenberg; X. Bai; M. Baker; S. W. Barwick; V. Baum; R. Bay; J. J. Beatty; J. Becker Tjus; K. -H. Becker; S. BenZvi; P. Berghaus; D. Berley; E. Bernardini; A. Bernhard; D. Z. Besson; G. Binder; D. Bindig; M. Bissok; E. Blaufuss; J. Blumenthal; D. J. Boersma; C. Bohm; D. Bose; S. Bser; O. Botner; L. Brayeur; H. -P. Bretz; A. M. Brown; R. Bruijn; J. Casey; M. Casier; D. Chirkin; A. Christov; B. Christy; K. Clark; F. Clevermann; S. Coenders; S. Cohen; D. F. Cowen; A. H. Cruz Silva; M. Danninger; J. Daughhetee; J. C. Davis; M. Day; C. De Clercq; S. De Ridder; P. Desiati; K. D. de Vries; M. de With; T. DeYoung; J. C. Daz-Vlez; M. Dunkman; R. Eagan; B. Eberhardt; J. Eisch; S. Euler; P. A. Evenson; O. Fadiran; A. R. Fazely; A. Fedynitch; J. Feintzeig; T. Feusels; K. Filimonov; C. Finley; T. Fischer-Wasels; S. Flis; A. Franckowiak; K. Frantzen; T. Fuchs; T. K. Gaisser; J. Gallagher; L. Gerhardt; L. Gladstone; T. Glsenkamp; A. Goldschmidt; G. Golup; J. G. Gonzalez; J. A. Goodman; D. Gra; D. T. Grandmont; D. Grant; P. Gretskov; J. C. Groh; A. Gro; C. Ha; A. Haj Ismail; P. Hallen; A. Hallgren; F. Halzen; K. Hanson; D. Heereman; D. Heinen; K. Helbing; R. Hellauer; S. Hickford; G. C. Hill; K. D. Hoffman; R. Hoffmann; A. Homeier; K. Hoshina; W. Huelsnitz; P. O. Hulth; K. Hultqvist; S. Hussain; A. Ishihara; E. Jacobi; J. Jacobsen; K. Jagielski; G. S. Japaridze; K. Jero; O. Jlelati; B. Kaminsky; A. Kappes; T. Karg; A. Karle; M. Kauer; J. L. Kelley; J. Kiryluk; J. Kls; S. R. Klein; J. -H. Khne; G. Kohnen; H. Kolanoski; L. Kpke; C. Kopper; S. Kopper; D. J. Koskinen; M. Kowalski; M. Krasberg; A. Kriesten; K. Krings; G. Kroll; J. Kunnen; N. Kurahashi; T. Kuwabara; M. Labare; H. Landsman; M. J. Larson; M. Lesiak-Bzdak; M. Leuermann; J. Leute; J. Lnemann; O. Macas; J. Madsen; G. Maggi; R. Maruyama; K. Mase; H. S. Matis; F. McNally; K. Meagher; M. Merck; T. Meures; S. Miarecki; E. Middell; N. Milke; J. Miller; L. Mohrmann; T. Montaruli; R. Morse; R. Nahnhauer; U. Naumann; H. Niederhausen; S. C. Nowicki; D. R. Nygren; A. Obertacke; S. Odrowski; A. Olivas; A. Omairat; A. O'Murchadha; L. Paul; J. A. Pepper; C. Prez de los Heros; C. Pfendner; D. Pieloth; D. Pieloth; E. Pinat; J. Posselt; P. B. Price; G. T. Przybylski; L. Rdel; M. Rameez; K. Rawlins; P. Redl; R. Reimann; E. Resconi; W. Rhode; M. Ribordy; M. Richman; B. Riedel; J. P. Rodrigues; C. Rott; T. Ruhe; B. Ruzybayev; D. Ryckbosch; S. M. Saba; H. -G. Sander; M. Santander; S. Sarkar; K. Schatto; F. Scheriau; T. Schmidt; M. Schmitz; S. Schoenen; S. Schneberg; A. Schnwald; A. Schukraft; L. Schulte; O. Schulz; D. Seckel; Y. Sestayo; S. Seunarine; R. Shanidze; C. Sheremata; M. W. E. Smith; D. Soldin; G. M. Spiczak; C. Spiering; M. Stamatikos; T. Stanev; N. A. Stanisha; A. Stasik; T. Stezelberger; R. G. Stokstad; A. Stl; E. A. Strahler; R. Strm; G. W. Sullivan; H. Taavola; I. Taboada; A. Tamburro; A. Tepe; S. Ter-Antonyan; G. Tei?; S. Tilav; P. A. Toale; M. N. Tobin; S. Toscano; E. Unger; M. Usner; S. Vallecorsa; N. van Eijndhoven; A. Van Overloop; J. van Santen; M. Vehring; M. Voge; M. Vraeghe; C. Walck; T. Waldenmaier; M. Wallraff; Ch. Weaver; M. Wellons; C. Wendt; S. Westerhoff; N. Whitehorn; K. Wiebe; C. H. Wiebusch; D. R. Williams; H. Wissing; M. Wolf; T. R. Wood; K. Woschnagg; D. L. Xu; X. W. Xu; J. P. Yanez; G. Yodh; S. Yoshida; P. Zarzhitsky; J. Ziemann; S. Zierke; M. Zoll

2013-11-28

156

Implementing the De-thinning Method for High Energy Cosmic Rays Extensive Air Shower Simulations  

E-print Network

To simulate the interaction of cosmic rays with the Earth atmosphere requires highly complex computational resources and several statistical techniques have been developed to simplify those calculations. It is common to implement the thinning algorithms to reduce the number of secondary particles by assigning weights to representative particles in the evolution of the cascade. However, since this is a compression method with information loss, it is required to recover the original flux of secondary particles without introduce artificial biases. In this work we present the preliminary results of our version of the de-thinning algorithm for the reconstruction of thinned simulations of extensive air showers initiated by cosmic rays and photons in the energy range $10^{15} < E/\\mathrm{eV} < 10^{17}$.

Estupin, A; Nez, L A

2015-01-01

157

ACCELERATION OF ULTRA-HIGH-ENERGY COSMIC RAYS IN THE COLLIDING SHELLS OF BLAZARS AND GAMMA-RAY BURSTS: CONSTRAINTS FROM THE FERMI GAMMA-RAY SPACE TELESCOPE  

SciTech Connect

Fermi Gamma-ray Space Telescope measurements of spectra, variability timescales, and maximum photon energies give lower limits to the apparent jet powers and, through {gamma}{gamma} opacity arguments, the bulk Lorentz factors of relativistic jets. The maximum cosmic-ray particle energy is limited by these two quantities in Fermi acceleration scenarios. Recent data are used to constrain the maximum energies of cosmic-ray protons and Fe nuclei accelerated in colliding shells of gamma-ray bursts (GRBs) and blazars. The Fermi results indicate that Fe rather than protons are more likely to be accelerated to ultra-high energies in active galactic nuclei (AGNs), whereas powerful GRBs can accelerate both protons and Fe to {approx}>10{sup 20} eV. Emissivity of nonthermal radiation from radio galaxies and blazars is estimated from the First Fermi AGN Catalog, and shown to favor BL Lac objects and FR1 radio galaxies over flat spectrum radio quasars, FR2 radio galaxies, and long-duration GRBs as the sources of ultra-high-energy cosmic rays.

Dermer, Charles D.; Razzaque, Soebur, E-mail: dermer@nrl.navy.mi [Space Science Division, Code 7653, Naval Research Laboratory, Washington, DC 20375-5352 (United States)

2010-12-01

158

A minimal width of the arrival direction distribution of ultra-high energy cosmic rays detected with the Yakutsk array  

E-print Network

This paper presents the results of searches for anisotropy in arrival directions of ultra-high energy cosmic rays detected with the Yakutsk Array during the 1974--2008 observational period together with available data from other giant extensive air shower arrays working at present. A method of analysis based on a comparison of the minimal width of distributions in equatorial coordinates is applied. As a result, a hypothesis of isotropy in arrival directions is rejected at the $99.5\\%$ significance level. The observed decrease in the minimal width of distribution can be explained by the presence of cosmic ray sources in energy intervals and sky regions according to the recent indications inferred from data of the Yakutsk Array and Telescope Array experiments.

Ivanov, A A

2015-01-01

159

A new Monte Carlo Generator for Ultra-High Energy Cosmic Rays from the Local and Distant Universe  

E-print Network

For the understanding of the origin and propagation of ultra-high energy cosmic rays (UHECR) we developed a new approach to simulating UHECRs from an arbitrary number of sources based on Monte Carlo technique. The method consists of a combination of three steps. For distant sources we apply commonly accepted parameterizations to calculate the contribution to the observed cosmic ray flux. For sources of the local universe we use forward tracking through realistic matter distributions and magnetic fields resulting from explicit simulations of large-scale structure formation. From the calculations and the forward tracking we generate maps of the probability to observe a particle with a given energy from a discrete direction. To account for deflections in the galactic field, these probability maps are transformed by matrices calculated from backtracking of antiparticles through field parameterizations. Based on the combined probability maps, Monte Carlo production of individual UHECR data is performed which are t...

Dolag, Klaus; Mller, Gero; Walz, David; Winchen, Tobias

2012-01-01

160

Influence of hadronic interaction models and the cosmic ray spectrum on the high-energy atmospheric muon and neutrino flux  

NASA Astrophysics Data System (ADS)

The recent observations of muon charge ratio up to about 10 TeV and of atmospheric neutrinos up to energies of about 400 TeV has triggered a renewed interest into the high-energy interaction models and cosmic ray primary composition. A reviewed calculation of lepton spectra produced in cosmic ray induced extensive air showers is carried out with a primary cosmic ray spectrum that fits the latest direct measurements below the knee. In order to achieve this, we used a full Monte Carlo method to derive the inclusive differential spectra (yields) of muons, muon neutrinos and electron neutrinos at the surface for energies between 80 GeV and hundreds of PeV. Using these results the differential flux and the flavor ratios of leptons were calculated. The air shower simulator CORSIKA 6.990 was used for showering and propagation of the secondary particles through the atmosphere, employing the established high energy hadronic interaction models SIBYLL 2.1, QGSJet-01 and QGSJet-II-03. We show that the performance of the interaction models allows makes it possible to predict the spectra within experimental uncertainties, while SIBYLL generally yields a higher flux at the surface than the QGSJet models. The calculation of the flavor and charge ratios has lead to inconsistent results, mainly influenced by the different representations of the K/? ratio within the models. The influence of the knee of cosmic rays is reflected in the secondary spectra at energies between 100 and 200 TeV. Furthermore, we could quantify systematic uncertainties of atmospheric muon- and neutrino fluxes, associated to the models of the primary cosmic ray spectrum and the interaction models. For most recent parametrizations of the cosmic ray primary spectrum, atmospheric muons can be determined with an uncertainty smaller than +15/-13% of the average flux. Uncertainties of the muon and electron neutrino fluxes can be calculated within an average error of +32/-22% and +25/-19%, respectively. See the published paper [1].

Fedynitch, Anatoli; Becker Tjus, Julia; Desiati, Paolo

2013-06-01

161

ROLE OF LINE-OF-SIGHT COSMIC-RAY INTERACTIONS IN FORMING THE SPECTRA OF DISTANT BLAZARS IN TeV GAMMA RAYS AND HIGH-ENERGY NEUTRINOS  

SciTech Connect

Active galactic nuclei (AGNs) can produce both gamma rays and cosmic rays. The observed high-energy gamma-ray signals from distant blazars may be dominated by secondary gamma rays produced along the line of sight by the interactions of cosmic-ray protons with background photons. This explains the surprisingly low attenuation observed for distant blazars, because the production of secondary gamma rays occurs, on average, much closer to Earth than the distance to the source. Thus, the observed spectrum in the TeV range does not depend on the intrinsic gamma-ray spectrum, while it depends on the output of the source in cosmic rays. We apply this hypothesis to a number of sources and, in every case, we obtain an excellent fit, strengthening the interpretation of the observed spectra as being due to secondary gamma rays. We explore the ramifications of this interpretation for limits on the extragalactic background light and for the production of cosmic rays in AGNs. We also make predictions for the neutrino signals, which can help probe the acceleration of cosmic rays in AGNs.

Essey, Warren; Kusenko, Alexander [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); Kalashev, Oleg [Institute for Nuclear Research, 60th October Anniversary Prospect 7a, Moscow 117312 (Russian Federation); Beacom, John F. [Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210 (United States)

2011-04-10

162

Delayed GeV--TeV Photons from Gamma-Ray Bursts Producing High-Energy Cosmic Rays  

E-print Network

A scenario in which cosmic rays (CRs) above $10^{20}{\\rm eV}$ are produced by cosmological gamma-ray bursts (GRBs) is consistent with observations provided that deflections by the inter-galactic magnetic field (IGMF) delay and spread the arrival time of the CRs over $\\geq50{\\rm yr}$. The energy lost by the CRs as they propagate and interact with the microwave background is transformed by cascading into secondary GeV-TeV photons. We show that a significant fraction of these photons can arrive with delays much smaller than the CR delay if much of inter-galactic space is occupied by large-scale magnetic ``voids'', regions of size $\\gtrsim5{\\rm Mpc}$ and field weaker than $10^{-15}{\\rm G}$. Such voids might be expected, for example, in models where a weak primordial field is amplified in shocked, turbulent regions of the intergalactic medium during the formation of large-scale structure. For a field strength $\\sim4\\times10^{-11}{\\rm G}$ in the high field regions, the value required to account for observed galactic fields if the IGMF were frozen in the protogalactic plasma, the delay of CRs produced by a burst at a distance of $100{\\rm Mpc}$ is $\\sim100{\\rm yr}$, and the fluence of secondary photons above $10{\\rm GeV}$ on hour--day time scales is $I(>E)\\sim10^{-6}E_{\\rm TeV}^{-1}{\\rm cm}^{-2}$. This fluence is close to the detection threshold of current high-energy $\\gamma$-ray experiments. Detection of the delayed flux would support the GRB-CR association and would also provide information on the IGMF structure.

Eli Waxman; Paolo Coppi

1996-03-27

163

Early results of the LHCf experiment and their contribution to ultra-high-energy cosmic ray physics  

NASA Astrophysics Data System (ADS)

LHCf is an experiment dedicated to the measurement of neutral particles emitted in the very forward region of LHC collisions. The physics goal is to provide data for calibrating hadron interaction models that are used in the study of Extremely High-Energy Cosmic-Rays. The LHCf experiment acquired data from April to July 2010 during commissioning time of LHC operations at low luminosity. Production spectra of photons and neutrons emitted in the very forward region ($\\eta>$ 8.4) have been obtained. In this paper preliminary results of the photon spectra taken at $\\sqrt{s}$ = 7TeV are reported.

Adriani, O.; Bonechi, L.; Bongi, M.; Castellini, G.; D'Alessandro, R.; Faus, A.; Fukatsu, K.; Haguenauer, M.; Itow, Y.; Kasahara, K.; Macina, D.; Mase, T.; Masuda, K.; Matsubara, Y.; Menjo, H.; Mitsuka, G.; Muraki, Yasushi; Nakai, M.; Noda, K.; Papini, P.; Perrot, A.-L.; Ricciarini, S.; Sako, T.; Suzuki, K.; Suzuki, T.; Shimizu, Y.; Taki, K.; Tamura, T.; Torii, S.; Tricomi, A.; Velasco, J.; Turner, W. C.; Yoshida, K.; LHCf Collaboration

2011-03-01

164

Early results of the LHCf Experiment and their contribution to Ultra-High-Energy Cosmic Ray Physics  

E-print Network

LHCf is an experiment dedicated to the measurement of neutral particles emitted in the very forward region of LHC collisions. The physics goal is to provide data for calibrating hadron interaction models that are used in the study of Extremely High-Energy Cosmic-Rays. The LHCf experiment acquired data from April to July 2010 during commissioning time of LHC operations at low luminosity. Production spectra of photons and neutrons emitted in the very forward region ($\\eta>$ 8.4) have been obtained. In this paper preliminary results of the photon spectra taken at $\\sqrt{s}$ = 7TeV are reported.

Adriani, O; Bongi, M; Castellini, G; D'Alessandro, R; Faus, A; Fukatsu, K; Haguenauer, M; Itow, Y; Kasahara, K; Macina, D; Mase, T; Masuda, K; Matsubara, Y; Menjo, H; Mitsuka, G; Muraki, Y; Nakai, M; Noda, K; Papini, P; Perrot, A L; Ricciarini, S; Sako, T; Suzuki, K; Suzuki, T; Shimizu, Y; Taki, K; Tamura, T; Torii, S; Tricomi, A; Velasco, J; Turner, W C; Yoshida, K

2011-01-01

165

Bounds on the density of sources of ultra-high energy cosmic rays from the Pierre Auger Observatory  

SciTech Connect

We derive lower bounds on the density of sources of ultra-high energy cosmic rays from the lack of significant clustering in the arrival directions of the highest energy events detected at the Pierre Auger Observatory. The density of uniformly distributed sources of equal intrinsic intensity was found to be larger than ? (0.06?5) 10{sup ?4} Mpc{sup ?3} at 95% CL, depending on the magnitude of the magnetic deflections. Similar bounds, in the range (0.2?7) 10{sup ?4} Mpc{sup ?3}, were obtained for sources following the local matter distribution.

Collaboration: Pierre Auger Collaboration

2013-05-01

166

Solar panels as air Cherenkov detectors for extremely high energy cosmic rays  

E-print Network

Increasing interest towards the observation of the highest energy cosmic rays has motivated the development of new detection techniques. The properties of the Cherenkov photon pulse emitted in the atmosphere by these very rare particles indicate low-cost semiconductor detectors as good candidates for their optical read-out. The aim of this paper is to evaluate the viability of solar panels for this purpose. The experimental framework resulting from measurements performed with suitably-designed solar cells and large conventional photovoltaic areas is presented. A discussion on the obtained and achievable sensitivities follows.

S. Cecchini; I. D'Antone; L. Degli Esposti; G. Giacomelli; M. Guerra; I. Lax; G. Mandrioli; A. Parretta; A. Sarno; R. Schioppo; M. Sorel; M. Spurio

2000-02-07

167

Fermi LAT Results and Perspectives in Measurements of High Energy Galactic Cosmic Rays  

NASA Technical Reports Server (NTRS)

Real breakthrough during last 1-1.5 years in cosmic ray electrons: ATIC, HESS, Pamela, and finally Fermi-LAT. New quality data have made it possible to start quantitative modeling. With the new data more puzzles than before on CR electrons origin. Need "multi-messenger" campaign: electrons, positrons, gammas, X-ray, radio, neutrino... It is viable that we are dealing with at least two distinct mechanisms of "primary" electron (both signs) production: a softer spectrum of negative electrons, and a harder spectrum of both e(+)+e(-). Exotic (e.g. DM) origin is not ruled out. Upper limits on CR electrons anisotropy are set. Good perspectives to have the Fermi LAT results on proton spectrum and positron fraction.

Moiseev, Alexander

2010-01-01

168

PeV neutrinos from the propagation of ultra-high energy cosmic rays  

SciTech Connect

We discuss the possibility that the PeV neutrinos recently observed by IceCube are produced by the interactions of extragalactic cosmic rays during their propagation through the radiation backgrounds. We show that the fluxes resulting from the decays of neutrons produced in the interactions of cosmic ray protons with the CMB background are suppressed (E{sub ?}{sup 2}d?{sub ?}/dE < 10{sup ?10} GeV/cm{sup 2} s sr), with those resulting from the decays of pions produced in the interactions with the UV/optical/IR backgrounds being the dominant ones at PeV energies. The anti-neutrino fluxes produced by the decay of neutrons resulting from the photodisintegration of heavy nuclei with CMB photons are also shown to be quite suppressed (E{sub ?}{sup 2}d?{sub ?}/dE < 10{sup ?11} GeV/cm{sup 2} s sr), while those produced by photo-pion processes with UV/optical/IR backgrounds may be larger, although they are not expected to be above those achievable in the pure proton case. Scenarios with mixed composition and low cutoff rigidities can lead to PeV neutrino fluxes enhanced with respect to those in the pure Fe scenarios. We also discuss the possible impact of the Glashow resonance for the detection of these scenarios, showing that it plays a moderate role.

Roulet, Esteban; Mollerach, Silvia [CONICET, Centro Atmico Bariloche, Av. Bustillo 9500, 8400 Bariloche (Argentina); Sigl, Guenter; Vliet, Arjen van, E-mail: roulet@cab.cnea.gov.ar, E-mail: guenter.sigl@desy.de, E-mail: arjen.rene.van.vliet@desy.de, E-mail: mollerach@cab.cnea.gov.ar [Institut fr Theoretische Physik, Universitt Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany)

2013-01-01

169

Baryon Production at LHC and Very High Energy Cosmic Ray Spectra  

E-print Network

The spectra of baryons at LHC can explain the features of the proton spectra in cosmic rays (CR). It seems important to study all baryon data that are available from collider experiments in wide range of energies. Transverse momentum spectra of baryons from RHIC ($\\sqrt(s)$=62 and 200 GeV) and from LHC ($\\sqrt(s)$=0.9 and 7 TeV) have been considered. It is seen that the slope of distributions at low $p_T$'s is changing with energy. The QGSM fit of these spectra gives the average transverse momenta which behave as $s^{0.06}$ that is similar to the previously observed behavior of $\\Lambda^0$ hyperon spectra. The change in average transverse momenta that are slowly growing in VHE hadron interactions at CR detectors cannot cause the "knee" in measured cosmic ray proton spectra. In addition, the available data on heavy quark hadron production from LHC-b at $\\sqrt{s}$=7 TeV were also studied. The preliminary dependence of hadron average transverse momenta on their masses at LHC energy is presented. The possible sou...

Piskounova, Olga I

2015-01-01

170

Constraints on secondary 10-100 EeV gamma ray flux in the minimal bottom-up model of Ultra High Energy Cosmic Rays  

E-print Network

In a recently proposed model the cosmic rays spectrum at energies above EeV can be fitted with a minimal number of unknown parameters assuming that the extragalactic cosmic rays are only protons with a power law source spectrum. Within this minimal model, after fitting the observed HiRes spectrum with four parameters (proton injection spectrum power law index, maximum energy, minimum distance to sources and evolution parameter) we compute the flux of ultra-high energy photons due to photon-pion production and e+e- pair production by protons for several radio background models and a range of average extragalactic magnetic fields.

O. Kalashev; G. Gelmini; D. Semikoz

2007-06-26

171

Probing the origin of cosmic rays with extremely high energy neutrinos using the IceCube Observatory  

NASA Astrophysics Data System (ADS)

We have searched for extremely high energy neutrinos using data taken with the IceCube detector between May 2010 and May 2012. Two neutrino-induced particle shower events with energies around 1 PeV were observed, as reported previously. In this work, we investigate whether these events could originate from cosmogenic neutrinos produced in the interactions of ultrahigh energy cosmic rays with ambient photons while propagating through intergalactic space. Exploiting IceCubes large exposure for extremely high energy neutrinos and the lack of observed events above 100 PeV, we can rule out the corresponding models at more than 90% confidence level. The model-independent quasidifferential 90% C.L. upper limit, which amounts to E2??e+??+??=1.210-7GeVcm-2s-1sr-1 at 1 EeV, provides the most stringent constraint in the energy range from 10 PeV to 10 EeV. Our observation disfavors strong cosmological evolution of the highest energy cosmic-ray sources such as the Fanaroff-Riley type II class of radio galaxies.

Aartsen, M. G.; Abbasi, R.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Altmann, D.; Arguelles, C.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Baum, V.; Bay, R.; Beatty, J. J.; Becker Tjus, J.; Becker, K.-H.; BenZvi, S.; Berghaus, P.; Berley, D.; Bernardini, E.; Bernhard, A.; Besson, D. Z.; Binder, G.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Bose, D.; Bser, S.; Botner, O.; Brayeur, L.; Bretz, H.-P.; Brown, A. M.; Bruijn, R.; Casey, J.; Casier, M.; Chirkin, D.; Christov, A.; Christy, B.; Clark, K.; Clevermann, F.; Coenders, S.; Cohen, S.; Cowen, D. F.; Cruz Silva, A. H.; Danninger, M.; Daughhetee, J.; Davis, J. C.; Day, M.; De Clercq, C.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de With, M.; DeYoung, T.; Daz-Vlez, J. C.; Dunkman, M.; Eagan, R.; Eberhardt, B.; Eisch, J.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Fedynitch, A.; Feintzeig, J.; Feusels, T.; Filimonov, K.; Finley, C.; Fischer-Wasels, T.; Flis, S.; Franckowiak, A.; Frantzen, K.; Fuchs, T.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Gladstone, L.; Glsenkamp, T.; Goldschmidt, A.; Golup, G.; Gonzalez, J. G.; Goodman, J. A.; Gra, D.; Grandmont, D. T.; Grant, D.; Gretskov, P.; Groh, J. C.; Gro, A.; Ha, C.; Haj Ismail, A.; Hallen, P.; Hallgren, A.; Halzen, F.; Hanson, K.; Heereman, D.; Heinen, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Homeier, A.; Hoshina, K.; Huelsnitz, W.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobi, E.; Jacobsen, J.; Jagielski, K.; Japaridze, G. S.; Jero, K.; Jlelati, O.; Kaminsky, B.; Kappes, A.; Karg, T.; Karle, A.; Kauer, M.; Kelley, J. L.; Kiryluk, J.; Kls, J.; Klein, S. R.; Khne, J.-H.; Kohnen, G.; Kolanoski, H.; Kpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krasberg, M.; Kriesten, A.; Krings, K.; Kroll, G.; Kunnen, J.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Landsman, H.; Larson, M. J.; Lesiak-Bzdak, M.; Leuermann, M.; Leute, J.; Lnemann, J.; Macas, O.; Madsen, J.; Maggi, G.; Maruyama, R.; Mase, K.; Matis, H. S.; McNally, F.; Meagher, K.; Merck, M.; Meures, T.; Miarecki, S.; Middell, E.; Milke, N.; Miller, J.; Mohrmann, L.; Montaruli, T.; Morse, R.; Nahnhauer, R.; Naumann, U.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Obertacke, A.; Odrowski, S.; Olivas, A.; Omairat, A.; O'Murchadha, A.; Paul, L.; Pepper, J. A.; Prez de los Heros, C.; Pfendner, C.; Pieloth, D.; Pinat, E.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Rdel, L.; Rameez, M.; Rawlins, K.; Redl, P.; Reimann, R.; Resconi, E.; Rhode, W.; Ribordy, M.; Richman, M.; Riedel, B.; Rodrigues, J. P.; Rott, C.; Ruhe, T.; Ruzybayev, B.; Ryckbosch, D.; Saba, S. M.; Sander, H.-G.; Santander, M.; Sarkar, S.; Schatto, K.; Scheriau, F.; Schmidt, T.; Schmitz, M.; Schoenen, S.; Schneberg, S.; Schnwald, A.; Schukraft, A.; Schulte, L.; Schulz, O.; Seckel, D.; Sestayo, Y.; Seunarine, S.; Shanidze, R.; Sheremata, C.; Smith, M. W. E.; Soldin, D.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stanisha, N. A.; Stasik, A.; Stezelberger, T.; Stokstad, R. G.; Stl, A.; Strahler, E. A.; Strm, R.; Sullivan, G. W.; Taavola, H.; Taboada, I.; Tamburro, A.; Tepe, A.; Ter-Antonyan, S.; Tei?, G.; Tilav, S.; Toale, P. A.; Tobin, M. N.; Toscano, S.; Unger, E.; Usner, M.; Vallecorsa, S.; van Eijndhoven, N.; Van Overloop, A.; van Santen, J.; Vehring, M.; Voge, M.; Vraeghe, M.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Weaver, Ch.; Wellons, M.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Williams, D. R.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, D. L.; Xu, X. W.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; Ziemann, J.; Zierke, S.; Zoll, M.

2013-12-01

172

A search for anisotropy in the arrival directions of ultra high energy cosmic rays recorded at the Pierre Auger Observatory  

SciTech Connect

Observations of cosmic ray arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Veron-Cetty Veron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2pt-L, 2pt+ and 3pt methods, each giving a different measure of self-clustering in arrival directions, were tested on mock cosmic ray data sets to study the impacts of sample size and magnetic smearing on their results, accounting for both angular and energy resolutions. If the sources of UHECRs follow the same large scale structure as ordinary galaxies in the local Universe and if UHECRs are deflected no more than a few degrees, a study of mock maps suggests that these three methods can efficiently respond to the resulting anisotropy with a P-value = 1.0% or smaller with data sets as few as 100 events. Using data taken from January 1, 2004 to July 31, 2010 we examined the 20, 30, ..., 110 highest energy events with a corresponding minimum energy threshold of about 51 EeV. The minimum P-values found were 13.5% using the 2pt-L method, 1.0% using the 2pt+ method and 1.1% using the 3pt method for the highest 100 energy events. In view of the multiple (correlated) scans performed on the data set, these catalog-independent methods do not yield strong evidence of anisotropy in the highest energy cosmic rays.

Abreu, P.; ,

2012-01-01

173

High-energy cosmic-ray nuclei from high- and low-luminosity gamma-ray bursts and implications for multi-messenger astronomy  

E-print Network

Gamma-ray bursts (GRBs) are one of the candidates of ultra-high-energy (around 10^18.5 eV) cosmic-ray (UHECR) sources. We investigate high-energy cosmic-ray acceleration including heavy nuclei in GRBs by using Geant 4, and discuss its various implications, taking both of high-luminosity (HL) and low-luminosity (LL) GRBs into account. This is because LL GRBs may also make a significant contribution to the observed UHECR flux if they form a distinct population. We show that not only protons but also heavier nuclei can be accelerated up to ultra-high energies in the internal, (external) reverse and forward shock models. We also show that the condition for ultra-high-energy heavy nuclei such as iron to survive is almost the same as that for about TeV gamma-rays to escape from the source and for high-energy neutrinos not to be much produced. The multi-messenger astronomy by neutrino and GeV-TeV gamma-ray telescopes such as IceCube and KM3Net, GLAST and MAGIC will be important to see whether GRBs can be accelerators of ultra-high-energy heavy nuclei. We also demonstrate expected spectra of high-energy neutrinos and gamma rays, and discuss their detectabilities. In addition, we discuss implictaions of the GRB-UHECR hypothesis. We point out, since the number densities of HL-GRBs and LL-GRBs are quite different, its detemination by UHECR observations is also important.

Kohta Murase; Kunihito Ioka; Shigehiro Nagataki; Takashi Nakamura

2008-05-27

174

Tungsten fragmentation in nuclear reactions induced by high-energy cosmic-ray protons  

NASA Astrophysics Data System (ADS)

Tungsten fragmentation arising in nuclear reactions induced by cosmic-ray protons in space-vehicle electronics is considered. In modern technologies of integrated circuits featuring a three-dimensional layered architecture, tungsten is frequently used as a material for interlayer conducting connections. Within the preequilibrium model, tungsten-fragmentation features, including the cross sections for the elastic and inelastic scattering of protons of energy between 30 and 240 MeV; the yields of isotopes and isobars; their energy, charge, and mass distributions; and recoil energy spectra, are calculated on the basis of the TALYS and EMPIRE-II-19 codes. It is shown that tungsten fragmentation affects substantially forecasts of failures of space-vehicle electronics.

Chechenin, N. G.; Chuvilskaya, T. V.; Shirokova, A. A.; Kadmenskii, A. G.

2015-01-01

175

MEASUREMENTS OF THE RELATIVE ABUNDANCES OF HIGH-ENERGY COSMIC-RAY NUCLEI IN THE TeV/NUCLEON REGION  

SciTech Connect

We present measurements of the relative abundances of cosmic-ray nuclei in the energy range of 500-3980 GeV/nucleon from the second flight of the Cosmic Ray Energetics And Mass balloon-borne experiment. Particle energy was determined using a sampling tungsten/scintillating-fiber calorimeter, while particle charge was identified precisely with a dual-layer silicon charge detector installed for this flight. The resulting element ratios C/O, N/O, Ne/O, Mg/O, Si/O, and Fe/O at the top of atmosphere are 0.919 {+-} 0.123{sup stat} {+-} 0.030{sup syst}, 0.076 {+-} 0.019{sup stat} {+-} 0.013{sup syst}, 0.115 {+-} 0.031{sup stat} {+-} 0.004{sup syst}, 0.153 {+-} 0.039{sup stat} {+-} 0.005{sup syst}, 0.180 {+-} 0.045{sup stat} {+-} 0.006{sup syst}, and 0.139 {+-} 0.043{sup stat} {+-} 0.005{sup syst}, respectively, which agree with measurements at lower energies. The source abundance of N/O is found to be 0.054 {+-} 0.013{sup stat} {+-} 0.009{sup syst+0.010esc} {sub -0.017}. The cosmic-ray source abundances are compared to local Galactic (LG) abundances as a function of first ionization potential and as a function of condensation temperature. At high energies the trend that the cosmic-ray source abundances at large ionization potential or low condensation temperature are suppressed compared to their LG abundances continues. Therefore, the injection mechanism must be the same at TeV/nucleon energies as at the lower energies measured by HEAO-3, CRN, and TRACER. Furthermore, the cosmic-ray source abundances are compared to a mixture of 80% solar system abundances and 20% massive stellar outflow (MSO) as a function of atomic mass. The good agreement with TIGER measurements at lower energies confirms the existence of a substantial fraction of MSO material required in the {approx}TeV per nucleon region.

Ahn, H. S.; Ganel, O.; Han, J. H.; Kim, K. C.; Lee, M. H.; Malinin, A. [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States); Allison, P. S.; Beatty, J. J.; Brandt, T. J. [Department of Physics, Ohio State University, Columbus, OH 43210 (United States); Bagliesi, M. G.; Bigongiari, G.; Maestro, P.; Marrocchesi, P. S. [Department of Physics, University of Siena and INFN, Via Roma 56, 53100 Siena (Italy); Barbier, L. [Astroparticle Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Childers, J. T.; DuVernois, M. A. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Conklin, N. B.; Coutu, S. [Department of Physics, Penn State University, University Park, PA 16802 (United States); Jeon, J. A.; Lee, J., E-mail: ipark@ewha.ac.k [Department of Physics, Ewha Womans University, Seoul 120-750 (Korea, Republic of)

2010-06-01

176

VERY HIGH ENERGY GAMMA RAY Tadashi KIFUNE  

E-print Network

VERY HIGH ENERGY GAMMA RAY ASTRONOMY Tadashi KIFUNE Institute for Cosmic Ray Research, University for the photon of background radiation field. The gamma ray reactions characterize VHE gamma ray astronomy­based tech­ nique to detect TeV gamma rays. The current status of gamma ray astronomy in its growing stage

Enomoto, Ryoji

177

High Energy Gamma Rays  

E-print Network

This article reviews the present status of high energy gamma-ray astronomy at energies above 30 MeV. Observations in the past decade using both space- and ground-based experiments have been primarily responsible for giving a tremendous boost to our knowledge of the high energy Universe. High energy gamma-rays have been detected from a wide range of Galactic and extragalactic astrophysical sources, such as gamma-ray bursters, pulsars, and active galaxies. These observations have established high energy gamma-ray astronomy as a vital and exciting field, that has a bright future. This review summarizes the experimental techniques, observations and results obtained with recent experiments, and concludes with a short description of future prospects.

R. Mukherjee

2000-09-22

178

Abundances and energy spectra of high energy heavy cosmic-ray nuclei  

SciTech Connect

We have measured the relative abundances of the cosmic rays in the iron group region at energies from a few GeV/amu to approximately 70 GeV/amu. This is done using a balloon-borne instrument consisting of gas ionization chambers, a plastic scintillator, a plastic Cherenkov counter, and a CO/sub 2/ gas Cherenkov counter. The instrument was flown from Palestine, Texas in the fall of 1982 for a total exposure of 62 m/sup 2/-ster-hr at an average atmospheric depth of 4 g/cm/sup 2/. The elemental charge was determined for a combination of the scintillator and plastic Cherenkov detector. Results are reported on the /sub 22/Ti//sub 26/Fe, /sub 24/Cr//sub 26/Fe, /sub 20/Ca//sub 26/Fe, and /sub 28/Ni//sub 28/Fe abundance ratios from 2 to 70 GeV/amu. Within this work results on the previously unused method of relativistic rise in gas ionization chambers is detailed as well as results on the return to nonsaturation of plastic scintillators.

Barthelmy, S.D.

1985-01-01

179

Chinese high energy cosmic particle explorer (DAMPE)  

NASA Astrophysics Data System (ADS)

The first Chinese high energy cosmic particle explorer (DArk Matter Particle Explorer-DAMPE) aims to detect electron/gamma at the range between 5GeV and 10TeV in space. DAMPE would be on the lookout for gamma rays produced when dark matter particles annihilate each other. The craft would also tune in to a high-energy electron spectrum that may shed light on the mysterious propagation and acceleration of cosmic rays.DAMPE is composed of four major payloads from top to bottom:The plastic scintillator detector,The silicon tracker,The BGO calorimeter and The neutron detector. Under CASs new Innovation 2020 program, the qualification model of DAMPE has already been done, and the flight model will be done by the end of year 2014.

Chang, Jin; Hu, Yiming; Wu, Jian

180

Blind search for the real sample: Application to the origin of ultra-high energy cosmic rays  

E-print Network

We suggest a method for statistical tests which does not suffer from a posteriori manipulations with tested samples (e.g. cuts optimization) and does not require a somewhat obscure procedure of the penalty estimate. The idea of the method is to hide the real sample (before it has been studied) among a large number of artificial samples, drawn from a random distribution expressing the null hypothesis, and then to search for it as the one demonstrating the strongest hypothesized effect. The statistical significance of the effect in this approach is the inverse of the maximal number of random samples at which the search was successful. We have applied the method to revisit the problem of correlation between the arrival directions of ultra-high energy cosmic rays and BL Lac objects. No significant correlation was found.

Boris E. Stern; Juri Poutanen

2005-03-08

181

The JEM-EUSO mission: a space observatory to study the origin of Ultra-High Energy Cosmic Rays  

NASA Astrophysics Data System (ADS)

The Extreme Universe Space Observatory (EUSO) onboard the Japanese Experiment Module (JEM-EUSO) of the International Space Station (ISS) is an innovative space-based mission with the aim of detecting Ultra-High Energy Cosmic Rays (UHECRs) from the ISS, by using the Earth's atmosphere as a calorimeter viewed by a fluorescence telescope. An observatory able to produce an arrival direction map with more than several hundreds events above 5 1019 eV would give important information on the origin of the UHECRs and identify structures in the sky map that contain information about the source density and/or distribution. This is likely to lead to an understanding of the acceleration mechanisms with a high potential for producing discoveries in astrophysics and/or fundamental physics. The scientific motivations of the mission as well as the current development status of the instrument and its performance are reviewed.

Bertaina, M.; Parizot, E.

2014-11-01

182

Germ cell mutagenesis in medaka fish after exposures to high-energy cosmic ray nuclei: A human model  

PubMed Central

Astronauts beyond the Earth's orbit are exposed to high-energy cosmic-ray nuclei with high values of linear energy transfer (LET), resulting in much more biological damage than from x-rays or ?-rays and may result in mutations and cancer induction. The relative biological effectiveness of these nuclei depends on the LET, rising to as high as ?50 at LET values of ?100-200 keV/?m. An endpoint of concern is germ cell mutations passed on to offspring, arising from exposure to these nuclei. A vertebrate model for germ cell mutation is Medaka fish (Oryzias latipes). We exposed wild type males to doses of 1 GeV per nucleon Fe nuclei or to 290 MeV per nucleon C nuclei. They were mated to females with recessive mutations at five-color loci. The transparent embryos from >100 days of mating (representing exposed sperm, spermatids, or spermatogonia) were observed so as to detect dominant lethal mutations and total color mutations, even though the embryos might not hatch. The relative number of mutant embryos as a function of dose were compared with those induced by ?-rays. The relative biological effectiveness values for dominant lethal mutations and total color mutations for exposed sperm and spermatids were 1.3-2.1 for exposure to C nuclei and 1.5-3.0 for exposure to Fe nuclei. (The spermatogonial data were uncertain.) These low values, and the negligible number of viable mutations, compared with those for mutations in somatic cells and for neoplastic transformation, indicate that germ cell mutations arising from exposures to cosmic ray nuclei are not a significant hazard to astronauts. PMID:15829584

Shimada, Atsuko; Shima, Akihiro; Nojima, Kumie; Seino, Yo; Setlow, Richard B.

2005-01-01

183

FERMI LAT OBSERVATION OF DIFFUSE GAMMA RAYS PRODUCED THROUGH INTERACTIONS BETWEEN LOCAL INTERSTELLAR MATTER AND HIGH-ENERGY COSMIC RAYS  

SciTech Connect

Observations by the Large Area Telescope (LAT) on the Fermi mission of diffuse gamma-rays in a mid-latitude region in the third quadrant (Galactic longitude l from 200 deg. to 260 deg. and latitude |b| from 22 deg. to 60 deg.) are reported. The region contains no known large molecular cloud and most of the atomic hydrogen is within 1 kpc of the solar system. The contributions of gamma-ray point sources and inverse Compton scattering are estimated and subtracted. The residual gamma-ray intensity exhibits a linear correlation with the atomic gas column density in energy from 100 MeV to 10 GeV. The measured integrated gamma-ray emissivity is (1.63 +- 0.05) x 10{sup -26} photons s{sup -1}sr{sup -1} H-atom{sup -1} and (0.66 +- 0.02) x 10{sup -26} photons s{sup -1}sr{sup -1} H-atom{sup -1} above 100 MeV and above 300 MeV, respectively, with an additional systematic error of {approx}10%. The differential emissivity from 100 MeV to 10 GeV agrees with calculations based on cosmic ray spectra consistent with those directly measured, at the 10% level. The results obtained indicate that cosmic ray nuclei spectra within 1 kpc from the solar system in regions studied are close to the local interstellar spectra inferred from direct measurements at the Earth within {approx}10%.

Abdo, A. A. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Ackermann, M.; Ajello, M. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)

2009-10-01

184

Origin of the high energy cosmic neutrino background.  

PubMed

The diffuse background of very high energy extraterrestrial neutrinos recently discovered with IceCube is compatible with that expected from cosmic ray interactions in the Galactic interstellar medium plus that expected from hadronic interactions near the source and in the intergalactic medium of the cosmic rays which have been accelerated by the jets that produce gamma ray bursts. PMID:25415894

Dado, Shlomo; Dar, Arnon

2014-11-01

185

Origin of the High Energy Cosmic Neutrino Background  

NASA Astrophysics Data System (ADS)

The diffuse background of very high energy extraterrestrial neutrinos recently discovered with IceCube is compatible with that expected from cosmic ray interactions in the Galactic interstellar medium plus that expected from hadronic interactions near the source and in the intergalactic medium of the cosmic rays which have been accelerated by the jets that produce gamma ray bursts.

Dado, Shlomo; Dar, Arnon

2014-11-01

186

Mass entrainment and turbulence-driven acceleration of ultra-high energy cosmic rays in Centaurus A  

E-print Network

Observations of the FR I radio galaxy Centaurus A in radio, X-ray and gamma-ray bands provide evidence for lepton acceleration up to several TeV and clues about hadron acceleration to tens of EeV. Synthesising the available observational constraints on the physical conditions and particle content in the jets, inner lobes and giant lobes of Centaurus A, we aim to evaluate its feasibility as an ultra-high-energy cosmic-ray source. We apply several methods of determining jet power and affirm the consistency of various power estimates of ~ 1 x 10^43 erg s^-1. Employing scaling relations based on the results of Laing & Bridle (2002), we estimate particle number densities in the jets, encompassing available radio through X-ray observations. Our model is compatible with the jets ingesting ~ 3 x 10^21 g s^-1 of matter via external entrainment from hot gas and ~ 7 x 10^22 g s^-1 via internal entrainment from jet-contained stars. This leads to an imbalance between the internal lobe pressure securable from radiating...

Wykes, Sarka; Hardcastle, Martin J; Eilek, Jean A; Biermann, Peter L; Achterberg, Abraham; Bray, Justin D; Bicknell, Geoffrey V; Lazarian, Alex; Haverkorn, Marijke; Protheroe, Ray J; Bromberg, Omer

2013-01-01

187

VERY HIGH ENERGY GAMMA RAY Tadashi KIFUNE  

E-print Network

VERY HIGH ENERGY GAMMA RAY ASTRONOMY Tadashi KIFUNE Institute for Cosmic Ray Research, University radiation eld. The gamma ray reactions characterize VHE gamma ray astronomy. The Universe, through the high primordial black holes, acted, to some extent, as impetus for promoting gamma ray astronomy. Although

Enomoto, Ryoji

188

Leptonic origin of diffuse galactic high-energy gamma rays - Indications for a varying cosmic ray proton-to-electron ratio  

NASA Astrophysics Data System (ADS)

The flux of high-energy (more than 300 MeV) gamma rays - caused by nonthermal bremsstrahlung and inverse Compton scattering - and the synchrotron flux at 408 MHz are calculated with the same power-law spectrum of relativistic electrons. Both are compared with the values observed at higher latitudes in the anticenter direction by employing the COS-B data and the 408-MHz survey of Haslam et al. (1982). It is shown that with column densities for the interstellar gas taken from the literature the cosmic-ray-electron component accounts for nearly the total gamma-flux, provided the magnetic field strength is of the order 3-4 microG with an equivalent half-thickness of about 1200 pc. These findings demand a decrease of the cosmic-ray proton-to-electron ratio at higher latitudes in the anticenter direction compared to the value observed in the solar vicinity.

Pohl, M.; Schlickeiser, R.

1991-12-01

189

Measurements of cosmic-ray secondary nuclei at high energies with the first flight of the CREAM balloon-borne experiment  

E-print Network

We present new measurements of heavy cosmic-ray nuclei at high energies per- formed during the first flight of the balloon-borne cosmic-ray experiment CREAM (Cosmic-Ray Energetics And Mass). This instrument uses multiple charge detectors and a transition radiation detector to provide the first high accuracy measurements of the relative abundances of elements from boron to oxygen up to energies around 1 TeV/n. The data agree with previous measurements at lower energies and show a relatively steep decline (~E$^-0.6$ to E$^-0.5$) at high energies. They further show the source abundance of nitrogen relative to oxygen is ~10% in the TeV/n region.

Ahn, H S; Bagliesi, M G; Beatty, J J; Bigongiari, G; Boyle, P J; Brandt, T J; Childers, J T; Conklin, N B; Coutu, S; Duvernois, M A; Ganel, O; Han, J H; Hyun, H J; Jeon, J A; Kim, K C; Lee, J K; Lee, M H; Lutz, L; Maestro, P; Malinin, A; Marrocchesi, P S; Minnick, S A; Mognet, S I; Nam, S; Nutter, S L; Park, I H; Park, N H; Seo, E S; Sina, R; Swordy, S P; Wakely, S P; Wu, J; Yang, J; Yoon, Y S; Zei, R; Zinn, S Y

2008-01-01

190

Measurements of cosmic-ray secondary nuclei at high energies with the first flight of the CREAM balloon-borne experiment  

E-print Network

We present new measurements of heavy cosmic-ray nuclei at high energies per- formed during the first flight of the balloon-borne cosmic-ray experiment CREAM (Cosmic-Ray Energetics And Mass). This instrument uses multiple charge detectors and a transition radiation detector to provide the first high accuracy measurements of the relative abundances of elements from boron to oxygen up to energies around 1 TeV/n. The data agree with previous measurements at lower energies and show a relatively steep decline (~E$^-0.6$ to E$^-0.5$) at high energies. They further show the source abundance of nitrogen relative to oxygen is ~10% in the TeV/n region.

H. S. Ahn; P. S. Allison; M. G. Bagliesi; J. J. Beatty; G. Bigongiari; P. J. Boyle; T. J. Brandt; J. T. Childers; N. B. Conklin; S. Coutu; M. A. Duvernois; O. Ganel; J. H. Han; H. J. Hyun; J. A. Jeon; K. C. Kim; J. K. Lee; M. H. Lee; L. Lutz; P. Maestro; A. Malinin; P. S. Marrocchesi; S. A. Minnick; S. I. Mognet; S. Nam; S. L. Nutter; I. H. Park; N. H. Park; E. S. Seo; R. Sina; S. P. Swordy; S. P. Wakely; J. Wu; J. Yang; Y. S. Yoon; R. Zei; S. Y. Zinn

2008-08-12

191

Fermi LAT Observation of Diffuse Gamma-Rays Produced through Interactions Between Local Interstellar Matter and High Energy Cosmic Rays  

SciTech Connect

Observations by the Large Area Telescope (LAT) on the Fermi mission of diffuse {gamma}-rays in a mid-latitude region in the third quadrant (Galactic longitude l from 200{sup o} to 260{sup o} and latitude |b| from 22{sup o} to 60{sup o}) are reported. The region contains no known large molecular cloud and most of the atomic hydrogen is within 1 kpc of the solar system. The contributions of {gamma}-ray point sources and inverse Compton scattering are estimated and subtracted. The residual {gamma}-ray intensity exhibits a linear correlation with the atomic gas column density in energy from 100 MeV to 10 GeV. The measured integrated {gamma}-ray emissivity is (1.63 {+-} 0.05) x 10{sup -26} photons s{sup -1}sr{sup -1} H-atom{sup -1} and (0.66 {+-} 0.02) x 10{sup -26} photons s{sup -1}sr{sup -1} H-atom{sup -1} above 100 MeV and above 300 MeV, respectively, with an additional systematic error of {approx}10%. The differential emissivity from 100 MeV to 10 GeV agrees with calculations based on cosmic ray spectra consistent with those directly measured, at the 10% level. The results obtained indicate that cosmic ray nuclei spectra within 1 kpc from the solar system in regions studied are close to the local interstellar spectra inferred from direct measurements at the Earth within {approx}10%.

Abdo, A.A.; /Naval Research Lab, Wash., D.C. /Federal City Coll.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U. /Stockholm U., OKC; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, E.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, T.H.; /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /Milan Polytechnic /Royal Inst. Tech., Stockholm /Stockholm U., OKC /DAPNIA, Saclay /INFN, Perugia /Perugia U. /NASA, Goddard /Naval Research Lab, Wash., D.C. /George Mason U. /NASA, Goddard /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Stockholm U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /ASDC, Frascati /Naval Research Lab, Wash., D.C. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Trieste /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Bari U. /INFN, Bari /INFN, Bari; /more authors..

2012-03-30

192

Peculiar high energy cosmic ray stratospheric event reveals a heavy primary origin particle above the knee region of the cosmic ray spectrum  

SciTech Connect

We wish to put forward an explanation for a peculiar cosmic ray event with energy {sigma}E{sub {gamma}}{>=}2x10{sup 15} eV detected in 1975 by the balloon borne emulsion chamber experiment performed in the stratosphere, at the altitude {>=}30 km above sea level. For almost 30 years the event has been described as unusual, invoking new exotic mechanisms or models. In our opinion there is no need for an extraordinary explanation. Contrary to the widespread belief, the event gives us an example of 'unrecognized standard physics'. At the same time this event revealed a variety of features which are of considerable interest for cosmic rays, nuclear physics, and astrophysics. Here we show that the observed family is most likely to be a result of a heavy nucleus interaction with an air nucleus. In this case a primary particle would originally have been in the energy region above 'the knee' of the cosmic ray spectrum.

Kopenkin, V.; Fujimoto, Y. [Advanced Research Institute for Science and Engineering, Waseda University, Shinjuku, Tokyo, 169 (Japan)

2005-01-15

193

Solar panels as air Cherenkov detectors for extremely high energy cosmic rays  

E-print Network

Increasing interest towards the observation of the highest energy cosmic rayshas motivated the development of new detection techniques. The properties ofthe Cherenkov photon pulse emitted in the atmosphere by these very rareparticles indicate low-cost semiconductor detectors as good candidates fortheir optical read-out. The aim of this paper is to evaluate the viability of solar panels for thispurpose. The experimental framework resulting from measurements performed withsuitably-designed solar cells and large conventional photovoltaic areas ispresented. A discussion on the obtained and achievable sensitivities follows.

Cecchini, S; Esposti, L D; Giacomelli, G; Guerra, M; Lax, I; Mandrioli, G; Parretta, A; Sarno, A; Schioppo, R; Sorel, M; Spurio, M

2000-01-01

194

Mass entrainment and turbulence-driven acceleration of ultra-high energy cosmic rays in Centaurus A  

NASA Astrophysics Data System (ADS)

Observations of the FR I radio galaxy Centaurus A in radio, X-ray, and gamma-ray bands provide evidence for lepton acceleration up to several TeV and clues about hadron acceleration to tens of EeV. Synthesising the available observational constraints on the physical conditions and particle content in the jets, inner lobes and giant lobes of Centaurus A, we aim to evaluate its feasibility as an ultra-high-energy cosmic-ray source. We apply several methods of determining jet power and affirm the consistency of various power estimates of ~1 1043 erg s-1. Employing scaling relations based on previous results for 3C 31, we estimate particle number densities in the jets, encompassing available radio through X-ray observations. Our model is compatible with the jets ingesting ~3 1021 g s-1 of matter via external entrainment from hot gas and ~7 1022 g s-1 via internal entrainment from jet-contained stars. This leads to an imbalance between the internal lobe pressure available from radiating particles and magnetic field, and our derived external pressure. Based on knowledge of the external environments of other FR I sources, we estimate the thermal pressure in the giant lobes as 1.5 10-12 dyn cm-2, from which we deduce a lower limit to the temperature of ~1.6 108 K. Using dynamical and buoyancy arguments, we infer ~440-645 Myr and ~560 Myr as the sound-crossing and buoyancy ages of the giant lobes respectively, inconsistent with their spectral ages. We re-investigate the feasibility of particle acceleration via stochastic processes in the lobes, placing new constraints on the energetics and on turbulent input to the lobes. The same "very hot" temperatures that allow self-consistency between the entrainment calculations and the missing pressure also allow stochastic UHECR acceleration models to work.

Wykes, Sarka; Croston, Judith H.; Hardcastle, Martin J.; Eilek, Jean A.; Biermann, Peter L.; Achterberg, Abraham; Bray, Justin D.; Lazarian, Alex; Haverkorn, Marijke; Protheroe, Ray J.; Bromberg, Omer

2013-10-01

195

Propagation of high-energy cosmic rays in extragalactic turbulent magnetic fields: resulting energy spectrum and composition  

E-print Network

We extend previous studies of mixed-composition extragalactic cosmic-ray source models, by investigating the influence of a non-negligible extragalactic magnetic field on the propagated cosmic-ray spectrum and composition. We study the transport of charged particles in turbulent fields and the transition from a ballistic to a diffusive propagation regime. We introduce a method allowing a fast integration of the particle trajectories, which allows us to calculate extragalactic cosmic-ray spectra in the general case, without using either the diffusive or the rectilinear approximation. We find that the main features of the mixed-composition models -- regarding the interpretation of the ankle and the non-monotonous evolution of the average cosmic-ray mass -- remain essentially unchanged as long as the magnetic field intensity does not exceed a few nG.

N. Globus; D. Allard; E. Parizot

2007-09-11

196

An extended universality of electron distributions in cosmic ray showers of high energies and its application  

NASA Astrophysics Data System (ADS)

It is shown that the shape of any electron distribution in a high energy air shower is the same in all such showers, if taken at the same age, independently of the primary energy, mass and thus, of the interaction model. A universal behaviour has been also found within a single shower, such that the lateral distributions of electrons with fixed energies, at various shower ages, can be described by a single function of only one variable. The angular distributions of electrons with a fixed energy can be represented, at a given lateral distance, by a function of the product ?E? only, which is explained by a model of small angle electron scattering with simplified energy losses. These results have been obtained by Monte Carlo simulations of the extensive air showers. The electron universality can be used as a method for determining the longitudinal profile of any single shower from its optical images measured by the fluorescence light technique, which is particularly useful with showers observed with large fraction of the Cherenkov light.

Giller, Maria; ?mia?kowski, Andrzej; Wieczorek, Grzegorz

2015-01-01

197

Study of Dispersion of Mass Distribution of Ultra-High Energy Cosmic Rays using a Surface Array of Muon and Electromagnetic Detectors  

E-print Network

We consider a hypothetical observatory of ultra-high energy cosmic rays consisting of two surface detector arrays that measure independently electromagnetic and muon signals induced by air showers. Using the constant intensity cut method, sets of events ordered according to each of both signal sizes are compared giving the number of matched events. Based on its dependence on the zenith angle, a parameter sensitive to the dispersion of the distribution of the logarithmic mass of cosmic rays is introduced. The results obtained using two post-LHC models of hadronic interactions are very similar and indicate a weak dependence on details of these interactions.

Vcha, Jakub; Nosek, Dalibor; Ebr, Jan

2015-01-01

198

The Lateral Trigger Probability function for the Ultra-High Energy Cosmic Ray Showers detected by the Pierre Auger Observatory  

E-print Network

In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an extensive air shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 10^{17} and 10^{19} eV and zenith angles up to 65 degs. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte-Carlo results sho...

Abreu, P; Ahn, E J; Albuquerque, I F M; Allard, D; Allekotte, I; Allen, J; Allison, P; Castillo, J Alvarez; Alvarez-Muiz, J; Ambrosio, M; Aminaei, A; Anchordoqui, L; Andringa, S; Anti?i?, T; Anzalone, A; Aramo, C; Arganda, E; Arqueros, F; Asorey, H; Assis, P; Aublin, J; Ave, M; Avenier, M; Avila, G; Bcker, T; Balzer, M; Barber, K B; Barbosa, A F; Bardenet, R; Barroso, S L C; Baughman, B; Buml, J; Beatty, J J; Becker, B R; Becker, K H; Belltoile, A; Bellido, J A; BenZvi, S; Berat, C; Bertou, X; Biermann, P L; Billoir, P; Blanco, F; Blanco, M; Bleve, C; Blmer, H; Boh?ov, M; Boncioli, D; Bonifazi, C; Bonino, R; Borodai, N; Brack, J; Brogueira, P; Brown, W C; Bruijn, R; Buchholz, P; Bueno, A; Burton, R E; Caballero-Mora, K S; Caramete, L; Caruso, R; Castellina, A; Catalano, O; Cataldi, G; Cazon, L; Cester, R; Chauvin, J; Cheng, S H; Chiavassa, A; Chinellato, J A; Chou, A; Chudoba, J; Clay, R W; Coluccia, M R; Conceio, R; Contreras, F; Cook, H; Cooper, M J; Coppens, J; Cordier, A; Coutu, S; Covault, C E; Creusot, A; Criss, A; Cronin, J; Curutiu, A; Dagoret-Campagne, S; Dallier, R; Dasso, S; Daumiller, K; Dawson, B R; de Almeida, R M; De Domenico, M; De Donato, C; de Jong, S J; De La Vega, G; Junior, W J M de Mello; Neto, J R T de Mello; De Mitri, I; de Souza, V; de Vries, K D; Decerprit, G; del Peral, L; del Ro, M; Deligny, O; Dembinski, H; Dhital, N; Di Giulio, C; Diaz, J C; Castro, M L Daz; Diep, P N; Dobrigkeit, C; Docters, W; D'Olivo, J C; Dong, P N; Dorofeev, A; Anjos, J C dos; Dova, M T; D'Urso, D; Dutan, I; Ebr, J; Engel, R; Erdmann, M; Escobar, C O; Espadanal, J; Etchegoyen, A; Luis, P Facal San; Tapia, I Fajardo; Falcke, H; Farrar, G; Fauth, A C; Fazzini, N; Ferguson, A P; Ferrero, A; Fick, B; Filevich, A; Filip?i?, A; Fliescher, S; Fracchiolla, C E; Fraenkel, E D; Frhlich, U; Fuchs, B; Gaior, R; Gamarra, R F; Gambetta, S; Garca, B; Gmez, D Garca; Garcia-Pinto, D; Gascon, A; Gemmeke, H; Gesterling, K; Ghia, P L; Giaccari, U; Giller, M; Glass, H; Gold, M S; Golup, G; Albarracin, F Gomez; Berisso, M Gmez; Gonalves, P; Gonzalez, D; Gonzalez, J G; Gookin, B; Gra, D; Gorgi, A; Gouffon, P; Gozzini, S R; Grashorn, E; Grebe, S; Griffith, N; Grigat, M; Grillo, A F; Guardincerri, Y; Guarino, F; Guedes, G P; Guzman, A; Hague, J D; Hansen, P; Harari, D; Harmsma, S; Harton, J L; Haungs, A; Hebbeker, T; Heck, D; Herve, A E; Hojvat, C; Hollon, N; Holmes, V C; Homola, P; Hrandel, J R; Horneffer, A; Hrabovsk, M; Huege, T; Insolia, A; Ionita, F; Italiano, A; Jarne, C; Jiraskova, S; Josebachuili, M; Kadija, K; Kampert, K H; Karhan, P; Kasper, P; Kgl, B; Keilhauer, B; Keivani, A; Kelley, J L; Kemp, E; Kieckhafer, R M; Klages, H O; Kleifges, M; Kleinfeller, J; Knapp, J; Koang, D -H; Kotera, K; Krohm, N; Krmer, O; Kruppke-Hansen, D; Kuehn, F; Kuempel, D; Kulbartz, J K; Kunka, N; La Rosa, G; Lachaud, C; Lautridou, P; Leo, M S A B; Lebrun, D; Lebrun, P; de Oliveira, M A Leigui; Lemiere, A; Letessier-Selvon, A; Lhenry-Yvon, I; Link, K; Lpez, R; Agera, A Lopez; Louedec, K; Bahilo, J Lozano; Lu, L; Lucero, A; Ludwig, M; Lyberis, H; Maccarone, M C; Macolino, C; Maldera, S; Mandat, D; Mantsch, P; Mariazzi, A G; Marin, J; Marin, V; Maris, I C; Falcon, H R Marquez; Marsella, G; Martello, D; Martin, L; Martinez, H; Bravo, O Martnez; Mathes, H J; Matthews, J; Matthews, J A J; Matthiae, G; Maurizio, D; Mazur, P O; Medina-Tanco, G; Melissas, M; Melo, D; Menichetti, E; Menshikov, A; Mertsch, P; Meurer, C; Mi?anovi?, S; Micheletti, M I; Miller, W; Miramonti, L; Molina-Bueno, L; Mollerach, S; Monasor, M; Ragaigne, D Monnier; Montanet, F; Morales, B; Morello, C; Moreno, E; Moreno, J C; Morris, C; Mostaf, M; Moura, C A; Mueller, S; Muller, M A; Mller, G; Mnchmeyer, M; Mussa, R; , G Navarra; Navarro, J L; Navas, S; Necesal, P; Nellen, L; Nelles, A; Neuser, J; Nhung, P T; Niemietz, L; Nierstenhoefer, N; Nitz, D; Nosek, D; Noka, L; Nyklicek, M; Oehlschlger, J; Olinto, A; Oliva, P; Olmos-Gilbaja, V M; Ortiz, M; Pacheco, N; Selmi-Dei, D Pakk; Palatka, M; Pallotta, J; Palmieri, N; Parente, G; Parizot, E; Parra, A; Parsons, R D; Pastor, S; Paul, T; Pech, M; P?kala, J; Pelayo, R; Pepe, I M; Perrone, L; Pesce, R; Petermann, E; Petrera, S; Petrinca, P; Petrolini, A; Petrov, Y; Petrovic, J; Pfendner, C; Phan, N; Piegaia, R; Pierog, T; Pieroni, P; Pimenta, M; Pirronello, V; Platino, M; Ponce, V H; Pontz, M; Privitera, P; Prouza, M; Quel, E J; Querchfeld, S; Rautenberg, J; Ravel, O; Ravignani, D; Revenu, B; Ridky, J; Riggi, S; Risse, M; Ristori, P; Rivera, H; Rizi, V; Roberts, J; Robledo, C; de Carvalho, W Rodrigues; Rodriguez, G; Martino, J Rodriguez; Rojo, J Rodriguez; Rodriguez-Cabo, I; Rodrguez-Fras, M D; Ros, G; Rosado, J; Rossler, T; Roth, M; Rouill-d'Orfeuil, B; Roulet, E; Rovero, A C; Rhle, C; Salamida, F

2011-01-01

199

The Tunka - Multi-component EAS detector for high energy cosmic ray studies  

NASA Astrophysics Data System (ADS)

The EAS Cherenkov array Tunka-133, with about 3 km2 sensitive area, has been installed in the Tunka Valley, Siberia. The accessible energy range is 1015-1018 eV. In this contribution, a description of the array and main results obtained so far are presented. A current update of the array includes the deployment of scintillation stations, radio antennas, as well as optical stations. The deployments of these optical stations are the first step towards Tunka-HiSCORE, a wide-angle, large field-of-view gamma-ray telescope.

Berezhnev, S. F.; Besson, D.; Budnev, N. M.; Bker, M.; Breckner, M.; Chiavassa, A.; Chvalaev, O. A.; Gress, O. A.; Dyachok, A. N.; Epimakhov, S. N.; Hampf, D.; Haungs, A.; Hiller, R.; Horns, D.; Ivanova, A.; Karpov, N. I.; Kalmykov, N. N.; Kazarina, Yu.; Konstantinov, E. N.; Kostunin, D.; Korobchenko, A. V.; Korosteleva, E. E.; Kozhin, V. A.; Kunnas, M.; Kuzmichev, L. A.; Lubsandorzhiev, B. K.; Lubsandorzhiev, N. B.; Mirgazov, R. R.; Monhoev, R.; Nachtigall, R.; Panasyuk, M. I.; Pankov, L. V.; Pankov, A. L.; Pokhorukov, A.; Popova, E. G.; Porelli, A.; Prosin, V. V.; Ptuskin, V. S.; Rowell, G. P.; Schrder, F. G.; Semeney, Yu. A.; Shaibonov, B. A.; Silaev, A. A.; Silaev, A. A.; Skurikhin, A. V.; Spiering, C.; Spitschan, D.; Sveshnikova, L. G.; Wischnewski, R.; Yashin, I. V.; Zagorodnikov, A. V.

2013-12-01

200

Cosmic ray research Public lecture  

E-print Network

Cosmic ray research Public lecture Serendipity, colorful scientists and the birth of sub energy cosmic rays in Argentina 2 p.m., Wednesday, October 6, 2010 128 Jabara Hall Watkins Visiting powerful, high-energy cosmic rays that periodically bombard Earth. The project includes more than 450

201

Photodetection Aspects of JEM-EUSO and Studies of the Ultra-High Energy Cosmic Ray Sky  

E-print Network

In this thesis, an introduction to the Ultra-High Energy Cosmic Ray (UHECR) field is given, including air shower physics, UHECR astrophysics, and experimental techniques. The current questions in UHECR physics are mentioned, along with the experimental challenges encountered in the field. The physics of air fluorescence is also presented, and the JEM-EUSO experiment is introduced in detail. The original contributions in this thesis are divided into experimental work on photodetection aspects of JEM-EUSO and phenomenological studies of UHECR composition and source statistics. A comprehensive introduction to photomultiplier tubes (PMTs) and single photoelectron counting are given, and the measurement of PMT efficiency with an uncertainty of a few percent is discussed in detail. An experimental setup for measuring the air fluorescence yield is also introduced, and tests of the EUSO-Balloon high voltage power supply prototype are presented. A setup for sorting the JEM-EUSO PMTs is developed, including the assembly and calibration of data acquisition hardware and the development of acquisition and analysis software. This system is used to perform an absolute calibration of the EUSO-Balloon focal surface, along with measurements of the PMT pixel width and dead-space. In the phenomenological part of this work, it is shown that a distribution of source maximum energies must be considered in order to understand the energy spectrum and the composition of UHECRs. The number of sources which can be expected to contribute to the UHECR sky is also studied, finding that on the order of 1 source(s) contributes more than 50% of the flux at 100 EeV.

Carl Blaksley

2014-06-23

202

Measurement of the Shadowing of High-Energy Cosmic Rays by the Moon:A Search for TeV-Energy Antiprotons  

Microsoft Academic Search

The shadowing of high-energy cosmic rays by the Moon has been observed with a significance of 9.4 standard deviations with the L3+C muon spectrometer at CERN. A significant effect of the Earth magnetic field is observed. Since no event deficit on the east side of the Moon has been observed, an upper limit at 90% confidence level on the antiproton

P Achard; O Adriani; M Aguilar-Bentez; J Alcaraz; G Alemanni; James V Allaby; A Aloisio; M G Alviggi; H Anderhub; V P Andreev; F Anselmo; A Arefev; T Azemoon; T Aziz; P Bagnaia; A Bajo; G Baksay; L Baksay; S V Baldew; S Banerjee; A Barczyk; R Barillre; P Bartalini; M Basile; N Batalova; R Battiston; A Bay; F Becattini; U Becker; F Behner; L Bellucci; R Berbeco; J Berdugo; P Berges; B Bertucci; B L Betev; M Biasini; M Biglietti; A Biland; J J Blaising; S C Blyth; G J Bobbink; A Bhm; L Boldizsar; B Borgia; S Bottai; D Bourilkov; Maurice Bourquin; S Braccini; J G Branson; F Brochu; J D Burger; W J Burger; X D Cai; M Capell; G Cara Romeo; G Carlino; A Cartacci; J Casaus; F Cavallari; N Cavallo; C Cecchi; M Cerrada; M Chamizo-Llatas; Y H Chang; M Chemarin; A Chen; G Chen; H F Chen; H S Chen; G Chiefari; Luisa Cifarelli; F Cindolo; I Clare; R Clare; G Coignet; N Colino; S Costantini; B de la Cruz; S Cucciarelli; J A van Dalen; R De Asmundis; P L Dglon; J Debreczeni; A Degr; K Dehmelt; K Deiters; D Della Volpe; E Delmeire; P Denes; F De Notaristefani; A De Salvo; M Diemoz; M Dierckxsens; C Dionisi; M Dittmar; A Doria; M T Dova; D Duchesneau; M Duda; B Echenard; A Eline; A El-Hage; H El-Mamouni; A Engler; F J Eppling; P Extermann; M A Falagn; S Falciano; A Favara; J Fay; O Fedin; M Felcini; T Ferguson; H S Fesefeldt; E Fiandrini; J H Field; F Filthaut; P H Fisher; W Fisher; I Fisk; G Forconi; Klaus Freudenreich; C Furetta; Yu Galaktionov; S N Ganguli; P Garca-Abia; M Gataullin; S Gentile; S Giagu; Z F Gong; G Grenier; O Grimm; M W Grnewald; M Guida; V K Gupta; A Gurtu; L J Gutay; D Haas; D Hatzifotiadou; T Hebbeker; A Herv; J Hirschfelder; H Hofer; M Hohlmann; G Holzner; S R Hou; Y Hu; B N Jin; L W Jones; P de Jong; I Josa-Mutuberria; M Kaur; M N Kienzle-Focacci; J K Kim; Jasper Kirkby; E W Kittel; A Klimentov; A C Knig; M Kopal; V F Koutsenko; M Kraber; R W Krmer; A Krger; A Kunin; P Ladrn de Guevara; I Laktineh; G Landi; M Lebeau; A Lebedev; P Lebrun; P Lecomte; P Lecoq; P Le Coultre; J M Le Goff; R Leiste; M Levtchenko; P M Levchenko; C Li; S Likhoded; C H Lin; W T Lin; Frank L Linde; L Lista; Z A Liu; W Lohmann; E Longo; Y S L; C Luci; L Luminari; W Lustermann; Ma Wen Gan; L Malgeri; A Malinin; C Maa; J Mans; J P Martin; F Marzano; K Mazumdar; R R McNeil; S Mele; L Merola; M Meschini; W J Metzger; A Mihul; H Milcent; G Mirabelli; J Mnich; G B Mohanty; G S Muanza; A J M Muijs; B Musicar; M Musy; S Nagy; S Natale; M Napolitano; F Nessi-Tedaldi; H Newman; A Nisati; T Novk; H Nowak; R A Ofierzynski; G Organtini; I Pal; C Palomares; P Paolucci; R Paramatti; G Passaleva; S Patricelli; T Paul; M Pauluzzi; C Paus; Felicitas Pauss; M Pedace; S Pensotti; D Perret-Gallix; B Petersen; D Piccolo; F Pierella; M Pioppi; P A Pirou; E Pistolesi; V Plyaskin; M Pohl; V Pozhidaev; J Pothier; D Prokofev; D O Prokofiev; J Quartieri; G Rahal-Callot; M A Rahaman; P Raics; N Raja; R Ramelli; P G Rancoita; R Ranieri; A V Raspereza; P Razis; D Ren; M Rescigno; S Reucroft; S Riemann; K Riles; B P Roe; L Romero; A Rosca; C Rosemann; C Rosenbleck; S Rosier-Lees; S Roth; J A Rubio; G Ruggiero; H Rykaczewski; A Sakharov; S Saremi; S Sarkar; J Salicio; E Snchez; C Schfer; V Shchegelskii; Herwig Franz Schopper; D J Schotanus; C Sciacca; L Servoli; S Shevchenko; N Shivarov; V Shoutko; E Shumilov; A Shvorob; D Son; C Souga; P Spillantini; M Steuer; D P Stickland; B Stoyanov; A Strssner; K Sudhakar; G G Sultanov; L Z Sun; S Sushkov; H Suter; J D Swain; Z Szillsi; X W Tang; P Tarjan; L Tauscher; L Taylor; B Tellili; D Teyssier; C Timmermans; Samuel C C Ting; S M Ting; S C Tonwar; J Tth; C Tully; K L Tung; J Ulbricht; E Valente; R T Van de Walle; R Vsquez; V Veszpremi; G Vesztergombi; I Vetlitskii; D Vicinanza; Gert M Viertel; S Villa; M Vivargent; S Vlachos; I Vodopyanov; H Vogel; H Vogt; I Vorobev; A A Vorobyov; M Wadhwa; Q Wang; X L Wang; Z M Wang; M Weber; H Wilkens; S Wynhoff; L Xia; Z Z Xu; J Yamamoto; B Z Yang; C G Yang; H J Yang; M Yang; S C Yeh; A Zalite; Yu Zalite; Z P Zhang; J Zhao; G Y Zhu; R Y Zhu; H L Zhuang; A Zichichi; B Zimmermann; M Zller

2004-01-01

203

Energy spectrum of ultra-high energy cosmic rays observed with the Telescope Array using a hybrid technique  

NASA Astrophysics Data System (ADS)

We measure the spectrum of cosmic rays with energies greater than 1018.2 eV with the fluorescence detectors (FDs) and the surface detectors (SDs) of the Telescope Array Experiment using the data taken in our first 2.3-year observation from May 27, 2008 to September 7, 2010. A hybrid air shower reconstruction technique is employed to improve accuracies in determination of arrival directions and primary energies of cosmic rays using both FD and SD data. The energy spectrum presented here is in agreement with our previously published spectra and the HiRes results.

Abu-Zayyad, T.; Aida, R.; Allen, M.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, E. J.; Cho, W. R.; Fujii, H.; Fujii, T.; Fukuda, T.; Fukushima, M.; Hanlon, W.; Hayashi, K.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Hiyama, K.; Honda, K.; Iguchi, T.; Ikeda, D.; Ikuta, K.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Iwamoto, S.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kanbe, T.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kido, E.; Kim, H. B.; Kim, H. K.; Kim, J. H.; Kim, J. H.; Kitamoto, K.; Kitamura, S.; Kitamura, Y.; Kobayashi, K.; Kobayashi, Y.; Kondo, Y.; Kuramoto, K.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lim, S. I.; Lundquist, J. P.; Machida, S.; Martens, K.; Matsuda, T.; Matsuura, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Miyata, K.; Murano, Y.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nam, S. W.; Nonaka, T.; Ogio, S.; Ohnishi, M.; Ohoka, H.; Oki, K.; Oku, D.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Roh, S. Y.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Sampson, A. L.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Shin, J. I.; Shirahama, T.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T.; Suzuki, S.; Takahashi, Y.; Takeda, M.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Tsuyuguchi, Y.; Uchihori, Y.; Udo, S.; Ukai, H.; Urban, F.; Vasiloff, G.; Wada, Y.; Wong, T.; Yamakawa, Y.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zhou, X.; Zollinger, R.; Zundel, Z.

2015-02-01

204

High energy gamma-ray astronomy  

Microsoft Academic Search

The physics results of high energy gamma-ray astronomy are reported,\\u000aemphasizing recent achievements with ground-based detectors. This includes some\\u000aof the instrumental developments and latest projects. The fundamental\\u000acontribution of the field to the question of Cosmic Ray origin is highlighted.

H. J. Vlk

2005-01-01

205

High Energy Gamma-Ray Astronomy  

E-print Network

The physics results of high energy gamma-ray astronomy are reported, emphasizing recent achievements with ground-based detectors. This includes some of the instrumental developments and latest projects. The fundamental contribution of the field to the question of Cosmic Ray origin is highlighted.

H. J. Voelk

2004-01-19

206

High-resolution large area coordinate detector for investigations of high energy cosmic ray phenomena at the ground level  

Microsoft Academic Search

Coordinate detector DECOR is deployed around the Cherenkov water calorimeter NEVOD and is intended for detailed studies of angular, lateral and energy characteristics of multi-particle cosmic ray events (muon bundles, air showers, etc.) in a whole interval of zenith angles. Description of the coordinate detector and its data acquisition and triggering systems is given. In 2000, the first test runs

M. B. Amelchakov; V. M. Aynutdinov; N. S. Barbashina; D. V. Chernov; V. V. Kindin; R. P. Kokoulin; K. G. Kompaniets; G. Mannocchi; A. A. Petrukhin; Yu. N. Rodin; D. A. Room; O. Saavedra; V. V. Shutenko; G. Trinchero; N. N. Vonsovsky; E. E. Yanson; I. I. Yashin

2001-01-01

207

A theoretical analysis of the semiannual component in the heliocentric dependence of high-energy galactic cosmic rays  

Microsoft Academic Search

Annual and semiannual variations of the galactic cosmic rays and estimates of their radial derivatives have been used to determine the most significant terms at 1 AU in the convection-diffusion equation. It turns out that both the changes in sign and the absolute value of the semiannual variation may be explained through the interplay of convection, diffusion across magnetic field

G. E. Perona; E. Antonucci

1976-01-01

208

The Lateral Trigger Probability function for the UltraHigh Energy Cosmic Ray showers detected by the Pierre Auger Observatory  

Microsoft Academic Search

In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an Extensive Air Shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface

P. Abreu; M. Aglietta; E. J. Ahn; I. F. M. Albuquerque; D. Allard; I. Allekotte; J. Allen; P. Allison; J. Alvarez Castillo; M. Ambrosio; A. Aminaei; L. Anchordoqui; S. Andringa; T. Anti?i?; A. Anzalone; C. Aramo; E. Arganda; F. Arqueros; H. Asorey; P. Assis; J. Aublin; M. Avenier; G. Avila; T. Bcker; M. Balzer; K. B. Barber; A. F. Barbosa; R. Bardenet; S. L. C. Barroso; B. Baughman; J. Buml; J. J. Beatty; B. R. Becker; K. H. Becker; A. Belltoile; J. A. Bellido; S. BenZvi; C. Berat; X. Bertou; P. L. Biermann; P. Billoir; F. Blanco; M. Blanco; H. Blmer; M. Boh?ov; D. Boncioli; C. Bonifazi; R. Bonino; N. Borodai; J. Brack; P. Brogueira; W. C. Brown; R. Bruijn; P. Buchholz; A. Bueno; R. E. Burton; K. S. Caballero-Mora; L. Caramete; R. Caruso; A. Castellina; O. Catalano; G. Cataldi; L. Cazon; R. Cester; J. Chauvin; S. H. Cheng; A. Chiavassa; J. A. Chinellato; J. Chudoba; R. W. Clay; M. R. Coluccia; F. Contreras; H. Cook; M. J. Cooper; A. Cordier; U. Cotti; S. Coutu; C. E. Covault; A. Creusot; J. Cronin; A. Curutiu; S. Dagoret-Campagne; R. Dallier; S. Dasso; K. Daumiller; B. R. Dawson; R. M. de Almeida; C. De Donato; S. J. de Jong; G. De La Vega; I. De Mitri; V. de Souza; K. D. de Vries; G. Decerprit; L. del Peral; O. Deligny; H. Dembinski; N. Dhital; C. Di Giulio; J. C. Diaz; M. L. D?az Castro; P. N. Diep; C. Dobrigkeit; W. Docters; J. C. DOlivo; P. N. Dong; A. Dorofeev; J. C. dos Anjos; M. T. Dova; D. DUrso; I. Dutan; J. Ebr; R. Engel; M. Erdmann; C. O. Escobar; A. Etchegoyen; P. Facal San Luis; I. Fajardo Tapia; H. Falcke; G. Farrar; A. C. Fauth; N. Fazzini; A. P. Ferguson; A. Ferrero; B. Fick; A. Filevich; S. Fliescher; C. E. Fracchiolla; U. Frhlich; B. Fuchs; R. Gaior; R. F. Gamarra; S. Gambetta; B. Garc?a; D. Garc?a Gmez; D. Garca Gmez; A. Gascon; H. Gemmeke; K. Gesterling; P. L. Ghia; U. Giaccari; M. Giller; H. Glass; M. S. Gold; G. Golup; F. Gomez Albarracin; M. Gmez Berisso; P. Gonalves; D. Gonzalez; J. G. Gonzalez; B. Gookin; D. Gra; A. Gorgi; P. Gouffon; S. R. Gozzini; E. Grashorn; S. Grebe; N. Griffith; M. Grigat; A. F. Grillo; Y. Guardincerri; F. Guarino; G. P. Guedes; A. Guzman; J. D. Hague; P. Hansen; D. Harari; S. Harmsma; J. L. Harton; A. Haungs; T. Hebbeker; D. Heck; A. E. Herve; C. Hojvat; N. Hollon; V. C. Holmes; P. Homola; J. R. Hrandel; A. Horneffer; M. Hrabovsk; T. Huege; A. Insolia; F. Ionita; A. Italiano; C. Jarne; S. Jiraskova; K. Kadija; K. H. Kampert; P. Karhan; B. Kgl; B. Keilhauer; A. Keivani; J. L. Kelley; E. Kemp; R. M. Kieckhafer; H. O. Klages; M. Kleifges; J. Kleinfeller; D.-H. Koang; K. Kotera; N. Krohm; O. Krmer; D. Kruppke-Hansen; F. Kuehn; D. Kuempel; J. K. Kulbartz; N. Kunka; G. La Rosa; C. Lachaud; P. Lautridou; M. S. A. B. Leo; D. Lebrun; P. Lebrun; M. A. Leigui de Oliveira; A. Letessier-Selvon; I. Lhenry-Yvon; K. Link; R. Lpez; A. Lopez Agera; K. Louedec; J. Lozano Bahilo; A. Lucero; M. Ludwig; H. Lyberis; M. C. Maccarone; S. Maldera; D. Mandat; P. Mantsch; A. G. Mariazzi; J. Marin; V. Marin; I. C. Maris; H. R. Marquez Falcon; G. Marsella; D. Martello; L. Martin; H. Martinez; O. Mart?nez Bravo; H. J. Mathes; J. A. J. Matthews; G. Matthiae; D. Maurizio; P. O. Mazur; G. Medina-Tanco; M. Melissas; D. Melo; E. Menichetti; A. Menshikov; P. Mertsch; C. Meurer; S. Mi?anovi?; M. I. Micheletti; W. Miller; L. Miramonti; S. Mollerach; M. Monasor; D. Monnier Ragaigne; F. Montanet; B. Morales; C. Morello; E. Moreno; J. C. Moreno; M. Mostaf; C. A. Moura; S. Mueller; M. A. Muller; G. Mller; M. Mnchmeyer; R. Mussa; G. Navarra; J. L. Navarro; S. Navas; P. Necesal; L. Nellen; A. Nelles; P. T. Nhung; L. Niemietz; N. Nierstenhoefer; D. Nitz; D. Nosek; L. Noka; M. Nyklicek; J. Oehlschlger; A. Olinto; P. Oliva; V. M. Olmos-Gilbaja; N. Pacheco; D. Pakk Selmi-Dei; M. Palatka; J. Pallotta; N. Palmieri; G. Parente; E. Parizot; A. Parra; R. D. Parsons; S. Pastor; T. Paul; M. Pech; R. Pelayo; I. M. Pepe; L. Perrone; R. Pesce; E. Petermann; S. Petrera; P. Petrinca; A. Petrolini; Y. Petrov; J. Petrovic; C. Pfendner; N. Phan; R. Piegaia; T. Pierog; P. Pieroni; M. Pimenta; V. Pirronello; M. Platino; V. H. Ponce; M. Pontz; P. Privitera; M. Prouza; E. J. Quel; S. Querchfeld; J. Rautenberg; O. Ravel; D. Ravignani; B. Revenu; J. Ridky; S. Riggi; M. Risse; P. Ristori; H. Rivera; V. Rizi; J. Roberts; C. Robledo; W. Rodrigues de Carvalho; G. Rodriguez; J. Rodriguez Martino; I. Rodriguez-Cabo; M. D. Rodr?guez-Fr?as; G. Ros; J. Rosado; T. Rossler; M. Roth; B. Rouill-dOrfeuil; E. Roulet; A. C. Rovero; F. Salamida; H. Salazar; G. Salina; F. Snchez; M. Santander; C. E. Santo; E. M. Santos; F. Sarazin; B. Sarkar; S. Sarkar; R. Sato; N. Scharf; V. Scherini; H. Schieler; P. Schiffer; A. Schmidt; F. Schmidt; T. Schmidt; O. Scholten; H. Schoorlemmer; J. Schovancova

2011-01-01

209

Do cosmic rays drive jets?  

E-print Network

A sudden release of high energy cosmic rays at the centre of a wind sustaining a spiral magnetic field produces cavities of low density and low magnetic field along the axis. The trajectories of high energy cosmic rays are focussed onto the axis, and lower energy cosmic rays and thermal plasma can escape through the cavities. This may explain the jets often seen in accretion systems and elsewhere.

A. R. Bell

2005-07-21

210

Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory  

Microsoft Academic Search

The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies $E>E_{th}=5.5\\\\times 10^{19}$ eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at $E>E_{th}$ are heavy nuclei with charge $Z$,

P. Abreu; M. Aglietta; E. J. Ahn; I. F. M. Albuquerque; D. Allard; I. Allekotte; J. Allen; P. Allison; J. Alvarez Castillo; J. Alvarez-Muiz; M. Ambrosio; A. Aminaei; L. Anchordoqui; S. Andringa; T. Anticic; A. Anzalone; C. Aramo; E. Arganda; F. Arqueros; H. Asorey; P. Assis; J. Aublin; M. Avenier; G. Avila; T. Bcker; M. Balzer; K. B. Barber; A. F. Barbosa; R. Bardenet; S. L. C. Barroso; B. Baughman; J. Buml; J. J. Beatty; B. R. Becker; K. H. Becker; A. Belltoile; J. A. Bellido; S. BenZvi; C. Berat; X. Bertou; P. L. Biermann; P. Billoir; F. Blanco; M. Blanco; C. Bleve; H. Blmer; M. Bohcov; D. Boncioli; C. Bonifazi; R. Bonino; N. Borodai; J. Brack; P. Brogueira; W. C. Brown; R. Bruijn; P. Buchholz; A. Bueno; R. E. Burton; K. S. Caballero-Mora; L. Caramete; R. Caruso; A. Castellina; O. Catalano; G. Cataldi; L. Cazon; R. Cester; J. Chauvin; S. H. Cheng; A. Chiavassa; J. A. Chinellato; A. Chou; J. Chudoba; R. W. Clay; M. R. Coluccia; R. Conceio; F. Contreras; H. Cook; M. J. Cooper; J. Coppens; A. Cordier; U. Cotti; S. Coutu; C. E. Covault; A. Creusot; A. Criss; J. Cronin; A. Curutiu; S. Dagoret-Campagne; R. Dallier; S. Dasso; K. Daumiller; B. R. Dawson; R. M. de Almeida; M. De Domenico; C. De Donato; S. J. de Jong; G. De La Vega; W. J. M. de Mello Junior; I. De Mitri; V. de Souza; K. D. de Vries; G. Decerprit; L. del Peral; O. Deligny; H. Dembinski; N. Dhital; C. Di Giulio; J. C. Diaz; M. L. Daz Castro; P. N. Diep; C. Dobrigkeit; W. Docters; J. C. D'Olivo; P. N. Dong; A. Dorofeev; J. C. dos Anjos; M. T. Dova; D. D'Urso; I. Dutan; J. Ebr; R. Engel; M. Erdmann; C. O. Escobar; A. Etchegoyen; P. Facal San Luis; I. Fajardo Tapia; H. Falcke; G. Farrar; A. C. Fauth; N. Fazzini; A. P. Ferguson; A. Ferrero; B. Fick; A. Filevich; A. Filipcic; S. Fliescher; C. E. Fracchiolla; E. D. Fraenkel; U. Frhlich; B. Fuchs; R. Gaior; R. F. Gamarra; S. Gambetta; B. Garca; D. Garca Gmez; D. Garcia-Pinto; A. Gascon; H. Gemmeke; K. Gesterling; P. L. Ghia; U. Giaccari; M. Giller; H. Glass; M. S. Gold; G. Golup; F. Gomez Albarracin; M. Gmez Berisso; P. Gonalves; D. Gonzalez; J. G. Gonzalez; B. Gookin; D. Gra; A. Gorgi; P. Gouffon; S. R. Gozzini; E. Grashorn; S. Grebe; N. Griffith; M. Grigat; A. F. Grillo; Y. Guardincerri; F. Guarino; G. P. Guedes; A. Guzman; J. D. Hague; P. Hansen; D. Harari; S. Harmsma; J. L. Harton; A. Haungs; T. Hebbeker; D. Heck; A. E. Herve; C. Hojvat; N. Hollon; V. C. Holmes; P. Homola; J. R. Hrandel; A. Horneffer; M. Hrabovsk; T. Huege; A. Insolia; F. Ionita; A. Italiano; C. Jarne; S. Jiraskova; K. Kadija; K. H. Kampert; P. Karhan; P. Kasper; B. Kgl; B. Keilhauer; A. Keivani; J. L. Kelley; E. Kemp; R. M. Kieckhafer; H. O. Klages; M. Kleifges; J. Kleinfeller; J. Knapp; D.-H. Koang; K. Kotera; N. Krohm; O. Krmer; D. Kruppke-Hansen; F. Kuehn; D. Kuempel; J. K. Kulbartz; N. Kunka; G. La Rosa; C. Lachaud; P. Lautridou; M. S. A. B. Leo; D. Lebrun; P. Lebrun; M. A. Leigui de Oliveira; A. Lemiere; A. Letessier-Selvon; I. Lhenry-Yvon; K. Link R. Lpez; A. Lopez Agera; K. Louedec; J. Lozano Bahilo; A. Lucero; M. Ludwig; H. Lyberis; M. C. Maccarone; C. Macolino; S. Maldera; D. Mandat; P. Mantsch; A. G. Mariazzi; J. Marin; V. Marin; I. C. Maris; H. R. Marquez Falcon; G. Marsella; D. Martello; L. Martin; H. Martinez; O. Martnez Bravo; H. J. Mathes; J. Matthews; G. Matthiae; D. Maurizio; P. O. Mazur; G. Medina-Tanco; M. Melissas; D. Melo; E. Menichetti; A. Menshikov; P. Mertsch; C. Meurer; S. Micanovic; M. I. Micheletti; W. Miller; L. Miramonti; S. Mollerach; M. Monasor; D. Monnier Ragaigne; F. Montanet; B. Morales; C. Morello; E. Moreno; J. C. Moreno; C. Morris; M. Mostaf; C. A. Moura; S. Mueller; M. A. Muller; G. Mller; M. Mnchmeyer; R. Mussa; G. Navarra; J. L. Navarro; S. Navas; P. Necesal; L. Nellen; A. Nelles; P. T. Nhung; L. Niemietz; N. Nierstenhoefer; D. Nitz; D. Nosek; L. Nozka; M. Nyklicek; J. Oehlschlger; A. Olinto; P. Oliva; V. M. Olmos-Gilbaja; M. Ortiz; N. Pacheco; D. Pakk Selmi-Dei; M. Palatka; J. Pallotta; N. Palmieri; G. Parente; E. Parizot; A. Parra; R. D. Parsons; S. Pastor; T. Paul; M. Pech; J. Pekala; R. Pelayo; I. M. Pepe; L. Perrone; R. Pesce; E. Petermann; S. Petrera; P. Petrinca; A. Petrolini; Y. Petrov; J. Petrovic; C. Pfendner; N. Phan; R. Piegaia; T. Pierog; P. Pieroni; M. Pimenta; V. Pirronello; M. Platino; V. H. Ponce; M. Pontz; P. Privitera; M. Prouza; E. J. Quel; S. Querchfeld; J. Rautenberg; O. Ravel; D. Ravignani; B. Revenu; J. Ridky; S. Riggi; M. Risse; P. Ristori; H. Rivera; V. Rizi; J. Roberts; C. Robledo; W. Rodrigues de Carvalho; G. Rodriguez; J. Rodriguez Martino; J. Rodriguez Rojo; I. Rodriguez-Cabo; M. D. Rodrguez-Fras; G. Ros; J. Rosado; T. Rossler; M. Roth; B. Rouill-d'Orfeuil; E. Roulet; A. C. Rovero; C. Rhle; F. Salamida; H. Salazar; G. Salina

2011-01-01

211

The NUCLEON space experiment for direct high energy cosmic rays investigation in TeV-PeV energy range  

NASA Astrophysics Data System (ADS)

The NUCLEON satellite experiment is designed to investigate directly, above the atmosphere, the energy spectra of cosmic-ray nuclei and the chemical composition from 100 GeV to 1000 TeV as well as the cosmic-ray electron spectrum from 20 GeV to 3 TeV. NUCLEON is planned to be launched in 2014. This mission is aimed at clarifying the essential details of cosmic-ray origin in this energy interval: number and types of sources, identification of actual nearby sources, and the investigation of the mechanisms responsible for the knee. Specific features of the NUCLEON instrument are relatively small thickness and small weight. A special method of energy determination by the silicon tracker was developed for this case. In this paper we describe a design of the instrument and the results of accelerator beam tests in terms of charge and energy resolution. The overall evidences of the capability of the apparatus to achieve the declared aims are also presented.

Atkin, E.; Bulatov, V.; Dorokhov, V.; Gorbunov, N.; Filippov, S.; Grebenyuk, V.; Karmanov, D.; Kovalev, I.; Kudryashov, I.; Merkin, M.; Pakhomov, A.; Podorozhny, D.; Polkov, D.; Porokhovoy, S.; Shumikhin, V.; Sveshnikova, L.; Tkachenko, A.; Tkachev, L.; Turundaevskiy, A.; Vasiliev, O.; Voronin, A.

2015-01-01

212

High-energy X-Ray Detection of G359.89-0.08 (Sgr A-E): Magnetic Flux Tube Emission Powered by Cosmic Rays?  

NASA Astrophysics Data System (ADS)

We report the first detection of high-energy X-ray (E > 10 keV) emission from the Galactic center non-thermal filament G359.89-0.08 (Sgr A-E) using data acquired with the Nuclear Spectroscopic Telescope Array (NuSTAR). The bright filament was detected up to ~50 keV during a NuSTAR Galactic center monitoring campaign. The featureless power-law spectrum with a photon index ? ? 2.3 confirms a non-thermal emission mechanism. The observed flux in the 3-79 keV band is FX = (2.0 0.1) 10-12 erg cm-2 s-1, corresponding to an unabsorbed X-ray luminosity LX = (2.6 0.8) 1034 erg s-1 assuming a distance of 8.0 kpc. Based on theoretical predictions and observations, we conclude that Sgr A-E is unlikely to be a pulsar wind nebula (PWN) or supernova remnant-molecular cloud (SNR-MC) interaction, as previously hypothesized. Instead, the emission could be due to a magnetic flux tube which traps TeV electrons. We propose two possible TeV electron sources: old PWNe (up to ~100 kyr) with low surface brightness and radii up to ~30 pc or MCs illuminated by cosmic rays (CRs) from CR accelerators such as SNRs or Sgr A*.

Zhang, Shuo; Hailey, Charles J.; Baganoff, Frederick K.; Bauer, Franz E.; Boggs, Steven E.; Craig, William W.; Christensen, Finn E.; Gotthelf, Eric V.; Harrison, Fiona A.; Mori, Kaya; Nynka, Melania; Stern, Daniel; Tomsick, John A.; Zhang, William W.

2014-03-01

213

High-Energy X-Ray Detection of G359.89-0.08 (SGR A-E): Magnetic Flux Tube Emission Powered by Cosmic Rays?  

NASA Technical Reports Server (NTRS)

We report the first detection of high-energy X-ray (E (is) greater than 10 keV) emission from the Galactic center non-thermal filament G359.89-0.08 (Sgr A-E) using data acquired with the Nuclear Spectroscopic Telescope Array (NuSTAR). The bright filament was detected up to approximately 50 keV during a NuSTAR Galactic center monitoring campaign. The featureless power-law spectrum with a photon index gamma approximately equals 2.3 confirms a non-thermal emission mechanism. The observed flux in the 3-79 keV band is F(sub X) = (2.0 +/- 0.1) 10(exp -12)erg cm(-2) s(-1) , corresponding to an unabsorbed X-ray luminosity L(sub X) = (2.6+/-0.8)10(exp 34) erg s(-1) assuming a distance of 8.0 kpc. Based on theoretical predictions and observations, we conclude that Sgr A-E is unlikely to be a pulsar wind nebula (PWN) or supernova remnant-molecular cloud (SNR-MC) interaction, as previously hypothesized. Instead, the emission could be due to a magnetic flux tube which traps TeV electrons. We propose two possible TeV electron sources: old PWNe (up to (is) approximately 100 kyr) with low surface brightness and radii up to (is) approximately 30 pc or MCs illuminated by cosmic rays (CRs) from CR accelerators such as SNRs or Sgr A*.

Zhang, Shuo; Hailey, Charles J.; Baganoff, Frederick K.; Bauer, Franz E.; Boggs, Steven E.; Craig, William W.; Christensen, Finn E.; Gotthelf, Eric V.; Harrison, Fiona A.; Mori, Kaya; Nynka, Melania; Stern, Daniel; Tomsick, John A; Zhang, Will

2014-01-01

214

Cosmic absorption of ultra high energy particles  

E-print Network

This paper summarizes the limits on propagation of ultra high energy particles in the Universe, set up by their interactions with cosmic background of photons and neutrinos. By taking into account cosmic evolution of these backgrounds and considering appropriate interactions we derive the mean free path for ultra high energy photons, protons and neutrinos. For photons the relevant processes are the Breit-Wheeler process as well as the double pair production process. For protons the relevant reactions are the photopion production and the Bethe-Heitler process. We discuss the interplay between the energy loss length and mean free path for the Bethe-Heitler process. Neutrino opacity is determined by its scattering off the cosmic background neutrino. We compute for the first time the high energy neutrino horizon as a function of its energy.

Ruffini, R; Xue, S -S

2015-01-01

215

Cosmic Ray Dosimetry  

NASA Astrophysics Data System (ADS)

Radiation levels at aircraft cruising altitudes are twenty times higher than at sea level. Thus, on average, a typical airline pilot receives a larger annual radiation dose than some one working in nuclear industry. The main source of this radiation is from galactic cosmic radiation, high energy particles generated by exploding stars within our own galaxy. In this work we study cosmic rays dosimetry at various aviation altitudes using the PARMA model.

Si Belkhir, F.; Attallah, R.

2010-10-01

216

Fermi LAT Observation of Diffuse Gamma Rays Produced Through Interactions Between Local Interstellar Matter and High-energy Cosmic Rays  

Microsoft Academic Search

Observations by the Large Area Telescope (LAT) on the Fermi mission of diffuse gamma-rays in a mid-latitude region in the third quadrant (Galactic longitude l from 200 to 260 and latitude |b| from 22 to 60) are reported. The region contains no known large molecular cloud and most of the atomic hydrogen is within 1 kpc of the solar system.

A. A. Abdo; M. Ackermann; M. Ajello; W. B. Atwood; M. Axelsson; L. Baldini; J. Ballet; G. Barbiellini; D. Bastieri; B. M. Baughman; K. Bechtol; R. Bellazzini; B. Berenji; E. D. Bloom; E. Bonamente; A. W. Borgland; J. Bregeon; A. Brez; M. Brigida; P. Bruel; T. H. Burnett; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; P. Carlson; J. M. Casandjian; C. Cecchi; . elik; A. Chekhtman; C. C. Cheung; S. Ciprini; R. Claus; J. Cohen-Tanugi; J. Conrad; S. Cutini; C. D. Dermer; A. de Angelis; F. de Palma; S. W. Digel; E. do Couto e. Silva; P. S. Drell; R. Dubois; D. Dumora; C. Farnier; C. Favuzzi; S. J. Fegan; W. B. Focke; M. Frailis; Y. Fukazawa; S. Funk; P. Fusco; F. Gargano; D. Gasparrini; N. Gehrels; S. Germani; B. Giebels; N. Giglietto; F. Giordano; T. Glanzman; G. Godfrey; I. A. Grenier; M.-H. Grondin; J. E. Grove; L. Guillemot; S. Guiriec; Y. Hanabata; A. K. Harding; M. Hayashida; E. Hays; R. E. Hughes; G. Jhannesson; A. S. Johnson; R. P. Johnson; W. N. Johnson; T. Kamae; H. Katagiri; N. Kawai; M. Kerr; J. Kndlseder; M. L. Kocian; F. Kuehn; M. Kuss; J. Lande; L. Latronico; M. Lemoine-Goumard; F. Longo; F. Loparco; B. Lott; M. N. Lovellette; P. Lubrano; A. Makeev; M. N. Mazziotta; J. E. McEnery; C. Meurer; P. F. Michelson; W. Mitthumsiri; T. Mizuno; A. A. Moiseev; C. Monte; M. E. Monzani; A. Morselli; I. V. Moskalenko; S. Murgia; P. L. Nolan; J. P. Norris; E. Nuss; T. Ohsugi; A. Okumura; N. Omodei; E. Orlando; J. F. Ormes; M. Ozaki; D. Paneque; J. H. Panetta; D. Parent; M. Pepe; M. Pesce-Rollins; F. Piron; M. Pohl; T. A. Porter; S. Rain; R. Rando; M. Razzano; A. Reimer; O. Reimer; T. Reposeur; S. Ritz; L. S. Rochester; A. Y. Rodriguez; F. Ryde; H. F.-W. Sadrozinski; D. Sanchez; A. Sander; P. M. Saz Parkinson; T. L. Schalk; A. Sellerholm; C. Sgr; D. A. Smith; P. D. Smith; G. Spandre; P. Spinelli; J.-L. Starck; F. W. Stecker; M. S. Strickman; A. W. Strong; D. J. Suson; H. Tajima; H. Takahashi; T. Takahashi; T. Tanaka; J. B. Thayer; J. G. Thayer; D. J. Thompson; L. Tibaldo; D. F. Torres; G. Tosti; A. Tramacere; Y. Uchiyama; T. L. Usher; V. Vasileiou; N. Vilchez; V. Vitale; A. P. Waite; P. Wang; B. L. Winer; K. S. Wood; T. Ylinen; M. Ziegler

2009-01-01

217

PHYSICS OF OUR DAYS Physical conditions in potential accelerators of ultra-high-energy cosmic rays: updated Hillas plot and radiation-loss constraints  

NASA Astrophysics Data System (ADS)

We review basic constraints on the acceleration of ultra-high-energy (UHE) cosmic rays (CRs) in astrophysical sources, namely, the geometric (Hillas) criterion and the restrictions from radiation losses in different acceleration regimes. Using the latest available astrophysical data, we redraw the Hillas plot and find potential UHECR accelerators. For the acceleration in the central engines of active galactic nuclei, we constrain the maximal UHECR energy for a given black hole mass. Among active galaxies, only the most powerful ones, radio galaxies and blazars, are able to accelerate protons to UHE, although acceleration of heavier nuclei is possible in much more abundant lower-power Seyfert galaxies.

Ptitsyna, Kseniya V.; Troitsky, Sergei V.

2010-10-01

218

Observation of the Ankle and Evidence for a High-Energy Break in the Cosmic Ray Spectrum  

E-print Network

We have measured the cosmic ray spectrum at energies above $10^{17}$ eV using the two air fluorescence detectors of the High Resolution Fly's Eye experiment operating in monocular mode. We describe the detector, PMT and atmospheric calibrations, and the analysis techniques for the two detectors. We fit the spectrum to models describing galactic and extragalactic sources. Our measured spectrum gives an observation of a feature known as the ``ankle'' near $3\\times 10^{18}$ eV, and strong evidence for a suppression near $6\\times 10^{19}$ eV.

The High Resolution Fly's Eye Collaboration

2005-06-07

219

Diffuse fluxes of cosmic high-energy neutrinos  

NASA Technical Reports Server (NTRS)

Production spectra of high-energy neutrinos from galactic cosmic-ray interactions with interstellar gas and extragalactic ultrahigh-energy cosmic-ray interactions with microwave blackbody photons are presented and discussed. These production processes involve the decay of charged pions and are thus related to the production of cosmic gamma rays from the decay of neutral pions. Estimates of the neutrino fluxes from various diffuse cosmic sources are then made, and the reasons for significant differences with previous estimates are discussed. Small predicted event rates for a DUMAND (deep underwater muon and neutrino detector) type detection system, combined with a possible significant flux of prompt neutrinos from the atmosphere above 50 TeV, may make the study of diffuse extraterrestrial neutrinos more difficult than previously thought.

Stecker, F. W.

1979-01-01

220

26. Cosmic rays 1 26. COSMIC RAYS  

E-print Network

26. Cosmic rays 1 26. COSMIC RAYS Revised August 2011 by J.J. Beatty (Ohio State Univ.) and J or longer. Technically, "primary" cosmic rays are those particles accelerated at astrophysical sources decelerates and partially excludes the lower energy galactic cosmic rays from the inner solar system

221

24. Cosmic rays 1 24. COSMIC RAYS  

E-print Network

24. Cosmic rays 1 24. COSMIC RAYS Revised August 2011 by J.J. Beatty (Ohio State Univ.) and J or longer. Technically, "primary" cosmic rays are those particles accelerated at astrophysical sources decelerates and partially excludes the lower energy galactic cosmic rays from the inner solar system

222

24. Cosmic rays 1 24. COSMIC RAYS  

E-print Network

24. Cosmic rays 1 24. COSMIC RAYS Revised August 2009 by T.K. Gaisser and T. Stanev (Bartol or longer. Technically, "primary" cosmic rays are those particles accelerated at astrophysical sources decelerates and partially excludes the lower energy galactic cosmic rays from the inner solar system

223

Very High-Energy Gamma-Ray Sources.  

ERIC Educational Resources Information Center

Discusses topics related to high-energy, gamma-ray astronomy (including cosmic radiation, gamma-ray detectors, high-energy gamma-ray sources, and others). Also considers motivation for the development of this field, the principal results to date, and future prospects. (JN)

Weekes, Trevor C.

1986-01-01

224

Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory  

DOE PAGESBeta

The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > Eth = 5.5 x 1019 eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > Eth are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above Eth/Z (for illustrative values of Z = 6,13,26). If the anisotropies above Eth are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.

Abreu, P [Lisbon, IST; Aglietta, M [IFSI, Turin; Ahn, E J [Fermilab; Albuquerque, I F.M. [Sao Paulo U.; Allard, D [APC, Paris; Allekotte, I [Centro Atomico Bariloche; Allen, J [New York U.; Allison, P [Ohio State U.; Alvarez Castillo, J [Mexico U., ICN; Alvarez-Muniz, J [Santiago de Compostela U.; Ambrosio, M [Napoli Seconda U.; INFN, Naples; Nijmegen U., IMAPP

2011-06-17

225

North-south asymmetry for high-energy cosmic-ray electrons measured with the PAMELA experiment  

SciTech Connect

The north-south asymmetry for cosmic-ray particles was measured with one instrument of the PAMELA satellite-borne experiment in the period June 2006-May 2009. The analysis has been performed by two independent methods: by comparing the count rates in regions with identical geomagnetic conditions and by comparing the experimental distribution of particle directions with the simulated distribution that would be in the case of an isotropic particle flux. The dependences of the asymmetry on energy release in the PAMELA calorimeter and on time have been constructed. The asymmetry (N{sub n} - N{sub s})/(N{sub n} + N{sub s}) is 0.06 {+-} 0.004 at the threshold energy release in the calorimeter and gradually decreases with increasing energy release. The observed effect is shown to be produced by electrons in the energy range 10-100 GeV.

Karelin, A. V., E-mail: karelin@hotbox.ru ['MEPhI' National Research Nuclear University (Russian Federation); Adriani, O. [Structure of Florence and Physics Department of University of Florence, INFN (Italy)] [Structure of Florence and Physics Department of University of Florence, INFN (Italy); Barbarino, G. C. [Structure of Naples and Physics Department of University of Naples, INFN (Italy)] [Structure of Naples and Physics Department of University of Naples, INFN (Italy); Bazilevskaya, G. A. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation); Bellotti, R. [Structure of Bari and Physics Department of University of Bari, INFN (Italy)] [Structure of Bari and Physics Department of University of Bari, INFN (Italy); Boezio, M. [Structure of Trieste and Physics Department of University of Trieste, INFN (Italy)] [Structure of Trieste and Physics Department of University of Trieste, INFN (Italy); Bogomolov, E. A. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)] [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Bonechi, L.; Bongi, M. [Structure of Florence and Physics Department of University of Florence, INFN (Italy)] [Structure of Florence and Physics Department of University of Florence, INFN (Italy); Bonvicini, V. [Structure of Trieste and Physics Department of University of Trieste, INFN (Italy)] [Structure of Trieste and Physics Department of University of Trieste, INFN (Italy); Bottai, S. [Structure of Florence and Physics Department of University of Florence, INFN (Italy)] [Structure of Florence and Physics Department of University of Florence, INFN (Italy); Bruno, A. [Structure of Bari and Physics Department of University of Bari, INFN (Italy)] [Structure of Bari and Physics Department of University of Bari, INFN (Italy); Vacchi, A. [Structure of Trieste and Physics Department of University of Trieste, INFN (Italy)] [Structure of Trieste and Physics Department of University of Trieste, INFN (Italy); Vannuccini, E. [Structure of Florence and Physics Department of University of Florence, INFN (Italy)] [Structure of Florence and Physics Department of University of Florence, INFN (Italy); Vasilyev, G. I. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)] [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Voronov, S. A.; Galper, A. M.; Danilchenko, I. A. ['MEPhI' National Research Nuclear University (Russian Federation)] ['MEPhI' National Research Nuclear University (Russian Federation); Donato, C. De; Santis, C. De [Structure of Rome Tor Vergata and Physics Department of University of Rome Tor Vergata, INFN (Italy)] [Structure of Rome Tor Vergata and Physics Department of University of Rome Tor Vergata, INFN (Italy); and others

2013-08-15

226

Very High Energy Gamma-Ray Astronomy  

E-print Network

We present a review of the current status of very high energy gamma-ray astronomy. The development of the atmospheric Cherenkov imaging technique for ground-based gamma-ray astronomy has led to a rapid growth in the number of observatories. The detection of TeV gamma rays from Active Galactic Nuclei was unexpected and is providing new insights into the emission mechanisms in the jets. Next generation telescopes are under construction and will increase dramatically the knowledge available at this extreme end of the cosmic electromagnetic spectrum.

Michael Catanese; Trevor C. Weekes

1999-06-30

227

High-energy gamma-ray astronomy  

NASA Technical Reports Server (NTRS)

The subject of gamma-ray astronomy is discussed with emphasis on celestial gamma rays with energies in excess of 10 MeV. Early observations of such gamma rays are reviewed, a gamma-ray spark-chamber telescope is described together with a gas Cerenkov-counter telescope, and the gamma-ray sky is delineated. It is shown that the diffuse high-energy gamma radiation from the galactic plane probably results primarily from cosmic-ray interactions with interstellar matter. Mechanisms for gamma-ray production are identified, and it is noted that the general galactic radiation may prove to be of great value in studies of galactic structure. Possible sources are considered for the diffuse celestial radiation, and discrete sources are described, including the Crab pulsar, the Vela remnant, the Cygnus region, and Gould's Belt. Future developments in gamma-ray astronomy are considered.

Fichtel, C.; Kniffen, D.; Greisen, K.

1975-01-01

228

Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory  

SciTech Connect

The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > Eth = 5.5 x 1019 eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > Eth are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above Eth/Z (for illustrative values of Z = 6,13,26). If the anisotropies above Eth are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.

Abreu, P [Lisbon, IST; Aglietta, M [IFSI, Turin; Ahn, E J [Fermilab; Albuquerque, I F.M. [Sao Paulo U.; Allard, D [APC, Paris; Allekotte, I [Centro Atomico Bariloche; Allen, J [New York U.; Allison, P [Ohio State U.; Alvarez Castillo, J [Mexico U., ICN; Alvarez-Muniz, J [Santiago de Compostela U.; Ambrosio, M [Napoli Seconda U.; INFN, Naples; Nijmegen U., IMAPP

2011-06-17

229

The correlations between BL Lacs and ultra-high-energy cosmic rays deflected by using different GMF models  

E-print Network

Some studies suggested that a correlation between locations of BL Lacertae objects (BL Lacs) and the arrival directions of the ultrahigh energy cosmic rays (UHECRs) exists. Especially by assuming the primary particles charged +1 and using a galactic magnetic field (GMF) model to calculate the deflections of the UHECRs, the significance of correlation is improved. We construct a new GMF model by incorporating all progresses in the GMF measurements in recent years. Based on a thorough study of the deflections of the UHECRs measured by the AGASA experiment, we study the GFM model dependence of the correlation between the UHECRs and the selected BL Lacs using the new model together with others. It turns out that only specific one of those GMF models makes the correlation significant, even if neither GMF models themselves nor deflections of the UHECRs are not significantly different. It suggests that the significance of the correlation, calculated using a method suggested in those studies, is intensively depending on the GMF model. Great improvement in statistics may help to suppress the sensitivity to the GMF models.

Zhen Cao; Ben Zhong Dai; Jian Ping Yang; Li Zhang

2006-02-26

230

A METHOD TO SEARCH FOR CORRELATIONS OF ULTRA-HIGH ENERGY COSMIC-RAY MASSES WITH THE LARGE-SCALE STRUCTURES IN THE LOCAL GALAXY DENSITY FIELD  

SciTech Connect

One of the main goals of investigations using present and future giant extensive air shower (EAS) arrays is the mass composition of ultra-high energy cosmic rays (UHECRs). A new approach to the problem is presented, combining the analysis of arrival directions with the statistical test of the paired EAS samples. One of the ideas of the method is to search for possible correlations between UHECR masses and their separate sources; for instance, if there are two sources in different areas of the celestial sphere injecting different nuclei, but the fluxes are comparable so that arrival directions are isotropic, then the aim is to reveal a difference in the mass composition of cosmic-ray fluxes. The method is based on a non-parametric statistical test-the Wilcoxon signed-rank routine-which does not depend on the populations fitting any parameterized distributions. Two particular algorithms are proposed: first, using measurements of the depth of the EAS maximum position in the atmosphere; and second, relying on the age variance of air showers initiated by different primary particles. The formulated method is applied to the Yakutsk array data, in order to demonstrate the possibility of searching for a difference in average mass composition between the two UHECR sets, arriving particularly from the supergalactic plane and a complementary region.

Ivanov, A. A., E-mail: ivanov@ikfia.ysn.ru [Shafer Institute for Cosmophysical Research and Aeronomy, 31 Lenin Avenue, Yakutsk 677980 (Russian Federation)

2013-02-15

231

Detecting ultra-high energy cosmic rays from space with unprecedented acceptance: objectives and design of the JEM-EUSO mission  

NASA Astrophysics Data System (ADS)

The Extreme Universe Space Observatory on the Japanese Experiment Module (JEM-EUSO) of the International Space Station (ISS) is the first mission that will study from space Ultra High-Energy Cosmic Rays (UHECR). JEM-EUSO will observe Extensive Air Showers (EAS) produced by UHECRs traversing the Earth's atmosphere from above. For each event, the detector will make accurate measurements of the energy, arrival direction and nature of the primary particle using a target volume far greater than what is achievable from ground. The corresponding increase in statistics will help to clarify the origin and sources of UHECRs as well as the environment traversed during production and propagation. Possibly this will bring new light onto particle physics mechanisms operating at energies well beyond those achievable by man-made accelerators. The spectrum of scientific goals of the JEM-EUSO mission includes as exploratory objectives the detection of high-energy gamma rays and neutrinos, the study of cosmic magnetic fields, and tests of relativity and quantum gravity effects at extreme energies. In parallel JEM-EUSO will systematically perform observation of the surface of the Earth in the infra-red and ultra-violet ranges, studying also atmospheric phenomena (Transient Luminous Effects). The apparatus is a 2 t detector using Fresnel-based optics to focus the UV-light from EAS on a focal surface composed of about 6 000~multianode photomultipliers for a total of ~3 105 channels. A multi-layer parallel architecture has been devised to handle the data flow and select valid triggers, reducing it to a rate compatible with downlink constraints. Each processing level filters the event with increasingly complex algorithms using ASICs, FPGAs and DSPs in this order to reject spurious triggers and reduce the data rate.

Casolino, M.; Adams, J. H.; Bertaina, M. E.; Christl, M. J.; Ebisuzaki, T.; Gorodetzky, P.; Hachisu, Y.; Kajino, F.; Kawasaki, Y.; Medina-Tanco, G.; Miyamoto, H.; Ohomori, H.; Parizot, E.; Park, I.; Picozza, P.; Sakaki, N.; Santangelo, A.; Shinozaki, K.; Takizawa, Y.; Tsuno, K.; JEM-EUSO Collaboration

2011-10-01

232

Interacting Cosmic Rays with Molecular Clouds: A Bremsstrahlung Origin of Diffuse High-energy Emission from the Inner 21 of the Galactic Center  

NASA Astrophysics Data System (ADS)

The high-energy activity in the inner few degrees of the Galactic center is traced by diffuse radio, X-ray, and ?-ray emission. The physical relationship between different components of diffuse gas emitting at multiple wavelengths is a focus of this work. We first present radio continuum observations using the Green Bank Telescope and model the nonthermal spectrum in terms of a broken power-law distribution of ~GeV electrons emitting synchrotron radiation. We show that the emission detected by Fermi is primarily due to nonthermal bremsstrahlung produced by the population of synchrotron emitting electrons in the GeV energy range interacting with neutral gas. The extrapolation of the electron population measured from radio data to low and high energies can also explain the origin of Fe I 6.4 keV line and diffuse TeV emission, as observed with Suzaku, XMM-Newton, Chandra, and the H.E.S.S. observatories. The inferred physical quantities from modeling multiwavelength emission in the context of bremsstrahlung emission from the inner ~300 120 pc of the Galactic center are constrained to have the cosmic-ray ionization rate ~1-10 10-15 s-1, molecular gas heating rate elevating the gas temperature to 75-200 K, fractional ionization of molecular gas 10-6-10-5, large-scale magnetic field 10-20 ?G, the density of diffuse and dense molecular gas ~100 and ~103 cm-3 over 300 pc and 50 pc path lengths, and the variability of Fe I K? 6.4 keV line emission on yearly timescales. Important implications of our study are that GeV electrons emitting in radio can explain the GeV ?-rays detected by Fermi and that the cosmic-ray irradiation model, like the model of the X-ray irradiation triggered by past activity of Sgr A*, can also explain the origin of the variable 6.4 keV emission from Galactic center molecular clouds.

Yusef-Zadeh, F.; Hewitt, J. W.; Wardle, M.; Tatischeff, V.; Roberts, D. A.; Cotton, W.; Uchiyama, H.; Nobukawa, M.; Tsuru, T. G.; Heinke, C.; Royster, M.

2013-01-01

233

HIGH-ENERGY X-RAY DETECTION OF G359.890.08 (SGR AE): MAGNETIC FLUX TUBE EMISSION POWERED BY COSMIC RAYS?  

E-print Network

We report the first detection of high-energy X-ray (E > 10 keV) emission from the Galactic center non-thermal filament G359.890.08 (Sgr AE) using data acquired with the Nuclear Spectroscopic Telescope Array (NuSTAR). The ...

Zhang, Shuo

234

High energy gamma ray astronomy  

NASA Technical Reports Server (NTRS)

High energy gamma ray astronomy has evolved with the space age. Nonexistent twenty-five years ago, there is now a general sketch of the gamma ray sky which should develop into a detailed picture with the results expected to be forthcoming over the next decade. The galactic plane is the dominant feature of the gamma ray sky, the longitude and latitude distribution being generally correlated with galactic structural features including the spiral arms. Two molecular clouds were already seen. Two of the three strongest gamma ray sources are pulsars. The highly variable X-ray source Cygnus X-3 was seen at one time, but not another in the 100 MeV region, and it was also observed at very high energies. Beyond the Milky Way Galaxy, there is seen a diffuse radiation, whose origin remains uncertain, as well as at least one quasar, 3C 273. Looking to the future, the satellite opportunities for high energy gamma ray astronomy in the near term are the GAMMA-I planned to be launched in late 1987 and the Gamma Ray Observatory, scheduled for launch in 1990. The Gamma Ray Observatory will carry a total of four instruments covering the entire energy range from 30,000 eV to 3 x 10 to the 10th eV with over an order of magnitude increase in sensitivity relative to previous satellite instruments.

Fichtel, Carl E.

1987-01-01

235

Cosmic Rays from Cosmic Strings with Condensates  

E-print Network

We re-visit the production of cosmic rays by cusps on cosmic strings. If a scalar field (``Higgs'') has a linear interaction with the string world-sheet, such as would occur if there is a bosonic condensate on the string, cusps on string loops emit narrow beams of very high energy Higgses which then decay to give a flux of ultra high energy cosmic rays. The ultra-high energy flux and the gamma to proton ratio agree with observations if the string scale is $\\sim 10^{13}$ GeV. The diffuse gamma ray and proton fluxes are well below current bounds. Strings that are {\\it lighter} and have linear interactions with scalars produce an excess of direct and diffuse cosmic rays and are ruled out by observations, while heavier strings ($\\sim 10^{15}$ GeV) are constrained by their gravitational signatures. This leaves a narrow window of parameter space for the existence of cosmic strings with bosonic condensates.

Tanmay Vachaspati

2009-11-24

236

Cosmic Necklaces and Ultrahigh Energy Cosmic Rays  

SciTech Connect

Cosmic necklaces are hybrid topological defects consisting of monopoles and strings, with two strings attached to each monopole. We argue that the cosmological evolution of necklaces may significantly differ from that of cosmic strings. The typical velocity of necklaces can be much smaller than the speed of light, and the characteristic scale of the network much smaller than the horizon. We estimate the flux of high-energy protons produced by monopole annihilation in the decaying closed loops. For some reasonable values of the parameters it is comparable to the observed flux of ultrahigh-energy cosmic rays. {copyright} {ital 1997} {ital The American Physical Society}

Berezinsky, V. [INFN, Laboratori Nazionali del Gran Sasso, 67010 Assergi (Antarctica) (Italy)] [INFN, Laboratori Nazionali del Gran Sasso, 67010 Assergi (Antarctica) (Italy); Vilenkin, A. [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 (United States)] [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 (United States)

1997-12-01

237

Charge composition of high energy heavy primary cosmic ray nuclei. Ph.D. Thesis - Catholic Univ. of Am.  

NASA Technical Reports Server (NTRS)

A detailed study of the charge composition of primary cosmic radiation for about 5000 charged nuclei from neon to iron with energies greater than 1.16 GeV/nucleon is presented. Values are obtained after corrections were made for detector dependences, atmospheric attenuation, and solar modulation. New values of 38.5, 32.4, 23.7, and 16.8 g/sq cm for the attenuation mean free paths in air for the same charge groups are presented.

Price, R. D.

1974-01-01

238

Color Glass Condensate in Brane Models or Don't Ultra High Energy Cosmic Rays Probe $10^{15}eV$ Scale ?  

E-print Network

In a previous work hep-ph/0203165 we have studied propagation of relativistic particles in the bulk for some of most popular brane models. Constraints have been put on the parameter space of these models by calculating the time delay due to propagation in the bulk of particles created during the interaction of Ultra High Energy Cosmic Rays with protons in the terrestrial atmosphere. The question was however raised that probability of hard processes in which bulk modes can be produced is small and consequently, the tiny flux of UHECRs can not constrain brane models. Here we use Color Glass Condensate (CGC) model to show that effects of extra dimensions are visible not only in hard processes when the incoming particle hits a massive Kaluza-Klein mode but also through the modification of soft/semi-hard parton distribution. At classical level, for an observer in the CM frame of UHECR and atmospheric hadrons, color charge sources are contracted to a thin sheet with a width inversely proportional to the energy of the ultra energetic cosmic ray hadron and consequently they can see an extra dimension with comparable size. Due to QCD interaction a short life swarm of partons is produced in front of the sheet and its partons can penetrate to the extra-dimension bulk. This reduces the effective density of partons on the brane or in a classical view creates a delay in the arrival of the most energetic particles if they are reflected back due to the warping of the bulk. In CGC approximation the density of swarm at different distance from the classical sheet can be related and therefore it is possible (at least formally) to determine the relative fraction of partons in the bulk and on the brane at different scales. Results of this work are also relevant to the test of brane models in hadron colliders like LHC.

Houri Ziaeepour

2006-03-16

239

The Origin of Cosmic Rays  

ScienceCinema

Cosmic Rays reach the Earth from space with energies of up to more than 1020 eV, carrying information on the most powerful particle accelerators that Nature has been able to assemble. Understanding where and how cosmic rays originate has required almost one century of investigations, and, although the last word is not written yet, recent observations and theory seem now to fit together to provide us with a global picture of the origin of cosmic rays of unprecedented clarity. Here we will describe what we learned from recent observations of astrophysical sources (such as supernova remnants and active galaxies) and we will illustrate what these observations tell us about the physics of particle acceleration and transport. We will also discuss the ?end? of the Galactic cosmic ray spectrum, which bridges out attention towards the so called ultra high energy cosmic rays (UHECRs). At ~1020 eV the gyration scale of cosmic rays in cosmic magnetic fields becomes large enough to allow us to point back to their sources, thereby allowing us to perform ?cosmic ray astronomy?, as confirmed by the recent results obtained with the Pierre Auger Observatory. We will discuss the implications of these observations for the understanding of UHECRs, as well as some questions which will likely remain unanswered and will be the target of the next generation of cosmic ray experiments.

Pasquale Blasi

2010-01-08

240

The Origin of Cosmic Rays  

SciTech Connect

Cosmic Rays reach the Earth from space with energies of up to more than 1020 eV, carrying information on the most powerful particle accelerators that Nature has been able to assemble. Understanding where and how cosmic rays originate has required almost one century of investigations, and, although the last word is not written yet, recent observations and theory seem now to fit together to provide us with a global picture of the origin of cosmic rays of unprecedented clarity. Here we will describe what we learned from recent observations of astrophysical sources (such as supernova remnants and active galaxies) and we will illustrate what these observations tell us about the physics of particle acceleration and transport. We will also discuss the end of the Galactic cosmic ray spectrum, which bridges out attention towards the so called ultra high energy cosmic rays (UHECRs). At ~1020 eV the gyration scale of cosmic rays in cosmic magnetic fields becomes large enough to allow us to point back to their sources, thereby allowing us to perform cosmic ray astronomy, as confirmed by the recent results obtained with the Pierre Auger Observatory. We will discuss the implications of these observations for the understanding of UHECRs, as well as some questions which will likely remain unanswered and will be the target of the next generation of cosmic ray experiments.

Pasquale Blasi

2008-02-20

241

Introduction to Cosmic Rays  

E-print Network

Energetic particles, traditionally called Cosmic Rays, were discovered nearly a hundred years ago, and their origin is still uncertain. Their main constituents are the normal nuclei as in the standard cosmic abundances of matter, with some enhancements for the heavier elements; there are also electrons, positrons and anti-protons, but no anti-nuclei. Today we also have information on isotopic abundances, which show some anomalies, as compared with the interstellar medium. The known spectrum extends over energies from a few hundred MeV to 3*10^{20} eV and shows few clear spectral signatures: There is a small spectral break near 5*10^{15} eV, the "knee", where the spectrum turns down; there is another spectral break near 3*10^{18} eV, the "ankle", where the spectrum turns up again. Up to the ankle the cosmic rays are usually interpreted as originating from Galactic supernova explosions; however, we do not know what the origin of the knee is. The particles beyond the ankle have to be extragalactic, it is usually assumed, because the Larmor radii in the Galactic magnetic field are too large; this argument could be overcome if those particles were very heavy nuclei as Fe, an idea which appears to be inconsistent, however, with the airshower data immediately above the energy of the ankle. Due to interaction with the cosmic microwave background there is a strong cut-off expected near 5*10^{19} eV, which is, however, not seen; The high energy cosmic rays beyond this "GZK-cutoff" (after its discoverers Greisen, Zatsepin and Kuzmin) are the challenge to interpret. We will describe the various approaches to understand the origin and physics of cosmic rays (abridged).

Peter Biermann; Guenter Sigl

2002-02-22

242

Dual Phase Cosmic Rays  

E-print Network

A calculation based on flat spacetime symmetries shows how there can be two quantum phases. For one, extreme phase change determines a conventional classical trajectory and four-momentum, i.e. mass times four-velocity. The other phase occurs in an effective particle state, with the effective energy and momentum being the rate of change of the phase with respect to time and distance. A cosmic ray proton moves along a classical trajectory, but exists in an effective particle state with an effective energy that depends on the local gravitational potential. Assumptions are made so that a cosmic ray proton in an ultra-high energy state detected near the Earth was in a much less energetic state in interstellar space. A 300 EeV proton incident on the Earth was a 2 PeV proton in interstellar space. The model predicts such protons are in states with even more energy near the Sun than when near the Earth.

Richard Shurtleff

2007-12-30

243

30TH INTERNATIONAL COSMIC RAY CONFERENCE A Search for Prompt Very High Energy Emission from Satellite-detected Gamma-  

E-print Network

would allow us to constrain GRB models. Since its launch, in late 2004, the Swift satellite has been Satellite-detected Gamma- ray Bursts using Milagro P. M. SAZ PARKINSON & B. L. DINGUS ¡ FOR THE MILAGRO, including 57 since the launch of Swift (through May 2007). We discuss the results of the searches for prompt

California at Santa Cruz, University of

244

Computational Modeling of the Class I Low-Mass Protostar Elias 29 Applying Optical Constants of Ices Processed By High Energy Cosmic Ray Analogs  

NASA Astrophysics Data System (ADS)

We present a study of the effects of high energy cosmic rays (CRs) over the astrophysical ices, observed toward the embedded class I protostar Elias 29, by using computational modeling and laboratory data. Its spectrum was observed with the Infrared Space Observatory (ISO) covering 2.3190 ?m. The modeling employed the three-dimensional Monte Carlo radiative transfer code RADMC-3D and laboratory data of bombarded ice grains by CR analogs and unprocessed ices (not bombarded). We are assuming that Elias 29 has a self-irradiated disk with inclination i = 60.0, surrounded by an envelope with a bipolar cavity. The results show that absorption features toward Elias 29 are better reproduced by assuming a combination between unprocessed astrophysical ices at low temperature (H2O, CO, CO2) and bombarded ices (H2O:CO2) by high energy CRs. Evidences of the ice processing around Elias 29 can be observed by the good fitting around 5.58.0 ?m, by polar and apolar ice segregation in 15.1515.25 ?m, and by the presence of the CH4 and HCOOH ices. Given that non-nitrogen compounds were employed in this work, we assume that absorption around 5.58.0 ?m should not be associated with the NH4+ ion (see the 2003 work of Shutte & Khanna ), but more probably with aliphatic ethers (e.g., R1-OCH2-R2), CH3CHO, and related species. The results obtained in this paper are important because they show that the environment around protostars is better modeled considering processed samples and, consequently, demonstrate the chemical evolution of the astrophysical ices.

Rocha, W. R. M.; Pilling, S.

2015-04-01

245

Very high energy gamma ray astronomy  

NASA Technical Reports Server (NTRS)

Recent results in ground based very high energy gamma ray astronomy are reviewed. The various modes of the atmospheric Cerenkov technique are described, and the importance of cosmic ray rejection methods is stressed. The positive detections of the Crab pulsar that suggest a very flat spectrum and time-variable pulse phase are discussed. Observations of other pulsars (particularly Vela) suggest these features may be general. Evidence that a 4.8 hr modulated effect was detected from Cyg X-3 is strengthened in that the exact period originally proposed agrees well with a recent determination of the X-ray period. The southern sky observations are reviewed, and the significance of the detection of an active galaxy (NGC 5128) is considered for source models and future observations.

Grindlay, J. E.

1976-01-01

246

Study of Ultra-High Energy Cosmic Ray composition using Telescope Array's Middle Drum detector and surface array in hybrid mode  

NASA Astrophysics Data System (ADS)

Previous measurements of the composition of Ultra-High Energy Cosmic Rays (UHECRs) made by the High Resolution Fly's Eye (HiRes) and Pierre Auger Observatory (PAO) are seemingly contradictory, but utilize different detection methods, as HiRes was a stereo detector and PAO is a hybrid detector. The five year Telescope Array (TA) Middle Drum hybrid composition measurement is similar in some, but not all, respects in methodology to PAO, and good agreement is evident between data and a light, largely protonic, composition when comparing the measurements to predictions obtained with the QGSJetII-03 and QGSJet-01c models. These models are also in agreement with previous HiRes stereo measurements, confirming the equivalence of the stereo and hybrid methods. The data is incompatible with a pure iron composition, for all models examined, over the available range of energies. The elongation rate and mean values of Xmax are in good agreement with Pierre Auger Observatory data. This analysis is presented using two methods: data cuts using simple geometrical variables and a new pattern recognition technique.

Abbasi, R. U.; Abe, M.; Abu-Zayyad, T.; Allen, M.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Chae, M. J.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, T.; Fukushima, M.; Goto, T.; Hanlon, W.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, J. H.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lim, S. I.; Lundquist, J. P.; Machida, K.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Mukai, Y.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nonaka, T.; Nozato, A.; Ogio, S.; Ogura, J.; Ohnishi, M.; Ohoka, H.; Oki, K.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Sampson, A. L.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Shin, H. S.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T.; Suzawa, T.; Takamura, M.; Takeda, M.; Takeishi, R.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Uchihori, Y.; Udo, S.; Urban, F.; Vasiloff, G.; Wong, T.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.

2015-04-01

247

CORRELATIONS OF THE ARRIVAL DIRECTIONS OF ULTRA-HIGH ENERGY COSMIC RAYS WITH EXTRAGALACTIC OBJECTS AS OBSERVED BY THE TELESCOPE ARRAY EXPERIMENT  

SciTech Connect

We search for correlations between the positions of extragalactic objects and the arrival directions of ultra-high energy cosmic rays (UHECRs) with primary energy E ? 40 EeV as observed by the surface detector array of the Telescope Array (TA) experiment during the first 40 months of operation. We examine several public astronomical object catalogs, including the Veron-Cetty and Veron catalog of active galactic nuclei. We count the number of TA events correlated with objects in each catalog as a function of three parameters: the maximum angular separation between a TA event and an object, the minimum energy of the events, and the maximum redshift of the objects. We determine the combination of these parameters that maximizes the correlations, and we calculate the probability of having the same levels of correlations from an isotropic distribution of UHECR arrival directions. No statistically significant correlations are found when penalties for scanning over the above parameters and for searching in several catalogs are taken into account.

Abu-Zayyad, T.; Allen, M.; Anderson, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Hanlon, W. [High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT (United States); Aida, R. [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu, Yamanashi (Japan); Azuma, R.; Fukuda, T. [Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo (Japan); Cheon, B. G.; Cho, E. J. [Department of Physics and The Research Institute of Natural Science, Hanyang University, Seongdong-gu, Seoul (Korea, Republic of); Chiba, J. [Department of Physics, Tokyo University of Science, Noda, Chiba (Japan); Chikawa, M. [Department of Physics, Kinki University, Higashi Osaka, Osaka (Japan); Cho, W. R. [Department of Physics, Yonsei University, Seodaemun-gu, Seoul (Korea, Republic of); Fujii, H. [Institute of Particle and Nuclear Studies, KEK, Tsukuba, Ibaraki (Japan); Fujii, T. [Graduate School of Science, Osaka City University, Osaka (Japan); Fukushima, M. [Institute for Cosmic Ray Research, University of Tokyo, Kashiwa, Chiba (Japan); and others

2013-11-10

248

Correlations of the Arrival Directions of Ultra-high Energy Cosmic Rays with Extragalactic Objects as Observed by the Telescope Array Experiment  

NASA Astrophysics Data System (ADS)

We search for correlations between the positions of extragalactic objects and the arrival directions of ultra-high energy cosmic rays (UHECRs) with primary energy E >= 40 EeV as observed by the surface detector array of the Telescope Array (TA) experiment during the first 40 months of operation. We examine several public astronomical object catalogs, including the Veron-Cetty and Veron catalog of active galactic nuclei. We count the number of TA events correlated with objects in each catalog as a function of three parameters: the maximum angular separation between a TA event and an object, the minimum energy of the events, and the maximum redshift of the objects. We determine the combination of these parameters that maximizes the correlations, and we calculate the probability of having the same levels of correlations from an isotropic distribution of UHECR arrival directions. No statistically significant correlations are found when penalties for scanning over the above parameters and for searching in several catalogs are taken into account.

Abu-Zayyad, T.; Aida, R.; Allen, M.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, E. J.; Cho, W. R.; Fujii, H.; Fujii, T.; Fukuda, T.; Fukushima, M.; Hanlon, W.; Hayashi, K.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Hiyama, K.; Honda, K.; Iguchi, T.; Ikeda, D.; Ikuta, K.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Iwamoto, S.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kanbe, T.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, H. K.; Kim, J. H.; Kim, J. H.; Kitamoto, K.; Kitamura, S.; Kitamura, Y.; Kobayashi, K.; Kobayashi, Y.; Kondo, Y.; Kuramoto, K.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lim, S. I.; Lundquist, J. P.; Machida, S.; Martens, K.; Matsuda, T.; Matsuura, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Miyata, K.; Murano, Y.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nam, S. W.; Nonaka, T.; Ogio, S.; Ohnishi, M.; Ohoka, H.; Oki, K.; Oku, D.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Roh, S. Y.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Sampson, A. L.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Shin, J. I.; Shirahama, T.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T.; Suzuki, S.; Takahashi, Y.; Takeda, M.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Tsuyuguchi, Y.; Uchihori, Y.; Udo, S.; Ukai, H.; Urban, F.; Vasiloff, G.; Wada, Y.; Wong, T.; Yamakawa, Y.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zhou, X.; Zollinger, R.; Zundel, Z.

2013-11-01

249

Seminar I b -1. letnik, II.stopnja High energy cosmic gamma  

E-print Network

are protons or light nuclei and less than 0.1% are gamma rays. In gamma-ray astronomy nearly all discoveriesSeminar I b - 1. letnik, II.stopnja High energy cosmic gamma rays detectors Author:Ursa Skerbis energy gamma rays, which came from outer space. In this seminar an apparatus for their detection

?umer, Slobodan

250

Cosmic Rays at the Knee  

E-print Network

Several kinds of measurements are combined in an attempt to obtain a consistent estimate of the spectrum and composition of the primary cosmic radiation through the knee region. Assuming that the knee is a signal of the high-energy end of a galactic cosmic-ray population, I discuss possible signatures of a transition to an extra-galactic population and how they might be detected.

Thomas K. Gaisser

2006-08-25

251

RECENT STATUS OF VERY HIGH ENERGY GAMMA RAY ASTRONOMY AND PROSPECTS  

E-print Network

RECENT STATUS OF VERY HIGH ENERGY GAMMA RAY ASTRONOMY AND PROSPECTS T. KIFUNE Institute for Cosmic@icrr.u-tokyo.ac.jp Gamma-rays, located at the highest energy band of electromagnetic radiation, is directly coupled in Table 1. Gamma-rays are a direct probe of cosmic high energy particles, the products of the non

Enomoto, Ryoji

252

Solar cosmic ray phenomena  

Microsoft Academic Search

This review attempts to present an integrated view of the several types of solar cosmic ray phenomena. The relevant large and small scale properties of the interplanetary medium are first surveyed, and their use in the development of a quantitative understanding of the cosmic ray propagation processes summarised. Solar cosmic ray events, in general, are classified into two phenomenological categories:

K. G. McCracken; U. R. Rao

1970-01-01

253

High Energy X-Ray Detection OF G359.89-0.08 (Sgr A-E): Magnetic Flux Tube Emission Powered By Cosmic Rays?  

E-print Network

We report the first detection of high-energy X-ray (E>10 keV) emission from the Galactic Center non-thermal filament G359.89-0.08 (Sgr A-E) using data acquired with the Nuclear Spectroscopic Telescope Array (NuSTAR). The bright filament was detected up to ~50 keV during a NuSTAR Galactic Center monitoring campaign. The featureless power-law spectrum with a photon index of ~2.3 confirms a non-thermal emission mechanism. The observed flux in the 3-79 keV band is ~ 2.0e-12 erg/cm^2/s, corresponding to an unabsorbed X-ray luminosity of ~2.6e34 erg/s assuming a distance of 8.0 kpc. Based on theoretical predictions and observations, we conclude that Sgr A-E is unlikely to be a pulsar wind nebula (PWN) or supernova remnant-molecular cloud (SNR-MC) interaction, as previously hypothesized. Instead, the emission could be due to a magnetic flux tube which traps TeV electrons. We propose two possible TeV electron sources: old PWNe (up to ~100 kyr) with low surface brightness and radii up to ~30 pc or molecular clouds (MC...

Zhang, Shuo; Baganoff, Frederick K; Bauer, Franz E; Boggs, Steven E; Craig, William W; Christensen, Finn E; Gotthelf, Eric V; Harrison, Fiona A; Mori, Kaya; Nynka, Melania; Stern, Daniel; Tomsick, John A; Zhang, William W

2014-01-01

254

Ultra-High Energy Cosmic Rays Detected by the Pierre Auger Observatory: First Direct Evidence, and its Implications, that a Subset Originate in Nearby Radiogalaxies  

E-print Network

(abridged) The Pierre Auger Collaboration has reported 27 Ultra-High Energy Cosmic Ray Events (UHECRs) with energies above 56 EeV and well determined arrival directions as of 2007 August 31. They find that the arrival directions are not isotropic, but instead appear correlated with the positions of nearby AGNs. Our aim was to determine the sources of these UHECRs by comparing their arrival directions with more comprehensive source catalogs. Four (eight) of the 27 UHECRs with energy >56EeV detected by the Pierre Auger Observatory have arrival directions within 1.5deg (3.5deg) of the extended (>180kpc) radio structures of nearby radiogalaxies or the single nearby BLLac with extended radio structure. Conversely the radio structures of three (six) of all ten nearest extended radiogalaxies are within 1.5deg (3.5deg) of a UHECR; three of the remaining four radiogalaxies are in directions with lower exposure times. This correlation between nearby extended radiogalaxies and a subset of UHECRs is significant at the 99.9% level. This is the first direct observational proof that radio galaxies are a significant source of UHECRs. For the remaining ~20 UHECRs, an isotropic distribution cannot be ruled out at high significance. The correlation found by the Auger Collaboration between the 27 UHECRs and AGNs in the Veron-Cetty & Veron catalog at D < 71Mpc has a much lower significance when one considers only the ~20 UHECRs not `matched' to nearby extended radiogalaxies. No correlation is seen between UHECRs and supernovae, supernova remnants, nearby galaxies, or nearby groups and clusters of galaxies. The primary difference between the UHECR detections at the Pierre Auger Observatory and previous experiments may thus be that the Southern Hemisphere is more privileged with respect to nearby extended radiogalaxies.

Neil M. Nagar; Javier Matulich

2008-06-19

255

The Heliosphere and Galactic Cosmic Rays - Duration: 0:39.  

NASA Video Gallery

The heliosphere deflects galactic cosmic rays from entering the system. Galactic cosmic rays are a very high energy form of particle radiation that are extremely difficult to shield against and are...

256

OBSERVATIONS OF HIGH-ENERGY COSMIC-RAY ELECTRONS FROM 30 GeV TO 3 TeV WITH EMULSION CHAMBERS  

SciTech Connect

We have performed a series of cosmic-ray electron observations using balloon-borne emulsion chambers since 1968. While we previously reported the results from subsets of the exposures, the final results of the total exposures up to 2001 are presented here. Our successive experiments have yielded a total exposure of 8.19 m{sup 2} sr day at altitudes of 4.0-9.4 g cm{sup -2}. The performance of the emulsion chambers was examined by accelerator beam tests and Monte Carlo simulations, and the on-board calibrations were carried out by using the flight data. In this work, we present the cosmic-ray electron spectrum in the energy range from 30 GeV to 3 TeV at the top of the atmosphere, which is well represented by a power-law function with an index of -3.28 {+-} 0.10. The observed data can also be interpreted in terms of diffusive propagation models. The evidence of cosmic-ray electrons up to 3 TeV suggests the existence of cosmic-ray electron sources at distances within {approx}1 kpc and times within {approx}1 Multiplication-Sign 10{sup 5} yr ago.

Kobayashi, T. [Department of Physics and Mathematics, Aoyama Gakuin University, Sagamihara 252-5258 (Japan); Komori, Y. [Faculty of Health and Social Services, Kanagawa University of Human Services, Yokosuka 238-0013 (Japan); Yoshida, K.; Yanagisawa, K. [College of Systems Engineering and Science, Shibaura Institute of Technology, Saitama 337-8570 (Japan); Nishimura, J.; Yamagami, T.; Saito, Y. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara 229-8510 (Japan); Tateyama, N. [Faculty of Engineering, Kanagawa University, Yokohama 221-8686 (Japan); Yuda, T. [Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582 (Japan); Wilkes, R. J., E-mail: tadasik-112850@jasper.dti.ne.jp, E-mail: komori-y@kuhs.ac.jp, E-mail: yoshida@shibaura-it.ac.jp, E-mail: nisimura@icrr.u-tokyo.ac.jp, E-mail: tateyama@n.kanagawa-u.ac.jp, E-mail: yuda@icrr.u-tokyo.ac.jp, E-mail: wilkes@u.washington.edu [Department of Physics, University of Washington, Seattle, WA 98195-1560 (United States)

2012-12-01

257

29th International Cosmic Ray Conference Pune (2005) 00, 101106 Search for Very High Energy Emission from Satellite-triggered GRBs  

E-print Network

Emission from Satellite-triggered GRBs with the Milagro Observatory P. M. Saz Parkinson for the Milagro in the 100 GeV to 100 TeV energy range. More than 45 satellite-triggered gamma-ray bursts (GRBs) have significantly with the launch of Swift. We discuss the most recent results of a search for very high energy (VHE

California at Santa Cruz, University of

258

Evidences of high energy protons with energies beyond 0.4 GeV in the solar particle spectrum as responsible for the cosmic rays solar diurnal anisotropy  

E-print Network

Analysis on the daily variations of cosmic ray muons with $E_{\\mu}\\geq 0.2 GeV$ based on the data of two directional muon telescopes at sea level and with a rigidity of response to cosmic proton spectrum above 0.4 GV is presented. The analysis covers two months of observations and in 60% of days, abrupt transitions between a low to a high muon intensity and vice-verse is observed, the period of high muon intensity is from $\\sim 8.0h$ up to $\\sim 19.0h$ (local time) and coincides with the period when the interplanetary magnetic field (IMF) lines overtake the Earth. This behavior strongly suggest that the high muon intensity is due to a contribution of solar protons (ions) on the muon intensity produced by the galactic cosmic rays, responsible for the low muon intensity. This implies that the solar particle spectrum extends to energies beyond 1 GeV. We show that this picture can explain the solar daily variation origin, and it is a most accurate scenario than the assumption of corotating galactic cosmic ray with the IMF lines, specially in the high rigidity region. Obtained results are consistent with the data reported in others papers. Some aspects on the sensitivity of our muon telescopes are also presented.

C. E. Navia; C. R. A. Augusto; M. B. Robba; K. H. Tsui

2007-06-26

259

Evidences of high energy protons with energies beyond 0.4 GeV in the solar particle spectrum as responsible for the cosmic rays solar diurnal anisotropy  

E-print Network

Analysis on the daily variations of cosmic ray muons with $E_{\\mu}\\geq 0.2 GeV$ based on the data of two directional muon telescopes at sea level and with a rigidity of response to cosmic proton spectrum above 0.4 GV is presented. The analysis covers two months of observations and in 60% of days, abrupt transitions between a low to a high muon intensity and vice-verse is observed, the period of high muon intensity is from $\\sim 8.0h$ up to $\\sim 19.0h$ (local time) and coincides with the period when the interplanetary magnetic field (IMF) lines overtake the Earth. This behavior strongly suggest that the high muon intensity is due to a contribution of solar protons (ions) on the muon intensity produced by the galactic cosmic rays, responsible for the low muon intensity. This implies that the solar particle spectrum extends to energies beyond 1 GeV. We show that this picture can explain the solar daily variation origin, and it is a most accurate scenario than the assumption of corotating galactic cosmic ray wit...

Navia, C E; Robba, M B; Tsui, K H

2007-01-01

260

THE NuSTAR EXTRAGALACTIC SURVEY: A FIRST SENSITIVE LOOK AT THE HIGH-ENERGY COSMIC X-RAY BACKGROUND POPULATION  

SciTech Connect

We report on the first 10 identifications of sources serendipitously detected by the Nuclear Spectroscopic Telescope Array (NuSTAR) to provide the first sensitive census of the cosmic X-ray background source population at {approx}> 10 keV. We find that these NuSTAR-detected sources are Almost-Equal-To 100 times fainter than those previously detected at {approx}> 10 keV and have a broad range in redshift and luminosity (z = 0.020-2.923 and L{sub 10-40{sub keV}} Almost-Equal-To 4 Multiplication-Sign 10{sup 41}-5 Multiplication-Sign 10{sup 45} erg s{sup -1}); the median redshift and luminosity are z Almost-Equal-To 0.7 and L{sub 10-40{sub keV}} Almost-Equal-To 3 Multiplication-Sign 10{sup 44} erg s{sup -1}, respectively. We characterize these sources on the basis of broad-band Almost-Equal-To 0.5-32 keV spectroscopy, optical spectroscopy, and broad-band ultraviolet-to-mid-infrared spectral energy distribution analyses. We find that the dominant source population is quasars with L{sub 10-40{sub keV}} > 10{sup 44} erg s{sup -1}, of which Almost-Equal-To 50% are obscured with N{sub H} {approx}> 10{sup 22} cm{sup -2}. However, none of the 10 NuSTAR sources are Compton thick (N{sub H} {approx}> 10{sup 24} cm{sup -2}) and we place a 90% confidence upper limit on the fraction of Compton-thick quasars (L{sub 10-40{sub keV}} > 10{sup 44} erg s{sup -1}) selected at {approx}> 10 keV of {approx}< 33% over the redshift range z = 0.5-1.1. We jointly fitted the rest-frame Almost-Equal-To 10-40 keV data for all of the non-beamed sources with L{sub 10-40{sub keV}} > 10{sup 43} erg s{sup -1} to constrain the average strength of reflection; we find R < 1.4 for {Gamma} = 1.8, broadly consistent with that found for local active galactic nuclei (AGNs) observed at {approx}> 10 keV. We also constrain the host-galaxy masses and find a median stellar mass of Almost-Equal-To 10{sup 11} M{sub Sun }, a factor Almost-Equal-To 5 times higher than the median stellar mass of nearby high-energy selected AGNs, which may be at least partially driven by the order of magnitude higher X-ray luminosities of the NuSTAR sources. Within the low source-statistic limitations of our study, our results suggest that the overall properties of the NuSTAR sources are broadly similar to those of nearby high-energy selected AGNs but scaled up in luminosity and mass.

Alexander, D. M.; Del Moro, A.; Lansbury, G. B.; Aird, J. [Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Stern, D.; Assef, R. J. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Mail Stop 169-221, Pasadena, CA 91109 (United States); Ajello, M.; Boggs, S. E. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Ballantyne, D. R. [Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Bauer, F. E. [Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Brandt, W. N. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Christensen, F. E.; Craig, W. W. [DTU Space-National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Civano, F.; Hickox, R. C. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); Comastri, A. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Elvis, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Grefenstette, B. W.; Harrison, F. A. [Cahill Center for Astrophysics, 1216 East California Boulevard, California Institute of Technology, Pasadena, CA 91125 (United States); Hailey, C. J. [Columbia Astrophysics Laboratory, 550 W 120th Street, Columbia University, NY 10027 (United States); and others

2013-08-20

261

Cosmic x ray physics  

NASA Technical Reports Server (NTRS)

The annual progress report on Cosmic X Ray Physics for the period 1 Jan. to 31 Dec. 1990 is presented. Topics studied include: soft x ray background, new sounding rocket payload: x ray calorimeter, and theoretical studies.

Mccammon, Dan; Cox, D. P.; Kraushaar, W. L.; Sanders, W. T.

1991-01-01

262

Is the Ultra-high Energy Cosmic-Ray Excess Observed by the Telescope Array Correlated with IceCube Neutrinos?  

NASA Astrophysics Data System (ADS)

The Telescope Array (TA) has observed a statistically significant excess in cosmic rays with energies above 57 EeV in a region of approximately 1150 deg2 centered on coordinates R.A. = 146.7, decl. = 43.2. We note that the location of this excess correlates with 2 of the 28 extraterrestrial neutrinos recently observed by IceCube. The overlap between the two IceCube neutrinos and the TA excess is statistically significant at the 2? level. Furthermore, the spectrum and intensity of the IceCube neutrinos is consistent with a single source which would also produce the TA excess. Finally, we discuss possible source classes with the correct characteristics to explain the cosmic-ray and neutrino fluxes with a single source.

Fang, Ke; Fujii, Toshihiro; Linden, Tim; Olinto, Angela V.

2014-10-01

263

Spectral index of high-energy cosmic rays by the Compton-Getting effect at solar time frame with the Tibet air shower array  

Microsoft Academic Search

We report on the spectral index of cosmic rays around 10 TeV energy region obtained by observation of the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun with the Tibet III air shower array during the period from 1999 to 2005. The spectral index has turned out to be 2.990.54, which is consistent with 2.74 by the

S. Ayabe; X. J. Bi; D. Chen; S. W. Cui; Danzengluobu; L. K. Ding; X. H. Ding; C. F. Feng; Zhaoyang Feng; Z. Y. Feng; X. Y. Gao; Q. X. Geng; H. W. Guo; H. H. He; M. He; K. Hibino; N. Hotta; Haibing Hu; H. B. Hu; J. Huang; Q. Huang; H. Y. Jia; F. Kajino; K. Kasahara; Y. Katayose; C. Kato; K. Kawata; Labaciren; G. M. Le; A. F. Li; J. Y. Li; Y.-Q. Lou; H. Lu; S. L. Lu; X. R. Meng; K. Mizutani; J. Mu; K. Munakata; A. Nagai; H. Nanjo; M. Nishizawa; M. Ohnishi; I. Ohta; H. Onuma; T. Ouchi; S. Ozawa; J. R. Ren; T. Saito; M. Sakata; T. Sasaki; M. Shibata; A. Shiomi; T. Shirai; H. Sugimoto; M. Takita; Y. H. Tan; N. Tateyama; T. K. Sako; S. Torii; H. Tsuchiya; S. Udo; B. Wang; H. Wang; X. Wang; Y. G. Wang; H. R. Wu; L. Xue; Y. Yamamoto; C. T. Yan; X. C. Yang; S. Yasue; Z. H. Ye; G. C. Yu; A. F. Yuan; T. Yuda; H. M. Zhang; J. L. Zhang; N. J. Zhang; X. Y. Zhang; Y. Zhang; Yi Zhang; Zhaxisangzhu; X. X. Zhou

2008-01-01

264

Stable quark matter in cosmic rays?  

E-print Network

Stable lumps of quark matter may be present in cosmic rays at a flux level, which can be detected by high precision cosmic ray experiments sensitive to anomalous "nuclei" with high mass-to-charge ratio. The properties of these lumps, called strangelets, are described, and so is the production and propagation of strangelets in cosmic rays. Two experiments underway which are sensitive to a strangelet flux in the predicted range are briefly described. Finally it is summarized how strangelets circumvent the acceleration problem encountered by conventional candidates for ultra-high energy cosmic rays and move the Greisen-Zatsepin-Kuzmin cutoff to energies well above the observed maximum energies.

Jes Madsen

2005-12-20

265

Cosmic Ray Astronomy  

E-print Network

Cosmic ray astronomy attempts to identify and study the sources of ultrahigh energy cosmic rays. It is unique in its reliance on charged particles as the information carriers. While no discrete source of ultrahigh energy cosmic rays has been identified so far, a new generation of detectors is acquiring the huge exposure that is needed at the highest energies, where deflection by magnetic fields is minimized and the background from distant sources is eliminated by pion photoproduction. In this paper, we summarize the status of cosmic ray astronomy, describing the detectors and the analysis techniques.

Paul Sommers; Stefan Westerhoff

2008-02-09

266

Cosmic Rays above the Knee  

E-print Network

An overview on the present observational status and phenomenological understanding of cosmic rays above 10^16 eV is given. Above these energies the cosmic ray flux is expected to be gradually dominated by an extra-galactic component. In order to investigate the nature of this transition, current experimental activities focus on the measurement of the cosmic ray flux and composition at the 'ankle' or 'dip' feature at several EeV. At the ultra high energy end of the spectrum, the flux suppression above 50 EeV is now well established by the measurements of HiRes and the Pierre Auger Observatory and we may enter the era of charged particle astronomy.

Michael Unger

2008-12-15

267

Cosmic Rays from Gamma Ray Bursts in the Galaxy  

E-print Network

The rate of terrestrial irradiation events by galactic gamma-ray bursts (GRBs) is estimated using recent standard-energy results. We assume that GRBs accelerate high-energy cosmic rays, and present results of three-dimensional simulations of cosmic rays moving in the Galactic magnetic field and diffusing through pitch-angle scattering. An on-axis GRB extinction event begins with a powerful prompt gamma-ray and neutron pulse, followed by a longer-lived phase from cosmic-ray protons and neutron-decay protons that diffuse towards Earth. Our results force a reinterpretation of reported ~ 10^{18} eV cosmic-ray anisotropies and offer a rigorous test of the model where high-energy cosmic rays originate from GRBs, which will soon be tested with the Auger Observatory.

Charles D. Dermer; Jeremy M. Holmes

2005-06-16

268

Instrumentation for very high energy gamma-ray astronomy  

Microsoft Academic Search

Considerable progress has been made in the last half-decade in the field of very high energy (VHE) gamma-ray astronomy (photons with energies between 1011 and 1013 eV). The high background level due to the isotropic cosmic ray flux which has bedevilled the field since its inception in the early 1960's can now be reduced to such a degree that significant

M. F. Cawley; T. C. Weekes

1995-01-01

269

How Cosmic Rays Affect Humans  

NSDL National Science Digital Library

In this lesson about cosmic rays, students will describe why cosmic rays are dangerous to astronauts. Includes information about student preconceptions. This is activity 3 of 4 from "The Cosmic Ray Telescope for the Effects of Radiation (CRaTER)."

2012-08-03

270

Terrestrial cosmic rays  

Microsoft Academic Search

This paper reviews the basic physics of those cosmic rays which can affect terrestrial electronics. Cosmic rays at sea level consist mostly of neutrons, protons, pions, muons, electrons, and photons. The particles which cause significant soft fails in electronics are those particles with the strong interaction: neutrons, protons, and pions. At sea level, about 95% of these particles are neutrons.

James F. Ziegler

1996-01-01

271

Origin of Cosmic Rays  

Microsoft Academic Search

Contents Introduction S 1. Primary Cosmic Rays Near the Earth a) Chemical composition b) Energy spectrum S 2. Radio-Astronomical Data a) Magnetic bremsstrahlung (synchrotron radiation) b) Certain results of observations and their interpretation (structure of the Galaxy, discrete sources) S 3. Lifetime of Cosmic Rays and Character of Their Motion in the Galaxy and the Metagalaxy a) Nuclear lifetime of

V. L. Ginzburg; S. I. Syrovatsky

1961-01-01

272

Cosmic Ray Impact on Extrasolar Earth-Like Planets in Close-in Habitable Zones  

Microsoft Academic Search

Because of their different origins, cosmic rays can be subdivided into galactic cosmic rays and solar\\/stellar cosmic rays. The flux of cosmic rays to planetary surfaces is mainly determined by two planetary parameters: the atmospheric density and the strength of the internal magnetic moment. If a planet exhibits an extended magnetosphere, its surface will be protected from high-energy cosmic ray

J.-M. Griemeier; A. Stadelmann; U. Motschmann; N. K. Belisheva; H. Lammer; H. K. Biernat

2005-01-01

273

X-Rays from NGC 3256: High-Energy Emission in Starburst Galaxies and Their Contribution to the Cosmic X-Ray Background  

Microsoft Academic Search

The infrared-luminous galaxy NGC 3256 is a classic example of a merger-induced nuclear starburst system. We find here that it is the most X-ray-luminous star-forming galaxy yet detected (L{sub 0.5-10keV} =1.6x10⁴² ergs s-1). Long-slit optical spectroscopy and a deep, high-resolution ROSAT X-ray image show that the starburst is driving a ''superwind'' which accounts for 20% of the observed soft X-ray

Edward C. Moran; Matthew D. Lehnert; David J. Helfand

1999-01-01

274

Cosmic-ray astrochemistry.  

PubMed

Gas-phase chemistry in the interstellar medium is driven by fast ion-molecule reactions. This, of course, demands a mechanism for ionization, and cosmic rays are the ideal candidate as they can operate throughout the majority of both diffuse and dense interstellar clouds. Aside from driving interstellar chemistry via ionization, cosmic rays also interact with the interstellar medium in ways that heat the ambient gas, produce gamma rays, and produce light element isotopes. In this paper we review the observables generated by cosmic-ray interactions with the interstellar medium, focusing primarily on the relevance to astrochemistry. PMID:23812538

Indriolo, Nick; McCall, Benjamin J

2013-10-01

275

Some aspects of the scientific significance of high energy gamma ray astrophysics  

Microsoft Academic Search

The attraction of high energy gamma-ray astronomy lies in this radiation relating directly to those processes in astrophysical situations which deviate most from thermo-dynamic equilibrium. Some examples of these phenomena which are known to or expected to emit gamma rays are cosmic rays as they interact in intergalactic space, the high energy particles in the magnetic fields of neutron stars,

Carl E. Fichtel

1991-01-01

276

Ultra-high-energy cosmic neutrinos: at 1015 eV energies and above  

NASA Astrophysics Data System (ADS)

The high-energy neutrino astronomy has finally bloomed. The discovery of the first 1015 eV (PeV or 106 GeV) neutrino events by the IceCube Collaboration followed by the dedicated search for 1012-1015 eV events exhibited the evidence of an astrophysical neutrino flux. The estimated flux level is around E2??e+??+??=310-8 GeV cm s sr, consistent with the intensity expected from the energetics of extragalactic cosmic rays. The strong bound of neutrino flux in the 1018-eV range, which amounts to E2??e+??+??=1.210-7 GeV cm s sr at 11019 eV provided by IceCube has reached the flux region predicted for some ultra-high-energy cosmic-ray source class candidates, leading to astrophysically meaningful constraints on the origin of cosmic rays. It disfavors strong cosmological evolution of the highest energy cosmic ray sources such as the Fanaroff-Riley type-II class of radio Galaxies. We live in an era when neutrinos provide clues to resolve long-standing mystery of ultra-high-energy cosmic rays.

Yoshida, Shigeru

2014-04-01

277

Cosmic Ray Physics with ACORDE at LHC  

E-print Network

The use of large underground high-energy physics experiments, for comic ray studies, have been used, in the past, at CERN, in order to measure, precisely, the inclusive cosmic ray flux in the energy range from 2x10^10 - 2x10^12 eV. ACORDE, ALICE Cosmic Rays DEtector, will act as Level 0 cosmic ray trigger and, together with other ALICE apparatus, will provide precise information on cosmic rays with primary energies around 10^15 - 10^17 eV. This paper reviews the main detector features, the present status, commissioning and integration with other apparatus. Finally, we discuss the ACORDE-ALICE cosmic ray physics program.

C. Pagliarone; A. Fernandez-Tellez

2007-09-19

278

Ultra high-energy comic rays: probing the local Universe  

E-print Network

A general view is presented on the problem of propagation of ultra high-energy cosmic rays through the intergalactic and galactic magnetic fields. Especial emphasis is given to the possibility of correlating the present events with potential sources face to the uncertainties in the intervening magnetic fields. Given high enough statistics, the latter problem can be transformed into a powerful tool for the study of cosmic magnetic fields. Finally, the three pairs of events pointed out by the AGASA collaboration as a possible evidence for clustering are analyzed.

Gustavo Medina Tanco

1998-09-16

279

Large Scale Distribution of Ultra High Energy Cosmic Rays Detected at the Pierre Auger Observatory with Zenith Angles up to 80  

NASA Astrophysics Data System (ADS)

We present the results of an analysis of the large angular scale distribution of the arrival directions of cosmic rays with energy above 4 EeV detected at the Pierre Auger Observatory including for the first time events with zenith angle between 60 and 80. We perform two Rayleigh analyses, one in the right ascension and one in the azimuth angle distributions, that are sensitive to modulations in right ascension and declination, respectively. The largest departure from isotropy appears in the E\\gt 8 EeV energy bin, with an amplitude for the first harmonic in right ascension r1? =(4.4+/- 1.0) {{10}-2}, that has a chance probability P(?slant r1? )=6.4 {{10}-5}, reinforcing the hint previously reported with vertical events alone.

Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Awal, N.; Badescu, A. M.; Barber, K. B.; Buml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S. G.; Blanco, M.; Bleve, C.; Blmer, H.; Boh?ov, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Bridgeman, A.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceio, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Daz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; DOlivo, J. C.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filip?i?, A.; Fox, B. D.; Fratu, O.; Freire, M. M.; Frhlich, U.; Fuchs, B.; Fujii, T.; Gaior, R.; Garca, B.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gmez Berisso, M.; Gmez Vitale, P. F.; Gonalves, P.; Gonzalez, J. G.; Gonzlez, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hrandel, J. R.; Horvath, P.; Hrabovsk, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kp, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kgl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krmer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leo, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lpez, R.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mari?, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martnez Bravo, O.; Martraire, D.; Masas Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Meissner, R.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mi?anovi?, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Mostaf, M.; Moura, C. A.; Muller, M. A.; Mller, G.; Mller, S.; Mnchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P. H.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Noka, L.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Oliveira, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; P?kala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.

2015-04-01

280

Gamma-ray astronomy at high energies  

Microsoft Academic Search

Progress in high-energy gamma-ray astronomy has depended upon the development of sophisticated detectors and analysis techniques. Observations in this decade using space-based and ground-based detectors have observed gamma-ray emission from a variety of sources. For the first time a consistent picture of the gamma-ray sky has emerged. This article describes the detection techniques in gamma-ray astronomy, the nature of the

C. M. Hoffman; C. Sinnis; P. Fleury; M. Punch

1999-01-01

281

Cosmic rays and hadronic interactions  

SciTech Connect

The cosmic ray spectrum extends to particles with energy E{approx} 10{sup 20} eV, that corresponds (assuming that the primary particle is a proton) to a nucleon-nucleon c.m. energy {radical}(s) Asymptotically-Equal-To 430TeV, 50 times higher than the current LHC energy. These very high energy particles can be studied via the observation of the showers they generate in the atmosphere. The interpretation of the data requires therefore the modeling of hadronic interactions in an energy range beyond what can be studied in accelerator experiments. The theoretical problem of estimating the relevant properties of hadronic interactions in this energy range is therefore of central importance for the interpretation of the cosmic ray data. Viceversa, it is in principle possible to obtain information about hadronic interactions from the cosmic ray observations, but this program has to confront the fact that the (freely available) cosmic ray beam has an unknown energy spectrum and an unknown mass composition.

Lipari, Paolo [INFN sez. Roma, and Dipartimento di Fisica, Universita di Roma Sapienza (Italy)

2013-03-25

282

Cosmic Ray Energetics And Mass  

NASA Astrophysics Data System (ADS)

The 6 flights of the Cosmic Ray Energetics and Mass (CREAM) balloon payload over Antarctica accumulated 161 days of exposure. The instrument is configured with complementary and redundant particle detectors for direct measurements of high energy cosmic ray elemental spectra. The calorimeter and Silicon Charge Detectors (SCD) from one of the two instruments are being re-configured for the International Space Station, dubbed ISS-CREAM. The other calorimeter and detectors that are too large to fit in the ISS Japanese Experiment Module Exposed Facility envelope are kept for balloon flights. The large area Timing Charged Detector (TCD) and newly developed Transition Radiation Detector (TRD) will be used for studying the propagation history of cosmic rays by measuring relative abundances of secondary particles, e.g., Boron. This Boron and Carbon Cosmic Rays in the Upper Stratosphere (BACCUS) balloon payload will provide in-flight cross calibration of the calorimeter and TRD for Z > 3 particles. The status of the payload construction and flight preparation will be reported.

Seo, Eun-Suk

283

Cosmic rays in astrospheres  

E-print Network

Cosmic rays passing through large astrospheres can be efficiently cooled inside these "cavities" in the interstellar medium. Moreover, the energy spectra of these energetic particles are already modulated in front of the astrospherical bow shocks. We study the cosmic ray flux in and around lambda Cephei as an example for an astrosphere. The large-scale plasma flow is modeled hydrodynamically with radiative cooling. We studied the cosmic ray flux in a stellar wind cavity using a transport model based on stochastic differential equations. The required parameters, most importantly, the elements of the diffusion tensor, are based on the heliospheric parameters. The magnetic field required for the diffusion coefficients is calculated kinematically. We discuss the transport in an astrospheric scenario with varying parameters for the transport coefficients. We show that large stellar wind cavities can act as sinks for the galactic cosmic ray flux and thus can give rise to small-scale anisotropies in the direction to...

Scherer, Klaus; Bomans, Dominik; Ferreira, Stefan; Fichtner, Horst; Kleimann, Jens; Strauss, Dutoit; Weis, Kerstin; Wiengarten, Tobias; Wodzinski, Thomas

2015-01-01

284

Cosmic rays in astrospheres  

NASA Astrophysics Data System (ADS)

Context. Cosmic rays passing through large astrospheres can be efficiently cooled inside these "cavities" in the interstellar medium. Moreover, the energy spectra of these energetic particles are already modulated in front of the astrospherical bow shocks. Aims: We study the cosmic ray flux in and around ? Cephei as an example for an astrosphere. The large-scale plasma flow is modeled hydrodynamically with radiative cooling. Methods: We study the cosmic ray flux in a stellar wind cavity using a transport model based on stochastic differential equations. The required parameters, most importantly, the elements of the diffusion tensor, are based on the heliospheric parameters. The magnetic field required for the diffusion coefficients is calculated kinematically. We discuss the transport in an astrospheric scenario with varying parameters for the transport coefficients. Results: We show that large stellar wind cavities can act as sinks for the Galactic cosmic ray flux and thus can give rise to small-scale anisotropies in the direction to the observer. Conclusions: Small-scale cosmic ray anisotropies can naturally be explained by the modulation of cosmic ray spectra in huge stellar wind cavities.

Scherer, K.; van der Schyff, A.; Bomans, D. J.; Ferreira, S. E. S.; Fichtner, H.; Kleimann, J.; Strauss, R. D.; Weis, K.; Wiengarten, T.; Wodzinski, T.

2015-04-01

285

Cosmic ray propagation in the local superbubble  

NASA Technical Reports Server (NTRS)

It is suggested that a ring of HI gas lying in the galactic plane is part of a supershell which formed some 3 x to the 7th power years ago. The consequences of a closed magnetic supershell for cosmic ray propagation are examined and it is concluded that there is no evidence which precludes the production and trapping of cosmic rays in such a region. A consequence of superbubble confinement is that the mean age of cosmic rays would be independent of energy. This can be tested by high energy observations of the isotopic composition of Be.

Steitmatter, R. E.; Balasubrahmanyan, V. K.; Protheroe, R. J.; Ormes, J. F.

1984-01-01

286

A design study of atmospheric Cerenkov radiation telescope for very high energy gamma-ray astronomy  

Microsoft Academic Search

Detection of cosmic sources of very high energy gamma rays based on the atmospheric Cerenkov technique is discussed. Very high energy gamma-rays initiate, on entering the terrestrial atmosphere, electron-photon cascade showers with in turn produce Cerenkov photons in the air. Parabolic reflectors are used to focus these photons onto fast photomultipliers. Two methods of deployment of parabolic reflectors are in

S. K. Gupta; P. V. Ramana Murthy; S. C. Tonwar; P. R. Vishwanath

1985-01-01

287

Very High Energy Gamma-Ray Astronomy  

Microsoft Academic Search

We present a review of the current status of very high energy gamma-ray astronomy. The development of the atmospheric Cerenkov imaging technique for ground-based gamma-ray astronomy has led to a rapid growth in the number of observatories. The detection of TeV gamma-rays from active galactic nuclei was unexpected and is providing new insights into the emission mechanisms in the jets.

Michael Catanese; Trevor C. Weekes

1999-01-01

288

Constraining the Low-Energy Cosmic Ray Spectrum  

Microsoft Academic Search

While the cosmic ray spectrum is easily observed at high energies, below about 100 MeV cosmic rays are excluded from the inner solar system by the magnetic field coupled to the solar wind. This means that the cosmic ray spectrum below 100 MeV cannot be directly observed. However, there are several secondary observables which can tell us about low-energy cosmic

Nick Indriolo; B. D. Fields; B. J. McCall

2008-01-01

289

The intergalactic propagation of ultrahigh energy cosmic ray nuclei  

SciTech Connect

We investigate the propagation of ultra-high energy cosmic ray nuclei (A = 1-56) from cosmologically distant sources through the cosmic radiation backgrounds. Various models for the injected composition and spectrum and of the cosmic infrared background are studied using updated photodisintegration cross-sections. The observational data on the spectrum and the composition of ultra-high energy cosmic rays are jointly consistent with a model where all of the injected primary cosmic rays are iron nuclei (or a mixture of heavy and light nuclei).

Hooper, Dan; /Fermilab; Sarkar, Subir; /Oxford U., Theor. Phys.; Taylor, Andrew M.; /Oxford U.

2006-08-01

290

A Cerenkov-delta E-Cerenkov detector for high energy cosmic ray isotopes and an accelerator study of Ar-40 and Fe-56 fragmentation. Ph.D. Thesis  

NASA Technical Reports Server (NTRS)

A high energy cosmic ray detector--the High Energy Isotope Spectrometer Telescope (HEIST) is described. It is a large area (0.25 m(swp 2) SR) balloon borne isotope spectrometer designed to make high resolution measurements of isotopes in the element range from neon to nickel (10 Z 28) at energies of about 2 GeV/nucleon. HEIST determines the mass of individual nuclei by measuring both the change in the Lorentz factor (delta gamma) that results from traversing the NaI stack, and the energy loss (delta E) in the stack. Since the total energy of an isotope is given by E = (gamma M), the mass M can be determined by M = delta E/delta, gamma. The instrument is designed to achieve a typical mass resolution of 0.2 amu. The isotopic composition of the fragments from the breakup of high energy An-40 and Fe-56 nuclei are measured experimentally. Isotope yields are compared with calculated yields based on semi-empirical cross-section formulae.

Lau, K. H.

1985-01-01

291

Research in particles and fields. [cosmic rays, gamma rays, and cosmic plasma  

NASA Technical Reports Server (NTRS)

Research activities in cosmic rays, gamma rays, and astrophysical plasmas are reviewed. Energetic particle and photon detector systems flown on spacecraft and balloons were used to carry out the investigations. Specific instruments mentioned are: the high energy isotope spectrometer telescope, the electron/isotope spectrometer, the heavy isotope spectrometer telescope, and magnetometers. Solar flares, planetary magnetospheres, element abundance, the isotopic composition of low energy cosmic rays, and heavy nuclei are among the topics receiving research attention.

Stone, E. C.; Buffington, A.; Davis, L., Jr.; Prince, T. A.; Vogt, R. E.

1984-01-01

292

Cosmic Rays and Climate  

E-print Network

Among the most puzzling questions in climate change is that of solar-climate variability, which has attracted the attention of scientists for more than two centuries. Until recently, even the existence of solar-climate variability has been controversial??perhaps because the observations had largely involved correlations between climate and the sunspot cycle that had persisted for only a few decades. Over the last few years, however, diverse reconstructions of past climate change have revealed clear associations with cosmic ray variations recorded in cosmogenic isotope archives, providing persuasive evidence for solar or cosmic ray forcing of the climate. However, despite the increasing evidence of its importance, solar-climate variability is likely to remain controversial until a physical mechanism is established. Although this remains a mystery, observations suggest that cloud cover may be influenced by cosmic rays, which are modulated by the solar wind and, on longer time scales, by the geomagnetic fiel...

Kirkby, Jasper

2007-01-01

293

INTERACTING COSMIC RAYS WITH MOLECULAR CLOUDS: A BREMSSTRAHLUNG ORIGIN OF DIFFUSE HIGH-ENERGY EMISSION FROM THE INNER 2 Degree-Sign Multiplication-Sign 1 Degree-Sign OF THE GALACTIC CENTER  

SciTech Connect

The high-energy activity in the inner few degrees of the Galactic center is traced by diffuse radio, X-ray, and {gamma}-ray emission. The physical relationship between different components of diffuse gas emitting at multiple wavelengths is a focus of this work. We first present radio continuum observations using the Green Bank Telescope and model the nonthermal spectrum in terms of a broken power-law distribution of {approx}GeV electrons emitting synchrotron radiation. We show that the emission detected by Fermi is primarily due to nonthermal bremsstrahlung produced by the population of synchrotron emitting electrons in the GeV energy range interacting with neutral gas. The extrapolation of the electron population measured from radio data to low and high energies can also explain the origin of Fe I 6.4 keV line and diffuse TeV emission, as observed with Suzaku, XMM-Newton, Chandra, and the H.E.S.S. observatories. The inferred physical quantities from modeling multiwavelength emission in the context of bremsstrahlung emission from the inner {approx}300 Multiplication-Sign 120 pc of the Galactic center are constrained to have the cosmic-ray ionization rate {approx}1-10 Multiplication-Sign 10{sup -15} s{sup -1}, molecular gas heating rate elevating the gas temperature to 75-200 K, fractional ionization of molecular gas 10{sup -6}-10{sup -5}, large-scale magnetic field 10-20 {mu}G, the density of diffuse and dense molecular gas {approx}100 and {approx}10{sup 3} cm{sup -3} over 300 pc and 50 pc path lengths, and the variability of Fe I K{alpha} 6.4 keV line emission on yearly timescales. Important implications of our study are that GeV electrons emitting in radio can explain the GeV {gamma}-rays detected by Fermi and that the cosmic-ray irradiation model, like the model of the X-ray irradiation triggered by past activity of Sgr A*, can also explain the origin of the variable 6.4 keV emission from Galactic center molecular clouds.

Yusef-Zadeh, F.; Roberts, D. A.; Royster, M. [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States)] [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Hewitt, J. W. [Code 662, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)] [Code 662, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Wardle, M. [Department of Physics and Astronomy, and Research Center for Astronomy, Astrophysics and Astrophotonics, Macquarie University, Sydney, NSW 2109 (Australia)] [Department of Physics and Astronomy, and Research Center for Astronomy, Astrophysics and Astrophotonics, Macquarie University, Sydney, NSW 2109 (Australia); Tatischeff, V. [Center de Spectrometrie Nucleaire et de Spectrometrie de Massse, IN2P3/CNRS and Univ. Paris-Sud, F-91405 Orsay Campus (France)] [Center de Spectrometrie Nucleaire et de Spectrometrie de Massse, IN2P3/CNRS and Univ. Paris-Sud, F-91405 Orsay Campus (France); Cotton, W. [NRAO, 520 Edgemont Road, Charlottesville, VA 22903 (United States)] [NRAO, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Uchiyama, H.; Nobukawa, M.; Tsuru, T. G. [Cosmic Ray Group, Physics, Kyoto University, Kitashirakawa-Oiwake-Cho, Sakyo, Kyoto 606-8502 (Japan)] [Cosmic Ray Group, Physics, Kyoto University, Kitashirakawa-Oiwake-Cho, Sakyo, Kyoto 606-8502 (Japan); Heinke, C. [Department of Physics, Room 238 CEB, University of Alberta, Edmonton, AB T6G 2G7 (Canada)] [Department of Physics, Room 238 CEB, University of Alberta, Edmonton, AB T6G 2G7 (Canada)

2013-01-01

294

Investigation of primary cosmic rays at the Moon's surface  

SciTech Connect

The possibility of experimentally studying primary cosmic rays at the Moon's surface is considered. A mathematical simulations of showers initiated in the lunar regolith by high-energy particles of primary cosmic rays is performed. It is shown that such particles can in principle be recorded by simultaneously detecting three components of backscattered radiation (secondary neutrons, gamma rays, and radio emission).

Kalmykov, N. N., E-mail: kalm@eas.sinp.msu.ru; Konstantinov, A. A. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)] [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation); Muhamedshin, R. A. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)] [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation); Podorozhniy, D. M.; Sveshnikova, L. G.; Turundaevskiy, A. N. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)] [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation); Tkachev, L. G. [Joint Institute for Nuclear Research (Russian Federation)] [Joint Institute for Nuclear Research (Russian Federation); Chubenko, A. P. [Russian Academy of Sciences, Lebedev Institute of Physics (Russian Federation)] [Russian Academy of Sciences, Lebedev Institute of Physics (Russian Federation); Vasilyev, O. A. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)] [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

2013-01-15

295

Propagation of Cosmic Rays in the Galaxy and their measurements at  

E-print Network

Propagation of Cosmic Rays in the Galaxy and their measurements at very high energies with LORA Satyendra oudam #12;Propagation of Cosmic Rays in the Galaxy and their measurements at very high energies, Enschede (www.ipskampdrukkers.nl). ISBN 978-90-819014-0-6 #12;Propagation of Cosmic Rays in the Galaxy

Hörandel, Jörg R.

296

Discovery of cosmic rays  

NASA Astrophysics Data System (ADS)

The mysterious invisible radiation that ionized air was studied a century ago by many scientists. Finally, on 7 August 1912, Victor Hess in his seventh balloon flight that year, reached an altitude of about 5000 m. With his electroscopes on board the hydrogen-filled balloon he observed that the ionization instead of decreasing with altitude increased significantly. Hess had discovered cosmic rays, a discovery that gave him the 1936 Nobel Prize in physics. When research resumed after World War I focus was on understanding the nature of the cosmic radiation. Particles or radiation? Positive or negative? Electrons, positrons or protons? Progress came using new instruments like the Geiger-Muller tube and around 1940 it was clear that cosmic rays were mostly protons.

Carlson, Per

2013-02-01

297

Galactic cosmic rays and nucleosynthesis  

SciTech Connect

The nucleosynthesis of the light elements Li, Be and B by galactic cosmic rays is presented. Observations of cosmic rays and the nuclear reactions responsible for Li, Be and B nucleosynthesis are described, followed by some words on propagation. At the end, some open questions concerning galactic cosmic rays are discussed.

Kiener, Juergen [CSNSM, CNRS-IN2P3 and Universite Paris-Sud, Bat. 104-108, 91405 Orsay Campus (France)

2010-03-01

298

Detecting Gamma-Ray Bursts with Ultra-High Energy Neutrinos  

NASA Astrophysics Data System (ADS)

Gamma-ray bursts are candidate sources of ultra-high energy cosmic rays and neutrinos. While cosmic rays are scattered in the intervening magnetic field, neutrinos point back to their sources being charge neutral and make neutrino astronomy possible. Detection of ultrahigh energy neutrinos by future experiments such as ANITA, ANTARES, Ice-Cube and RICE can provide useful information such as particle acceleration, radiation mechanism and magnetic field about the sources and their progenitors. Detection of ultrahigh energy neutrinos which point back to their sources may establish gamma-ray bursts as the sources of GZK cosmic rays.

Razzaque, Soebur; Mszros, Peter; Waxman, Eli

299

Catching Cosmic Rays with a DSLR  

ERIC Educational Resources Information Center

Cosmic rays are high-energy particles from outer space that continually strike the Earth's atmosphere and produce cascades of secondary particles, which reach the surface of the Earth, mainly in the form of muons. These particles can be detected with scintillator detectors, Geiger counters, cloud chambers, and also can be recorded with commonly

Sibbernsen, Kendra

2010-01-01

300

Green River Community College Cosmic Ray Detector  

Microsoft Academic Search

The Washington Area Large scale Time coincidence Array (WALTA) researches high-energy cosmic ray and has placed particle detector arrays around the Seattle area to increase the accuracy of muon information. Green River Community College is one of the schools in collaboration with WALTA and offers its students under-graduate research by working with the particle detector arrays, data collecting and reporting.

Andrea Roma; Crissy Harrington; Mirela Isic; Andrew Adams; Ron Draper

2008-01-01

301

RECENT STATUS OF VERY HIGH ENERGY GAMMA RAY ASTRONOMY AND PROSPECTS  

E-print Network

RECENT STATUS OF VERY HIGH ENERGY GAMMA RAY ASTRONOMY AND PROSPECTS T. KIFUNE Institute for Cosmic cm \\Gamma2 s \\Gamma1 sr \\Gamma1 difficult to observe VHE fl­ray astronomy was founded@icrr.u­tokyo.ac.jp Gamma­rays, located at the highest energy band of electromagnetic radiation, is directly coupled

Enomoto, Ryoji

302

The high energy cosmic-radiation detection (HERD) facility onboard China's Space Station  

NASA Astrophysics Data System (ADS)

The High Energy cosmic-Radiation Detection (HERD) facility is one of several space astronomy payloads of the cosmic lighthouse program onboard China's Space Station, which is planned for operation starting around 2020 for about 10 years. The main scientific objectives of HERD are indirect dark matter search, precise cosmic ray spectrum and composition measurements up to the knee energy, and high energy gamma-ray monitoring and survey. HERD is composed of a 3-D cubic calorimeter (CALO) surrounded by microstrip silicon trackers (STKs) from five sides except the bottom. CALO is made of about 104 cubes of LYSO crystals, corresponding to about 55 radiation lengths and 3 nuclear interaction lengths, respectively. The top STK microstrips of seven X-Y layers are sandwiched with tungsten converters to make precise directional measurements of incoming electrons and gamma-rays. In the baseline design, each of the four side SKTs is made of only three layers microstrips. All STKs will also be used for measuring the charge and incoming directions of cosmic rays, as well as identifying back scattered tracks. With this design, HERD can achieve the following performance: energy resolution of 1% for electrons and gamma-rays beyond 100 GeV, 20% for protons from 100 GeV to 1 PeV; electron/proton separation power better than 10-5; effective geometrical factors of >3 m2sr for electron and diffuse gamma-rays, >2 m2sr for cosmic ray nuclei. R and D is under way for reading out the LYSO signals with optical fiber coupled to image intensified CCD and the prototype of one layer of CALO.

Zhang, S. N.; Adriani, O.; Albergo, S.; Ambrosi, G.; An, Q.; Bao, T. W.; Battiston, R.; Bi, X. J.; Cao, Z.; Chai, J. Y.; Chang, J.; Chen, G. M.; Chen, Y.; Cui, X. H.; Dai, Z. G.; D'Alessandro, R.; Dong, Y. W.; Fan, Y. Z.; Feng, C. Q.; Feng, H.; Feng, Z. Y.; Gao, X. H.; Gargano, F.; Giglietto, N.; Gou, Q. B.; Guo, Y. Q.; Hu, B. L.; Hu, H. B.; He, H. H.; Huang, G. S.; Huang, J.; Huang, Y. F.; Li, H.; Li, L.; Li, Y. G.; Li, Z.; Liang, E. W.; Liu, H.; Liu, J. B.; Liu, J. T.; Liu, S. B.; Liu, S. M.; Liu, X.; Lu, J. G.; Mazziotta, M. N.; Mori, N.; Orsi, S.; Pearce, M.; Pohl, M.; Quan, Z.; Ryde, F.; Shi, H. L.; Spillantini, P.; Su, M.; Sun, J. C.; Sun, X. L.; Tang, Z. C.; Walter, R.; Wang, J. C.; Wang, J. M.; Wang, L.; Wang, R. J.; Wang, X. L.; Wang, X. Y.; Wang, Z. G.; Wei, D. M.; Wu, B. B.; Wu, J.; Wu, X.; Wu, X. F.; Xia, J. Q.; Xiao, H. L.; Xu, H. H.; Xu, M.; Xu, Z. Z.; Yan, H. R.; Yin, P. F.; Yu, Y. W.; Yuan, Q.; Zha, M.; Zhang, L.; Zhang, L.; Zhang, L. Y.; Zhang, Y.; Zhang, Y. J.; Zhang, Y. L.; Zhao, Z. G.

2014-07-01

303

Galactic Cosmic Rays: From Earth to Sources  

NASA Technical Reports Server (NTRS)

For nearly 100 years we have known that cosmic rays come from outer space, yet proof of their origin, as well as a comprehensive understanding of their acceleration, remains elusive. Direct detection of high energy (up to 10(exp 15)eV), charged nuclei with experiments such as the balloon-born, antarctic Trans-Iron Galactic Element Recorder (TIGER) have provided insight into these mysteries through measurements of cosmic ray abundances. The abundance of these rare elements with respect to certain intrinsic properties suggests that cosmic rays include a component of massive star ejecta. Supernovae and their remnants (SNe & SNRs), often occurring at the end of a massive star's life or in an environment including massive star material, are one of the most likely candidates for sources accelerating galactic comic ray nuclei up to the requisite high energies. The Fermi Gamma-ray Space Telescope Large Area Detector (Fermi LAT) has improved our understanding of such sources by widening the window of observable energies and thus into potential sources' energetic processes. In combination with multiwavelength observations, we are now better able to constrain particle populations (often hadron-dominated at GeV energies) and environmental conditions, such as the magnetic field strength. The SNR CTB 37A is one such source which could contribute to the observed galactic cosmic rays. By assembling populations of SNRs, we will be able to more definitively define their contribution to the observed galactic cosmic rays, as well as better understand SNRs themselves. Such multimessenger studies will thus illuminate the long-standing cosmic ray mysteries, shedding light on potential sources, acceleration mechanisms, and cosmic ray propagation.

Brandt, Theresa J.

2012-01-01

304

Cosmic-ray isotopic composition  

NASA Technical Reports Server (NTRS)

The 'age' of the cosmic rays and the origin of cosmic ray source matter are discussed. General approaches to the interpretation of the abundances of secondary radioactive nuclides are reviewed using Be-10 as an illustration. The present state of Be-10 based cosmic ray age determinations are summarized, briefly mentioning some recent results based on the isotope Al-26. The effects of nonhomogeneous propagation models on the interpretation of the radioactive isotope observations are mentioned. The cosmic ray source isotopic composition is discussed, emphasizing the neon composition. Mass histogram findings on the abundance of various elements in cosmic rays are described and possible reasons for some abundance enhancements are considered.

Wiedenbeck, M. E.

1983-01-01

305

High Energy Cosmic Neutrinos Astronomy: The ANTARES Project  

E-print Network

Neutrinos may offer a unique opportunity to explore the far Universe at high energy. The ANTARES collaboration aims at building a large undersea neutrino detector able to observe astrophysical sources (AGNs, X-ray binary systems, ...) and to study particle physics topics (neutrino oscillation, ...). After a description of the research opportunities of such a detector, a status report of the experiment will be made.

S. Basa

1999-04-16

306

Research Paper Cosmic Ray Impact on Extrasolar Earth-Like Planets in Close-in Habitable Zones  

Microsoft Academic Search

Because of their different origins, cosmic rays can be subdivided into galactic cosmic rays and solar\\/stellar cosmic rays. The flux of cosmic rays to planetary surfaces is mainly determined by two planetary parameters: the atmospheric density and the strength of the internal mag- netic moment. If a planet exhibits an extended magnetosphere, its surface will be protected from high-energy cosmic

J.-M. GRIEMEIER; A. STADELMANN; U. MOTSCHMANN; N. K. BELISHEVA; H. LAMMER; H. K. BIERNAT

307

Cosmic Rays Near the Equator and to >50 S Latitude in 2004-2006; Observations from the COSPIN High Energy Telescope on Ulysses and the CRNC Telescope on IMP- 8.  

NASA Astrophysics Data System (ADS)

Cosmic ray modulation models that include gradient and curvature drifts predict that, for the present sign of the heliospheric magnetic field, the modulated cosmic ray intensity should decrease from the equator towards the poles near solar minimum, corresponding to negative latitude gradients. In the previous high latitude phases of the Ulysses mission near solar minimum in 1994-95, positive latitude gradients were found, consistent with predictions for the sign of the heliospheric field observed at that time. Also, quasi-periodic intensity modulations produced by CIRs in the current sheet were observed to persist to near-polar latitudes. Since its aphelion and distant Jupiter flyby near the heliospheric equator in 2004 Ulysses has been climbing steadily in latitude. Ulysses remained in the region swept by the heliospheric current sheet through 2005. It exited the current sheet region in early 2006 at a latitude of about 38 S. By July 2006 it had reached a latitude of >50 S, well above the current sheet. In the same period, solar activity has steadily decreased, though a few large solar energetic particle/CME events continued to occur through 2005. Since early 2006, no significant solar events have disrupted measurement of modulated cosmic ray intensities, which continue rising towards solar minimum levels. With measurements of >35 MeV/n protons and helium from the COSPIN High Energy Telescope on Ulysses compared to observations in nearly identical energy ranges from the IMP-8 CRNC experiment near Earth, we have been attempting to measure the magnitude and sign of latitude gradients as Ulysses rises in latitude. In the current sheet region, we find no evidence for latitude gradients in either protons or helium, and we find much smaller intensity variations in response to CIRs than observed in the similar phase of the previous solar cycle. We will report continuing observations to latitudes >50 S relating to our search for latitude gradients and also for evidence of the persistence of intensity modulations produced by CIRs to high latitudes. This work was supported in part by NASA/JPL Contract 1247101.

McKibben, R. B.; Lopate, C.; Connell, J. J.

2006-12-01

308

Extragalactic Very High Energy Gamma-Ray Background  

NASA Astrophysics Data System (ADS)

We study the origin of the extragalactic diffuse gamma-ray background using the data from the Fermi telescope. To estimate the background level, we count photons at high Galactic latitudes |b| > 60. Subtracting photons associated with known sources and the residual cosmic-ray and Galactic diffuse backgrounds, we estimate the extragalactic gamma-ray background (EGB) flux. We find that the spectrum of EGB in the very high energy band above 30 GeV follows the stacked spectrum of BL Lac objects. Large Area Telescope data reveal the positive (1 + z) k , 1 < k < 4 cosmological evolution of the BL Lac source population consistent with that of their parent population, Fanaroff-Riley type I radio galaxies. We show that EGB at E > 30 GeV could be completely explained by emission from unresolved BL Lac objects if k ~= 3.

Neronov, A.; Semikoz, D. V.

2012-09-01

309

EXTRAGALACTIC VERY HIGH ENERGY GAMMA-RAY BACKGROUND  

SciTech Connect

We study the origin of the extragalactic diffuse gamma-ray background using the data from the Fermi telescope. To estimate the background level, we count photons at high Galactic latitudes |b| > 60 Degree-Sign . Subtracting photons associated with known sources and the residual cosmic-ray and Galactic diffuse backgrounds, we estimate the extragalactic gamma-ray background (EGB) flux. We find that the spectrum of EGB in the very high energy band above 30 GeV follows the stacked spectrum of BL Lac objects. Large Area Telescope data reveal the positive (1 + z) {sup k}, 1 < k < 4 cosmological evolution of the BL Lac source population consistent with that of their parent population, Fanaroff-Riley type I radio galaxies. We show that EGB at E > 30 GeV could be completely explained by emission from unresolved BL Lac objects if k {approx_equal} 3.

Neronov, A. [ISDC Data Center for Astrophysics, Chemin d'Ecogia 16, CH-1290 Versoix (Switzerland); Semikoz, D. V. [APC, 10 rue Alice Domon et Leonie Duquet, F-75205 Paris Cedex 13 (France)

2012-09-20

310

Muon Charge Ratio of Ultrahigh Energy Cosmic Rays  

E-print Network

The muon charge ratio of ultrahigh energy cosmic rays may provide information to detect the composition of the primary cosmic rays. We propose to extract the charge information of high energy muons in very inclined extensive air showers by analyzing their relative lateral positions in the shower transverse plane.

Bo-Qiang Ma

2008-08-19

311

Cosmic Rays: "A Thin Rain of Charged Particles."  

ERIC Educational Resources Information Center

Discussed are balloons and electroscopes, understanding cosmic rays, cosmic ray paths, isotopes and cosmic-ray travel, sources of cosmic rays, and accelerating cosmic rays. Some of the history of the discovery and study of cosmic rays is presented. (CW)

Friedlander, Michael

1990-01-01

312

Cosmic reionization by primordial cosmic rays  

NASA Astrophysics Data System (ADS)

Context. After the so-called cosmic recombination, the expanding universe entered into a period of darkness since most of the matter was in a neutral state. About a billion years later, however, the intergalactic space was once again ionized. The process, known as the cosmic reionization, required the operation of mechanisms that are not well understood. Among other ionizing sources, Population III stars, mini-quasars, and X-ray emitting microquasars have been invoked. Aims: We propose that primordial cosmic rays, accelerated at the termination points of the jets of the first microquasars, may have contributed to the reionization of the intergalactic space as well. Methods: We quantify the ionization power of cosmic rays (electrons and protons) in the primordial intergalactic medium. This power is calculated using extensive particle cascade simulations. Results: We establish that, depending on the fraction of electrons to protons accelerated in the microquasar jets, cosmic rays should have contributed to the reionization of the primordial intergalactic medium as much as X-rays from microquasar accretion disks. If the primordial magnetic field was of the order of 10-17 G, as some models suggest, cosmic rays had an important role in ionizing the neutral material far beyond the birth places of the first stars.

Tueros, M.; del Valle, M. V.; Romero, G. E.

2014-10-01

313

On Cosmic Ray Propagation  

NASA Astrophysics Data System (ADS)

Cosmic ray propagation is diffusive because of pitch angle scattering by waves. We demonstrate that if the high-amplitude magnetic turbulence with (delta B)/B ~ 1 is present on top of the mean field gradient, the diffusion becomes asymmetric. As an example, we solve this diffusion problem in one dimension analytically with a Markov chain analysis. The cosmic ray density markedly differs from the standard diffusion prediction. The equation for the continuous limit is also derived, which shows limitations of the convection-diffusion equation. There is an interesting connection of this problem to laboratory experimental studies of particle transport in multi-mirror machines. The implications of the results are discussed. Supported by grant DOE grant DE-FG02-07ER54940 and NSF grant AST-1209665.

Medvedev, Mikhail

2014-06-01

314

Cosmic Rays in Thunderstorms  

NASA Astrophysics Data System (ADS)

Cosmic Rays in Thunderstorms Cosmic rays are protons and heavier nuclei that constantly bombard the Earth's atmosphere with energies spanning a vast range from 109 to 1021 eV. At typical altitudes up to 10-20 km they initiate large particle cascades, called extensive air showers, that contain millions to billions of secondary particles depending on their initial energy. These particles include electrons, positrons, hadrons and muons, and are concentrated in a compact particle front that propagates at relativistic speed. In addition, the shower leaves behind a trail of lower energy electrons from ionization of air molecules. Under thunderstorm conditions these electrons contribute to the electrical and ionization processes in the cloud. When the local electric field is strong enough the secondary electrons can create relativistic electron run-away avalanches [1] or even non-relativistic avalanches. Cosmic rays could even trigger lightning inception. Conversely, strong electric fields also influence the development of the air shower [2]. Extensive air showers emit a short (tens of nanoseconds) radio pulse due to deflection of the shower particles in the Earth's magnetic field [3]. Antenna arrays, such as AERA, LOFAR and LOPES detect these pulses in a frequency window of roughly 10-100 MHz. These systems are also sensitive to the radiation from discharges associated to thunderstorms, and provide a means to study the interaction of cosmic ray air showers and the electrical processes in thunderstorms [4]. In this presentation we discuss the involved radiation mechanisms and present analyses of thunderstorm data from air shower arrays [1] A. Gurevich et al., Phys. Lett. A 165, 463 (1992) [2] S. Buitink et al., Astropart. Phys. 33, 1 (2010) [3] H. Falcke et al., Nature 435, 313 (2005) [4] S. Buitink et al., Astron. & Astrophys. 467, 385 (2007)

Buitink, Stijn; Scholten, Olaf; van den Berg, Ad; Ebert, Ute

2013-04-01

315

Relativistic heavy cosmic rays  

NASA Technical Reports Server (NTRS)

During three balloon flights of a 1 sq m sr ionization chamber/Cerenkov counter detector system, measurements were made of the atmospheric attenuation, flux, and charge composition of cosmic ray nuclei with 16 is less than or = Z is less than or = 30 and rigidity greater than 4.5 GV. The attenuation mean free path in air of VH (20 less than or = Z less than or = 30) nuclei is found to be 19.7 + or - 1.6 g/sq cm, a value somewhat greater than the best previous measurement. The attenuation mean free path of iron is found to be 15.6 + or - 2.2 g/sq cm, consistent with predictions of geometric cross-section formulae. An absolute flux of VH nuclei 10 to 20% higher than earlier experiments at similar geomagnetic cutoff and level of solar activity was measured. The relative abundances of even-charged nuclei are found to be in good agreement with results of other recent high resolution counter experiments. The observed cosmic ray chemical composition implies relative abundances at the cosmic ray source of Ca/Fe = 0.12 + or - 0.04 and S/Fe = 0.14 + or - 0.05.

Mewaldt, R. A.; Fernandez, J. I.; Israel, M. H.; Klarmann, J.; Binns, W. R.

1972-01-01

316

Strangelets accelerated by pulsars in galactic cosmic rays  

E-print Network

It is shown that nuggets of strange quark matter may be extracted from the surface of pulsars and accelerated by strong electric fields to high energies if pulsars are strange stars with the crusts, comprised of nuggets embedded in a uniform electron background. Such high energy nuggets called usually strangelets give an observable contribution into galactic cosmic rays and may be detected by the upcoming cosmic ray experiment Alpha Magnetic Spectrometer AMS-02 on the International Space Station.

K. S. Cheng; V. V. Usov

2006-11-20

317

Ultrahigh Energy Cosmic Rays from Gamma Ray Bursts: Implications of the Recent Observational Results by Milagro  

E-print Network

It has been speculated earlier that Gamma Ray Bursts are sources of ultrahigh energy cosmic rays. Recently, the search for high energy photons from Gamma Ray Bursts by Milagro group has put limits on the isotropic luminosity of these transient sources in very high energy photons. The implications of the results obtained by Milagro to our understanding of the ultrahigh energy cosmic ray spectrum from these sources have been discussed in the present work.

Nayantara Gupta

2004-10-07

318

Cosmic rays and space weather  

NASA Astrophysics Data System (ADS)

It is well known that in periods of great FEP (Flare Energetic Particle), fluxes can be so big that memory of computers and other electronics in space may be destroyed, satellites and spacecrafts became dead (each year insurance companies paid more than 500,000,000 dollars for these failures). In these periods is necessary to switch off some part of electronics for short time to protect computer memories. These periods are also dangerous for astronauts on space-ships, and passengers and crew in commercial jets (especially during S5 radiation storms according to classification of NOAA). The problem is how to forecast exactly these dangerous phenomena. We show that exact forecast can be made by using high-energy particles (about 5-10 GeV/nucleon and higher) which transportation from the Sun is characterized by much bigger diffusion coefficient than for small and middle energy particles. Therefore high energy particles came from the Sun much more early (8-20 minutes after acceleration and escaping into solar wind) than main part of smaller energy particles caused dangerous situation for electronics and people health (about 30-60 minutes later). We describe here principles and experience of automatically working programs "FEP-Search-1 min", "FEP-Search-2 min","FEP-Search-5 min", developed and checked in the Emilio Segre' Observatory of Israel Cosmic Ray Center (2025 m above sea level, cut-off rigidity 10.8 GV). The second step is automatically determination of flare energetic particle spectrum, and then automatically determination of diffusion coefficient in the interplanetary space, time of ejection and energy spectrum of FEP in source; forecasting of expected FEP flux and radiation hazard for space-probes in space, satellites in the magnetosphere, jets and various objects in the atmosphere and on the ground. We will describe also the theory and experience of high energy cosmic ray using for forecasting of major geomagnetic storms accompanied by Forbush-effects (what influenced very much on communications, working of navigation systems, satellites and high-level technology systems in space and, the atmosphere, and on the ground). The review and original part will contain following parts: 1. Introduction (cosmic rays as object and instrument of space weather monitoring and forecasting). 2. On-line search of the start of great Flare Energetic Particle (FEP) events, automatically formation of Alerts, estimation of probability of false alerts and probability of missing alerts (realized in Israel Cosmic Ray Center and Emilio Segre Observatory). 3. On-line determination of flare energetic particle spectrum by the method of coupling functions. 4. Automatically determination of diffusion coefficient in the interplanetary space, time of ejection and energy spectrum of FEP in source; forecasting of expected FEP flux and radiation hazard for space-probes in space, satellites in the magnetosphere, jets and various objects in the atmosphere, and on the ground in dependence of cut-off rigidity. 5. Cosmic ray using for forecasting of major geomagnetic storms accompanied by Forbush-effects.

Dorman, L. I.

2003-04-01

319

Point source search techniques in ultra high energy gamma ray astronomy  

Microsoft Academic Search

Searches for point astrophysical sources of ultra high energy (UHE) gamma rays are plagued by large numbers of background events from isotropic cosmic rays. Some of the methods that have been used to estimate the expected number of background events coming from the direction of a possible source are found to contain biases. Search techniques that avoid this problem are

D. E. Alexandreas; D. Berley; S. Biller; G. M. Dion; J. A. Goodman; T. J. Haines; C. M. Hoffman; E. Horch; X.-Q. Lu; C. Sinnis; G. B. Yodh; W. Zhang

1993-01-01

320

Research Concerning Detection of Cosmic Rays  

NASA Astrophysics Data System (ADS)

Throughout my academic career at Loyola I have carried out research with the Loyola University Cosmic Event Detection System concerning the possibility of detection of ultra high energy cosmic rays (UHECRs) based on radio meteor scattering methods. This research was furthered through summer internships and research fellowships at Adler Planetarium Chicago and Stony Brook University in New York. At Adler Planetarium we used a helium balloon carrying a Geiger counter and other equipment to record the cosmic ray flux at various points in the atmosphere. The results clearly show the flux depends on the atmospheric density. At Stony Brook University I studied their advanced system for detecting cosmic rays in similar manner to radio meteor scattering principles. Research there focused on detection algorithms and also on the possibility of utilizing Digital Tv (DTv) signals for further research. Through the research a solid understanding of cosmic rays was formed including topics such as origins and energy scales of cosmic rays, both of which pose unanswered questions. )

Grady, Maxwell; Cunningham, John; Kuhlmann, Steve; Spinka, Hal; Underwood, Dave; Hammergren, Mark

2010-02-01

321

Development of TUS pinhole cameras for observing transient luminous events from space and establishing role of those events as a background for ultra-high-energy cosmic-ray measurements  

NASA Astrophysics Data System (ADS)

The TUS (tracking ultraviolet setup) experiment is intended for the observation from space of ultraviolet (UV) fluorescence induced both by ultra-high-energy cosmic rays (UHECRs) with energies above 5 1019 eV and by transient luminous events (TLEs) occurring in the upper atmosphere. These two types of events are very different in terms of duration, lateral shape, and intensity; thus, each behaves as a background for the other. The TUS is equipped with two conventional pinhole cameras as auxiliary instrumentation to detect and efficiently distinguish TLEs from UHECRs. Each pinhole camera contains a MAPMT (multi-anode photo-multiplier tube) and its associated analog and digital electronics. The R11265-03-M64 MAPMT has been custom-made for space applications by Hamamatsu Photonics, particularly for the future EUSO (Extreme Universe Space Observatory) UHECR space mission. Thus, the TUS pinhole system will be the test bench for the deployment in space of a large number, 5000, of MAPMTs. In this study, we present the design and fabrication of the pinhole cameras, and we estimate the detectability of TLEs with respect to atmospheric light background.

Kim, Ji Eun; Lee, Jik; Park, A. H.; Park, I. H.; Garipov, G. K.; Khrenov, B. A.; Klimov, P. A.; Panasyuk, M. I.

2014-03-01

322

Are extragalactic gamma ray bursts the source of the highest energy cosmic rays?  

E-print Network

Recent observations with the large air shower arrays of ultra high energy cosmic rays (UHECR) and recent measurements/estimates of the redshifts of gamma ray bursts (GRBs) seem to rule out extragalactic GRBs as the source of the cosmic rays that are observed near Earth, including those with the highest energies.

Arnon Dar

1999-01-03

323

The High Energy cosmic-Radiation Detection (HERD) Facility onboard China's Future Space Station  

E-print Network

The High Energy cosmic-Radiation Detection (HERD) facility is one of several space astronomy payloads of the cosmic lighthouse program onboard China's Space Station, which is planned for operation starting around 2020 for about 10 years. The main scientific objectives of HERD are indirect dark matter search, precise cosmic ray spectrum and composition measurements up to the knee energy, and high energy gamma-ray monitoring and survey. HERD is composed of a 3-D cubic calorimeter (CALO) surrounded by microstrip silicon trackers (STKs) from five sides except the bottom. CALO is made of about 10$^4$ cubes of LYSO crystals, corresponding to about 55 radiation lengths and 3 nuclear interaction lengths, respectively. The top STK microstrips of seven X-Y layers are sandwiched with tungsten converters to make precise directional measurements of incoming electrons and gamma-rays. In the baseline design, each of the four side SKTs is made of only three layers microstrips. All STKs will also be used for measuring the cha...

Zhang, S N

2014-01-01

324

How to Detect Cosmic Rays  

NSDL National Science Digital Library

In this lesson on cosmic rays, students will explain two examples of a cosmic ray detector. Includes information about student preconceptions and a demonstration that requires a geiger counter and optional access to a small radioactive source that emits energetic helium nuclei (alpha particles), e.g., the mineral the mineral autunite, which contains uranium. This is activity two of four from The Cosmic Ray Telescope for the Effects of Radiation (CRaTER).

325

PARSEC: PARametrized Simulation Engine for Cosmic rays  

NASA Astrophysics Data System (ADS)

PARSEC (PARametrized Simulation Engine for Cosmic rays) is a simulation engine for fast generation of ultra-high energy cosmic ray data based on parameterizations of common assumptions of UHECR origin and propagation. Implemented are deflections in unstructured turbulent extragalactic fields, energy losses for protons due to photo-pion production and electron-pair production, as well as effects from the expansion of the universe. Additionally, a simple model to estimate propagation effects from iron nuclei is included. Deflections in the Galactic magnetic field are included using a matrix approach with precalculated lenses generated from backtracked cosmic rays. The PARSEC program is based on object oriented programming paradigms enabling users to extend the implemented models and is steerable with a graphical user interface.

Bretz, Hans-Peter; Erdmann, Martin; Schiffer, Peter; Walz, David; Winchen, Tobias

2015-02-01

326

Particles and Cosmology: Learning from Cosmic Rays  

E-print Network

The density budget of the Universe is reviewed, and then specific particle candidates for non-bayonic dark matter are introduced, with emphasis on the relevance of cosmic-ray physics. The sizes of the neutrino masses indicated by recent atmospheric and solar neutrino experiments may be too small to contribute much hot dark matter. My favoured candidate for the dominant cold dark matter is the lightest supersymmetric particle, which probably weighs between about 50 GeV and about 600 GeV. Strategies to search for it via cosmic rays due to annihilations in the halo, Sun and Earth, or via direct scattering experiments, are mentioned. Possible superheavy relic particles are also discussed, in particular metastable string- or M-theory cryptons, that may be responsible for the ultra-high-energy cosmic rays. Finally, it is speculated that a non-zero contribution to the cosmological vacuum energy might result from incomplete relaxation of the quantum-gravitational vacuum.

John Ellis

1999-11-23

327

The HEAO-3 Cosmic Ray Isotope spectrometer  

NASA Technical Reports Server (NTRS)

This paper describes the Cosmic Ray Isotope instrument launched aboard the HEAO-3 satellite on September 20, 1979. The primary purpose of the experiment is to measure the isotopic composition of cosmic ray nuclei from Be-7 to Fe-58 over the energy range 0.5 to 7 GeV/nucleon. In addition charge spectra will be measured between beryllium and tin over the energy range 0.5 to 25 GeV/nucleon. The charge and isotope abundances measured by the experiment provide essential information needed to further our understanding of the origin and propagation of high energy cosmic rays. The instrument consists of 5 Cerenkov counters, a 4 element neon flash tube hodoscope and a time-of-flight system. The determination of charge and energy for each particle is based on the multiple Cerenkov technique and the mass determination will be based upon a statistical analysis of particle trajectories in the geomagnetic field.

Bouffard, M.; Engelmann, J. J.; Koch, L.; Soutoul, A.; Lund, N.; Peters, B.; Rasmussen, I. L.

1982-01-01

328

The LDEF ultra heavy cosmic ray experiment  

NASA Technical Reports Server (NTRS)

The LDEF Ultra Heavy Cosmic Ray Experiment (UHCRE) used 16 side viewing LDEF trays giving a total geometry factor for high energy cosmic rays of 30 sq m sr. The total exposure factor was 170 sq m sr y. The experiment is based on a modular array of 192 solid state nuclear track detector stacks, mounted in sets of four in 48 pressure vessels. The extended duration of the LDEF mission has resulted in a greatly enhanced potential scientific yield from the UHCRE. Initial scanning results indicate that at least 1800 cosmic ray nuclei with Z greater than 65 were collected, including the world's first statistically significant sample of actinides. Post flight work to date and the current status of the experiment are reviewed.

Osullivan, D.; Thompson, A.; Bosch, J.; Keegan, R.; Wenzel, K.-P.; Smit, A.; Domingo, C.

1992-01-01

329

Neutrons and antiprotons in ultrahigh energy cosmic rays  

E-print Network

The neutron fraction in the very high energy cosmic rays near the Greisen-Zatsepin-Kuzmin (GZK) cutoff energy is analyzed by taking into account the time dilation effect of the neutron decays and also the pion photoproduction behaviors above the GZK cutoff. We predict a non-trivial neutron fraction above the GZK cutoff and a negligibly small neutron fraction below. However, there should be a large antiproton fraction in the high energy cosmic rays below the GZK cutoff in several existing models for the observed cosmic-ray events above and near the GZK cutoff. Such a large antiproton fraction can manifest itself by the muon charge ratio $\\mu^+/\\mu^-$ in the collisions of the primary nucleon cosmic rays with the atmosphere, if there is no neutron contribution. We suggest to use the muon charge ratio as one of the information to detect the composition of the primary cosmic rays near or below the GZK cutoff.

W-Y. P. Hwang; Bo-Qiang Ma

2005-09-06

330

Antiprotons in cosmic rays  

NASA Technical Reports Server (NTRS)

Recent experimental observations and results are discussed. It was found that the approximately 50 antiprotons collected in balloon experiments to date have generated considerable theoretical interest. Clearly, confirmatory experiments and measurements over an extended energy range are required before definite conclusions are drawn. Antiproton measurements have a bearing on astrophysical problems ranging from cosmic ray propagation to issues of cosmological import. The next generation of balloon experiments and the Particle Astrophysics Magnet Facility being discussed for operation on NASA's space station should provide data and insights of highest interest.

Balasubrahmanyan, V. K.; Ormes, J. F.; Streitmatter, R. E.

1987-01-01

331

Background modelling in very-high-energy gamma-ray astronomy  

Microsoft Academic Search

Context: Ground based Cherenkov telescope systems measure astrophysical gamma-ray emission against a background of cosmic-ray induced air showers. The subtraction of this background is a major challenge for the extraction of spectra and morphology of gamma-ray sources. Aims: The unprecedented sensitivity of the new generation of ground based very-high-energy gamma-ray experiments such as HESS has lead to the discovery of

D. Berge; S. Funk; J. Hinton

2007-01-01

332

The Monoceros very-high-energy gamma-ray source  

NASA Astrophysics Data System (ADS)

The H.E.S.S. telescope has detected a new very high energy gamma-ray point-like source, HESS J0632+058. It is the first point-like source detected by H.E.S.S. without any obvious counterpart. The excess lies in a region where interaction between the Monoceros supernova remnant and the Rosette Nebula may occur. The energy spectrum of the observed gamma-rays is well described by a power law of index 2.5, and the gamma-ray flux above 400 GeV corresponds to 3.7% of that from the Crab Nebula. Different objects at other wavelengths may be associated with this source. HESS J0632+058 lies just within the 99% position confidence contour for an EGRET source, 3EG J0634+0521, and the EGRET spectrum is consistent with an extrapolation of the H.E.S.S. spectrum. A study of CO observations, in particular from NANTEN, was made to trace dense molecular clouds which may be coincident with the source position and may be an efficient target for cosmic rays accelerated by the Monoceros SNR. No coincident cloud was found. An X-ray source detected by ROSAT, 1RXS J063258.3+054857, is coincident with the gamma-ray source. Another possible association is a Be star, MWC 148.

Fiasson, A.; Hinton, J. A.; Gallant, Y.; et al.

333

Cosmic rays and tests of fundamental principles  

E-print Network

It is now widely acknowledged that cosmic rays experiments can test possible new physics directly generated at the Planck scale or at some other fundamental scale. By studying particle properties at energies far beyond the reach of any man-made accelerator, they can yield unique checks of basic principles. A well-known example is provided by possible tests of special relativity at the highest cosmic-ray energies. But other essential ingredients of standard theories can in principle be tested: quantum mechanics, uncertainty principle, energy and momentum conservation, effective space-time dimensions, hamiltonian and lagrangian formalisms, postulates of cosmology, vacuum dynamics and particle propagation, quark and gluon confinement, elementariness of particles... Standard particle physics or string-like patterns may have a composite origin able to manifest itself through specific cosmic-ray signatures. Ultra-high energy cosmic rays, but also cosmic rays at lower energies, are probes of both "conventional" and new Physics. Status, prospects, new ideas, and open questions in the field are discussed. The Post Scriptum shows that several basic features of modern cosmology naturally appear in a SU(2) spinorial description of space-time without any need for matter, relativity or standard gravitation. New possible effects related to the spinorial space-time structure can also be foreseen. Similarly, the existence of spin-1/2 particles can be naturally related to physics beyond Planck scale and to a possible pre-Big Bang era.

Luis Gonzalez-Mestres

2011-09-22

334

Cosmic Ray Positrons from Cosmic Strings  

E-print Network

We study the spectrum of cosmic ray positrons produced by a scaling distribution of non-superconducting cosmic strings. In this scenario, the positrons are produced from the jets which form from the cosmic string cusp annihilation process. The spectral shape is a robust feature of our scenario, and is in good agreement with the results from the recent PAMELA and ATIC experiments. In particular, the model predicts a sharp upper cutoff in the spectrum, and a flux which rises as the upper cutoff is approached. The energy at which the flux peaks is determined by the initial jet energy. The amplitude of the flux can be adjusted by changing the cosmic string tension and also depends on the cusp annihilation efficiency.

Robert Brandenberger; Yi-Fu Cai; Wei Xue; Xinmin Zhang

2009-01-25

335

Phenomenology of cosmic ray air showers  

E-print Network

The properties of cosmic rays with energies above 1PeV have to be deduced from the spacetime structure and particle content of the air showers which they initiate. In this review, a summary of the phenomenology of these giant air showers is presented. We describe the hadronic interaction models used to extrapolate results from collider data to ultra high energies, an also the main electromagnetic processes that govern the longitudinal shower evolution as well as the lateral spread of particles.

M. T. Dova

2005-05-30

336

Cosmic Ray Neutron Flux Measurements  

Microsoft Academic Search

Cosmic rays are high-energetic particles originating from outer space that bombard the upper atmosphere of the Earth. Almost 90% of cosmic ray particles consist of protons, electrons and heavy ions. When these particles hit the Earth's atmosphere, cascade of secondary particles are formed. The most abundant particles reach to the surface of the Earth are muons, electrons and neutrons. In

Mathes Dayananda

2009-01-01

337

Testing Galactic Cosmic Ray Models  

NASA Technical Reports Server (NTRS)

Models of the Galactic Cosmic Ray Environment are used for designing and planning space missions. The exising models will be reviewed. Spectral representations from these models will be compared with measurements of galactic cosmic ray spectra made on balloon flights and satellite flights over a period of more than 50 years.

Adams, James H., Jr.

2010-01-01

338

Cosmic Rays, Clouds, and Climate  

Microsoft Academic Search

It has been proposed that Earth's climate could be affected by changes in cloudiness caused by variations in the intensity of galactic cosmic rays in the atmosphere. This proposal stems from an observed correlation between cosmic ray intensity and Earth's average cloud cover over the course of one solar cycle. Some scientists question the reliability of the observations, whereas others,

K. S. Carslaw; R. G. Harrison; J. Kirkby

2002-01-01

339

Testing Galactic Cosmic Ray Models  

NASA Technical Reports Server (NTRS)

Models of the Galactic Cosmic Ray Environment are used for designing and planning space missions. The existing models will be reviewed. Spectral representations from these models will be compared with measurements of galactic cosmic ray spectra made on balloon flights and satellite flights over a period of more than 50 years.

Adams, James H., Jr.

2009-01-01

340

Superbubbles and Local Cosmic Rays  

NASA Technical Reports Server (NTRS)

We consider the possibility that distinctive features of the local cosmic ray spectra and composition are influenced by the Solar system being embedded within the cavity of an ancient superbubble. Shifts in the measured cosmic ray composition between 10(exp 11) and 10(exp 20) eV as well as the "knee" and "second knee" may be understood in this picture.

Streitmatter, Robert E.; Jones, Frank C.

2005-01-01

341

Spiral arms as cosmic ray source distributions  

NASA Astrophysics Data System (ADS)

The Milky Way is a spiral galaxy with (or without) a bar-like central structure. There is evidence that the distribution of suspected cosmic ray sources, such as supernova remnants, are associated with the spiral arm structure of galaxies. It is yet not clearly understood what effect such a cosmic ray source distribution has on the particle transport in our Galaxy. We investigate and measure how the propagation of Galactic cosmic rays is affected by a cosmic ray source distribution associated with spiral arm structures. We use the PICARD code to perform high-resolution 3D simulations of electrons and protons in galactic propagation scenarios that include four-arm and two-arm logarithmic spiral cosmic ray source distributions with and without a central bar structure as well as the spiral arm configuration of the NE2001 model for the distribution of free electrons in the Milky Way. Results of these simulation are compared to an axisymmetric radial source distribution. Also, effects on the cosmic ray flux and spectra due to different positions of the Earth relative to the spiral structure are studied. We find that high energy electrons are strongly confined to their sources and the obtained spectra largely depend on the Earth's position relative to the spiral arms. Similar finding have been obtained for low energy protons and electrons albeit at smaller magnitude. We find that even fractional contributions of a spiral arm component to the total cosmic ray source distribution influences the spectra on the Earth. This is apparent when compared to an axisymmetric radial source distribution as well as with respect to the Earth's position relative to the spiral arm structure. We demonstrate that the presence of a Galactic bar manifests itself as an overall excess of low energy electrons at the Earth. Using a spiral arm geometry as a cosmic ray source distributions offers a genuine new quality of modeling and is used to explain features in cosmic ray spectra at the Earth that are else-wise attributed to other propagation effects. We show that realistic cosmic ray propagation scenarios have to acknowledge non-axisymmetric source distributions.

Werner, M.; Kissmann, R.; Strong, A. W.; Reimer, O.

2015-04-01

342

High energy gamma ray results from the second small astronomy satellite  

NASA Technical Reports Server (NTRS)

A high energy (35 MeV) gamma ray telescope employing a thirty-two level magnetic core spark chamber system was flown on SAS 2. The high energy galactic gamma radiation is observed to dominate over the general diffuse radiation along the entire galactic plane, and when examined in detail, the longitudinal and latitudinal distribution seem generally correlated with galactic structural features, particularly with arm segments. The general high energy gamma radiation from the galactic plane, explained on the basis of its angular distribution and magnitude, probably results primarily from cosmic ray interactions with interstellar matter.

Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Thompson, D. J.; Bignami, G. F.; Oegelman, H.; Oezel, M. F.; Tuemer, T.

1974-01-01

343

Cosmic Ray Related Undergraduate Experiments Roger W. Clay, Ziawuddin Kurban \\Lambda and Neville R. Wild  

E-print Network

Cosmic Ray Related Undergraduate Experiments Roger W. Clay, Ziawuddin Kurban \\Lambda and Neville R for a modest cost. We also describe some related experi­ ments. #12; 1 Introduction Primary cosmic rays presumed to be a high energy neutrino component. All these components of the cosmic ray beam are currently

Adelaide, University of

344

PAMELA measurements of high energy cosmic ray  

E-print Network

of a time-of-flight system, a permanent magnetic spectrometer, an electromagnetic calorimeter, a neutron longitudinal and transverse shower profile variables in the calorimeter for separating electromagnetic in identified positron events due to the production of neutral pions which decay electromagnetically. Positron

Haviland, David

345

Terrestrial Effects of High Energy Cosmic Rays  

E-print Network

are typically too energetic to be redirected [7]. . . . . . . . . . . . . . . . . 70 5.4 LET vs RBE. Circles shown above represent cells. If the energy is deposited on a number of critical points on a cell, the cell gets killed. Low LET radiation is ine cient... of photons and electrons with the atmospheric nuclei. Both photons and electrons interact with matter in di erent ways. The photon interaction can be described by pair production, photoelectric e ect and the Compton e ect. Pair production is the dominant...

Atri, Dimitra

2011-04-26

346

Supernova Remnants, Cosmic Rays, and GLAST  

SciTech Connect

The shock waves of supernova remnants (SNRs) are the traditional sources of Galactic cosmic rays, at least up to about 3000 TeV (the "knee" energy in the cosmic-ray spectrum). In the last decade or so, X-ray observations have confirmed in a few SNRs the presence of synchrotron-X-ray-emitting electrons with energies of order 100 TeV. TeV photons from SNRs have been observed with ground-based air Cerenkov telescopes as well, but it is still unclear whether they are due to hadronic processes (inelastic p-p scattering of cosmic-ray protons from thermal gas, with secondary neutral pions decaying to gamma rays), or to leptonic processes (inverse-Compton upscattering of cosmic microwave background photons, or bremsstrahlung). The spatial structure of synchrotron X-rays as observed with the Chandra X-ray Observatory suggests the remarkable possibility that magnetic fields are amplified by orders of magnitude in strong shock waves. The electron spectra inferred from X-rays reach 100 TeV, but at that energy are cutting off steeply, well below the "knee" energy. Are the cutoff processes due only to radiative losses so that ion spectra might continue unsteepened? Can we confirm the presence of energetic ions in SNRs at all? Are typical SNRs capable of supplying the pool of Galactic cosmic rays? Is strong magnetic-field amplification a property of strong astrophysical shocks in general? These major questions require the next generation of observational tools. I shall outline the theoretical and observational framework of particle acceleration to high energies in SNRs, and shall describe how GLAST will advance this field.

Professor Steve Reynolds

2006-02-13

347

Supernova Remnants, Cosmic Rays, and GLAST  

SciTech Connect

The shock waves of supernova remnants (SNRs) are the traditional sources of Galactic cosmic rays, at least up to about 3000 TeV (the 'knee' energy in the cosmic-ray spectrum). In the last decade or so, X-ray observations have confirmed in a few SNRs the presence of synchrotron-X-ray-emitting electrons with energies of order 100 TeV. TeV photons from SNRs have been observed with ground-based air Cerenkov telescopes as well, but it is still unclear whether they are due to hadronic processes (inelastic p-p scattering of cosmic-ray protons from thermal gas, with secondary neutral pions decaying to gamma rays), or to leptonic processes (inverse-Compton upscattering of cosmic microwave background photons, or bremsstrahlung). The spatial structure of synchrotron X-rays as observed with the Chandra X-ray Observatory suggests the remarkable possibility that magnetic fields are amplified by orders of magnitude in strong shock waves. The electron spectra inferred from X-rays reach 100 TeV, but at that energy are cutting off steeply, well below the 'knee' energy. Are the cutoff processes due only to radiative losses so that ion spectra might continue unsteepened? Can we confirm the presence of energetic ions in SNRs at all? Are typical SNRs capable of supplying the pool of Galactic cosmic rays? Is strong magnetic-field amplification a property of strong astrophysical shocks in general? These major questions require the next generation of observational tools. I shall outline the theoretical and observational framework of particle acceleration to high energies in SNRs, and shall describe how GLAST will advance this field.

Reynolds, Steve (North Carolina State University) [North Carolina State University

2006-02-13

348

Cosmic ray source abundances and the acceleration of cosmic rays  

NASA Astrophysics Data System (ADS)

The galactic cosmic ray elemental source abundances display a fractionation that is possibly based on first ionization potential (FIP) or volatility. A few elements break the general correlation of FIP and volatility and the abundances of these may help to distinguish between models for the origin of the cosmic ray source material. Data from the Cosmic Ray Isotope Spectrometer instrument on NASA's Advanced Composition Explorer spacecraft were used to derive source abundances for several of these elements (Na, Cu, Zn, Ga, Ge). Three (Na, Cu, Ge) show depletions which could be consistent with a volatility-based source fractionation model. .

George, J. S.; Wiedenbeck, M. E.; Barghouty, A. F.; Binns, W. R.; Christian, E. R.; Cummings, A. C.; Hink, P. L.; Klarmann, J.; Leske, R. A.; Lijowski, M.; Mewaldt, R. A.; Stone, E. C.; von Rosenvinge, T. T.; Yanasak, N. E.

2000-09-01

349

A theory of Cosmic Rays  

E-print Network

We present a theory of non-solar cosmic rays (CRs) in which the bulk of their observed flux is due to a single type of CR source at all energies. The total luminosity of the Galaxy, the broken power-law spectra with their observed slopes, the position of the `knee(s)' and `ankle', and the CR composition and its variation with energy are all predicted in terms of very simple and completely `standard' physics. The source of CRs is extremely `economical': it has only one parameter to be fitted to the ensemble of all of the mentioned data. All other inputs are `priors', that is, theoretical or observational items of information independent of the properties of the source of CRs, and chosen to lie in their pre-established ranges. The theory is part of a `unified view of high-energy astrophysics' --based on the `Cannonball' model of the relativistic ejecta of accreting black holes and neutron stars. The model has been extremely successful in predicting all the novel properties of Gamma Ray Bursts recently observed with help of the Swift satellite. If correct, this model is only lacking a satisfactory theoretical understanding of the `cannon' that emits the cannonballs in catastrophic processes of accretion.

Arnon Dar; Alvaro De Rujula

2008-05-07

350

Some aspects of the scientific significance of high energy gamma ray astrophysics  

NASA Technical Reports Server (NTRS)

The attraction of high energy gamma-ray astronomy lies in this radiation relating directly to those processes in astrophysical situations which deviate most from thermo-dynamic equilibrium. Some examples of these phenomena which are known to or expected to emit gamma rays are cosmic rays as they interact in intergalactic space, the high energy particles in the magnetic fields of neutron stars, the death of a black hole, the explosion and residual of a supernova, lumps of Weakly Interacting Massive Particles, energetic solar particles interacting near the sun, and very high energy particles in the extreme conditions associated with active galaxies. Although the intensities are known to be low as seen near the earth, a partially compensating characteristic is that the very penetrating nature of high energy gamma rays increases the probability that they can escape from their origin and reach the solar system.

Fichtel, Carl E.

1991-01-01

351

Hadronic Cross sections: from cyclotrons to colliders to cosmic rays  

E-print Network

We present evidence for the saturation of the Froissart bound at high energy for {\\em all hadronic} total cross sections at high energies, and use this to unify $pp$ (and $\\bar p p$) total cross sections over the energy range from cyclotrons to colliders to ultra-high energy cosmic rays, an energy span from $\\sqrt s = 4$ GeV to 80 TeV.

Martin M. Block

2010-09-02

352

Cosmic rays in the heliosphere  

NASA Technical Reports Server (NTRS)

The different types of cosmic ray particles and their role in the heliosphere are briefly described. The rates of various energetic particles were examined as a function of time and used to derive various differential energy gradients. The Pioneer and Voyager cosmic ray observations throughout the heliosphere are indeed giving a perspective on the three-dimensional character and size of the heliosphere. Most clearly the observations are emphasizing the role that transient variations in the outer heliosphere, and most likely the heliospheric boundary shock, play in the 11 year solar cycle modulation of cosmic rays.

Webber, William R.

1987-01-01

353

Application of solar arrays in high-energy gamma-ray astronomy  

Microsoft Academic Search

SummaryThe previously suggested use of large solar-energy arrays for additional applications in astronomy and astrophysics is herein\\u000a analysed for the case of high-energy gamma-ray astronomy. We have studied by Monte Carlo techniques the response of an array\\u000a of 800 m2 reflective area to the ?erenkov light produced by relativistic electrons of high-energy cascades, initiated by primary cosmic\\u000a rays (gamma-rays and

C. Castagnoli; G. Navarra; M. Dardo; C. Morello

1983-01-01

354

Hydrodynamics of interstellar medium including cosmic rays  

Microsoft Academic Search

A relatively high pressure of cosmic rays in the interstellar medium causes noticeable dynamic effects. A system of MHD equations, that takes into account the action of cosmic rays, is discussed. The influence of cosmic rays on the stability of hydrostatic equilibrium of galactic halo is considered. The interaction between long hydromagnetic waves and cosmic rays is analyzed.

V. S. Ptuskin

1986-01-01

355

Hydrodynamics of interstellar medium including cosmic rays  

NASA Astrophysics Data System (ADS)

A relatively high pressure of cosmic rays in the interstellar medium causes noticeable dynamic effects. A system of MHD equations, that takes into account the action of cosmic rays, is discussed. The influence of cosmic rays on the stability of hydrostatic equilibrium of galactic halo is considered. The interaction between long hydromagnetic waves and cosmic rays is analyzed.

Ptuskin, V. S.

1986-08-01

356

Cosmic rays are on the air Studying the properties of radio signals from cosmic-ray  

E-print Network

Cosmic rays are on the air Studying the properties of radio signals from cosmic-ray induced air showers #12;#12;Cosmic rays are on the air Studying the properties of radio signals from cosmic-ray;#12;Contents 1 Introduction 1 1.1 Discovery of cosmic rays . . . . . . . . . . . . . . . . . . . . . . . 1 1

van Suijlekom, Walter

357

Cosmic ray modulation by interplanetary disturbances  

NASA Astrophysics Data System (ADS)

Interplanetary disturbances such as ICMEs (Interplanetary Coronal Mass Ejections) and CIRs (Corotating Interaction Regions), modulate high-energy cosmic rays reaching the Earth. Prior to the arrival of the disturbances at the Earth, ground based high-energy muon detectors can detect precursory effects in cosmic-ray anisotropy, such as precursory deficit and/or excess of intensity along the sunward IMF (Interplanetary Magnetic Field) direction. With suitable analyses, these precursors are found typically around 8 hours prior to the disturbance arrival at the Earth. The objective of this work is to analyze these precursors by using the Global Muon Detector Network (GMDN), an international network formed by four multidirectional muon detectors viewing a full range of the pitch angle measured from the sunward IMF direction. By analyzing the variation of the count rate global distribution of the observed intensity (instead of analyzing the count rate) precursory signatures can be enhanced when compared with analyses of count rates. For some events, it is possible to make almost a global distribution map of cosmic ray density using all the directional channels of the detectors. Precursory signature is generally accompanied by the interplanetary shock, but there are also some signatures not associated with the shock.

Braga, Carlos Roberto; Dal Lago, Alisson; Schuch, Nelson Jorge; da Silva, Marlos; Echer, Ezequiel; Demtrio Gonzalez Alarcon, Walter; Munakata, Kazuoki; Kuwabara, Takao; Kato, Chihiro; Bieber, John W.

358

Cosmic rays and grain alignment  

NASA Astrophysics Data System (ADS)

The recent detection of interstellar polarization in the solid CO feature near 4.67mum shows that CO-mantled grains can be aligned in cold molecular clouds. These observations conflict with a theory of grain alignment which attributes the polarization in molecular clouds to the effects of cosmic rays: according to this theory, oblate spheroidal grains with H_2O- and CO_2-dominated ice mantles are spun up to suprathermal energies by molecular evaporation from cosmic ray impact sites, but spin-up does not occur for CO-mantled grains. Motivated by this conflict, we re-examine the effects of cosmic rays on the alignment of icy grains. We show that the systematic torques produced by cosmic rays are insufficient to cause suprathermal spin. In principle, the random torques due to cosmic rays can enhance the efficiency of Davis-Greenstein alignment by raising the grain rotational temperature. However, a significant enhancement would require cosmic ray fluxes 6-7 orders of magnitude larger than the flux in a typical cold cloud.

Lazarian, A.; Roberge, W. G.

1997-06-01

359

Radar Detection of Cosmic Rays  

NASA Astrophysics Data System (ADS)

Progress in the study of high energy cosmic ray physics is limited by low flux. In order to collect substantial statistics above 10^19 eV, the two largest ground arrays currently in operation cover 800 km^2 (Telescope Array, Utah) and 3000 km^2 (Auger Observatory, Argentina). The logistics and cost of an order-of-magnitude increase in ground array aperture is prohibitive. In the literature, radar detection experiments have been proposed but substantial results have not been reported. We have deployed a low-power (1500 W) bistatic radar facility overlapping the Telescope Array (TA) in Delta, Utah. Data acquisition systems for the radar receivers were developed in parallel. This system has taught us a great deal, but our current focus is building and deploying a 40 kW transmitter and new high-gain transmitting antenna. Theoretical simulations of CR air shower scattering of radar show that coincidences with the ground array should be detected with this new system. An FCC license for the new transmitter/antenna has been obtained. Systems monitoring and data logging systems, as well as a new, intelligent self-triggered DAQ continue to be developed. We hope to deploy the self-triggered DAQ during the first few months of 2012 and complete the transmitte

Myers, Isaac

2012-03-01

360

Anomalous cosmic rays  

NASA Astrophysics Data System (ADS)

Anomalous cosmic rays (ACRs) first started showing up in observations 40 years ago. Within a few years a paradigm was developed to explain their origin: they begin their life as interstellar neutral atoms that drift into the heliosphere, become singly ionized by chargeexchange with a solar wind ion or by photoionization, are picked up by the expanding solar wind, and accelerated to the observed energies by diffusive shock acceleration at the solar wind termination shock. This paradigm became widely accepted and withstood the tests of further observations until 16 December 2004, when Voyager 1 crossed the termination shock and didn't find their source. In August 2007, Voyager 2 crossed the termination shock and also did not find the source location of ACRs. Clearly, the source location was not at the termination shock where the two Voyagers crossed. Alternative models have been proposed with acceleration elsewhere on the shock or by other acceleration processes in the heliosheath. We discuss the latest observations of ACRs from the Voyager spacecraft and hopefully shed more light on this ongoing puzzle.

Cummings, Alan C.; Stone, Edward C.

2013-02-01

361

Calculations of cosmic-ray helium transport in shielding materials  

NASA Technical Reports Server (NTRS)

The transport of galactic cosmic-ray helium nuclei and their secondaries through bulk shielding is considered using the straight-ahead approximation to the Boltzmann equation. A data base for nuclear interaction cross sections and secondary particle energy spectra for high-energy light-ion breakup is presented. The importance of the light ions H-2, H-3, and He-3 for cosmic-ray risk estimation is discussed, and the estimates of the fractional contribution to the neutron flux from helium interactions compared with other particle interactions are presented using a 1977 solar minimum cosmic-ray spectrum.

Cucinotta, Francis A.

1993-01-01

362

The survival of heavy nuclei in cosmic ray source environments  

NASA Technical Reports Server (NTRS)

The results are discussed that were obtained from the Goddard balloon spectrometer experiment to study the composition and energy distribution of high energy cosmic rays. The significant findings indicate that: (1) On a total energy scale, protons constitute only a minor proportion of the cosmic rays. They account for only 20 percent; the rest of the cosmic rays are complex nuclei. (2) All the nuclei have the same power low spectrum in total energy and so the composition appears to be independent of energy.

Balasubrahmanyan, V. K.

1972-01-01

363

Nineteenth International Cosmic Ray Conference. HE Sessions, Volume 6  

NASA Technical Reports Server (NTRS)

Papers contributed to the 19th International Cosmic Ray Conference which address high energy interactions and related phenomena are compiled. Particular topic areas include cross sections; particle production; nuclei and nuclear matter; nucleus-nucleus collisions; gamma ray and hadron spectra; C-jets, a-jets, and super families; and emulsion chamber simulations.

Jones, F. C. (compiler)

1985-01-01

364

Quantum Black Holes from Cosmic Rays  

E-print Network

We investigate the possibility for cosmic ray experiments to discover non-thermal small black holes with masses in the TeV range. Such black holes would result due to the impact between ultra high energy cosmic rays or neutrinos with nuclei from the upper atmosphere and decay instantaneously. They could be produced copiously if the Planck scale is in the few TeV region. As their masses are close to the Planck scale, these holes would typically decay into two particles emitted back-to-back. Depending on the angles between the emitted particles with respect to the center of mass direction of motion, it is possible for the simultaneous showers to be measured by the detectors.

Xavier Calmet; Lauretiu Ioan Caramete; Octavian Micu

2012-11-19

365

Cosmic Ray Electron Science with GLAST  

NASA Technical Reports Server (NTRS)

Cosmic ray electrons at high energy carry information about their sources, their definition in local magnetic fields and their interactions with the photon fields through which they travel. The spectrum of the particles is affected by inverse Compton losses and synchrotron losses, the rates of which are proportional to the square of the particle's energy making the spectra very steep. However, GLAST will be able to make unique and very high statistics measurements of electrons from approx. 20 to approx. 700 GeV that will allow us to search for anisotropies in anival direction and spectral features associated with some dark matter candidates. Complementary information on electrons of still higher energy will be required to see effects of possible individual cosmic ray sources.

Ormes, J. F.; Moiseev, Alexander

2007-01-01

366

Cosmic Ray Electron Science with GLAST  

NASA Astrophysics Data System (ADS)

Cosmic ray electrons at high energy carry information about their sources, their diffusion in local magnetic fields and their interactions with the photon fields through which they travel. The spectrum of the particles is affected by inverse Compton losses and synchrotron losses, the rates of which are proportional to the square of the particle's energy making the spectra very steep. However, GLAST will be able to make unique and very high statistics measurements of electrons from ~20 to ~700 GeV that will allow us to search for anisotropies in arrival direction and spectral features associated with some dark matter candidates. Complementary information on electrons of still higher energy will be required to see effects of possible individual cosmic ray sources.

Ormes, J. F.; Moiseev, Alexander

2007-07-01

367

Lunar/Solar effects on Cosmic Rays  

E-print Network

Lunar/Solar effects on Cosmic Rays By: Sophia Bauer & Jenna Valdez #12;Introduction When cosmic be less cosmic rays coming into the earth's atmosphere from the direction of the moon. We were interested in if the moon has an effect on the number of cosmic rays, and therefore muons that make it to the earth

California at Santa Cruz, University of

368

A search for ultra-high-energy gamma rays at the South Pole  

SciTech Connect

Recently it has been discovered that some X-ray binary systems (such as Cygnus X-3 and Vela X-1) emit gamma rays with energies greater than 100 terraelectronvolts. The gamma rays arise from the decay of neutral {pi}-mesons which in turn are produced by the interaction of energetic protons with gas in the region around the X-ray binary. These protons--the grandparents of the gamma rays--are accelerated in the complex electric and magnetic fields associated with the neutron star and accretion disc of the binary system. Only a fraction of the protons interact, and those which escape are injected into the interstellar medium to become cosmic rays. It is more fruitful to study the gamma rays as a clue to cosmic ray origin, rather than to look at the incoming proton beam itself: Unlike the charged protons which random walk as they are scattered by magnetic fields in the galaxy, the gamma rays travel in straight lines. This makes it possible to identify point sources, provided the exceedingly small gamma-ray signal can be picked out from the more abundant and isotropic cosmic-ray background. Detection of high-energy cosmic and gamma rays is rather complicated. The South Pole provides a unique location for studying X-ray binary systems which are candidate sources of ultra-high-energy gamma rays: Many more are visible than from northern latitudes and, most importantly, every source remains at constant elevation. This latter feature is particularly crucial because most of the sources detected so far appear to be sporadic emitters of radiations.

Pomerantz, M.A.; Perrett, J. (Univ. of Delaware, Newark (USA)); Watson, A.A.; Ogden, P.; Smith, N. (Univ. of Leeds (England))

1988-01-01

369

Very high-energy gamma-ray astronomy  

Microsoft Academic Search

Very high-energy gamma-ray astronomy has emerged as an exciting and vital field. In the last seven years, major discoveries have been made by experiments in space and on the ground. In space, instruments on the Compton Gamma Ray Observatory have identified high-energy emission from a variety of astrophysical sources, including gamma-ray bursts, spin-down pulsars, and active galaxies of the blazar

Ren A. Ong

1998-01-01

370

Significance of medium energy gamma ray astronomy in the study of cosmic rays  

NASA Technical Reports Server (NTRS)

Medium energy (about 10 to 30 MeV) gamma ray astronomy provides information on the product of the galactic electron cosmic ray intensity and the galactic matter to which the electrons are dynamically coupled by the magnetic field. Because high energy (greater than 100 MeV) gamma ray astronomy provides analogous information for the nucleonic cosmic rays and the relevant matter, a comparison between high energy and medium energy gamma ray intensities provides a direct ratio of the cosmic ray electrons and nucleons throughout the galaxy. A calculation of gamma ray production by electron bremsstrahlung shows that: bremsstrahlung energy loss is probably not negligible over the lifetime of the electrons in the galaxy; and the approximate bremsstrahlung calculation often used previously overestimates the gamma ray intensity by about a factor of two. As a specific example, expected medium energy gamma ray intensities are calculated for the speral arm model.

Fichtel, C. E.; Kniffen, D. A.; Thompson, D. J.; Bignami, G. F.; Cheung, C. Y.

1975-01-01

371

Status and future of high energy diffuse gamma-ray astronomy  

NASA Technical Reports Server (NTRS)

There are two distinctly different high energy diffuse gamma-ray components, one well correlated with broad galactic features and the other apparently isotropic and presumably extragalactic. The observed diffuse galactic high energy gamma radiation is generally thought to be produced in interactions between the cosmic rays and the interstellar matter and photons. It should then ultimately be possible to obtain from the diffuse galactic emission a detailed picture of the galactic cosmic-ray distribution, a high contrast view of the general structure of the galaxy, and further insight into molecular clouds. Two of the candidates for the explanation of the extragalactic diffuse radiation are the sum of emission from active galaxies and matter-antimatter annihilation. A major advancement in the study of the properties of both galactic and extragalactic gamma radiation should occur over the next decade.

Fichtel, C. E.

1983-01-01

372

The origin of cosmic rays  

E-print Network

The search for the origin of cosmic rays is a quest of almost a hundred years. A recent theoretical proposal gives quantitative predictions, which can be tested with data. Specifically, it has been suggested, that all cosmic rays can be attributed to just three source sites: i) supernova explosions into the interstellar medium, ii) supernova explosions into a stellar wind, and iii) powerful radiogalaxies. The cosmic rays from any extragalactic source suffer from interaction with the microwave background, leading to the Greisen-Zatsepin-Kuzmin cutoff. While the particle energies, the spectrum and the chemical composition of cosmic rays over the energy range from about GeV to about 100 EeV can be interpreted in the theory, there are exciting measurements now: New measurements show that there are cosmic ray events beyond the Greisen-Zatsepin-Kuzmin cutoff. We discuss here possible sources, and specifically ask whether powerful radiogalaxies are suitable candidates. The basic concepts used here are the minimal hypothesis that the intergalactic magnetic field is given by the galaxy distribution, and the observation that radio galaxies also cluster like galaxies.

Peter L. Biermann

1995-01-04

373

Cosmic-Ray Accelerators in Milky Way studied with the Fermi Gamma-ray Space Telescope  

SciTech Connect

High-energy gamma-ray astrophysics is now situated at a confluence of particle physics, plasma physics and traditional astrophysics. Fermi Gamma-ray Space Telescope (FGST) and upgraded Imaging Atmospheric Cherenkov Telescopes (IACTs) have been invigorating this interdisciplinary area of research. Among many new developments, I focus on two types of cosmic accelerators in the Milky-Way galaxy (pulsar, pulsar wind nebula, and supernova remnants) and explain discoveries related to cosmic-ray acceleration.

Kamae, Tuneyoshi; /SLAC /KIPAC, Menlo Park

2012-05-04

374

Gravity, Cosmic Rays and the LHC  

E-print Network

The high energy proton beams expected when the Large Hadron Collider (LHC) comes online should provide a pass/fail test for a gravity-related explanation of ultrahigh energy cosmic rays. The model predicts that particles have two kinds energies, equal for null gravitational potentials and, in the potential at the Earth, differing significantly above one TeV. If correct, a 7 TeV trajectory energy proton at the LHC would deliver a 23.5 TeV particle state energy in a collision.

Richard Shurtleff

2008-01-20

375

The source abundances of galactic cosmic rays  

NASA Technical Reports Server (NTRS)

The galactic cosmic ray source abundances have been determined from two complete datasets, one at low and the other at high energy. For both exponential and truncated exponential pathlength distributions (PLD), the two sets of source abundances show significant differences for the primary elements, i.e., the Fe/O ratio. An energy dependent PLD reduces but does not eliminate the discrepancy, and this may indicate an energy dependence in the source composition. New source abundances for Na, P, Cl, Ca, and Mn are derived.

Dwyer, R. D.; Garcia-Munoz, M.; Guzik, T. G.; Meyer, P.; Simpson, J. A.; Wefel, J. P.

1982-01-01

376

Space-atmospheric interactions of energetic cosmic rays  

NASA Astrophysics Data System (ADS)

Ultra-high energy cosmic rays are the most energetic particles in the Universe of which origin still remain a mystery since a century from their descovery. They are unique messengers coming from far beyond our Milky Way Galaxy, which provides insights into the fundamental matter, energy, space and time. As subatomic particles flying through space to nearly light speed, the ultra-high energy cosmic rays are so rare that they strike the Earth's atmosphere at a rate of up to only one particle per square kilometer per year or century. While the atmosphere is used as a giant calorimeter where cosmic rays induced air showers are initiated and the medium through which Cherenkov or fluorescence light or radio waves propagate, all cosmic ray measurements (performed either from space or ground) rely on an accurate atmospheric monitoring and understanding of atmospheric effects. The interdisciplinary link between Astroparticle Physics and Atmospheric Environment through the ultra-high energy comic rays space - atmospheric interactions, based on the present ground- and future space-based cosmic ray observatories, will be presented.

Isar, Paula Gina

2015-02-01

377

Cosmic Rays and Sunspot Numbers  

NSDL National Science Digital Library

In this activity students analyze and compare two or more graphs to determine if there is a correlation between sunspot number and the variation of cosmic ray flux. They discover that cosmic rays are very energetic particles, mostly protons and electrons, that enter the solar system from the depths of interstellar space and that although the Earth's magnetic field partially shields us from these particles, so too does the much more extended solar wind with its own magnetic field. This is a three-part lesson in which students will construct line graphs displaying the cosmic ray flux and sunspot numbers for a period of time, and then determine if there is a correlation. In order to compare these two sets of data, students will need to scale the data in order to visualize the results. Teacher and student notes for the graphing calculator are included.

Susan Higley

378

Asymmetric diffusion of cosmic rays  

E-print Network

Cosmic ray propagation is diffusive because of pitch angle scattering by waves. We demonstrate that if the high-amplitude magnetohydrodynamic turbulence with $\\tilde B/\\langle B\\rangle \\sim 1$ is present on top of the mean field gradient, the diffusion becomes asymmetric. As an example, we consider the vertical transport of cosmic rays in our Galaxy propagating away from a point-like source. We solve this diffusion problem analytically using a one-dimensional Markov chain analysis. We obtained that the cosmic ray density markedly differs from the standard diffusion prediction and has a sizable effect on their distribution throughout the galaxy. The equation for the continuous limit is also derived, which shows limitations of the convection-diffusion equation.

Medvedev, Mikhail V

2015-01-01

379

The microphysics and macrophysics of cosmic rays  

SciTech Connect

This review paper commemorates a century of cosmic ray research, with emphasis on the plasma physics aspects. Cosmic rays comprise only ?10{sup ?9} of interstellar particles by number, but collectively their energy density is about equal to that of the thermal particles. They are confined by the Galactic magnetic field and well scattered by small scale magnetic fluctuations, which couple them to the local rest frame of the thermal fluid. Scattering isotropizes the cosmic rays and allows them to exchange momentum and energy with the background medium. I will review a theory for how the fluctuations which scatter the cosmic rays can be generated by the cosmic rays themselves through a microinstability excited by their streaming. A quasilinear treatment of the cosmic raywave interaction then leads to a fluid model of cosmic rays with both advection and diffusion by the background medium and momentum and energy deposition by the cosmic rays. This fluid model admits cosmic ray modified shocks, large scale cosmic ray driven instabilities, cosmic ray heating of the thermal gas, and cosmic ray driven galactic winds. If the fluctuations were extrinsic turbulence driven by some other mechanism, the cosmic ray background coupling would be entirely different. Which picture holds depends largely on the nature of turbulence in the background medium.

Zweibel, Ellen G. [Departments of Astronomy and Physics and Center for Magnetic Self-Organization, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)] [Departments of Astronomy and Physics and Center for Magnetic Self-Organization, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2013-05-15

380

A study of M31, M87, NGC 253, and M82 in high-energy gamma rays  

NASA Technical Reports Server (NTRS)

The data from the Energetic Gamma Ray Experiment Telescope (EGRET) all-sky survey are examined for emission from the nearby galaxies M31, M87, NGC 253, and M82 in the high-energy (E greater than MeV) gamma-ray range. No significant emission is observed from any of these galaxies. The derived upper limits for all four galaxies are consistent with that expected from cosmic-ray interactions. For M87, the combination of the high-energy gamma-ray and radio data point to a lower limit of 7 microG for the magnetic field in the disk and 4 microG for the magnetic field in the halo, consistent with equipartition arguments. A study of NGC 253 and M82 show that EGRET observations do not sufficiently constrain the mean cosmic-ray energy density to provide more details on the cosmic-ray distribution in starburst galaxies.

Sreekumar, P.; Bertsch, D. L.; Dingus, B. L.; Esposito, J. A.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Lin, Y. C.

1994-01-01

381

WMAP, Planck, cosmic rays and unconventional cosmologies  

E-print Network

The claim by Gurzadyan et al. that the cosmological sky is a weakly random one where "the random perturbation is a minor component of mostly regular signal" has given rise to a series of useful exchanges. The possibility that the Cosmic Microwave Background radiation (CMB) data present trends in this direction would have strong implications for unconventional cosmologies. Similarly, data on ultra-high energy cosmic rays may contain signatures from new Physics generated beyond the Planck scale. It therefore seems legitimate, from a phenomenological point of view, to consider pre-Big Bang cosmologies as well as patterns where standard particles would not be the ultimate constituents of matter and the presently admitted principles of Physics would not necessarily be the fundamental ones. We discuss here prospects for some noncyclic, nonstandard cosmologies.

Luis Gonzalez-Mestres

2011-10-27

382

Cosmic rays at fluid discontinuities  

NASA Technical Reports Server (NTRS)

Cosmic-ray transport near discontinuities in the background fluid velocity is considered. Matching conditions for the cosmic-ray distribution are derived for both shear and compressive (shock) discontinuities, keeping terms to second order in the ratio of fluid speed to energetic-particle speed. Acceleration is found at shear discontinuities, which is not present in the first-order theory, and a modification of the matching condition at shocks. If there is no particle source concentrated at a shock, the new condition reduces to that obtained from first-order theory. Monte Carlo simulations show good agreement with the theory.

Jokipii, J. R.; Kota, J.; Morfill, G.

1989-01-01

383

Fun Times with Cosmic Rays  

NASA Technical Reports Server (NTRS)

Who would have thought cosmic rays could be so hip? Although discovered 90 years ago on death-defying manned balloon flights hip even by twenty-first-century extremesport standards cosmic rays quickly lost popularity as way-cool telescopes were finding way-too-cool phenomena across the electromagnetic spectrum. Yet cosmic rays are back in vogue, boasting their own set of superlatives. Scientists are tracking them down with new resolve from the Arctic to Antarctica and even on the high western plains of Argentina. Theorists, too, now see cosmic rays as harbingers of funky physics. Cosmic rays are atomic and subatomic particles - the fastest moving bits of matter in the universe and the only sample of matter we have from outside the solar system (with the exception of interstellar dust grains). Lower-energy cosmic rays come from the Sun. Mid-energy particles come from stellar explosions - either spewed directly from the star like shrapnel, or perhaps accelerated to nearly the speed of light by shock waves. The highest-energy cosmic rays, whose unequivocal existence remains one of astronomy's greatest mysteries, clock in at a staggering 10(exp 19) to 10(exp 22) electron volts. This is the energy carried in a baseball pitch; seeing as how there are as many atomic particles in a baseball as there are baseballs in the Moon, that s one powerful toss. No simple stellar explosion could produce them. At a recent conference in Albuquerque, scientists presented the first observational evidence of a possible origin for the highest-energy variety. A team led by Elihu Boldt at NASA s Goddard Space Flight Center found that five of these very rare cosmic rays (there are only a few dozen confirmed events) come from the direction of four 'retired' quasar host galaxies just above the arm of the Big Dipper, all visible with backyard telescopes: NGC 3610, NGC 3613, NGC 4589, and NGC 5322. These galaxies are billions of years past their glory days as the brightest beacons in the universe. Yet they still harbor central, supermassive black holes, which could generate energetic particles if they are spinning.

Wanjek, Christopher

2003-01-01

384

The cosmic ray source composition  

NASA Technical Reports Server (NTRS)

The cosmic ray source composition is shown to be related to the observed cosmic ray abundances by a set of linear equations which are valid for either ad hoc pathlength distributions or quantitative solutions to Galactic propagation models. These relations can be used to propagate abundances from the source or to the source, and the method described here allows a simple propagation of abundance uncertainties. A simultaneous analysis of B/C and (21-25)Fe indicates a need for truncation of the pathlength distribution.

Margolis, S. H.

1983-01-01

385

The high energy X-ray universe  

PubMed Central

Since its beginning in the early 1960s, the field of X-ray astronomy has exploded, experiencing a ten-billion-fold increase in sensitivity, which brought it on par with the most advanced facilities at all wavelengths. I will briefly describe the revolutionary first discoveries prior to the launch of the Chandra and XMM-Newton X-ray observatories, present some of the current achievements, and offer some thoughts about the future of this field. PMID:20404148

Giacconi, Riccardo

2010-01-01

386

Cosmic Rays -Richard Mewaldt http://www.srl.caltech.edu/personnel/dick/cos_encyc.html 1 of 3 09/22/2006 08:22 AM  

E-print Network

Cosmic Rays - Richard Mewaldt http://www.srl.caltech.edu/personnel/dick/cos_encyc.html 1 of 3 09 in 1996. It presents a general introduction to the field of cosmic rays. Cosmic Rays R. A. Mewaldt California Institute of Technology Cosmic rays are high energy charged particles, originating in outer space

Shepherd, Simon

387

Evaluation of Galactic Cosmic Ray Models  

NASA Technical Reports Server (NTRS)

Models of the galactic cosmic ray spectra have been tested by comparing their predictions to an evaluated database containing more than 380 measured cosmic ray spectra extending from 1960 to the present.

Adams, James H., Jr.; Heiblim, Samuel; Malott, Christopher

2009-01-01

388

Frontiers of Cosmic Ray Science 205 Long-Term Variations of Cosmic Rays and Terrestrial  

E-print Network

Frontiers of Cosmic Ray Science 205 Long-Term Variations of Cosmic Rays and Terrestrial Environmentth International Cosmic Ray Conference (August 2003, Tsukuba, Japan): SH 3.4 "Long-term variations," SH 3.5 "Long-term variation of cosmic rays studied by cosmogenic nuclides," SH 3.6 "Terrestrial

Usoskin, Ilya G.

389

Cosmic-Ray Detectors With Interdigitated Electrodes  

NASA Technical Reports Server (NTRS)

Detectors measure both positions of incidence and energies of incident charged particles. Stack of detector wafers intercept cosmic ray. Measure positions of incidence to determine cosmic-ray trajectory and charge generated within them (proportional to cosmic-ray energy dissipated within them). Interdigital electrode pattern repeated over many rows and columns on tops of detector wafers in stack. Electrode pattern defines pixels within which points of incidence of incident cosmic rays located.

Cunningham, Thomas J.; Mazed, Mohammed; Holtzman, Melinda J.; Fossum, Eric R.

1995-01-01

390

Cosmic-ray-veto detector system  

NASA Astrophysics Data System (ADS)

To reduce the cosmic-ray-induced neutron background, we are testing a cosmic-ray veto option with a neutron detector system that uses plastic scintillator slabs mounted on the outside of a H-3-tube detector. The scintillator slabs eliminate unwanted cosmic-ray events, enabling the detector to assay low-level plutonium samples, for which a low-background coincident signature is critical. This report describes the design and testing of the prototype cosmic-ray-veto detector system.

Miller, D. W.; Menlove, H. O.

1992-12-01

391

Cosmic-Ray Signatures of Dark Matter Decay  

E-print Network

In light of recent observations of an anomalous excess of high-energy positrons and electrons by the PAMELA and Fermi LAT experiments, we investigate exotic cosmic-ray signatures in scenarios with unstable dark matter that decays with an extremely long lifetime. We identify decay modes capable of explaining the observed anomalies and mention constraints arising from measurements of antiprotons and gamma rays. We also discuss complementary tests by measurements of anisotropies in diffuse gamma rays which should be accessible to Fermi.

David Tran

2009-11-12

392

Real-time cosmic ray monitoring system for space weather  

NASA Astrophysics Data System (ADS)

We have developed a real-time system to monitor high-energy cosmic rays for use in space weather forecasting and specification. Neutron monitors and muon detectors are used for our system, making it possible to observe cosmic rays with dual energy range observations. In large solar energetic particle (SEP) events, the ground level enhancement (GLE) can provide the earliest alert for the onset of the SEP event. The loss cone precursor anisotropy predicts the arrival of interplanetary shocks and the associated interplanetary coronal mass ejections (ICMEs), while the occurrence of bidirectional cosmic ray streaming indicates that Earth is within a large ICME. This article describes a set of real-time Web displays that clearly show the appearance of the GLE, loss cone precursor, and other space weather phenomena related to cosmic rays.

Kuwabara, T.; Bieber, J. W.; Clem, J.; Evenson, P.; Pyle, R.; Munakata, K.; Yasue, S.; Kato, C.; Akahane, S.; Koyama, M.; Fujii, Z.; Duldig, M. L.; Humble, J. E.; Silva, M. R.; Trivedi, N. B.; Gonzalez, W. D.; Schuch, N. J.

2006-08-01

393

Modulation and diffusion theory of cosmic rays  

NASA Technical Reports Server (NTRS)

Papers given on the modulation of galactic cosmic rays by the solar wind at the 14th International Cosmic Ray Conference are reviewed. Some of the topics treated in this review are Pioneer and Helios radial gradient measurement, heliolatitude effects in modulation models, diffusion (scattering) theory - including pitch angle diffusion diagrams - solar flare particle transport theory and cosmic ray fluctuations at neutron monitor energies.

Forman, M. A.

1975-01-01

394

How Cosmic Rays Affect Learning Objectives  

E-print Network

1 CRaTER: How Cosmic Rays Affect Humans Learning Objectives: · Students will be able to describe why cosmic rays are dangerous to astronauts. · Studentswilllearntodesignascientificinstrument. · Students will think critically about how to protect astronauts from cosmic rays. Preparation: None

Christian, Eric

395

Research in cosmic and gamma ray astrophysics  

NASA Technical Reports Server (NTRS)

Discussed here is research in cosmic ray and gamma ray astrophysics at the Space Radiation Laboratory (SRL) of the California Institute of Technology. The primary activities discussed involve the development of new instrumentation and techniques for future space flight. In many cases these instrumentation developments were tested in balloon flight instruments designed to conduct new investigations in cosmic ray and gamma ray astrophysics. The results of these investigations are briefly summarized. Specific topics include a quantitative investigation of the solar modulation of cosmic ray protons and helium nuclei, a study of cosmic ray positron and electron spectra in interplanetary and interstellar space, the solar modulation of cosmic rays, an investigation of techniques for the measurement and interpretation of cosmic ray isotopic abundances, and a balloon measurement of the isotopic composition of galactic cosmic ray boron, carbon, and nitrogen.

Stone, Edward C.; Mewaldt, Richard A.; Prince, Thomas A.

1992-01-01

396

Transition Effects of Cosmic Rays in the Atmosphere  

Microsoft Academic Search

The calculation of the multiplication of the soft component of the cosmic rays in the upper atmosphere is refined by use of the exact high energy radiative formulae of Bethe and Heitler, and the resulting diffusion equations are solved by the method of Snyder. Comparison with the vertical counter work of Pfotzer, and of Carmichael and Dymond, and with the

R. Serber

1938-01-01

397

Cosmic ray and neutrino tests of special relativity  

Microsoft Academic Search

Searches for anisotropies due to Earth's motion relative to a preferred frame modern versions of the Michelson-Morley experiment provide precise verifications of special relativity. We describe other tests, independent of this motion, that are or can become even more sensitive. The existence of high-energy cosmic rays places strong constraints on Lorentz non-invariance. Furthermore, if the maximum attainable speed

Sidney Coleman; Sheldon L. Glashow

1997-01-01

398

Nineteenth International Cosmic Ray Conference. HE Sessions, Volume 8  

NASA Technical Reports Server (NTRS)

Papers submitted for presentation at the 19th International Cosmic Ray Conference are compiled. The present volume contains papers addressing high energy interactions and related phenomena. Specific topic areas include muons, neutrinos, magnetic monopoles, nucleon decay, searches for new particles, and acoustic and thermoluminescence detection techniques.

Jones, F. C. (compiler)

1985-01-01

399

Cosmic gamma-ray bursts  

Microsoft Academic Search

The results of the observation of cosmic gamma-ray bursts are discussed and available theoretical models are presented. Emphasis is placed on a cosmological model in which a gamma burst results from a powerful (? 10511053 erg) and very short ( ?10 100 s) energy release which occurs in a compact ( ? 106107 cm) region and gives rise to a

Konstantin A Postnov

1999-01-01

400

The Cosmic Ray Electron Excess  

NASA Technical Reports Server (NTRS)

This slide presentation reviews the possible sources for the apparent excess of Cosmic Ray Electrons. The presentation reviews the Advanced Thin Ionization Calorimeter (ATIC) instrument, the various parts, how cosmic ray electrons are measured, and shows graphs that review the results of the ATIC instrument measurement. A review of Cosmic Ray Electrons models is explored, along with the source candidates. Scenarios for the excess are reviewed: Supernova remnants (SNR) Pulsar Wind nebulae, or Microquasars. Each of these has some problem that mitigates the argument. The last possibility discussed is Dark Matter. The Anti-Matter Exploration and Light-nuclei Astrophysics (PAMELA) mission is to search for evidence of annihilations of dark matter particles, to search for anti-nuclei, to test cosmic-ray propagation models, and to measure electron and positron spectra. There are slides explaining the results of Pamela and how to compare these with those of the ATIC experiment. Dark matter annihilation is then reviewed, which represent two types of dark matter: Neutralinos, and kaluza-Kline (KK) particles, which are next explained. The future astrophysical measurements, those from GLAST LAT, the Alpha Magnetic Spectrometer (AMS), and HEPCAT are reviewed, in light of assisting in finding an explanation for the observed excess. Also the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) could help by revealing if there are extra dimensions.

Chang, J.; Adams, J. H.; Ahn, H. S.; Bashindzhagyan, G. L.; Christl, M.; Ganel, O.; Guzik, T. G.; Isbert, J.; Kim, K. C.; Kuznetsov, E. N.; Panasyuk, M. I.; Panov, A. D.; Schmidt, W. K. H.; Seo, E. S.; Sokolskaya, N. V.; Watts, J. W.; Wefel, J. P.; Wu, J.; Zatsepin, V. I.

2008-01-01

401

Acceleration of ULtra High Energy Cosmic Rays: Cosmic Zevatrons?  

E-print Network

In this lecture I outline some of the underlying physics issues associated with accelerators plausibly capable of explaining the UHECRs up to ZeV energies. I concentrate on the concentrate on mechanisms and their constraints, but provide a brief background on on observations and the constraints they supply, as well.

T. W. Jones

2002-10-21

402

High energy-resolution inelastic x-ray scattering  

SciTech Connect

A brief review is presented of various aspects of high energy-resolution inelastic x-ray scattering based on synchrotron sources. We show what kinematical advantages are provided by the photon probe and propose mirror and monochromator designs to achieve an optically efficient beam line for inelastic x-ray scattering.

Hastings, J.B.; Moncton, D.E.; Fujii

1984-01-01

403

The future of high energy gamma ray astronomy and its potential astrophysical implications  

NASA Technical Reports Server (NTRS)

Future satellites should carry instruments having over an order of magnitude greater sensitivity than those flown thus far as well as improved energy and angular resolution. The information to be obtained from these experiments should greatly enhance knowledge of: the very energetic and nuclear processes associated with compact objects; the structure of our galaxy; the origin and dynamic pressure effects of the cosmic rays; the high energy particles and energetic processes in other galaxies; and the degree of matter-antimatter symmetry of the universe. The relevant aspects of extragalactic gamma ray phenomena are emphasized along with the instruments planned. The high energy gamma ray results of forthcoming programs such as GAMMA-1 and the Gamma Ray Observatory should justify even more sophisticated telescopes. These advanced instruments might be placed on the space station currently being considered by NASA.

Fichtel, C. E.

1982-01-01

404

On the interaction of high-energy cosmic leptons with neutralino dark matter  

SciTech Connect

The interaction of neutralino cold dark matter with cosmic-ray electrons is considered in terms of the supersymmetric Standard Model. The production of heavy supersymmetric particles in collisions and their decay are shown to give rise to leptons and neutrinos with certain energies and to relativistic neutralinos. The possibility of detecting dark matter through its interaction with cosmic rays is discussed.

Flanchik, A. B., E-mail: alex.svs.fl@gmail.com [National Academy of Sciences of Ukraine, Radio Astronomy Institute (Ukraine)

2011-12-15

405

Cosmic Rays and Gamma Ray Bursts From Microblazars  

E-print Network

Highly relativistic jets from merger and accretion induced collapse of compact stellar objects, which may produce the cosmological gamma ray bursts (GRBs), are also very efficient and powerful cosmic ray accelerators. The expected luminosity, energy spectrum and chemical composition of cosmic rays from Galactic GRBs, most of which do not point in our direction, can explain the observed properties of Galactic cosmic rays.

Arnon Dar

1998-09-13

406

Kinetic theory of cosmic rays and gamma rays in supernova remnants. I. Uniform interstellar medium  

Microsoft Academic Search

Kinetic models of particle acceleration in supernova remnants (SNRs) are used to determine the cosmic ray (CR) nucleon and, for the first time, also the associated ?-ray spectrum during SN shock propagation in a uniform interstellar medium. SNR evolution is followed numerically taking into account the backreaction of accelerated CRs on the overall dynamics. The high energy CRs also produce

E. G. Berezhko; H. J. Vlk

1997-01-01

407

Kinetic theory of cosmic rays and gamma rays in supernova remnants. I. Uniform interstellar medium  

Microsoft Academic Search

Kinetic models of particle acceleration in supernova remnants (SNRs) are used to determine the cosmic ray (CR) nucleon and, for the first time, also the associated gamma-ray spectrum during SN shock propagation in a uniform interstellar medium. SNR evolution is followed numerically taking into account the backreaction of accelerated CRs on the overall dynamics. The high energy CRs also produce

E. G. Berezhko; H. J. Vlk

1997-01-01

408

Search for AntiparticleSearch for Antiparticle in Cosmic Raysin Cosmic Rays  

E-print Network

Search for AntiparticleSearch for Antiparticle in Cosmic Raysin Cosmic Rays with BESSwith BESS ·University of Denver J. Ormes, N. Thakur #12;CosmicCosmic--Ray Antiproton ChronologyRay Antiproton ChronologySearch for Primordial Antiparticles in CosmicAntiparticles in Cosmic RaysRays Primary origins relatively enhanced at

Yamamoto, Hirosuke

409

Cosmic x ray physics  

NASA Technical Reports Server (NTRS)

This final report covers the period 1 January 1985 - 31 March 1992. It is divided into the following sections: the soft x-ray background; proportional counter and filter calibrations; sounding rocket flight preparations; new sounding rocket payload: x-ray calorimeter; and theoretical studies. Staff, publications, conference proceedings, invited talks, contributed talks, colloquia and seminars, public service lectures, and Ph. D. theses are listed.

Mccammon, Dan; Cox, D. P.; Kraushaar, W. L.; Sanders, W. T.

1992-01-01

410

PREFACE: Cosmic Ray Anisotropy Workshop 2013 (CRA2013)  

NASA Astrophysics Data System (ADS)

In the search for the origin of cosmic rays in our galaxy, various observations are combined as pieces of a complex puzzle to account for the variability of the galactic sources and their local environments, as well as of the properties of the interstellar medium in which cosmic particles propagate. In this puzzle, multi-wavelength observations aim to pinpoint the properties of cosmic-ray sources, based on electromagnetic and neutrino emissions associated with hadronic acceleration processes. The detailed study of the energy spectrum and composition of cosmic rays on Earth, on the other hand, aims to probe the combined and interwoven effects of injection, by acceleration processes, and propagation in the interstellar medium. The observation of arrival directions of cosmic rays on Earth, in addition, potentially provides valuable information on the distribution of the closest and more recent active galactic sources as well as on the properties of the local interstellar magnetic field. The quasi-isotropic distribution of galactic cosmic rays tells the global story of their journey from their sources. The turbulent magnetized galactic medium sufficiently scrambles the arrival directions of cosmic rays on Earth so that their main injection direction is concealed. On the other hand, the observations of a small but significant energy-dependent anisotropy are starting to provide clues on how cosmic rays propagate throughout the local interstellar medium. Anisotropy observations have been used to study diffusion properties of GeV cosmic rays inside the termination shock of the heliosphere and their dependencies on solar cycles. At TeV energy, cosmic rays are sensitive to larger-scale magnetic structures, such as the turbulent boundary between the heliosphere and the local interstellar medium or its elongated tail. At higher energy, it is expected that the interstellar magnetic field within the particle mean free path has major contributions to their arrival directions on Earth. In this workshop, we addressed the potential use of high-energy cosmic-ray anisotropy observations as a probe into the properties of particle transport in astrophysical magnetized plasmas, such as the heliosphere and the local interstellar medium. Along with experts from the fields of astronomy, astrophysics, plasma physics, heliospheric physics and interstellar medium, we discussed how each field can contribute to the understanding of cosmic-ray propagation in our local interstellar magnetic field. This will represent another piece in the search for cosmic-ray sources in the galaxy.

2014-08-01

411

Monte Carlo calibration of the SMM gamma ray spectrometer for high energy gamma rays and neutrons  

Microsoft Academic Search

The Gamma Ray Spectrometer (GRS) on the Solar Maximum Mission spacecraft was primarily designed and calibrated for nuclear gamma ray line measurements, but also has a high energy mode which allows the detection of gamma rays at energies above 10 MeV and solar neutrons above 20 MeV. The GRS response has been extrapolated until now for high energy gamma rays

J. F. Cooper; C. Reppin; D. J. Forrest; E. L. Chupp; G. H. Share; R. L. Kinzer

1985-01-01

412

An absence of neutrinos associated with cosmic-ray acceleration in ?-ray bursts.  

PubMed

Very energetic astrophysical events are required to accelerate cosmic rays to above 10(18)?electronvolts. GRBs (?-ray bursts) have been proposed as possible candidate sources. In the GRB 'fireball' model, cosmic-ray acceleration should be accompanied by neutrinos produced in the decay of charged pions created in interactions between the high-energy cosmic-ray protons and ?-rays. Previous searches for such neutrinos found none, but the constraints were weak because the sensitivity was at best approximately equal to the predicted flux. Here we report an upper limit on the flux of energetic neutrinos associated with GRBs that is at least a factor of 3.7 below the predictions. This implies either that GRBs are not the only sources of cosmic rays with energies exceeding 10(18)?electronvolts or that the efficiency of neutrino production is much lower than has been predicted. PMID:22517161

2012-04-19

413

Detecting radio emission from cosmic ray air showers and neutrinos with a digital radio telescope  

Microsoft Academic Search

We discuss the possibilities of measuring ultra-high energy cosmic rays and neutrinos with radio techniques. We review a few of the properties of radio emission from cosmic ray air showers and show how these properties can be explained by coherent geosynchrotron emission from electronpositron pairs in the shower as they move through the geomagnetic field. This should allow one to

Heino Falcke; Peter Gorham

2003-01-01

414

On the e$^+$e$^-$ excesses and the knee of the cosmic ray spectra -- hints of cosmic rays acceleration at young supernova remnants  

E-print Network

Supernova remnants have long been regarded as sources of the Galactic cosmic rays up to petaelectronvolts, but convincing evidence is still lacking. In this work we explore the common origin of the subtle features of the cosmic ray spectra, such as the knee of cosmic ray spectra and the excesses of electron/positron fluxes recently observed by ATIC, H.E.S.S., Fermi-LAT and PAMELA. Numerical calculation shows that those features of cosmic ray spectra can be well reproduced in a scenario with e$^+$e$^-$ pair production by interactions between high energy cosmic rays and background photons in an environment similar to the young supernova remnant. The success of such a coherent explanation serves in turn as an evidence that at least a portion of cosmic rays might be accelerated at young supernova remnants.

Hong-Bo Hu; Qiang Yuan; Bo Wang; Chao Fan; Jian-Li Zhang; Xiao-Jun Bi

2009-06-17

415

Fractional diffusion of cosmic rays  

E-print Network

We consider the propagation of galactic cosmic rays under assumption that the interstellar medium is a fractal one. An anomalous diffusion equation in terms of fractional derivatives is used to describe of cosmic ray propagation. The anomaly in used model results from large free paths ("Levy flights") of particles between galactic inhomogeneities and long time a particle stays in a trap. An asymptotical solution of the anomalous diffusion equation for point instantaneous and impulse sources with inverse power spectrum relating to supernova bursts is found. It covers both subdiffusive and superdiffusive regimes and is expressed in terms of the stable distributions. The energy dependence of spectral exponent of observed particles in different regimes is discussed.

A. A. Lagutin; V. V. Uchaikin

2001-07-13

416

Concerning the Nature of the Cosmic Ray Power Law Exponents  

E-print Network

We have recently shown that the cosmic ray energy distributions as detected on earthbound, low flying balloon or high flying satellite detectors can be computed by employing the heats of evaporation of high energy particles from astrophysical sources. In this manner, the experimentally well known power law exponents of the cosmic ray energy distribution have been theoretically computed as 2.701178 for the case of ideal Bose statistics, 3.000000 for the case of ideal Boltzmann statistics and 3.151374 for the case of ideal Fermi statistics. By "ideal" we mean virtually zero mass (i.e. ultra-relativistic) and noninteracting. These results are in excellent agreement with the experimental indices of 2.7 with a shift to 3.1 at the high energy ~ PeV "knee" in the energy distribution. Our purpose here is to discuss the nature of cosmic ray power law exponents obtained by employing conventional thermal quantum field theoretical models such as quantum chromodynamics to the cosmic ray sources in a thermodynamic scheme wherein gamma and zeta function regulation is employed. The key reason for the surprising accuracy of the ideal boson and ideal fermion cases resides in the asymptotic freedom or equivalently the Feynman "parton" structure of the ultra-high energy tails of spectral functions.

A. Widom; J. Swain; Y. N. Srivastava

2015-02-07

417

Cosmogenic gamma rays and the composition of cosmic rays  

SciTech Connect

We discuss the prospects of detecting the sources of ultrahigh energy (UHE) cosmic ray (CR) nuclei via their emission of cosmogenic {gamma} rays in the GeV to TeV energy range. These {gamma} rays result from electromagnetic cascades initiated by high energy photons, electrons, and positrons that are emitted by CRs during their propagation in the cosmic radiation background and are independent of the simultaneous emission of {gamma} rays in the vicinity of the source. The corresponding production power by UHE CR nuclei (with mass number A and charge Z) is dominated by pion photo production ({proportional_to}A) and Bethe-Heitler pair production ({proportional_to}Z{sup 2}). We show that the cosmogenic {gamma}-ray signal from a single steady UHE CR source is typically more robust with respect to variations of the source composition and injection spectrum than the accompanying signal of cosmogenic neutrinos. We study the diffuse emission from the sum of extragalactic CR sources as well as the point-source emission of the closest sources.

Ahlers, Markus [C. N. Yang Institute for Theoretical Physics, SUNY at Stony Brook, Stony Brook, New York 11794-3840 (United States); Salvado, Jordi [Departament d'Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona, 647 Diagonal, E-08028 Barcelona (Spain)

2011-10-15

418

The origin of galactic cosmic rays  

E-print Network

The origin of galactic cosmic rays is one of the most interesting unsolved problems in astroparticle physics. Experimentally, the problem is attacked by a multi-disciplinary effort, namely by direct measurements of cosmic rays above the atmosphere, by air shower observations, and by the detection of TeV $\\gamma$ rays. Recent experimental results are presented and their implications on the contemporary understanding of the origin of galactic cosmic rays are discussed.

Joerg R. Hoerandel

2007-10-29

419

Treatment of foods with high-energy X rays  

NASA Astrophysics Data System (ADS)

The treatment of foods with ionizing energy in the form of gamma rays, accelerated electrons, and X rays can produce beneficial effects, such as inhibiting the sprouting in potatoes, onions, and garlic, controlling insects in fruits, vegetables, and grains, inhibiting the growth of fungi, pasteurizing fresh meat, poultry, and seafood, and sterilizing spices and food additives. After many years of research, these processes have been approved by regulatory authorities in many countries and commercial applications have been increasing. High-energy X rays are especially useful for treating large packages of food. The most attractive features are product penetration, absorbed dose uniformity, high utilization efficiency and short processing time. The ability to energize the X-ray source only when needed enhances the safety and convenience of this technique. The availability of high-energy, high-power electron accelerators, which can be used as X-ray generators, makes it feasible to process large quantities of food economically. Several industrial accelerator facilities already have X-ray conversion equipment and several more will soon be built with product conveying systems designed to take advantage of the unique characteristics of high-energy X rays. These concepts will be reviewed briefly in this paper.

Cleland, M. R.; Meissner, J.; Herer, A. S.; Beers, E. W.

2001-07-01

420

Cosmic ray penetration in diffuse clouds  

E-print Network

Cosmic rays are a fundamental source of ionization for molecular and diffuse clouds, influencing their chemical, thermal, and dynamical evolution. The amount of cosmic rays inside a cloud also determines the $\\gamma$-ray flux produced by hadronic collisions between cosmic rays and cloud material. We study the spectrum of cosmic rays inside and outside of a diffuse cloud, by solving the stationary transport equation for cosmic rays including diffusion, advection and energy losses due to ionization of neutral hydrogen atoms. We found that the cosmic ray spectrum inside a diffuse cloud differs from the one in the interstellar medium for energies smaller than $E_{br}\\approx 100$ MeV, irrespective of the model details. Below $E_{br}$, the spectrum is harder (softer) than that in the interstellar medium if the latter is a power law $\\propto p^{-s}$ with $s$ larger (smaller) than $\\sim0.42$.

Morlino, G

2015-01-01

421

Nineteenth International Cosmic Ray Conference. Conference Papers: Invited Rapporteur, Highlight, Miscellaneous, Volume 9  

NASA Technical Reports Server (NTRS)

Invited talks, rapporteur talks, and highlight talks are included. Topics of the invited and highlight talks include astrophysical jets, gamma-ray line astronomy, cosmic rays and gamma rays in astrophysics, the early universe, elementary particle physics, solar flares and acceleration of energetic particles, cosmogenic nuclei, extragalactic astronomy, composition of solar flare particles, very high energy gamma ray sources, gamma-ray bursts, shock acceleration in the solar wind, cosmic rays in deep underground detectors, spectrum of cosmic rays at 10 to the 19th power eV, and nucleus-nucleus interactions.

Jones, F. C. (compiler)

1986-01-01

422

Cosmic Rays Help Drive Galactic Winds  

NASA Astrophysics Data System (ADS)

Cosmic rays deposit both momentum and energy into thermal gas when magnetic fields are present (Wentzel, 1968; Kulsrud Pearce, 1969). Since we observe evidence of magnetic fields, cosmic-rays, and hot gas in galactic disks, it is plausible that cosmic rays may add momentum and energy to gas, and therefore help drive galactic-scale outflows. Building on past work by Breitschwerdt, Zirakashvili, Ptuskin, and others, our group investigates "hybrid" galactic winds driven by cosmic-ray and thermal-gas pressure. We have found that such a wind can fit mid-latitude Galactic X-ray emission observed by ROSAT towards the center of the Galaxy, and also (with some physically motivated modifications) fits radio-synchrotron survey data. We are now building estimates of the gamma-ray emission for this wind. So far, we also find that the parameters of such a wind are plausible for the conditions of the central Milky Way. More generally, we illustrate how cosmic-ray driving may increase the prevalance of galactic winds. For this talk, I will review the hydrodynamics of cosmic rays, including the work of other groups on cosmic-ray driven winds. I will highlight how cosmic ray pressure can help drive Galactic winds, how such a wind may work in our Galaxy, and include estimates of the impact of cosmic-ray diffusivity and the driving of cool clouds (observed within extragalactic winds and important to constrain wind velocities) within such a wind.

Everett, John; Zweibel, Ellen; Schiller, Quintin; Hu, Kaiqi

423

Intergalactic Propagation of UHE Cosmic Rays  

E-print Network

We discuss the intergalactic propagation of ultra-high-energy cosmic rays (UHECRs) with energies E \\geq 10^{18.5} eV. We consider the propagation of UHECRs under the influence of the energy-dependent deflection by a weak random magnetic field in the intergalactic medium and energy losses by photo-pion and pair production. We calculate arrival spectra taking full account of the kinematics of photo-pion production and the Poisson statistics of the photo-pion interaction rate. We give estimates for the deflection of UHECRs from the line of sight to the source, time delays with respect to photons from the same source, arrival spectra and source statistics. These estimates are confirmed by numerical simulations of the propagation in energy evolution of UHECRs. These simulations demonstrate that the often-used continuous approximation in the treatment of energy losses due to photo-pion production on the cosmic microwave background (CMWB) cannot be justified for UHECRs. We discuss the implications of these results for the observed flux of particles above the Greisen-Zatsepin-Kuz'min cut-off in two of the scenarios that have been proposed for the production of these particles: continuous production in the large shock waves associated with powerful radio galaxies, or possibly large-scale structure formation, and the impulsive production at relativistic blast waves associated with cosmological gamma-ray bursts.

Abraham Achterberg; Yves A. Gallant; Colin A. Norman; Donald B. Melrose