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1

High Energy Cosmic Rays  

E-print Network

T.Hebbeker High Energy Cosmic Rays Thomas Hebbeker RWTH Aachen University Gent 03.07.2008 1.2 http://www.physik.rwth-aachen.de/~hebbeker/ or: google hebbeker #12;T.Hebbeker Cosmic Rays Discovery / Properties Influence on Earth / Life / Science High Energy Cosmic Rays Cosmic Sources and Propagation Auger-Observatory First Auger Results #12;T

Hebbeker, Thomas

2

Cosmic Rays High Energy Particles  

E-print Network

T.Hebbeker Cosmic Rays High Energy Particles from the Universe Thomas Hebbeker RWTH Aachen.Hebbeker Cosmic Rays Discovery / Properties Influence on Earth / Life / Science High Energy Cosmic Rays Cosmic + + + + + + + + ++ + + + + Ionizing radiation discharges electrometer #12;T.Hebbeker Electric Properties of Cosmic Rays 1927 Clay

Hebbeker, Thomas

3

Cosmic Rays High Energy Particles  

E-print Network

T.Hebbeker Cosmic Rays High Energy Particles from the Universe Thomas Hebbeker RWTH Aachen #12;T.Hebbeker Cosmic Rays Discovery / Properties Influence on Earth / Life / Science High Energy Cosmic Rays Cosmic Sources and Propagation Auger-Observatory First Auger Results #12;T.Hebbeker Cosmic

Hebbeker, Thomas

4

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

5

Imaging the High Energy Cosmic Ray Sky  

E-print Network

Imaging the High Energy Cosmic Ray Sky PETTER HOFVERBERG Licentiate Thesis Stockholm, Sweden 2006 #12;#12;Licentiate Thesis Imaging the High Energy Cosmic Ray Sky Petter Hofverberg Particle Stockholm, Sweden 2006 #12;Cover illustration: The sky coverage of cosmic rays for the SEASA array

Haviland, David

6

PAMELA measurements of high energy cosmic ray  

E-print Network

PAMELA measurements of high energy cosmic ray positrons LAURA ROSSETTO Doctoral Thesis Stockholm, Sweden 2012 #12;#12;Doctoral Thesis PAMELA measurements of high energy cosmic ray positrons Laura from the calorimeter, positrons can be identified from the significant background due to cosmic ray

Haviland, David

7

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

8

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

9

Terrestrial effects of high energy cosmic rays  

NASA Astrophysics Data System (ADS)

On geological timescales, the Earth is likely to be exposed to higher than the usual 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 and photons. Increased ionization leads to changes in atmospheric chemistry, resulting in ozone depletion. This increases the flux of solar UVB radiation at the surface, which is potentially harmful to living organisms. Increased ionization affects the global electrical circuit, which could enhance the low-altitude cloud formation rate. Secondary particles such as muons and thermal neutrons produced as a result of hadronic interactions of the primary cosmic rays with the atmosphere are able to reach the ground, enhancing the biological radiation dose. The muon flux dominates the radiation dose from cosmic rays causing damage to DNA and an increase in mutation rates and cancer, which can have serious biological implications for surface and sub-surface life. Using CORSIKA, we perform massive computer simulations and construct lookup tables for 10 GeV - 1 PeV primaries, which can be used to quantify these effects from enhanced cosmic ray exposure to any astrophysical source. These tables are freely available to the community and can be used for other studies. We use these tables to study the terrestrial implications of galactic shock generated by the infall of our galaxy toward the Virgo cluster. Increased radiation dose from muons could be a possible mechanism explaining the observed periodicity in biodiversity in paleobiology databases.

Atri, Dimitra

10

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

11

Ultra high-energy cosmic ray observations  

NASA Astrophysics Data System (ADS)

The year 2007 has furnished us with outstanding results about the origin of the most energetic cosmic rays: a flux suppression as expected from the GZK-effect has been observed in the data of the HiRes and Auger experiments and correlations between the positions of nearby AGN and the arrival directions of trans-GZK events have been observed by the Pierre Auger Observatory. The latter finding marks the beginning of ultra high-energy cosmic ray astronomy and is considered a major breakthrough starting to shed first light onto the sources of the most extreme particles in nature. This report summarizes those observations and includes other major advances of the field, mostly presented at the 30th International Cosmic Ray Conference held in Mérida, Mexico, in July 2007. With increasing statistics becoming available from current and even terminated experiments, systematic differences amongst different experiments and techniques can be studied in detail which is hoped to improve our understanding of experimental techniques and their limitations.

Kampert, K.-H.

2008-07-01

12

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

13

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

14

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

15

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

16

Very High Energy Cosmic Rays and Their Interactions  

E-print Network

The investigation of high energy cosmic rays and their interactions is a very active field of research. This article summarizes the progress made during the last years as reflected by the contributions to the XIII International Symposium on Very High Energy Cosmic Ray Interactions held in Pylos, Greece.

Ralph Engel

2005-04-15

17

Cosmic rays at ultra high energies (Neutrinos!)  

NASA Astrophysics Data System (ADS)

Resonant photo-pion production with the cosmic microwave background predicts a suppression of extragalactic protons above the famous Greisen Zatsepin Kuzmin cutoff at about EGZK ? 5 × 1010 GeV. Current cosmic ray data measured by the AGASA and HiRes Collaborations do not unambiguously confirm the GZK cutoff and leave a window for speculations about the origin and chemical composition of the highest energy cosmic rays. In this work we analyze the possibility of strongly interacting neutrino primaries and derive model-independent quantitative requirements on the neutrino nucleon inelastic cross section for a viable explanation of the cosmic ray data. Search results on weakly interacting cosmic particles from the AGASA and RICE experiments are taken into account simultaneously. Using a flexible parameterization of the inelastic neutrino nucleon cross section we find that a combined fit of the data does not favor the Standard Model neutrino nucleon inelastic cross section, but requires, at 90% confidence level, a steep increase within one energy decade around EGZK by four orders of magnitude. We illustrate such an enhancement within some extensions of the Standard Model. The impact of new cosmic ray data or cosmic neutrino search results on this scenario, notably from the Pierre Auger Observatory soon, can be immediately evaluated within our approach.

Ahlers, Markus; Ringwald, Andreas; Tu, Huitzu

2006-01-01

18

Terrestrial Effects of High Energy Cosmic Rays  

E-print Network

tables for 10 GeV - 1 PeV primaries, which can be used to quantify these effects from enhanced cosmic ray exposure to any astrophysical source. These tables are freely available to the community and can be used for other studies. We use these tables...

Atri, Dimitra

2011-04-26

19

Ultra-high energy cosmic rays  

NASA Astrophysics Data System (ADS)

Experimental efforts to reveal the nature and origin of cosmic rays with energy above 1018 eV led to several important steps forward in recent years. The existence of a suppression of the flux above 4×1019 eV has been confirmed. It occurs at the energy threshold for pion-production in proton collisions with the cosmic microwave background, as anticipated almost fifty years ago. The flux measurements alone are however insufficient to confidently establish whether the suppression is due to energy loss effects along propagation over cosmological distances, or else because the sources reach their maximum acceleration power. There are indications obtained with the Pierre Auger Observatory of a trend from a light towards a heavier composition as the energy increases. There is some tension between these indications and those from the HiRes and Telescope Array experiments, which are compatible with a pure proton composition. This is a most important issue to be settled in the near future. At present there is no statistically significant evidence for anisotropy in the distribution of arrival directions at the highest energies that could favor one specific astrophysical scenario for cosmic ray origin over another. There are hints for a large scale pattern in the distribution of arrival directions that need to be confirmed with independent data. In this paper we summarize recent measurements of the energy spectrum of cosmic rays with the highest energies, the evidence for their composition, and the searches for anisotropies in the distribution of their arrival directions.

Harari, Diego

2014-09-01

20

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

21

High Energy Cosmic Electrons: Messengers from Nearby Cosmic Ray Sources or Dark Matter?  

NASA Technical Reports Server (NTRS)

This slide presentation reviews the recent discoveries by the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM) on board the Fermi Gamma-Ray Telescope in reference to high energy cosmic electrons, and whether their source is cosmic rays or dark matter. Specific interest is devoted to Cosmic Ray electrons anisotropy,

Moiseev, Alexander

2011-01-01

22

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

23

Heavy quark production in ultra high energy cosmic ray interactions  

NASA Astrophysics Data System (ADS)

In this paper we present a comprehensive study of the heavy quark production in ultra high energy cosmic ray interactions in the atmosphere considering that the primary cosmic ray can be either a photon, neutrino or a proton. The analysis is performed using a unified framework - the dipole formalism - and the saturation effects, associated to the physical process of parton recombination, are taken into account. We demonstrate that the contribution of heavy quarks for cosmic ray interactions is in general non-negligible and can be dominant depending of the process considered. Moreover, our results indicate that new dynamical mechanisms should be included in order to obtain reliable predictions for the heavy quark production in pp collisions at ultra high cosmic ray energies.

Gonçalves, V. P.; Gratieri, D. R.

2015-02-01

24

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

25

Experimental Summary: Very High Energy Cosmic Rays and their Interactions  

NASA Astrophysics Data System (ADS)

The XVII International Symposium on Very High Energy Cosmic Ray Interactions, held in August of 2012 in Berlin, was the first one in the history of the Symposium,where a plethora of high precision LHC data with relevance for cosmic ray physics was presented. This report aims at giving a brief summary of those measurements andit discusses their relevance for observations of high energy cosmic rays. Enormous progress has been made also in air shower observations and in direct measurements of cosmic rays, exhibiting many more structure in the cosmic ray energy spectrum than just a simple power law with a knee and an ankle. At the highest energy, the flux suppression may not be dominated by the GZK-effect but by the limiting energy of a nearby source or source population. New projects and application of new technologies promise further advances also in the near future. We shall discuss the experimental and theoretical progress in the field and its prospects for coming years.

Kampert, Karl-Heinz

2013-06-01

26

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

27

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

28

High Energy Cosmic Rays and Neutrinos from Newborn Pulsars  

NASA Astrophysics Data System (ADS)

Newborn pulsars offer favorable sites for cosmic ray acceleration and interaction. Particles could be striped off the star surface and accelerated in the pulsar wind up to PeV-100 EeV energies, depending on the pulsar's birth period and magnetic field strength. Once accelerated, the cosmic rays interact with the surrounding supernova ejecta until they escape the source. By assuming a normal distribution of pulsar birth periods centered at 300,ms, we find the combined contribution of extragalactic pulsars produce ultrahigh energy cosmic rays that agree with both the observed energy spectrum and composition trend reported by the Auger Observatory. Meanwhile, we point out their Galactic counterparts naturally give rise to a cosmic ray flux peaked at very high energies (VHE, between 10^16 and 10^18 ,eV), which can bridge the gap between predictions of cosmic rays produced by supernova remnants and the observed spectrum and composition just below the ankle. Young pulsars in the universe would also contribute to a diffuse neutrino background due to the photomeson interactions, whose detectability and typical neutrino energy are discussed. Lastly, we predict a neutrino emission level for the future birth of a nearby pulsar.

Fang, Ke; Kotera, Kumiko; Olinto, Angela

2013-04-01

29

Ultra High Energy Cosmic Rays Propagation and Spectrum  

E-print Network

The status of the observations of Ultra High Energy Cosmic Rays will be reviewed, focusing on the the latest results of HiRes and Auger observatories. A comprehensive analytical computation scheme to compute the expected UHECR spectrum on earth will be presented, applying such scheme to interpret the experimental results. The phenomenological scenarios favored by HiRes and Auger in terms of chemical composition and spectrum will be also presented.

Aloisio, Roberto

2011-01-01

30

Ultra High Energy Cosmic Rays Propagation and Spectrum  

NASA Astrophysics Data System (ADS)

The status of the observations of Ultra High Energy Cosmic Rays will be reviewed, focusing on the the latest results of HiRes and Auger observatories. A comprehensive analytical computation scheme to compute the expected UHECR spectrum on earth will be presented, applying such scheme to interpret the experimental results. The phenomenological scenarios favored by HiRes and Auger in terms of chemical composition and spectrum will be also presented.

Aloisio, Roberto

2011-09-01

31

On the Origin of Ultra High Energy Cosmic Rays  

SciTech Connect

Turbulence-driven plasma accelerators produced by magnetized accretion disks around black holes are proposed as the mechanism mainly responsible for observed cosmic ray protons with ultra high energies 10{sup 19}-10{sup 21} eV. The magnetized disk produces a voltage comparable to these cosmic ray energies. Here we present a Poynting model in which this voltage provides all of the energy to create the jet-like structures observed to be ejected from accretion disks, and this voltage also accelerates ions to high energies at the top of the expanding structure. Since the inductive electric field E = -v x B driving expansion has no component parallel to the magnetic field B, ion acceleration requires plasma wave generation - either a coherent wave accelerator as recently proposed, or instability-driven turbulence. We find that turbulence can tap the full inductive voltage as a quasi-steady accelerator, and even higher energies are produced by transient events on this structure. We find that both MHD modes due to the current and ion diffusion due to kinetic instability caused by the non-Maxwellian ion distribution contribute to acceleration. We apply our results to extragalactic giant radiolobes, whose synchrotron emissions serve to calibrate the model, and we discuss extrapolating to other astrophysical structures. Approximate calculations of the cosmic ray intensity and energy spectrum are in rough agreement with data and serve to motivate more extensive MHD and kinetic simulations of turbulence that could provide more accurate cosmic ray and synchrotron spectra to be compared with observations. A distinctive difference from previous models is that the cosmic ray and synchrotron emissions arise from different parts of the magnetic structure, thus providing a signature for the model.

Fowler, T; Colgate, S; Li, H

2009-07-01

32

Search for very high energy gamma rays from possible ultra-high energy cosmic ray sources by the MAGIC Telescope  

E-print Network

The origin of ultra-high energy (UHE) cosmic rays is still an open question. In the present work, we searched the possible UHE cosmic ray sources using the MAGIC telescope for the associated very high energy (VHE) gamma ray emission. Due to constrained propagation distance of such cosmic rays, we selected nearby galaxies in vicinity of the direction of the AGASA triplet and a HiRes UHE cosmic ray event: NGC 3610 and NGC 3613 (quasar remnants); Arp 299 (a system of colliding galaxies). No significant excess in the VHE region was found found from these objects or their surrounding region. At multi-100 GeV regime, the upper limits on fluxes were given against gamma ray sources in surrounding region. The presented limits constrain the flux of a new hypothetical source in the region, provided the cosmic rays are emitted from a single point-like origin.

K. Shinozaki; M. Teshima; for the MAGIC Collaboration

2007-09-17

33

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. Keränen; J. Maalampi

2005-03-10

34

TESTING THE ORIGIN OF HIGH-ENERGY COSMIC RAYS  

SciTech Connect

Recent accurate measurements of cosmic-ray (CR) protons and nuclei by ATIC-2, CREAM, and PAMELA reveal (1) unexpected spectral hardening in the spectra of CR species above a few hundred GeV per nucleon, (2) a harder spectrum of He compared to protons, and (3) softening of the CR spectra just below the break energy. These newly discovered features may offer a clue to the origin of the observed high-energy Galactic CRs. We discuss possible interpretations of these spectral features and make predictions for the secondary CR fluxes and secondary-to-primary ratios, anisotropy of CRs, and diffuse Galactic {gamma}-ray emission in different phenomenological scenarios. Our predictions can be tested by currently running or near-future high-energy astrophysics experiments.

Vladimirov, A. E.; Moskalenko, I. V.; Porter, T. A. [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States); Johannesson, G. [Science Institute, University of Iceland, Dunhaga 5, IS-107 Reykjavik (Iceland)

2012-06-10

35

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

36

Ultra High Energy Cosmic Rays: Anisotropies and Spectrum  

E-print Network

The recent results of the Pierre Auger Observatory on the possible correlation of Ultra High Energy Cosmic Rays events and several nearby discrete sources could be the starting point of a new era with charged particles astronomy. In this paper we introduce a simple model to determine the effects of any local distribution of sources on the expected flux. We consider two populations of sources: faraway sources uniformly distributed and local point sources. We study the effects on the expected flux of the local distribution of sources, referring, in particular, to the set of astrophysical objects whose correlation with the Auger events seems experimentally confirmed.

Aloisio, R

2011-01-01

37

Cosmic Ray Positrons at High Energies: A New Measurement  

E-print Network

We present a new measurement of the cosmic-ray positron fraction e+/(e+ + e-) obtained from the first balloon flight of the High Energy Antimatter Telescope (HEAT). Using a magnet spectrometer combined with a transition radiation detector, an electromagnetic calorimeter, and time-of-flight counters we have achieved a high degree of background rejection. Our results do not indicate a major contribution to the positron flux from primary sources. In particular, we see no evidence for the significant rise in the positron fraction at energies above ~10 GeV previously reported.

HEAT Collaboration

1995-05-30

38

High energy cosmic ray charge and energy spectra measurements  

NASA Technical Reports Server (NTRS)

In 1976, 1977, and 1978, a series of three balloon flights was conducted to measure the energy spectra of cosmic ray nuclei. A gas Cerenkov detector with different gas thresholds of 8.97, 13.12, and 17.94 GeV/n was employed to extend these measurements to high energies. The total collection factor for these flights is more than 20 sq m ster-hr. Individual charge resolution was achieved over the charge range Z equals 4-26, and overlapping differential spectra were obtained from the three flights up to approximately 100.0 GeV/n.

Chappell, J. H.; Webber, W. R.

1981-01-01

39

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

2009-04-09

40

Ultra-high energy cosmic rays: Observational results  

NASA Astrophysics Data System (ADS)

The study of ultra-high energy cosmic rays has experienced a jump in statistics as well as improved instrumentation. The number of detected cosmic rays has increased by more than a factor of ten over the past decade, and measurements are checked using multiple detection techniques. The energy spectrum clearly has a spectral hardening known as "the ankle" and also a "GZK-like" downturn above 1019.5 eV. Evidence of trans-GZK arrival directions correlating with AGNs and/or the large-scale matter distribution within the GZK sphere has not been confirmed so far. More data are needed to verify and understand that anisotropy. A search for neutron fluxes from discrete sources in the Galaxy has yielded no detection, and the neutron flux upper limits constrain models for EeV proton production. Additional constraint has come from measuring the first harmonic in right ascension of the cosmic ray arrival directions, which has yielded upper limits below 2% at energies up to 2 EeV.

Sommers, Paul

2012-12-01

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

On high energy cosmic rays from the CREAM instrument  

NASA Astrophysics Data System (ADS)

The Cosmic Ray Energetics And Mass (CREAM) experiment is a balloon-borne, high energy particle detector designed to measure cosmic ray nuclei from protons through Iron at energies up to 1015 eV. It has succeeded in measuring this broad range of charge and energy through multiple Antarctic flights, data from the first of which will be presented here, using complementary charge and energy detectors. These included a Timing Charge Detector (TCD), a Transition Radiation Detector (TRD), a Silicon Charge Detector (SCD), and a Calorimeter. The TRD and Calorimeter provide both tracking and an energy determination. The TCD and SCD provide excellent charge resolution, of order 0.2 e. Together, these have enabled us to construct absolute spectra for individual primary nuclei, Carbon, Oxygen, Neon, Magnesium, Silicon, and Iron, as well as the less abundant secondary, Nitrogen. Our spectra agree well with previous measurements, and for several nuclei extend to the highest energies yet measured. The well-resolved charge species have also permitted us to form the secondary to primary ratios of Boron to Carbon and Nitrogen to Oxygen, also up to the highest energies measured and in agreement with previous data. Since charged particles like cosmic rays bend in magnetic fields which permeate our galaxy, traditional pointing astronomy is not possible. Instead, we use the spectra and ratios to provide us with clues to cosmic rays' origins, acceleration mechanism, and propagation history. In particular, the CREAM I Boron to Carbon ratio fits a propagation model with index of delta = 0.5 - 0.6 while the CREAM II primary nuclei spectra all have an index of 2.66 +/- 0.04. This last suggests that they all have the same acceleration mechanism, and after accounting for propagation energy loss consistent with the Boron to Carbon ratio, that the mechanism is likely Fermi first order acceleration. Finally, Nitrogen serves as a particularly useful test bed for these findings. Its ratio with Oxygen is consistent with a small amount of Nitrogen existing in the cosmic ray source, ˜ 10% with respect to the source's Oxygen content, given propagation conditions again based on the Boron to Carbon ratio. At the highest energies, this source flux is seen, as expected, to emerge over the secondary flux in the Nitrogen spectrum itself.

Brandt, Theresa J.

43

ENERGY SPECTRA OF COSMIC-RAY NUCLEI AT HIGH ENERGIES  

SciTech Connect

We present new measurements of the energy spectra of cosmic-ray (CR) nuclei from the second flight of the balloon-borne experiment Cosmic-Ray Energetics And Mass (CREAM). The instrument included different particle detectors to provide redundant charge identification and measure the energy of CRs up to several hundred TeV. The measured individual energy spectra of C, O, Ne, Mg, Si, and Fe are presented up to approx10{sup 14} eV. The spectral shape looks nearly the same for these primary elements and it can be fitted to an E {sup -2.66} {sup +}- {sup 0.04} power law in energy. Moreover, a new measurement of the absolute intensity of nitrogen in the 100-800 GeV/n energy range with smaller errors than previous observations, clearly indicates a hardening of the spectrum at high energy. The relative abundance of N/O at the top of the atmosphere is measured to be 0.080 +- 0.025 (stat.)+-0.025 (sys.) at approx800 GeV/n, in good agreement with a recent result from the first CREAM flight.

Ahn, H. S.; Ganel, O.; Han, J. H.; Kim, K. C.; Lee, M. H.; Malinine, A. [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States); Allison, P.; 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. [Department of Physics, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Minnick, S., E-mail: paolo.maestro@pi.infn.i [Department of Physics, Kent State University, Tuscarawas, New Philadelphia, OH 44663 (United States)

2009-12-10

44

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

45

Inductive acceleration of ultra-high energy cosmic rays  

NASA Astrophysics Data System (ADS)

Ultra high energy cosmic rays (UHECRs) are charged particles that have energy in excess of 1018 eV and are mostly of extra-galactic origin. Their astrophysical origin and the acceleration mechanisms are still unknown, 50 years after their discovery and 100 years after cosmic rays in general were first identified. Lower energy cosmic rays (CRs), up to approximately 1015 eV ("the knee") are of galactic origin, presumably accelerated in supernova remnants. The UHECRs above "the ankle" at 1018 eV can't be contained by the Galactic magnetic field and are thus extragalactic. Considerable progress in CR research has recently been stimulated by the construction and the successful operation of the Pierre Auger observatory. Among the key yearly results is the correlation of the arrival directions of the UHECRs with the large scale structure, though the precise nature of the acceleration sites remains unknown. Noteworthy, a large number of UHECRs come from the direction of Cen A, the nearest AGN. The most commonly suggested mechanism of CR acceleration, initially due to Fermi, suggests that particles gain energy stochastically, by experiencing multiple scatterings off magnetohydrodynamic turbulence. Thus, the rate of the acceleration is low. In this work we investigate an alternative novel mechanism, specific to the UHECRs. We point out that relativistic outflows carrying large scale magnetic field have large inductive potential and may accelerate protons to ultra-high energies. We suggest that magnetized jets of Active Galactic Nuclei (AGN) can accelerate UHECRs via regular energy gain in the inductive electric fields. Cyclotron motion of a CR particle in a sheared magnetic field may become unstable for sufficiently large Larmor radii, comparable with the shear scales. As an unbound particle crosses the jet, it gains the inductive potential square root(L/c), where L is the Poynting luminosity of a jet. Key features of the mechanism are that (i) highest rigidity cosmic rays are accelerated most efficiently; (ii) maximum possible acceleration rate does reach the inverse relativistic gyro-frequency. In this work we study the kinetic motion of the UHECRs in realistic electromagnetic configurations of astrophysical jets. The key issue is the condition for particle motion to become unstable: large energy gains require stronger magnetic fields, which reduce the Larmor radius and make the motion more stable (bound). We find that large energy gains, more than an order of magnitude, are indeed possible for generic profiles of the magnetic field and the velocity shear inside the jet. On the other hand, the CRs that gained the full jet potential are typically beamed along the jet direction - this poses a problem, e.g., in the case of Cen A, whose jets are directed at large angles to the line of sight.

Alvarez, Jorge Alonso

46

Investigation of the solar cosmic high-energy rays  

NASA Astrophysics Data System (ADS)

We propose to use the ground-based extensive air shower (EAS) arrays and underground muon detectors to study the solar cosmic high-energy rays (SCR) generated during powerful solar flares. During both the 21st and the 22nd solar activity cycles the Baksan Underground Scintillation Telescope (BUST) recorded three short-term bursts of muon intensity correlating with the Ground Level Enhancements (GLE) of SCR. No similar muon bursts were found at the BUST in the current 23rd solar cycle. The primary protons causing those muon bursts have energies greater than 500 GeV, 100 times as large as the threshold energy of the neutron monitors which are used for the SCR study on the Earth surface. The threshold energy of EAS arrays is also greater than that of neutron monitors. The total counting rate of two Baksan EAS arrays ``Andyrchy'' and ``Carpet'' was examined during the GLE events observed in the 23rd solar activity cycle. Significant excesses above the galactic cosmic ray background were found during several GLE events. The statistical accuracy of neutron monitors by the 5-minute data is about 1 %. This quantity for the ``Andyrchy'' and ``Carpet'' is 0.05 % and 0.03 %, respectively. It allows us to fix lesser intensity rises at greater threshold energy of particles. There are GLE events recorded only at the polar neutron monitors (e.g., Apatity), which have low threshold energies (about 1 GeV). The middle-latitude monitors (e.g., Moscow) with a greater threshold didn't show any excess at the same time. In these cases ``Andyrchy'' and ``Carpet'' recorded statistically significant rises (5-8 standard deviations) despite their greater threshold energy - 5.8 GeV. These facts allow us to extend the SCR spectrum of those events to a higher energy region.

Karpov, S. N.; Alekseenko, V. V.; Zaichenko, A. N.; Karpova, Z. M.; Petkov, V. B.; Poddubny, V. Ya.; Khaerdinov, N. S.

2003-04-01

47

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

48

Ultra High Energy Cosmic Rays: The disappointing model  

E-print Network

We develop a model inspired by the Auger mass composition for ultra high energy cosmic rays (UHECR). The cruicial experimental fact for the model is given by the strong proton dominance in energy range 1 - 3 EeV in agreement with the HiRes data. At higher energies the Auger data show progressively heavier mass composition reaching the Iron-dominated one at $E \\sim 35$ EeV. Assuming extragalactic origin of this EeV proton component, we argue that it disappears at higher energies due to low maximum-energy of acceleration for the protons $E_{\\rm max}^{\\rm acc} \\sim (4 - 10)$ EeV. For rigidity acceleration mechanism the maximum energy for nuclei is Z times higher, where Z is a nucleus charge number, and thus maximum energy for Iron nuclei does not exceed 100 - 300 EeV. This energy is close to the maximum energy observed by Auger. The cutoff of the spectrum is provided by photo-disintegration of the nuclei strengthened by acceleration cutoff. This model has disappointing consequences for future observations in UHE...

Aloisio, R; Gazizov, A

2011-01-01

49

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

50

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

E-print Network

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.

Philipp Baerwald; Mauricio Bustamante; Walter Winter

2014-07-07

51

High energy neutrinos from astrophysical accelerators of cosmic ray nuclei  

NASA Astrophysics Data System (ADS)

Ongoing experimental efforts to detect cosmic sources of high energy neutrinos are guided by the expectation that astrophysical accelerators of cosmic ray protons would also generate neutrinos through interactions with ambient matter and/or photons. However, there will be a reduction in the predicted neutrino flux if cosmic ray sources accelerate not only protons but also significant numbers of heavier nuclei, as is indicated by recent air shower data. We consider plausible extragalactic sources such as active galactic nuclei, gamma ray bursts and starburst galaxies and demand consistency with the observed cosmic ray composition and energy spectrum at Earth after allowing for propagation through intergalactic radiation fields. This allows us to calculate the expected neutrino fluxes from the sources, normalized to the observed cosmic ray spectrum. We find that the likely signals are still within reach of next generation neutrino telescopes such as IceCube.PACS95.85.Ry98.70.Rz98.54.Cm98.54.EpReferencesFor a review, see:F.HalzenD.HooperRep. Prog. Phys.6520021025A.AchterbergIceCube CollaborationPhys. Rev. Lett.972006221101A.AchterbergIceCube CollaborationAstropart. Phys.262006282arXiv:astro-ph/0611063arXiv:astro-ph/0702265V.NiessANTARES CollaborationAIP Conf. Proc.8672006217I.KravchenkoPhys. Rev. D732006082002S.W.BarwickANITA CollaborationPhys. Rev. Lett.962006171101V.Van ElewyckPierre Auger CollaborationAIP Conf. Proc.8092006187For a survey of possible sources and event rates in km3 detectors see e.g.,W.BednarekG.F.BurgioT.MontaruliNew Astron. Rev.4920051M.D.KistlerJ.F.BeacomPhys. Rev. D742006063007A. Kappes, J. Hinton, C. Stegmann, F.A. Aharonian, arXiv:astro-ph/0607286.A.LevinsonE.WaxmanPhys. Rev. Lett.872001171101C.DistefanoD.GuettaE.WaxmanA.LevinsonAstrophys. J.5752002378F.A.AharonianL.A.AnchordoquiD.KhangulyanT.MontaruliJ. Phys. Conf. Ser.392006408J.Alvarez-MunizF.HalzenAstrophys. J.5762002L33F.VissaniAstropart. Phys.262006310F.W.SteckerC.DoneM.H.SalamonP.SommersPhys. Rev. Lett.6619912697(Erratum-ibid. 69 (1992) 2738)F.W.SteckerPhys. Rev. D722005107301A.AtoyanC.D.DermerPhys. Rev. Lett.872001221102L.A.AnchordoquiH.GoldbergF.HalzenT.J.WeilerPhys. Lett. B6002004202E.WaxmanJ.N.BahcallPhys. Rev. Lett.7819972292C.D.DermerA.AtoyanPhys. Rev. Lett.912003071102D.GuettaD.HooperJ.Alvarez-MunizF.HalzenE.ReuveniAstropart. Phys.202004429J.Alvarez-MunizF.HalzenD.W.HooperPhys. Rev. D622000093015A.LoebE.WaxmanJCAP06052006003S. Inoue, G. Sigl, F. Miniati, E. Armengaud, arXiv:astro-ph/0701167.E.WaxmanJ.N.BahcallPhys. Rev. D591999023002Phys. Rev. D642001023002K.MannheimR.J.ProtheroeJ.P.RachenPhys. Rev. D632001023003arXiv:astro-ph/9908031M.AhlersL.A.AnchordoquiH.GoldbergF.HalzenA.RingwaldT.J.WeilerPhys. Rev. D722005023001E.WaxmanAstrophys. J.4521995L1Note that the neutrino spectral shape can deviate from that for protons if the Feynman plateau is not flat in pseudo-rapidity space;L.AnchordoquiH.GoldbergC.NunezPhys. Rev. D712005065014This is in fact suggested by Tevatron data;F.AbeCDF CollaborationPhys. Rev. D4119902330J.G.LearnedS.PakvasaAstropart. Phys.31995267F.HalzenD.SaltzbergPhys. Rev. Lett.8119984305J.F.BeacomN.F.BellD.HooperS.PakvasaT.J.WeilerPhys. Rev. D682003093005(Erratum-ibid. D 72 (2005) 019901)L.A.AnchordoquiH.GoldbergF.HalzenT.J.WeilerPhys. Lett. B593200442L.A.AnchordoquiH.GoldbergF.HalzenT.J.WeilerPhys. Lett. B621200518A.M.HillasAnn. Rev. Astron. Astrophys.221984425For a general discussion on the acceleration time-scale in these sources see, e.g.,D.F.TorresL.A.AnchordoquiRep. Prog. Phys.6720041663M.C.BegelmanB.RudakM.SikoraAstrophys. J.362199038M.J.ChodorowskiA.A.ZdziarskiM.SikoraAstrophys. J.4001992181S.MichalowskiD.AndrewsJ.EickmeyerT.GentileN.MistryR.TalmanK.UenoPhys. Rev. Lett.391977737J.L.PugetF.W.SteckerJ.H.BredekampAstrophys. J.2051976638D.HooperS.SarkarA.M.TaylorAstropart. Phys.272007199The non-thermal energy release in GRBs is much smaller than that output by AGN.P.L.BiermannP.A.StrittmatterAstrophys. J.3221987643R.J.ProtheroeA.P.SzaboPhys. Rev. Lett.6919922885J.P.RachenP.L.BiermannAstron. Astrophys.2721993161J.P.Ra

Anchordoqui, Luis A.; Hooper, Dan; Sarkar, Subir; Taylor, Andrew M.

2008-02-01

52

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

53

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

California at Santa Cruz, University of

54

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

2012-11-21

55

THE COMPOSITION OF ULTRA HIGH ENERGY COSMIC RAYS THROUGH HYBRID  

E-print Network

for detecting cosmic rays. This analysis combines both ground array and fluorescence data in a hybrid analysis iron. However, above 1019.3 eV, the statistical power is limited and the data is compatible either proton or iron MCs. The shapes of the Xmax distributions independent of their means are compared, showing

56

High-energy Neutrino Astronomy: The Cosmic Ray Connection  

E-print Network

This is a review of neutrino astronomy anchored to the observational fact that Nature accelerates protons and photons to energies in excess of $10^{20}$ and $10^{13}$ eV, respectively. Although the discovery of cosmic rays dates back close to a century, we do not know how and where they are accelerated. Basic elementary-particle physics dictates a universal upper limit on their energy of $5\\times10^{19}$ eV, the so-called Greisen-Kuzmin-Zatsepin cutoff; however, particles in excess of this energy have been observed by all experiments, adding one more puzzle to the cosmic ray mystery. Mystery is fertile ground for progress: we will review the facts as well as the speculations about the sources including gamma ray bursts, blazars and top-down scenarios. The important conclusion is that, independently of the specific blueprint of the source, it takes a kilometer-scale neutrino observatory to detect the neutrino beam associated with the highest energy cosmic rays and gamma rays. We also briefly review the ongoing efforts to commission such instrumentation.

Francis Halzen; Dan Hooper

2002-07-08

57

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

58

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

59

HIGH-ENERGY EMISSION INDUCED BY ULTRA-HIGH-ENERGY PHOTONS AS A PROBE OF ULTRA-HIGH-ENERGY COSMIC-RAY ACCELERATORS EMBEDDED IN THE COSMIC WEB  

SciTech Connect

The photomeson production in ultra-high-energy cosmic-ray (UHECR) accelerators such as {gamma}-ray bursts and active galaxies may lead to ultra-high-energy (UHE) {gamma}-ray emission. We show that the generation of UHE pairs in magnetized structured regions where the sources are embedded is inevitable, and accompanying {approx}> 0.1 TeV synchrotron emission provides an important probe of UHECR acceleration. It would especially be relevant for powerful transient sources, and synchrotron pair echoes may be detected by future CTA via coordinated search for transients of duration {approx}0.1-1 yr for the structured regions of {approx}Mpc. Detections will be useful for knowing structured extragalactic magnetic fields as well as properties of the sources.

Murase, Kohta [Department of Physics, Center for Cosmology and AstroParticle Physics, Ohio State University, Columbus, OH 43210 (United States)

2012-02-15

60

Radio detection of ultra high energy cosmic rays and neutrinos  

NASA Astrophysics Data System (ADS)

Air showers produced in the interactions of cosmic rays and neutrinos produce radio frequency signals. In the atmosphere the dominant mechanism is geosynchrotron emission, and in dense media such as ice the Askaryan mechanism leads to coherent impulsive Cherenkov emission. Ground-based antenna arrays, balloon-borne interferometers, and buried arrays have been deployed to exploit this mechanism. The status of observations using this technique will be reviewed, and the prospects for future experiments will be discussed.

Beatty, James J.

2013-02-01

61

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

62

Isotropy of the arrival directions of ultra high energy cosmic rays  

Microsoft Academic Search

THERE has been little success in the search for anisotropies in the arrival directions of ultra high energy cosmic rays. Data on 50 events of very high energy, having an arrival direction which is `not obviously isotropic', have however, been collected by the Sydney extensive air shower group1. The data were recorded over a period of 5 yr and, as

J. Linsley; A. A. Watson

1974-01-01

63

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

64

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

65

18. Supernova remnants and the origin of cosmic rays 18.1 High-energy emission from SNR  

E-print Network

18. Supernova remnants and the origin of cosmic rays 18.1 High-energy emission from SNR We have already mentioned supernova remnants as possible sources of cosmic rays, and indeed synchrotron emission rays, then the cosmic-ray density in and near the SNR should be very high, so one should be able to see

Pohl, Martin Karl Wilhelm

66

High energy cosmic ray particles and the most powerful new type discharges in thunderstorm atmosphere  

E-print Network

The runaway breakdown -- extensive atmospheric shower discharge (RB - EAS) excited in thunderstorm atmosphere by high energy cosmic ray particles ($\\epsilon_p>10^{17} - 10^{19}$ eV) generate very powerful radio pulse. The RB - EAS theory is compared with observations of radio pulses. An agreement between the theory and experiment is established. The existence of nowaday satellite and ground based systems which obtain regularly a large amount of observational radio data could allow to use them in combination with other methods for effective study of high energy cosmic ray particles

Gurevich, A V

2004-01-01

67

High energy cosmic ray particles and the most powerful new type discharges in thunderstorm atmosphere  

E-print Network

The runaway breakdown -- extensive atmospheric shower discharge (RB - EAS) excited in thunderstorm atmosphere by high energy cosmic ray particles ($\\epsilon_p>10^{17} - 10^{19}$ eV) generate very powerful radio pulse. The RB - EAS theory is compared with observations of radio pulses. An agreement between the theory and experiment is established. The existence of nowaday satellite and ground based systems which obtain regularly a large amount of observational radio data could allow to use them in combination with other methods for effective study of high energy cosmic ray particles

A. V. Gurevich; K. P. Zybin

2004-03-30

68

Upper limits on the ultra-high energy cosmic ray flux from unresolved sources  

NASA Astrophysics Data System (ADS)

The Pierre Auger Observatory is the world's largest ultra-high energy cosmic ray detector. Its goals include answering basic questions about the origins and composition of cosmic rays at the highest energies. We outline the scientific motivation for constructing such an observatory and we highlight some of the significant results produced so far by this world-class instrument. We present the results of our own contributions toward calibrating the timing characteristics of the instrument followed by two alternative techniques for analyzing cosmic ray arrival direction data. The first technique is based on a Bayesian statistical framework and is presented as a solution to some of the difficulties in applying a standard analysis to identify anisotropy in the cosmic ray flux. The second analysis we present is based on a Markov Chain Monte Carlo method for identifying sources of cosmic rays in our arrival direction data. We are able to use our method to set an upper limit of 0.15 per square km per year on the flux from any potential sources producing ultra-high energy cosmic rays with energy E ? 3 EeV. We conclude with a proposal for enhancing the already successful observatory with an array of non-imaging Cherenkov detectors. According to our simulation work, such an array could serve as both an independent measure of the cosmic ray energy and, if the array is dense enough, it could also provide insight into the composition of ultra-high energy cosmic rays on an event by event basis.

Burton, Ross E.

69

Lookup tables to compute high energy cosmic ray induced atmospheric ionization and changes in 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 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 GeV - 1 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.

Dimitra Atri; Adrian L. Melott; Brian C. Thomas

2010-05-03

70

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

71

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

72

Shock Acceleration of High-Energy Cosmic Rays: The Importance of the Magnetic-Field Angle  

E-print Network

Shock Acceleration of High-Energy Cosmic Rays: The Importance of the Magnetic-Field Angle Joe-mail: giacalon@lpl.arizona.edu Abstract. The physics of particle acceleration by collisionless shocks of the accelerated particles. We show that the acceleration rate is strongly dependent on Bn and is a maximum

73

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; Jörg Behrens

2010-01-01

74

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

75

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

76

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

77

Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum and composition  

E-print Network

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 $\\sim Z$ 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 $Espectrum, the average mass and on its spread, in partic...

Mollerach, Silvia

2013-01-01

78

Detection of High Energy Cosmic Ray with the Advanced Thin Ionization Calorimeter, ATIC  

NASA Astrophysics Data System (ADS)

ATIC is a balloon-borne investigation of cosmic ray spectra, from below 50 GeV to near 100 TeV total energy, using a fully active Bismuth Germanate (BGO) calorimeter. It is equipped with the first large area mosaic of small fully depleted silicon detector pixels capable of charge identification in cosmic rays from H to Fe. As a redundancy check for the charge identification and a coarse particle tracking system, three projective layers of x-y scintillator hodoscopes were employed, above, in the center and below a Carbon interaction `target'. Very high energy ?-rays and their energy spectrum may provide insight to the flux of extremely high energy neutrinos which will be investigated in detail with several proposed cubic kilometer scale neutrino observatories in the next decade.

Fazely, Ali R.

2003-06-01

79

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 supernovæ 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

80

Modeling high-energy cosmic ray induced terrestrial muon flux: A lookup table  

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. Typical cosmic ray energies may be much higher than the ?1GeV flux which normally dominates. 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. Secondary particles such as muons and thermal neutrons produced as a result of nuclear interactions are able to reach the ground, enhancing the radiation dose. Muons contribute 85% to the radiation dose from cosmic rays. This enhanced dose could be potentially harmful to the biosphere. This mechanism has been discussed extensively in literature but has never been quantified. Here, we have developed a lookup table that can be used to quantify this effect by modeling terrestrial muon flux from any arbitrary cosmic ray spectra with 10 GeV to 1 PeV primaries. This will enable us to compute the radiation dose on terrestrial planetary surfaces from a number of astrophysical sources.

Atri, Dimitra; Melott, Adrian L.

2011-06-01

81

Magnetowave Induced Plasma Wakefield Acceleration for Ultra High Energy Cosmic Rays  

E-print Network

Magnetowave induced plasma wakefield acceleration (MPWA) in a relativistic astrophysical outflow has been proposed as a viable mechanism for the acceleration of cosmic particles to ultra high energies. Here we present simulation results that clearly demonstrate the viability of this mechanism for the first time. We invoke the high frequency and high speed whistler mode for the driving pulse. The plasma wakefield so induced validates precisely the theoretical prediction. We show that under appropriate conditions, the plasma wakefield maintains very high coherence and can sustain high-gradient acceleration over a macroscopic distance. Invoking gamma ray burst (GRB) as the source, we show that MPWA production of ultra high energy cosmic rays (UHECR) beyond ZeV 10^21 eV is possible.

Feng-Yin Chang; Pisin Chen; Guey-Lin Lin; Kevin Reil; Richard Sydora

2007-09-07

82

The Composition of Ultra High Energy Cosmic Rays at Telescope Array  

NASA Astrophysics Data System (ADS)

Telescope Array (TA) is the largest cosmic ray observatory in the Northern Hemisphere and is sensitive to Ultra High Energy Cosmic Rays (UHECR) with energies above 10^18 eV. UHECR observatories rely on the extensive air shower (EAS) produced when cosmic rays interact in the atmosphere. The point in an EAS that has the largest number of particles is called shower maximum, Xmax, and is sensitive to cosmic ray composition. TA uses surface detector (SD) as well as fluorescence detector (FD) observation methods and may observe Xmax in monocular mode, using single FD station, stereo mode, using a pair of FD stations, or hybrid mode, using one FD station combined with the SD. Hybrid and stereo observation allow for accurate reconstruction of cosmic ray arrival directions and Xmax. Both hybrid and stereo modes provide resolutions better than 1^o in arrival direction and 30 g/cm^2 in Xmax. Both of these observation methods are sufficiently accurate for composition analysis using Xmax. In this talk, the most recent TA composition analysis is presented. The results are compatible with the predictions of QGSJet01/II proton Monte Carlo and incompatible with QGSJet01/II iron for energies between 10^18.2 and 10^19.3 eV.

Barcikowski, Elliott

2012-03-01

83

Space Program KOSMOTEPETL (project KLYPVE and TUS) for the study of extremely high energy cosmic rays  

Microsoft Academic Search

The scientific goal of the KOSMOTEPETL program is to observe and to study ultra high energy cosmic rays through the fluorescent tracks that they produce in the Earth atmosphere with the help of satellite based optical cameras based on the technology of a large mirror-concentrator of light. At low orbits (400-600 km) a mirror with an area of 400 m2

B. A. Khrenov; M. I. Panasyuk; V. V. Alexandrov; D. I. Bugrov; A. Cordero; G. K. Garipov; J. Linsley; O. Martinez; H. Salazar; O. A. Saprykin; A. A. Silaev; D. V. Surogatov; V. S. Syromyatnikov; L. Villaseñor; A. Zepeda

2001-01-01

84

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

NASA Astrophysics Data System (ADS)

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 ECR ? 5 × 10 9 GeV.

Koch, Ben; Drescher, Hans-Joachim; Bleicher, Marcus

2006-06-01

85

Showering from high-energy cosmic rays. Can be measured in the high school science lab  

NASA Astrophysics Data System (ADS)

In particle physics a `shower' is the avalanche of secondary particles produced by an incoming particle with high energy. This production requires the interaction with mass. A shower produced by high-energy cosmic rays usually covers a wide area, on the order of a square kilometer. The secondary particles can be observed by using scintillators. In view of the large area affected and the relatively simple equipment needed, this is an ideal project to involve high-school students and their teachers. Showering can also be observed indoors, on a muchsmaller scale.

Buisman, Henk; Wilke de Souza, Daniel; Steijger, Jos

2014-09-01

86

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

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

A search for correlations of TeV gamma-rays with ultra-high energy cosmic rays  

E-print Network

A search was conducted for TeV gamma-rays emitted from the direction of the ultra-high energy cosmic ray detected by the Fly's Eye Experiment with E ~ 3 x 10**20 eV. No enhancement was found at a level of 10**-10 gamma/cm**2-sec for E>350 GeV. This upper limit is consistent with theoretical estimates based on topological defects as sources of UHE cosmic rays. An upper limit was also set for the flux of TeV gamma rays from 3C147, the most prominent AGN in the error box.

C. W. Akerlof; S. Biller; P. Boyle; J. Buckley; D. A. Carter-Lewis; M. Catanese; M. F. Cawley; V. Connaughton; D. J. Fegan; J. Finley; J. Gaidos; A. M. Hillas; F. Krennrich; R. C. Lamb; R. Lessard; J. McEnery; G. Mohanty; N. A. Porter; J. Quinn; A. Rodgers; H. J. Rose; F. Samuelson; M. S. Schubnell; G. Sembroski; R. Srinivasan; T. C. Weekes; J. Zweerink; .

1997-06-12

89

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

90

Ultra High Energy Cosmic Rays from decays of Holeums in Galactic Halos  

E-print Network

Stable, quantized gravitational bound states of primordial black holes called Holeums could have been produced in the early universe and could be a component of the Super Heavy Dark Matter (SHDM) present in galactic halos. We show that Holeums of masses of the order of 10**13 to 10**14 GeV and above are stable enough to survive in the present-day universe. We identify such Holeums as promising candidates for the SHDM "X-particle" and show that the decay of such Holeums by pressure ionization can give rise to cosmic rays of all observed energies, including Ultra High Energy Cosmic Rays (UHECR). The absence of the GZK cut-off is explained by the galactic halo origin of the UHECR. We predict that the cosmic rays are a manifestation of the end-stage Hawking radiation burst of the primordial black holes (PBH) liberated by the ionization of Holeums. Antimatter detected in cosmic rays could be a signature of their Holeum origin.

Abhijit L. Chavda; L. K. Chavda

2008-06-03

91

"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

92

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

93

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

94

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

2007-08-13

95

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

96

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

97

Ultra high energy cosmic rays: implications of Auger data for source spectra and chemical composition  

NASA Astrophysics Data System (ADS)

We use a kinetic-equation approach to describe the propagation of ultra high energy cosmic ray protons and nuclei and calculate the expected spectra and mass composition at the Earth for different assumptions on the source injection spectra and chemical abundances. When compared with the spectrum, the elongation rate Xmax(E) and dispersion ?(Xmax) as observed with the Pierre Auger Observatory, several important consequences can be drawn: a) the injection spectra of nuclei must be very hard, ~ E-? with ?~ 1- 1.6; b) the maximum energy of nuclei of charge Z in the sources must be ~ 5Z× 1018 eV, thereby not requiring acceleration to extremely high energies; c) the fit to the Auger spectrum can be obtained only at the price of adding an ad hoc light extragalactic component with a steep injection spectrum ~ E-2.7). In this sense, at the ankle EA? 5× 1018 eV) all the components are of extragalactic origin, thereby suggesting that the transition from Galactic to extragalactic cosmic rays occurs below the ankle. Interestingly, the additional light extragalactic component postulated above compares well, in terms of spectrum and normalization, with the one recently measured by KASCADE-Grande.

Aloisio, R.; Berezinsky, V.; Blasi, P.

2014-10-01

98

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

99

Constraints on the Source of Ultra-high-energy Cosmic Rays Using Anisotropy versus Chemical Composition  

NASA Astrophysics Data System (ADS)

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; Taylor, Andrew M.; Lemoine, Martin; Wang, Xiang-Yu; Waxman, Eli

2013-10-01

100

The high-energy diffuse cosmic gamma-ray background radiation from blazars  

NASA Technical Reports Server (NTRS)

We predict the spectrum and flux of the high-energy diffuse cosmic gamma-ray background radiation produced by blazars. Our calculations are based on the Compton Observatory EGRET observations of high-energy gamma-rays from these objects, the Whipple observation of TeV gamma-rays from Mrk 421, and radio population studies of flat-spectrum radio sources. Our statistical analysis gives a result consistent with a linear correlation. We then use the radio luminosity function and redshift evolution to calculate the gamma-ray background. We find that blazars cannot account for the flux level or steep spectrum of the background observed by SAS 2 in the sub-GeV range, but could likely provide the dominant background component in the multi-GeV energy range and above. We predict a differential photon spectral index for this component of about 2 up to about 10 GeV. Above that energy, the spectrum should gradually steepen owing to pair production by interactions of the gamma-rays with intergalactic infrared photons. Using the calculations of this effect by Stecker et al. (1992), we estimate a spectral index of about 3.5 for energies above a TeV.

Stecker, F. W.; Salamon, M. H.; Malkan, M. A.

1993-01-01

101

Modeling the Galactic Magnetic Field and its Application in verifying a Pulsar Origin of Very High Energy Cosmic Rays  

NASA Astrophysics Data System (ADS)

Deflection of Cosmic Ray charged particles under the influence of magnetic fields (Galactic and Extragalactic) causes a nearly isotropic distribution of their observed fluxes especially in lower energy ranges. Anyhow, as very high energy cosmic rays experience less deflections in their paths, they may point out the direction of their sources within a few degrees. We used a Galactic magnetic field model to study the possible Galactic sources of these cosmic rays. The propagation of cosmic rays in this Galactic magnetic field is simulated to estimate average deflection angles into their straight-line paths from their sources. Pulsars with suitable characteristics are selected and deflection regions around them are defined. Compared with the observational data (i.e. detected directions of observed CRs), the possibility of a Galactic origin of ultra high energy cosmic rays is examined. We defined deflection angles in terms of energies for sources in a distance d into center and anti-center directions. The probability of observing cosmic rays of di?erent energies from the direction of a source in a distance d is studied and the possibility of a pulsar origin of very high energy cosmic rays due to some recent models, is discussed.

Davoudifar, Pantea; Rowshan Tabari, Keihanak

2014-03-01

102

Interactions of High Energy Cosmic Rays with Extragalactic Infrared Radiation Background  

E-print Network

We consider the modification of extragalactic cosmic ray spectrum caused by cosmic ray interactions with infrared background photons which are present in the extragalactic space together with relic photons. It is assumed that cosmic ray spectrum at superhigh energies has extragalactic origin and is proton dominated.

E. V. Bugaev; P. A. Klimai

2005-09-14

103

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

104

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

105

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 < 0.5 or so. On the other hand, the present experimental and astrophysical limits allow a rather fast 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

106

New detection technologies for ultra-high energy cosmic rays and neutrinos  

NASA Astrophysics Data System (ADS)

Even with an accumulated data set from an integrated six years of lifetime from the Auger experiment, no point sources of charged cosmic rays have be identified at the highest energies. Significantly increased apertures such as promised by the JEMEUSO mission will be required to identify these sources from the cosmic ray signatures themselves. However, in employing water-cherenkov surface detectors as well as fluorescence telescopes, Auger has demonstrated the power provided by the hybrid technology approach. New detection technologies thus provide a valuable tool, in particular for the study of systematic effects. Over the past decade, in particular radio detection of cosmic ray air-showers has become a viable future detection technology to enhance and complement existing air-shower experiments. Following the proof-of-principle provided by the Lopes experiment, this technology is now being pursued in all major air-shower detectors. In the MHz regime, the radio signal is dominated by geomagnetic emission from the electrons deflected in the earth magnetic field, with secondary contributions from a global charge excess. As the majority of the energy in the shower is carried by these electron and the radio signal traverses the atmosphere basically unattenuated, this approach not only promises superior energy resolution but may also provide an independent handle on the longitudinal shower development and hence the primary composition. Theoretical signal predictions provided by detailed Monte-Carlo simulations as well as analytic shower parametrizations are in good agreement with measurements provided by the AERA and Codalema experiments. Recent efforts also include studies of the radio emission in the GHz regime, where the ambient noise is significantly reduced, yet the emission mechanism in this regime has not been firmly established yet. As neutrinos are not deflected in the intergalactic magnetic fields, the detection of neutrino-induced cascades in dense media provides another promising approachfor the identification of the sources of cosmic rays. The low event rates and large required target volumes limit the experimental methods to far-ranging signatures .from the cascade, such as acoustic emission from the quasi-instantaneous energy deposit or Cherenkov emission from the charged particles in the cascade. Searching for optical Cherenkov photons in a cubic-kilometer of Antarctic ice, the IceCube experiment has recently found an excess of high-energy neutrinos in the TeV-PeV range.Yet its effective volume is too small to detect the GZK flux predicted from interaction of the highest-energy cosmic rays with the ambient cosmic microwave background. Seeking to increase the observed target volume, radio observations of the rim of the moon have energy thresholds well beyond the EeV scale and thus are more likely to find interactions of charged cosmic rays than GZK neutrinos. The currently best sensitivity to this flux is provided from searches for GHz radio emission of neutrino-induced cascades in the antarctic ice from the ANITA ballon experiment. While no high-energy neutrinos have been found, a geomagnetic emission component from air-showers

Böser, Sebastian

2013-06-01

107

Global anisotropy of arrival directions of ultra-high-energy cosmic rays: capabilities of space-based detectors  

Microsoft Academic Search

Planned space-based ultra-high-energy cosmic-ray detectors (TUS, JEM-EUSO and S-EUSO) are best suited for searches of global anisotropies in the distribution of arrival directions of cosmic-ray particles because they will be able to observe the full sky with a single instrument. We calculate quantitatively the strength of anisotropies associated with two models of the origin of the highest-energy particles: the extragalactic

O. E. Kalashev; B. A. Khrenov; P. Klimov; S. Sharakin; S. V. Troitsky

2008-01-01

108

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

Microsoft Academic Search

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 Véron-Cetty Véron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2pt–L, 2pt+

P. Abreu; M. Aglietta; M. Ahlers; E. J. Ahn; I. F. M. Albuquerque; D. Allard; I. Allekotte; J. Allen; P. Allison; A. Almela; J. Alvarez Castillo; J. Alvarez-Muñiz; M. Ambrosio; A. Aminaei; L. Anchordoqui; S. Andringa; T. Anticic; C. Aramo; E. Arganda; F. Arqueros; H. Asorey; P. Assis; J. Aublin; M. Avenier; G. Avila; T. Bäcker; A. M. Badescu; M. Balzer; K. B. Barber; A. F. Barbosa; R. Bardenet; S. L. C. Barroso; B. Baughman; J. Bäuml; J. J. Beatty; B. R. Becker; K. H. Becker; A. Bellétoile; J. A. Bellido; S. BenZvi; C. Berat; X. Bertou; P. L. Biermann; P. Billoir; F. Blanco; M. Blanco; C. Bleve; H. Blümer; M. Bohácová; D. Boncioli; C. Bonifazi; R. Bonino; N. Borodai; J. Brack; I. Brancus; P. Brogueira; W. C. Brown; R. Bruijn; P. Buchholz; A. Bueno; R. E. Burton; K. S. Caballero-Mora; B. Caccianiga; 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. Chirinos Diaz; J. Chudoba; M. Cilmo; R. W. Clay; M. R. Coluccia; R. Conceição; F. Contreras; H. Cook; M. J. Cooper; J. Coppens; A. Cordier; 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; I. De Mitri; V. de Souza; K. D. de Vries; L. del Peral; M. del Río; O. Deligny; H. Dembinski; N. Dhital; C. Di Giulio; M. L. Díaz Castro; P. N. Diep; F. Diogo; 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; J. Espadanal; A. Etchegoyen; P. Facal San Luis; I. Fajardo Tapia; H. Falcke; G. Farrar; A. C. Fauth; N. Fazzini; A. P. Ferguson; B. Fick; A. Filevich; A. Filipcic; S. Fliescher; C. E. Fracchiolla; E. D. Fraenkel; O. Fratu; U. Fröhlich; B. Fuchs; R. Gaior; R. F. Gamarra; S. Gambetta; B. García; S. T. Garcia Roca; D. Garcia-Gamez; D. Garcia-Pinto; A. Gascon; H. Gemmeke; P. L. Ghia; U. Giaccari; M. Giller; H. Glass; M. S. Gold; G. Golup; F. Gomez Albarracin; M. Gómez Berisso; P. F. Gómez Vitale; P. Gonçalves; D. Gonzalez; J. G. Gonzalez; B. Gookin; A. Gorgi; P. Gouffon; 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; T. A. Harrison; J. L. Harton; A. Haungs; T. Hebbeker; D. Heck; A. E. Herve; C. Hojvat; N. Hollon; V. C. Holmes; P. Homola; J. R. Hörandel; A. Horneffer; P. Horvath; M. Hrabovský; T. Huege; A. Insolia; F. Ionita; A. Italiano; C. Jarne; S. Jiraskova; M. Josebachuili; K. Kadija; K. H. Kampert; P. Karhan; P. Kasper; B. Kégl; 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. Krömer; D. Kruppke-Hansen; F. Kuehn; D. Kuempel; J. K. Kulbartz; N. Kunka; G. La Rosa; C. Lachaud; R. Lauer; P. Lautridou; S. Le Coz; M. S. A. B. Leão; D. Lebrun; P. Lebrun; M. A. Leigui de Oliveira; A. Letessier-Selvon; I. Lhenry-Yvon; K. Link; R. López; A. Lopez Agüera; K. Louedec; J. Lozano Bahilo; L. Lu; A. Lucero; M. Ludwig; H. Lyberis; 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. Martínez Bravo; H. J. Mathes; J. Matthews; G. Matthiae; D. Maurel; 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; I. A. Minaya; L. Miramonti; L. Molina-Bueno; S. Mollerach; M. Monasor; D. Monnier Ragaigne; F. Montanet; B. Morales; C. Morello; E. Moreno; J. C. Moreno; M. Mostafá; C. A. Moura; M. A. Muller; G. Müller; M. Münchmeyer; R. Mussa; G. Navarra; J. L. Navarro; S. Navas; P. Necesal; L. Nellen; A. Nelles; J. Neuser; P. T. Nhung; M. Niechciol; L. Niemietz; N. Nierstenhoefer; D. Nitz; D. Nosek; L. Nožka; M. Nyklicek; J. Oehlschläger; A. Olinto; M. Ortiz; N. Pacheco; D. Pakk Selmi-Dei; M. Palatka; J. Pallotta; N. Palmieri; G. Parente; E. Parizot; A. Parra; 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; R. Piegaia; T. Pierog; P. Pieroni; M. Pimenta; V. Pirronello; M. Platino; V. H. Ponce; M. Pontz; A. Porcelli; 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; W. Rodrigues de Carvalho; G. Rodriguez; J. Rodriguez Martino; J. Rodriguez Rojo; I. Rodriguez-Cabo; M. D. Rodríguez-Frías; G. Ros; J. Rosado; T. Rossler; M. Roth; B. Rouillé-dOrfeuil; E. Roulet

2012-01-01

109

Galactic PeVatrons: modeling the new sources of high-energy cosmic rays.  

NASA Astrophysics Data System (ADS)

Recent observations (experiments Tunka, KASCADE, etc.) indicate that the spectrum of galactic cosmic rays in the energy range of 10(14) - 10(16) eV has notable features (fluctuations) against the background of a general power law. There are breaks in the spectrum and the spectral index varies from 2.93 to 3.21 on them. A possible explanation for this behavior of the spectrum is the imposition of particle spectra from the sources with different spectral indices of accelerated particles. One of these sources could be the systems of two colliding shocks. Such systems can often occur, for example, in active starforming regions near the Galactic Center or in stellar clusters. Special attention is paid to the regions where the shock of the expanding supernova remnant approaches the stellar wind of nearby massive star (or stars). The number of these systems is estimated as 10 systems per Galaxy. Using the non-linear time-dependent model of charged particle acceleration in two shocks colliding system we have shown that these systems have a set of important features and can make a significant contribution to the total flux of galactic cosmic rays in the high energy range 10(12) - 10(16) eV. Numerical calculations showed that the particles accelerated in the system have very hard spectral energy distribution with the index gamma=1. Maximal energies of the proton component accelerated via two-shocks systems extend well above the “knee” and can reach up to 10(15)-10({17)) eV depending on the magnitude of the amplified magnetic field, flows velocities and the system’s size. Hard spectrum of the particles on these energies and high proton intensity (up to 10(36) erg/s) make these sources possibly responsible for the fluctuations in the galactic cosmic rays spectrum.

Gladilin, Petr; Bykov, Andrey; Osipov, Sergey

110

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

111

Ultra-high energy cosmic ray nuclei from individual magnetized sources  

NASA Astrophysics Data System (ADS)

We investigate the dependence of composition, spectrum and angular distributions of ultra-high energy cosmic rays above 1019 eV from individual sources on their magnetization. We find that, especially for sources within a few megaparsecs of the observer, observable spectra and composition are severely modified if the source is surrounded by fields of {\\sim }10^{-7} G on scales of a few megaparsecs. Low energy particles diffuse over larger distances during their energy loss time. This leads to considerable hardening of the spectrum up to the energy where the loss distance becomes comparable to the source distance. Magnetized sources thus have very important consequences for observations, even if cosmic rays arrive within a few degrees of the source direction. At the same time, details in spectra and chemical composition may be intrinsically unpredictable because they depend on the unknown magnetic field structure. If primaries are predominantly nuclei of atomic mass A accelerated up to a maximum energy Emax with spectra not much softer than E-2, secondary protons from photo-disintegration can produce a conspicuous peak in the spectrum at energy {\\simeq } E_{\\max }/A . A related feature appears in the average mass dependence on energy.

Sigl, Günter

2004-08-01

112

Saturation physics in ultra high energy cosmic rays: heavy quark production  

NASA Astrophysics Data System (ADS)

In this work we estimate the heavy quark production in the interaction of ultra high energy cosmic rays in the atmosphere, considering that the primary cosmic ray is a proton or a photon. At these energies the saturation momentum Qsat2(x) stays above the hard scale ?c2 = 4mc2, implying charm production probing the saturation regime. In particular, we show that the ep HERA data presents a scaling on ?c ? (Q2 + ?c2)/Qsat2(x). We derive our results considering the dipole picture and the Color Glass Condensate formalism, which one shows to be able to describe the heavy quark production in ?p and pp collisions. Nuclear effects are considered for the scattering of primaries with the air nuclei and we provide a parametrization for the charm and bottom differential cross sections, d?/dxF, which can be used as an input for numerical implementations for lepton flux. Implications on the flux of prompt leptons at the Earth are analyzed and a large suppression is predicted.

Gonçalves, Victor P.; Machado, Magno V. T.

2007-04-01

113

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

114

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} ? (2–10)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 Atómico Bariloche, Av. Bustillo 9500 (8400) (Argentina)

2013-10-01

115

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

116

Ultra high energy neutrino nucleon cross section from cosmic ray experiments and neutrino telescopes  

NASA Astrophysics Data System (ADS)

We deduce the cosmogenic neutrino flux by jointly analysing ultra high energy cosmic ray data from HiRes-I and II, AGASA and the Pierre Auger Observatory. We make two determinations of the neutrino flux by using a model-dependent method and a model-independent method. The former is well-known, and involves the use of a power-law injection spectrum. The latter is a regularized unfolding procedure. We then use neutrino flux bounds obtained by the RICE experiment to constrain the neutrino nucleon inelastic cross section at energies inaccessible at colliders. The cross section bounds obtained using the cosmogenic fluxes derived by unfolding are the most model-independent bounds to date.

Barger, V.; Huber, Patrick; Marfatia, Danny

2006-11-01

117

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

118

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

119

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

120

Origin of Ultra-high-energy Galactic Cosmic Rays: The Isotropy Problem  

NASA Astrophysics Data System (ADS)

We study the propagation of ultra-high-energy cosmic rays (UHECRs) in the Galaxy, concentrating on the energy range below the ankle in the spectrum at 4 EeV. A Monte Carlo method, based on analytical solutions to the time-dependent diffusion problem, is used to account for intermittency by placing sources at random locations. Assuming a source population that scales with baryon mass density or star formation (e.g., long GRB), we derive constraints arising from intermittency and the observational limits on the composition and anisotropy. It is shown that the composition and anisotropy at 1018 eV are difficult to reproduce and require that either (1) the particle mean free path is much smaller than a gyroradius, implying the escape time is very long, (2) the composition is heavier than suggested by recent Auger data, (3) the ultra-high-energy sub-ankle component is mostly extragalactic, or (4) we are living in a rare lull in the UHECR production, and the current UHECR intensity is far below the Galactic time average. We therefore recommend a strong observational focus on determining the UHECR composition around 1018 eV.

Pohl, Martin; Eichler, David

2011-12-01

121

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

122

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

123

Magnetars in the Metagalaxy: An Origin for Ultra High Energy Cosmic Rays in the Nearby Universe  

E-print Network

I show that the relativistic winds of newly born magnetars with khz initial spin rates, occurring in all normal galaxies, can accelerate ultrarelativistic light ions with an E^{-1} injection spectrum, steepening to E^{-2} at higher energies, with an upper cutoff above 10^{21} eV. Interactions with the CMB yield a spectrum in good accord with the observed spectrum of Ultra-High Energy Cosmic Rays (UHECR), if ~ 5-10% of the magnetars are born with voltages sufficiently high to accelerate the UHECR. The form the spectrum spectrum takes depends on the gravitational wave losses during the magnetars' early spindown - pure electromagnetic spindown yields a flattening of the E^3 J(E) spectrum below 10^{20} eV, while a moderate GZK ``cutoff'' appears if gravitational wave losses are strong enough. I outline the physics such that the high energy particles escape with small energy losses from a magnetar's natal supernova, including Rayleigh-Taylor ``shredding'' of the supernova envelope, expansion of a relativistic blast wave into the interstellar medium, acceleration of the UHE ions through surf-riding in the electromgnetic fields of the wind, and escape of the UHE ions in the rotational equator with negligible radiation loss. The abundance of interstellar supershells and unusually large supernova remnants suggests that most of the initial spindown energy is radiated in khz gravitational waves for several hours after each supernova, with effective strains from sources at typical distances ~ 3 x 10^{-21}. Such bursts of gravitational radiation should correlate with bursts of ultra-high energy particles. The Auger experiment should see such bursts every few years.

Jonathan Arons

2003-04-01

124

The estimation of background production by cosmic rays in high-energy gamma ray telescopes  

NASA Technical Reports Server (NTRS)

A calculational method of estimating instrumental background in high-energy gamma-ray telescopes, using the hadronic Monte Carlo code FLUKA87, is presented. The method is applied to the SAS-2 and EGRET telescope designs and is also used to explore the level of background to be expected for alternative configurations of the proposed GRITS telescope, which adapts the external fuel tank of a Space Shuttle as a gamma-ray telescope with a very large collecting area. The background produced in proton-beam tests of EGRET is much less than the predicted level. This discrepancy appears to be due to the FLUKA87 inability to transport evaporation nucleons. It is predicted that the background in EGRET will be no more than 4-10 percent of the extragalactic diffuse gamma radiation.

Edwards, H. L.; Nolan, P. L.; Lin, Y. C.; Koch, D. G.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kniffen, D. A.; Hughes, E. B.

1991-01-01

125

Progress in the measurement of high-energy galactic cosmic ray electrons  

NASA Technical Reports Server (NTRS)

Cosmic ray electron measurements by individual threshold detector elements show that about 30 percent of observed electron-like galactic cosmic showers are really proton initiated events. The cosmic electron spectrum at about 10 GeV exhibits a consistent dropoff in intensity leading to a best fit at a power law of spectral index -3.2; a break in the spectrum should occur above 10 GeV.

Silverberg, R. F.

1973-01-01

126

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

127

Search for primary photons and neutrinos in the ultra-high energy cosmic rays with the Pierre Auger Observatory  

NASA Astrophysics Data System (ADS)

Along with primary protons and nuclei most of the scenarios of the origin of cosmic rays predict fluxes of photons and neutrinos at the highest energies. Thanks to the huge collection area and the hybrid design, combining ground array and fluorescence detection techniques, the Pierre Auger Observatory is a unique tool to search for primary photons and neutrinos in ultra-high energy cosmic rays. Implications of these searches extend from astrophysics to fundamental and particle physics. Current results and future perspectives are reported.

Scherini, V.; Pierre Auger Collaboration

2011-03-01

128

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

129

Observation of ultra-high-energy cosmic rays with the ANITA balloon-borne radio interferometer  

Microsoft Academic Search

We report the observation of 16 cosmic-ray events of mean energy of 1.5×1019eV, via a process known as geosynchrotron emission where radio pulses originate from the interaction of the cosmic-ray air shower with the Antarctic geomagnetic field. These are the first ultra-wideband, far-field measurements of the radio spectral density of geosynchrotron emission in the range from 300 to 1000MHz. The

A. Romero-Wolf; S. Hoover; J. Nam; P. W. Gorham; E. Grashorn; P. Allison; S. W. Barwick; J. J. Beatty; K. Belov; D. Z. Besson; W. R. Binns; C. Chen; P. Chen; J. M. Clem; A. Connolly; P. F. Dowkontt; M. A. DuVernois; R. C. Field; D. Goldstein; A. G. Vieregg; C. L. Hebert; M. H. Israel; A. Javaid; J. Kowalski; J. G. Learned; K. M. Liewer; J. T. Link; E. Lusczek; S. Matsuno; B. C. Mercurio; C. Miki; P. Mio?inovi?; C. J. Naudet; J. Ng; R. J. Nichol; K. Palladino; K. Reil; M. Rosen; L. Ruckman; D. Saltzberg; D. Seckel; G. S. Varner; D. Walz; F. Wu

2010-01-01

130

Testing large-scale (an)isotropy of ultra-high energy cosmic rays  

SciTech Connect

We present a simple yet powerful method to test models of cosmic-ray (CR) origin using the distribution of CR arrival directions. The method is statistically unambiguous in the sense that it is binless and does not invoke scanning over unknown parameters, and general in the sense that it can be applied to any model that predicts a continuous distribution of CRs over the sky. We show that it provides a powerful discrimination between an isotropic distribution and predictions from the ''matter tracer'' model, a benchmark model that assumes small CR deflections and a continuous distribution of sources tracing the distribution of matter in the Universe. Our method is competitive or superior in statistical power to existing methods, and is especially sensitive in the case of relatively few high-energy events. Applying the method to the present data we find that neither an isotropic distribution nor the matter tracer model can be excluded. Based on estimates of its statistical power, we expect that the proposed test will lead to meaningful constraints on models of CR origin with the data that will be accumulated within the next few years by the Pierre Auger Observatory and the Telescope Array.

Koers, Hylke B.J.; Tinyakov, Peter, E-mail: hkoers@ulb.ac.be, E-mail: petr.tiniakov@ulb.ac.be [Service de Physique Theorique, Universite Libre de Bruxelles (U.L.B.), CP225, Bld. du Triomphe, B-1050 Bruxelles (Belgium)] [Service de Physique Theorique, Universite Libre de Bruxelles (U.L.B.), CP225, Bld. du Triomphe, B-1050 Bruxelles (Belgium)

2009-04-15

131

The Isotropy Problem of Sub-ankle Ultra High Energy Cosmic Rays  

NASA Astrophysics Data System (ADS)

We study the time dependent propagation of sub-ankle ultra high energy cosmic rays (UHECRs) originating from point-like Galactic sources. We show that drift in the Galactic magnetic field (GMF) may play an important role in the propagation of UHECRs and their measured anisotropy, particularly when the transport is anisotropic. To fully account for the discreteness of UHECR sources in space and time, a Monte Carlo method is used to randomly place sources in the Galaxy. The low anisotropy measured by Auger is not generally characteristic of the theoretical models, given that the sources are distributed in proportion to the star formation rate, but it can possibly be understood as (1) intermittency effects due to the discrete nature of the sources or, with extreme parameters, (2) a cancellation of drift current along a current sheet with outward radial diffusive flux. We conclude that it is possible to interpret the Galactic sub-ankle CR flux as being due entirely to intermittent discrete Galactic sources distributed in proportion to star formation, but only with a probability of roughly 35%, of which the spectrum is in accord with observations about 30% of the time. An alternative explanation for the low anisotropy may be that they are mostly extragalactic and/or heavy.

Kumar, Rahul; Eichler, David

2014-01-01

132

Planck-scale Lorentz violation constrained by Ultra-High-Energy Cosmic Rays  

NASA Astrophysics Data System (ADS)

We investigate the consequences of higher dimension Lorentz violating, CPT even kinetic operators that couple standard model fields to a non-zero vector field in an Effective Field Theory framework. Comparing the ultra-high energy cosmic ray spectrum reconstructed in the presence of such terms with data from the Pierre Auger observatory allows us to establish two sided bounds on the coefficients of the mass dimension five and six operators for the proton and pion. Our bounds imply that for both protons and pions, the energy scale of Lorentz symmetry breaking must be well above the Planck scale. In particular, the dimension five operators are constrained at the level of 10-3MPlanck-1. The magnitude of the dimension six proton coefficient is bounded at the level of 10-6MPlanck-2 except in a narrow range where the pion and proton coefficients are both negative and nearly equal. In this small area, the magnitude of the dimension six proton coefficient must only be below 10-3MPlanck-2. Constraints on the dimension six pion coefficient are found to be much weaker, but still below MPlanck-2.

Maccione, Luca; Taylor, Andrew M.; Mattingly, David M.; Liberati, Stefano

2009-04-01

133

The Galactic magnetic field and propagation of ultra-high energy cosmic rays  

E-print Network

The puzzle of ultra-high energy cosmic rays (UHECRs) still remains unresolved. With the progress in preparation of next generation experiments (AUGER, EUSO, OWL) grows also the importance of directional analysis of existing and future events. The Galactic magnetic field (GMF) plays the key role in source identification even in this energy range. We first analyze current status of our experimental and theoretical knowledge about GMF and introduce complex up-to-date model of GMF. Then we present two examples of simple applications of influence of GMF on UHECR propagation. Both examples are based on Lorentz equation solution. The first one is basic directional analysis of the incident directions of UHECRs and the second one is a simulation of a change of chemical composition of CRs in the energy range 10^13 - 10^19 eV. The results of these simple analyses are surprisingly rich - e.g. the rates of particle escape from the Galaxy or the amplifications of particle flux in specific directions.

Michael Prouza; Radomir Smida

2003-07-09

134

The Galactic magnetic field and propagation of ultra-high energy cosmic rays  

E-print Network

The puzzle of ultra-high energy cosmic rays (UHECRs) still remains unresolved. With the progress in preparation of next generation experiments (AUGER, EUSO, OWL) grows also the importance of directional analysis of existing and future events. The Galactic magnetic field (GMF) plays the key role in source identification even in this energy range. We first analyze current status of our experimental and theoretical knowledge about GMF and introduce complex up-to-date model of GMF. Then we present two examples of simple applications of influence of GMF on UHECR propagation. Both examples are based on Lorentz equation solution. The first one is basic directional analysis of the incident directions of UHECRs and the second one is a simulation of a change of chemical composition of CRs in the energy range 10^13 - 10^19 eV. The results of these simple analyses are surprisingly rich - e.g. the rates of particle escape from the Galaxy or the amplifications of particle flux in specific directions.

Prouza, M; Prouza, Michael; Smida, Radomir

2003-01-01

135

Constraints on the source of ultra-high energy cosmic rays using anisotropy vs chemical composition  

E-print Network

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 t...

Liu, Ruo-Yu; Lemoine, Martin; Wang, Xiang-Yu; Waxman, Eli

2013-01-01

136

Search for Anisotropy of Ultra-High Energy Cosmic Rays with the Telescope Array Experiment  

E-print Network

We study the anisotropy of Ultra-High Energy Cosmic Ray (UHECR) events collected by the Telescope Array (TA) detector in the first 40 months of operation. Following earlier studies, we examine event sets with energy thresholds of 10 EeV, 40 EeV, and 57 EeV. We find that the distributions of the events in right ascension and declination are compatible with an isotropic distribution in all three sets. We then compare with previously reported clustering of the UHECR events at small angular scales. No significant clustering is found in the TA data. We then check the events with E>57 EeV for correlations with nearby active galactic nuclei. No significant correlation is found. Finally, we examine all three sets for correlations with the large-scale structure of the Universe. We find that the two higher-energy sets are compatible with both an isotropic distribution and the hypothesis that UHECR sources follow the matter distribution of the Universe (the LSS hypothesis), while the event set with E>10 EeV is compatibl...

Abu-Zayyad, T; 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; 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; Lim, S I; Machida, S; Martens, K; Martineau, J; 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; 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; Sonley, T J; 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; Vasiloff, G; Wada, Y; Wong, T; Wood, M; Yamakawa, Y; Yamane, R; Yamaoka, H; Yamazaki, K; Yang, J; Yoneda, Y; Yoshida, S; Yoshii, H; Zhou, X; Zollinger, R; Zundel, Z

2012-01-01

137

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

138

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

139

Anisotropy expectations for ultra-high-energy cosmic rays with future high-statistics experiments  

NASA Astrophysics Data System (ADS)

Context. Ultra-high-energy cosmic rays (UHECRs) have attracted a lot of attention in astroparticle physics and high-energy astrophysics, due to their challengingly high energies, and to their ability to constrain the physical processes and astrophysical parameters in the most energetic sources of the universe. Despite their very large acceptance, current detectors have failed to detect significant anisotropies in their arrival directions, which had been expected to lead to the long-sought identification of their sources. Some indications about the composition of the UHECRs, which may become heavier at the highest energies, have even called into question the possibility that such a goal could be achieved in the foreseeable future. Aims: We investigate the potential value of a new-generation detector, with an exposure increased by one order of magnitude, to overcome the current situation and make notable progress in detecting anisotropies and thus in the study of UHECRs. We take as an example the expected performances of the JEM-EUSO detector, assuming a uniform full-sky coverage with a total exposure of 300 000 km2 sr yr. Methods: We simulated realistic UHECR sky maps for a wide range of possible astrophysical scenarios allowed by the current constraints, taking the energy losses and photo-dissociation of the UHE protons and nuclei into account, as well as their deflections by intervening magnetic fields. These sky maps, built for both the expected statistics of JEM-EUSO and the current Pierre Auger Observatory statistics, as a reference, were analysed from the point of view of their intrinsic anisotropies, using the two-point correlation function. A statistical study of the resulting anisotropies was performed for each astrophysical scenario, varying the UHECR source composition and spectrum and the source density and exploring a set of five hundred independent realizations for each choice of a parameter set. Results: We find that significant anisotropies are expected to be detected by a next-generation UHECR detector, for essentially all the astrophysical scenarios studied, and give precise, quantitative meaning to this statement. Conclusions: Our results show that a gain of one order of magnitude in the total exposure of UHECR detectors would make a significant difference compared to the existing experiments, and would allow considerable progress in the study of these mysterious particles and their sources.

Rouillé d'Orfeuil, B.; Allard, D.; Lachaud, C.; Parizot, E.; Blaksley, C.; Nagataki, S.

2014-07-01

140

Ultra High Energy Cosmic Ray Puzzle and the Plasma Wakefield Acceleration  

E-print Network

Magnetowave induced plasma wakefield acceleration (MPWA) in a relativistic astrophysical outflow has been proposed as a viable mechanism for the acceleration of cosmic particles to ultra high energies. Here we present simulation results that demonstrate the viability of this mechanism. We invoke the high frequency and high speed whistler mode for the driving pulse. The plasma wakefield so induced validates precisely the theoretical prediction. This mechanism is shown capable of accelerating charged particles to ZeV energies in Active Galactic Nuclei (AGN).

Feng-Yin Chang; Pisin Chen; Guey-Lin Lin; Robert J. Noble; Kevin Reil; Richard Sydora

2008-08-04

141

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

142

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

143

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

144

Detection of high energy cosmic rays with the resonant gravitational wave detector NAUTILUS and EXPLORER  

E-print Network

The cryogenic resonant gravitational wave detectors NAUTILUS and EXPLORER, made of an aluminum alloy bar, can detect cosmic ray showers. At temperatures above 1 K, when the material is in the normal conducting state, the measured signals are in good agreement with the values expected based on the cosmic rays data and on the thermo-acoustic model. When NAUTILUS was operated at the temperature of 0.14 K, in superconductive state, large signals produced by cosmic ray interactions, more energetic than expected, were recorded. The NAUTILUS data in this case are in agreement with the measurements done by a dedicated experiment on a particle beam. The biggest recorded event was in EXPLORER and excited the first longitudinal mode to a vibrational energy of about 670 K, corresponding to about 360 TeV absorbed in the bar. Cosmic rays can be an important background in future acoustic detectors of improved sensitivity. At present, they represent a useful tool to verify the gravitational wave antenna performance.

P. Astone; D. Babusci; M. Bassan; P. Bonifazi; G. Cavallari; E. Coccia; S. D'Antonio; V. Fafone; G. Giordano; C. Ligi; A. Marini; G. Mazzitelli; Y. Minenkov; I. Modena; G. Modestino; A. Moleti; G. V. Pallottino; G. Pizzella; L. Quintieri; A. Rocchi; F. Ronga; R. Terenzi; M. Visco

2008-06-14

145

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 ?1 GeV to beyond 10(20) eV, where the rate is less than 1 particle per km(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 4 × 10(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

146

A search for flaring very-high-energy cosmic ?-ray sources with the L3+C muon spectrometer  

NASA Astrophysics Data System (ADS)

The L3+C muon detector at the CERN electron positron collider, LEP, is used for the detection of very-high-energy cosmic ?-ray sources through the observation of muons of energies above 20, 30, 50 and 100 GeV. Daily or monthly excesses in the rate of single-muon events pointing to some particular direction in the sky are searched for. The periods from mid July to November 1999, and April to November 2000 are considered. Special attention is also given to a selection of known ?-ray sources. No statistically significant excess is observed for any direction or any particular source.

L3 Collaboration; Adriani, O.; Aguilar-Benitez, M.; van den Akker, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M. G.; Anderhub, H.; Andreev, V. P.; Anselmo, F.; Arefiev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Bähr, J.; Baldew, S. V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillère, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J. J.; Blyth, S. C.; Bobbink, G. J.; Böhm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J. G.; Brochu, F.; Burger, J. D.; Burger, W. J.; Cai, X. D.; Capell, M.; Romeo, G. Cara; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y. H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chiarusi, T.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de La Cruz, B.; Cucciarelli, S.; de Asmundis, R.; Déglon, P.; Debreczeni, J.; Degré, A.; Dehmelt, K.; Deiters, K.; Della Volpe, D.; Delmeire, E.; Denes, P.; Denotaristefani, F.; de Salvo, A.; Diemoz, M.; Dierckxsens, M.; Ding, L. K.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M. T.; Duchesneau, D.; Duda, M.; Duran, I.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F. J.; Extermann, P.; Faber, G.; Falagan, M. A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher, P. H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Yu.; Ganguli, S. N.; Garcia-Abia, P.; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z. F.; Grabosch, H. J.; Grenier, G.; Grimm, O.; Groenstege, H.; Gruenewald, M. W.; Guida, M.; Guo, Y. N.; Gupta, S. K.; Gupta, V. K.; Gurtu, A.; Gutay, L. J.; Haas, D.; Haller, Ch.; Hatzifotiadou, D.; Hayashi, Y.; He, Z. X.; Hebbeker, T.; Hervé, A.; Hirschfelder, J.; Hofer, H.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S. R.; Huo, A. X.; Ito, N.; Jin, B. N.; Jindal, P.; Jing, C. L.; Jones, L. W.; de Jong, P.; Josa-Mutuberría, I.; Kantserov, V.; Kaur, M.; Kawakami, S.; Kienzle-Focacci, M. N.; Kim, J. K.; Kirkby, J.; Kittel, W.; Klimentov, A.; König, A. C.; Kok, E.; Korn, A.; Kopal, M.; Koutsenko, V.; Kräber, M.; Kuang, H. H.; Kraemer, R. W.; Krüger, A.; Kuijpers, J.; Kunin, A.; de Guevara, P. Ladron; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Coultre, P. Le; Goff, J. M. Le; Lei, Y.; Leich, H.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Li, L.; Li, Z. C.; Likhoded, S.; Lin, C. H.; Lin, W. T.; Linde, F. L.; Lista, L.; Liu, Z. A.; Lohmann, W.; Longo, E.; Lu, Y. S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W. G.; Ma, X. H.; Ma, Y. Q.; Malgeri, L.; Malinin, A.; Maña, C.; Mans, J.; Martin, J. P.; Marzano, F.; Mazumdar, K.; McNeil, R. R.; Mele, S.; Meng, X. W.; Merola, L.; Meschini, M.; Metzger, W. J.; Mihul, A.; van Mil, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G. B.; Monteleoni, B.; Muanza, G. S.; Muijs, A. J. M.; Musicar, B.; Musy, M.; Nagy, S.; Nahnhauer, R.; Naumov, V. A.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Nowak, H.; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Parriaud, J.-F.; Passaleva, G.; Patricelli, S.; Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pieri, M.; Pioppi, M.; Piroué, P. A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofiev, D.; Quartieri, J.; Qing, C. R.; Rahal-Callot, G.; Rahaman, M. A.; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P. G.; Ranieri, R.; Raspereza, A.; Ravindran, K. C.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Rewiersma, P.; Riemann, S.; Riles, K.; Roe, B. P.; Rojkov, A.; Romero, L.; Rosca, A.; Rosemann, C.; Rosenbleck, C.; Rosier-Lees, S.; Roth, S.; Rubio, J. A.; Ruggiero, G.; Rykaczewski, H.; Saidi, R.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schäfer, C.; Schegelsky, V.; Schmitt, V.; Schoeneich, B.; Schopper, H.; Schotanus, D. J.; Sciacca, C.; Servoli, L.; Shen, C. Q.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D. P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sulanke, H.; Sultanov, G.; Sun, L. Z.; Sushkov, S.; Suter, H.; Swain, J. D.; Szillasi, Z.; Tang, X. W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, C.; Ting, Samuel C. C.

2006-06-01

147

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

148

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_{\

Aartsen, M G; 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; Tjus, J Becker; 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; Böser, 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; Silva, A H Cruz; 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; Díaz-Vélez, 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; Glüsenkamp, T; Goldschmidt, A; Golup, G; Gonzalez, J G; Goodman, J A; Góra, D; Grandmont, D T; Grant, D; Gretskov, P; Groh, J C; Groß, A; Ha, C; Ismail, A Haj; 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; Kläs, J; Klein, S R; Köhne, J -H; Kohnen, G; Kolanoski, H; Köpke, 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; Lünemann, J; Macías, 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; Heros, C Pérez de los; Pfendner, C; Pieloth, D; Pieloth, D; Pinat, E; Posselt, J; Price, P B; Przybylski, G T; Rädel, 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; Schöneberg, S; Schönwald, 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; Stößl, A; Strahler, E A; Ström, R; Sullivan, G W; Taavola, H; Taboada, I; Tamburro, A; Tepe, A; Ter-Antonyan, S; Teši?, 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

2013-01-01

149

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

150

Topics in Particle Astrophysics: Dark Matter, Gamma-Ray Bursts, and the Origin of Ultra-High-Energy Cosmic Rays  

NASA Astrophysics Data System (ADS)

Since the first observation of cosmic rays in the early 1900's, intensive astronomical and cosmological observations, and improvements in particle detectors have generated important discoveries such as the existence of gamma-ray bursts and pulsars; they have also generated puzzling evidence for dark matter and dark energy, and for the existence of particles in the interstellar medium with energy beyond 1020 eV. In this dissertation, I will investigate some of the current theoretical challenges posed by the latest cosmological and astrophysical observations, and attempt to provide a unifying solution to the problems. X-ray and gamma-ray observations can help understand the origin of the electron and positron signals reported by ATIC, PAMELA, PPB-BETS , and Fermi. It remains unclear whether the observed high-energy electrons and positrons are produced by relic particles, or by astrophysical sources. To distinguish between the two possibilities, one can compare the electron population in the local neighborhood with that in Dwarf Spheroidal Galaxies (dSphs), which are not expected to host as many gamma-ray bursts, pulsars, or other astrophysical sources. This can be accomplished using X-ray and gamma-ray observations. Assuming the signal detected by Fermi and ATIC comes from dark matter, we calculate the photon spectrum produced by electrons via inverse Compton scattering with the Cosmic Microwave Background radiation (CMB). Since little is known about the magnetic fields in dwarf spheroidals, we consider the propagation of charged particles with and without diffusion. Extending the analysis of the Fermi collaboration for the Draco dwarf spheroidal galaxy, we find that even in the absence of diffusion, the expected gamma-ray signal lies above the upper limits set by the Fermi telescope, thus favoring astrophysical sources such as gamma-ray bursts and pulsars. Furthermore, if one assumes that a local magnetic field exists in the dwarf spheroidal galaxy, the diffusion of the electrons gives rise to a signal that could also be detectable by future X-ray telescope experiments. Besides being one of the preferred explanation for the high-energy electron and positron excess suggested by ATIC, PAMELA, and Fermi, Gamma-Ray Bursts (GRBs) have also been invoked to explain the 511 keV emission from the galactic bulge. While independent explanations can be responsible for these phenomena, we explore the possibility of their common GRB-related origin, by modeling the GRB distribution and estimating their rates. For an expected long GRB rate in the Milky Way, neither of the two signals is generic; the local electron excess requires a 2% coincidence while the signal from the galactic center requires a 20% coincidence with respect to the timing of the latest GRB. The simultaneous explanation requires a 0.4% coincidence. Considering the large number of statistical "trials" created by multiple searches for new physics, the coincidences of a few per cent cannot be dismissed as unlikely. Alternatively, both phenomena can be explained by GRBs if the galactic rate is higher than expected. We also show that a similar result is difficult to obtain assuming a simplified short GRB distribution. Recent results from the Pierre Auger Observatory ( PAO), showing energy-dependent chemical composition of Ultra-High-Energy Cosmic Rays (UHECRs) with a growing fraction of heavy elements at high energies, suggest a possible non-negligible contribution to the spectrum from galactic sources. We show that in the case of UHECRs produced by gamma-ray bursts, or by rare types of supernova explosions that took place in the Milky Way in the past, the change in composition of the UHECR, spectrum can result from the difference in diffusion times for different species. The anisotropy in the direction of the galactic center is expected to be a few percent on average, but the locations of the most recent/closest bursts can be associated with the possible observed clustering of UHECRs.

Calvez, Antoine

151

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

E-print Network

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 $\\sim$ 2 or above for energies in excess of $10^{19}$ eV with a detector array layout similar to that of the Pierre Auger Observatory.

Letessier-Selvon, Antoine; Blanco, Miguel; Maris, Ioana C; Settimo, Mariangela

2014-01-01

152

The spectrum of high-energy cosmic rays measured with KASCADE-Grande  

NASA Astrophysics Data System (ADS)

The energy spectrum of cosmic rays between 1016 eV and 1018 eV, derived from measurements of the shower size (total number of charged particles) and the total muon number of extensive air showers by the KASCADE-Grande experiment, is described. The resulting all-particle energy spectrum exhibits strong hints for a hardening of the spectrum at approximately 2 · 1016 eV and a significant steepening at ?8 · 1016 eV. These observations challenge the view that the spectrum is a single power law between knee and ankle. Possible scenarios generating such features are discussed in terms of astrophysical processes that may explain the transition region from galactic to extragalactic origin of cosmic rays.

Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Link, K.; ?uczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.

2012-08-01

153

Potential of the ATLAS detector for studying high-energy solar cosmic rays  

SciTech Connect

The ATLAS detector is intended for testing the Standard Model and for seeking new physics at the Large Hadron Collider (LHC). In addition, it permits detecting cosmic-ray muons. At the same time, unusual bursts of the muon intensity that correlate with powerful solar flares were recorded and investigated earlier at the Baksan underground scintillation telescope in the period spanning 1981 and 2006 (2.5 solar cycles). The nature of these muon bursts and their relation to solar cosmic rays have so far remained not quite clear. The ATLAS detector possesses an excellent muon system that allows searches for similar muon bursts. Within the next few years, when the LHC and ATLAS should start operating, one expects an increase in the solar activity in the new 24th cycle. Owing to this, the probability of observing muon bursts may become higher.

Karpov, S. N., E-mail: karpovsn@jinr.ru; Karpova, Z.M., E-mail: zkarpova@jinr.ru; Bednyakov, V. A., E-mail: bedny@jinr.r [Joint Institute for Nuclear Research (Russian Federation)

2009-08-15

154

Chandra X-ray Observations of Pictor A: High Energy Cosmic Rays in a Radio Galaxy?  

E-print Network

We report X-ray observations of the nearby, powerful radio galaxy Pictor A with the Chandra Observatory and optical and near uv observations of its western radio hot spot with the Hubble Space Telescope. X-ray emission is detected from the nucleus, a 1.9 arcmin (110 kpc) long jet to the west of the nucleus, the western radio hot spot some 4.2 arcmin (240 kpc) from the nucleus, and the eastern radio lobe. The morphology of the western hot spot is remarkably similar to that seen at radio and optical wavelengths, where the emission is known to be synchrotron radiation. The X-ray spectrum of the hot spot is well described by an absorbed power law with photon index \\Gamma = 2.07 (+/- 0.11). The X-ray jet coincides with a weak radio jet and is laterally extended by \\simeq 2.0 arcsec (1.9 kpc). The observed jet is up to \\simeq 15 times brighter in X-rays than any counter jet, a difference ascribed to relativistic boosting as the western radio lobe is probably the closer. The jet's spectrum is well modelled by an absorbed power law with \\Gamma = 1.94 (+0.43/-0.49) and poorly fitted by a Raymond-Smith thermal plasma model. (Abstract truncated).

A. S. Wilson; A. J. Young; P. L. Shopbell

2000-08-29

155

Ulysses out-of-ecliptic observations of “27-day” variations in high energy cosmic ray intensity  

Microsoft Academic Search

We report the discovery that for latitudes above ~40°S, the observed recurring modulation of cosmic rays and anomalous nuclei occurs without the detection byUlysses of the solar wind velocity and magnetic field recurring enhancements that have, heretofore at lower latitudes, defined corotating interaction regions—i.e., the mechanism producing the recurring intensity variations >40°S appears to be located beyond the radial range

R. B. Mckibben; J. A. Simpson; M. Zhang; S. Bame; A. Balogh

1995-01-01

156

Extragalactic radiation and the ultra-high-energy cosmic-ray spectrum  

NASA Technical Reports Server (NTRS)

The effect of extragalactic microwave and submillimeter-radiation fields on the ultrahigh-energy cosmic-ray spectrum is reexamined. It is found that the general characteristics of the spectrum can be derived from fairly simple analytical arguments. It is shown that the various spectral features obtained by numerical calculations can be explored by simpler and more general means. This approach is illustrated using a newly derived lifetime-energy relation based on the new submillimeter observations.

Stecker, F. W.

1989-01-01

157

Detection techniques of radio emission from ultra high energy cosmic rays  

NASA Astrophysics Data System (ADS)

We discuss recent and future efforts to detect radio signals from extended air showers at the Pierre Auger Observatory in Malargue, Argentina. With the advent of low-cost, high-performance digitizers and robust digital signal processing software techniques, radio detection of cosmic rays has resurfaced as a promising measurement system. The inexpensive nature of the detector media (metallic wires, rods or parabolic dishes) and economies of scale working in our favor (inexpensive high-quality C-band amplifiers and receivers) make an array of radio antennas an appealing alternative to the expense of deploying an array of Cherenkov detector water tanks or 'fly's eye' optical telescopes for fluorescence detection. The calorimetric nature of the detection and the near 100% duty cycle gives the best of both traditional detection techniques. The history of cosmic ray detection detection will be discussed. A short review on the astrophysical properties of cosmic rays and atmospheric interactions will lead into a discussion of two radio emission channels that are currently being investigated.

Morris, Chad M.

158

A new measurement of the flux of the light cosmic-ray nuclei at high energies  

NASA Technical Reports Server (NTRS)

A new cosmic-ray detector utilizing a ring-imaging Cerenkov counter to determine the energy of light cosmic-ray nuclei was flown on high-altitude balloon from Fort Sumner, NM, in 1991 September. We describe the design and performance of this instrument and discuss the data analysis procedures. The measurement provides a new determination of the absolute flux and differential energy spectrum of the primary cosmic-ray species helium between 40 and 320 GeV/nucleon. The experiment also yields the spectra of carbon and oxygen and some information on the intensities of the secondary nuclei Li, Be, and B. A comparison between our results and previous measurements of heavier nuclei (Z greater than or equal to 4) from HEAO 3 and Spacelab 2 indicates good consistency between these measurements. The data set is compared with the results of a leaky box propagation model. We find good agreement with this model if the abundance of helium relative to oxygen at the source is taken to be 25 +/- 6 and if the source spectrum is given by a power law in energy proportional to E(exp -2.15).

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

1994-01-01

159

Can Ultra High Energy Cosmic Rays be Evidence for New Particle Physics?  

E-print Network

Candidate astrophysical acceleration sites capable of producing the highest energy cosmic rays (E > 10^{19.5} eV) appear to be at far greater distances than is compatible with their being known particles. The properties of a new particle which can account for observations are discussed and found to be tightly constrained. In order to travel 100's or 1000's of Mpc through the cosmic microwave background radiation without severe energy loss and yet produce a shower in Earth's atmosphere which is consistent with observations, it must be a hadron with mass of order a few GeV and lifetime greater than about 1 week. A particle with the required properties was identified years ago in the context of supersymmetric theories with a very light gluino. Laboratory experiments do not exclude it, as is discussed briefly.

Glennys R. Farrar

1998-01-05

160

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

161

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

162

Cosmic Rays  

NSDL National Science Digital Library

This series of web pages gives an elementary discussion of cosmic rays, followed by sections on high energy particles in the universe and high-energy particles from the Sun. It describes the existence particles whose velocity approaches that of light, their probable sources, and their measurement. This is part of a large work, "The Exploration of the Earth's Magnetosphere", that gives a non-mathematical introduction to planetary and solar magnetic fields, space weather, aurora, and charged particle motion. A Spanish translation is available.

Stern, David

2005-04-27

163

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

164

Cosmic-ray composition measurements with high-energy ionization spectrometers  

NASA Technical Reports Server (NTRS)

Element abundances of cosmic rays for elements Li through Si with energy above 0.8 GeV/amu were measured on a balloon-borne instrument containing a total absorption ionization spectrometer. Statistical techniques were used to analyze the five measurements of each particle to determine its charge and energy. The technique allows a determination of systematic errors to be made. Corrections for Landau fluctuations, spark-chamber inefficiency, and background particles were included. Comparison with other published results is made. There are differences in the shapes of the differential spectra determined from measurements using different techniques, and our intensities still lie somewhat below those of other workers.

Arens, J. F.; Ormes, J. F.

1975-01-01

165

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

166

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

167

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 Atómico 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 für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany)

2013-01-01

168

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

NASA Astrophysics Data System (ADS)

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?2d??/dE < 10-10 GeV/cm2 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?2d??/dE < 10-11 GeV/cm2 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; Sigl, Guenter; van Vliet, Arjen; Mollerach, Silvia

2013-01-01

169

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

E-print Network

29th International Cosmic Ray Conference Pune (2005) 00, 101­106 Search for Very High Energy-oral The Milagro gamma-ray observatory employs a water Cherenkov detector to observe extensive air in the 100 GeV to 100 TeV energy range. More than 45 satellite-triggered gamma-ray bursts (GRBs) have

California at Santa Cruz, University of

170

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

171

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 Véron-Cetty Véron 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 49.3 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.; Andringa, S. [LIP and Instituto Superior Técnico, Technical University of Lisbon (Portugal); Aglietta, M. [Istituto di Fisica dello Spazio Interplanetario (INAF), Università di Torino and Sezione INFN, Torino (Italy); Ahlers, M. [University of Wisconsin, Madison, WI (United States); Ahn, E.J. [Fermilab, Batavia, IL (United States); Albuquerque, I.F.M. [Universidade de São Paulo, Instituto de Física, São Paulo, SP (Brazil); Allard, D. [Laboratoire AstroParticule et Cosmologie (APC), Université Paris 7, CNRS-IN2P3, Paris (France); Allekotte, I. [Centro Atómico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET), San Carlos de Bariloche (Argentina); Allen, J. [New York University, New York, NY (United States); Allison, P. [Ohio State University, Columbus, OH (United States); Almela, A. [Universidad Tecnológica Nacional - Facultad Regional Buenos Aires, Buenos Aires (Argentina); Castillo, J. Alvarez [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Alvarez-Muñiz, J. [Universidad de Santiago de Compostela (Spain); Ambrosio, M.; Aramo, C. [Università di Napoli 'Federico II' and Sezione INFN, Napoli (Italy); Aminaei, A. [IMAPP, Radboud University Nijmegen (Netherlands); Anchordoqui, L. [University of Wisconsin, Milwaukee, WI (United States); Antici'c, T. [Rudjer Boškovi'c Institute, 10000 Zagreb (Croatia); Arganda, E. [IFLP, Universidad Nacional de La Plata and CONICET, La Plata (Argentina); Arqueros, F., E-mail: auger_spokesperson@fnal.gov [Universidad Complutense de Madrid, Madrid (Spain); Collaboration: Pierre Auger Collaboration; and others

2012-04-01

172

Sensitivity of JEM-EUSO to Ensemble Fluctuations in the Ultra-High Energy Cosmic Ray Flux  

NASA Astrophysics Data System (ADS)

The energy spectrum of ultra-high energy cosmic rays (UHECR) exhibits a number of features which presumably reflect the mechanisms of cosmic acceleration, the distribution of acceleration sites, the elemental composition of the cosmic rays, and propagation effects. A coherent explanation of all UHECR measurements taken over some 50 years has so far proved to be elusive. For example, there is more than one hypothesis for the mechanism(s) responsible for the changes in spectral index observed above 10^17 eV, including the very significant flux suppression at an energy near 4 x10^19 eV. Future large exposure observatories such as the Extreme Universe Space Observatory on the Japanese Experiment Module (JEM-EUSO) will allow high statistics observation of the region around this flux suppression. One feature which may become evident in this region is the so-called ensemble fluctuation, which constitutes fluctuation in the energy spectrum beyond expectations from Poisson statistics. This as-yet unobserved feature results from the discreetness of UHECR source distribution together with propagation effects and elemental composition, and may help to enhance our understanding of the complex of UHECR features. Here we evaluate the sensitivity of JEM-EUSO to this feature.

Paul, Thomas; Ahlers, Markus; Anchordoqui, Luis; Taylor, Andrew

2013-04-01

173

Cosmic rays  

NASA Astrophysics Data System (ADS)

The book presents a historical review of cosmic ray physics from the time of the discovery of cosmic rays up to the early 1950s, when accelerator experiments began to replace cosmic ray observations in the study of nuclear interactions at all but the highest energies. The discovery of radiation which constantly acts to produce atmospheric ionization and the demonstration of the extraterrestrial origin of this radiation are discussed, and studies leading to the elucidation of the nature of the primary radiation are reviewed. Attention is then given to studies of cosmic rays in the stratosphere, geomagnetic effects on cosmic rays, and cosmic ray showers. Discoveries of elementary particles in cosmic rays are discussed including positrons, muons and pions, and nuclear interactions occurring in cosmic rays are examined. Consideration is also given to spatial and temporal variations in cosmic ray intensity and their implications for the astrophysical origin of cosmic rays.

Dorman, I. V.

174

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

175

Diffuse fluxes of cosmic high-energy neutrinos  

Microsoft Academic Search

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

F. W. Stecker

1979-01-01

176

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

177

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 CAS’s 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

178

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

179

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

180

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

181

Evolution of the ultra high energy cosmic ray spectrum by transport equation  

SciTech Connect

Ultra-high energy proton primaries interacting with the 3/sup 0/K photon background are treated as a transport phenomenon. Baryon number is explicitly conserved and the evolved spectrum develops a bump at a scale of order 5x10/sup 19/ eV, below the cutoff, due to the pile-up of energy degraded protons. This may correspond in part to the observed ankle structure in the CR spectrum.

Hill, C.T.; Schramm, D.N.

1983-04-01

182

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

183

Implications of HERA results for very high energy cosmic ray physics  

E-print Network

Experimental results obtained with the HERA collider and recent progress in their theoretical interpretation are reviewed. After a short introduction to HERA physics, deep inelastic scattering and photoproduction are discussed as (virtual) photon-proton scattering. It is shown that the measurement and theoretical understanding of both photoproduction as well as low-x deep inelastic scattering are essential for obtaining reliable high energy extrapolations within hadron-hadron interaction models. Limitations of the predictive power of hadron interaction models due to the interplay of perturbative QCD and unitarity effects are discussed.

Ralph Engel

1998-11-13

184

Monte Carlo calculations of high energy nucleon meson cascades and applications to galactic cosmic ray transport  

NASA Technical Reports Server (NTRS)

Results obtained using a recently developed calculational method for determining the nucleon-meson cascade induced in thick materials by high-energy nucleons and charged pions are presented. The calculational method uses the intranuclear-cascade-evaporation model to treat nonelastic collisions by particles with energies approximately or smaller than GeV and an extrapolation model at higher energies. The following configurations are considered: (1) 19.2-GeV/c protons incident on iron; (2) 30.3-GeV/c protons incident on iron; (3) solar and galactic protons incident on the moon, and (4) galactic protons incident on tissue. For the first three configurations, experimental results are available and comparisons between the experimental and calculated results are given.

Armstrong, T. W.; Alsmiller, R. G., Jr.; Chandler, K. C.

1972-01-01

185

Anisotropy expectations for ultra-high-energy cosmic rays with future high statistics experiments  

E-print Network

UHECRs have attracted a lot of attention due to their challengingly high energies and their potential value to constrain physical processes and astrophysical parameters in the most energetic sources of the universe. Current detectors have failed to detect significant anisotropies which had been expected to allow source identification. Some indications about the UHECR composition, which may become heavier at the highest energies, has even put into question the possibility that such a goal could be achieved soon. We investigate the potential value of a new-generation detector, with 10 times larger exposure, to overcome the current situation and make significant progress in the detection of anisotropies and thus in the study of UHECRs. We take as an example the expected performances of the JEM-EUSO, assuming a uniform full-sky coverage with a total exposure of 300,000 km2 sr yr. We simulate realistic UHECR sky maps for a wide range of possible astrophysical scenarios allowed by the current constraints, taking in...

d'Orfeuil, Benjamin Rouillé; Lachaud, Cyril; Parizot, Etienne; Blaksley, Carl; Nagataki, Shigehiro

2014-01-01

186

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

187

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 showing how LTP functions from data are in good agreement with simulations.

The Pierre Auger Collaboration; P. Abreu; M. Aglietta; E. J. Ahn; I. F. M. Albuquerque; D. Allard; I. Allekotte; J. Allen; P. Allison; J. Alvarez Castillo; J. Alvarez-Muñiz; 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. Ave; M. Avenier; G. Avila; T. Bäcker; M. Balzer; K. B. Barber; A. F. Barbosa; R. Bardenet; S. L. C. Barroso; B. Baughman; J. Bäuml; J. J. Beatty; B. R. Becker; K. H. Becker; A. Bellétoile; J. A. Bellido; S. BenZvi; C. Berat; X. Bertou; P. L. Biermann; P. Billoir; F. Blanco; M. Blanco; C. Bleve; H. Blümer; M. Bohá?ová; 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. Conceição; F. Contreras; H. Cook; M. J. Cooper; J. Coppens; A. Cordier; 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; J. R. T. de Mello Neto; I. De Mitri; V. de Souza; K. D. de Vries; G. Decerprit; L. del Peral; M. del Río; O. Deligny; H. Dembinski; N. Dhital; C. Di Giulio; J. C. Diaz; M. L. Díaz 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; J. Espadanal; 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. Filip?i?; S. Fliescher; C. E. Fracchiolla; E. D. Fraenkel; U. Fröhlich; B. Fuchs; R. Gaior; R. F. Gamarra; S. Gambetta; B. García; D. García Gámez; 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. Gómez Berisso; P. Gonçalves; D. Gonzalez; J. G. Gonzalez; B. Gookin; D. Góra; 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. Hörandel; A. Horneffer; M. Hrabovský; T. Huege; A. Insolia; F. Ionita; A. Italiano; C. Jarne; S. Jiraskova; M. Josebachuili; K. Kadija; K. H. Kampert; P. Karhan; P. Kasper; B. Kégl; 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. Krömer; D. Kruppke-Hansen; F. Kuehn; D. Kuempel; J. K. Kulbartz; N. Kunka; G. La Rosa; C. Lachaud; P. Lautridou; M. S. A. B. Leão; D. Lebrun; P. Lebrun; M. A. Leigui de Oliveira; A. Lemiere; A. Letessier-Selvon; I. Lhenry-Yvon; K. Link; R. López; A. Lopez Agüera; K. Louedec; J. Lozano Bahilo; L. Lu; 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. Martínez Bravo; H. J. Mathes; J. Matthews; 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; L. Molina-Bueno; S. Mollerach; M. Monasor; D. Monnier Ragaigne; F. Montanet; B. Morales; C. Morello; E. Moreno; J. C. Moreno; C. Morris; M. Mostafá; C. A. Moura; S. Mueller; M. A. Muller; G. Müller; M. Münchmeyer; R. Mussa; G. Navarra ‡; J. L. Navarro; S. Navas; P. Necesal; L. Nellen; A. Nelles; J. Neuser; P. T. Nhung; L. Niemietz; N. Nierstenhoefer; D. Nitz; D. Nosek; L. Nožka; M. Nyklicek; J. Oehlschläger; 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. P?kala; 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

2011-11-28

188

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-Muñiz, 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; Bäcker, T; Balzer, M; Barber, K B; Barbosa, A F; Bardenet, R; Barroso, S L C; Baughman, B; Bäuml, J; Beatty, J J; Becker, B R; Becker, K H; Bellétoile, A; Bellido, J A; BenZvi, S; Berat, C; Bertou, X; Biermann, P L; Billoir, P; Blanco, F; Blanco, M; Bleve, C; Blümer, H; Bohá?ová, 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; Conceição, 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 Río, M; Deligny, O; Dembinski, H; Dhital, N; Di Giulio, C; Diaz, J C; Castro, M L Díaz; 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; Fröhlich, U; Fuchs, B; Gaior, R; Gamarra, R F; Gambetta, S; García, B; Gámez, D García; 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 Gómez; Gonçalves, P; Gonzalez, D; Gonzalez, J G; Gookin, B; Góra, 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; Hörandel, J R; Horneffer, A; Hrabovský, M; Huege, T; Insolia, A; Ionita, F; Italiano, A; Jarne, C; Jiraskova, S; Josebachuili, M; Kadija, K; Kampert, K H; Karhan, P; Kasper, P; Kégl, 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; Krömer, O; Kruppke-Hansen, D; Kuehn, F; Kuempel, D; Kulbartz, J K; Kunka, N; La Rosa, G; Lachaud, C; Lautridou, P; Leão, M S A B; Lebrun, D; Lebrun, P; de Oliveira, M A Leigui; Lemiere, A; Letessier-Selvon, A; Lhenry-Yvon, I; Link, K; López, R; Agüera, 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 Martínez; 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; Mostafá, M; Moura, C A; Mueller, S; Muller, M A; Müller, G; Münchmeyer, 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; Nožka, L; Nyklicek, M; Oehlschläger, 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; Rodríguez-Frías, M D; Ros, G; Rosado, J; Rossler, T; Roth, M; Rouillé-d'Orfeuil, B; Roulet, E; Rovero, A C; Rühle, C; Salamida, F

2011-01-01

189

Design of a wireless sensor network with nanosecond time resolution for mapping of high-energy cosmic ray shower events  

NASA Astrophysics Data System (ADS)

We describe a low-cost, low-power wireless sensor network we are developing for high time-resolution (ns-scale) characterization of particle showers produced by ultra-high-energy (UHE) cosmic rays, to infer shower direction at sites where hard-wired data connections may be inconvenient to install. The front-end particle detector is a scintillator block monitored by a photomultiplier tube (PMT). We keep the sensor nodes synchronized to within 1 ns using periodic highintensity optical pulses from a light-emitting-diode (LED) overdriven at very high current (~30 A) in short (4 ns) bursts. With minimal optics, this signal is resolvable under free-space transmission in ambient light conditions at multi-meter distances using a high-speed avalanche photodiode (APD) receiver at each node. PMT pulse waveforms are digitized relative to this precise time reference on a Field Programmable Gate Array (FPGA) using a Time-over-Threshold (ToT)/Time-to-Digital Converter (TDC) digitizer developed at BNL. A central server receives timestamped, digitized PMT pulse waveforms from the sensor nodes via Wi-Fi and performs real-time data visualization & analysis. Total cost per sensor node is a few thousand dollars, with total power consumption per sensor node under 1 Watt, suitable for, e.g., solar-powered installations at remote field locations.

Frank, Michael P.; Junnarkar, Sachin S.; Fagan, Triesha; O'Neal, Ray H.; Takai, Helio

2010-04-01

190

Measurement of the Flux of Ultra-High Energy Cosmic Rays by the Telescope Array FADC Fluorescence Detectors  

NASA Astrophysics Data System (ADS)

Ultra-high energy cosmic rays (UHECRs) produce the most powerful collisions between single particles and atmospheric matter. They have been studied since the early 20th century yet, to this date, there is no clear answer as to the acceleration process responsible for their production. The Telescope Array Project is an experiment designed to observe the showers of particles produced as by-products of the interactions between UHECRs and the atmosphere. As a hybrid experiment, it currently utilizes 38 fluorescence detectors (FDs) divided between three sites overlooking an array of 507 surface detectors (SDs). The project's mission is to study the energy, composition and origin of UHECRs using a variety of techniques which may include some or all of the experiment's apparatus. This document, in particular, is a presentation of the UHECR energy spectrum measured at Telescope Array using the fluorescence detection technique in monocular mode. Only data from the 24 FDs at Black Rock Mesa (BR) and Long Ridge (LR) stations are used here.

Stratton, Sean R.

191

The Effect of a Non-Isotropic Flux of Very High Energy Cosmic Rays on the values of Mean Shower Maxima  

NASA Astrophysics Data System (ADS)

In our previous works we described a statistical method to interpret the results of extensive air shower simulations. For an isotropically distributed flux of cosmic rays, we used this method to deduce diagrams of mean values of shower maxima versus energy decades. To have a more realistic result, we considered the effect of a non-isotropic flux of cosmic rays at different energy ranges. This effect was considered as a weight factor deduced from a set of observed data. We discussed about the effect of this weight factor on our final resulted diagrams of mean shower maxima and for different interaction models compared the resulted distributions of very high energy cosmic ray's mass composition.

Davoudifar, Pantea; Rowshan Tabari, Keihanak

2015-01-01

192

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

193

First results from the microwave air yield beam experiment (MAYBE): Measurement of GHz radiation for ultra-high energy cosmic ray detection  

NASA Astrophysics Data System (ADS)

We present measurements of microwave emission from an electron-beam induced air plasma performed at the 3 MeV electron Van de Graaff facility of the Argonne National Laboratory. Results include the emission spectrum between 1 and 15 GHz, the polarization of the microwave radiation and the scaling of the emitted power with respect to beam intensity. MAYBE measurements provide further insight on microwave emission from extensive air showers as a novel detection technique for Ultra-High Energy Cosmic Rays.

Williams, C.; Bohá?ová, M.; Bonifazi, C.; Cataldi, G.; Chemerisov, S.; de Mello Neto, J. R. T.; Facal San Luis, P.; Fox, B.; Gorham, P. W.; Hojvat, C.; Hollon, N.; Meyhandan, R.; Monasor, M.; Rouillé d'Orfeuil, B.; Santos, E. M.; Pochez, J.; Privitera, P.; Spinka, H.; Verzi, V.; Zhou, J.

2013-06-01

194

Measurement of the shadowing of high-energy cosmic rays by the Moon: A search for TeV-energy antiprotons  

NASA Astrophysics Data System (ADS)

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 to proton ratio of 0.11 is obtained for primary energies around 1 TeV.

L3 Collaboration; Achard, P.; Adriani, O.; Aguilar-Benitez, M.; van den Akker, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M. G.; Anderhub, H.; Andreev, V. P.; Anselmo, F.; Arefiev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Bähr, J.; Baldew, S. V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillère, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J. J.; Blyth, S. C.; Bobbink, G. J.; Böhm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J. G.; Brochu, F.; Burger, J. D.; Burger, W. J.; Cai, X. D.; Capell, M.; Romeo, G. Cara; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chiarusi, T.; Chang, Y. H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de La Cruz, B.; Cucciarelli, S.; de Asmundis, R.; Déglon, P.; Debreczeni, J.; Degré, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; Denotaristefani, F.; de Salvo, A.; Diemoz, M.; Dierckxsens, M.; Ding, L. K.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M. T.; Duchesneau, D.; Duda, M.; Duran, I.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F. J.; Extermann, P.; Faber, G.; Falagan, M. A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher, P. H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Yu.; Ganguli, S. N.; Garcia-Abia, P.; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z. F.; Grabosch, H. J.; Grenier, G.; Grimm, O.; Groenstege, H.; Gruenewald, M. W.; Guida, M.; Guo, Y. N.; Gupta, V. K.; Gurtu, A.; Gutay, L. J.; Haas, D.; Haller, Ch.; Hatzifotiadou, D.; Hayashi, Y.; He, Z. X.; Hebbeker, T.; Hervé, A.; Hirschfelder, J.; Hofer, H.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S. R.; Huo, A. X.; Ito, N.; Jin, B. N.; Jindal, P.; Jing, C. L.; Jones, L. W.; de Jong, P.; Josa-Mutuberría, I.; Kantserov, V.; Kaur, M.; Kawakami, S.; Kienzle-Focacci, M. N.; Kim, J. K.; Kirkby, J.; Kittel, W.; Klimentov, A.; König, A. C.; Kok, E.; Korn, A.; Kopal, M.; Koutsenko, V.; Kräber, M.; Kuang, H. H.; Kraemer, R. W.; Krüger, A.; Kuijpers, J.; Kunin, A.; de Guevara, P. Ladron; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Goff, J. M. Le; Lei, Y.; Leich, H.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Li, L.; Li, Z. C.; Likhoded, S.; Lin, C. H.; Lin, W. T.; Linde, F. L.; Lista, L.; Liu, Z. A.; Lohmann, W.; Longo, E.; Lu, Y. S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W. G.; Ma, X. H.; Ma, Y. Q.; Malgeri, L.; Malinin, A.; Maña, C.; Mans, J.; Martin, J. P.; Marzano, F.; Mazumdar, K.; McNeil, R. R.; Mele, S.; Meng, X. W.; Merola, L.; Meschini, M.; Metzger, W. J.; Mihul, A.; van Mil, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G. B.; Monteleoni, B.; Muanza, G. S.; Muijs, A. J. M.; Musicar, B.; Musy, M.; Nagy, S.; Nahnhauer, R.; Naumov, V. A.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Nowak, H.; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Parriaud, J.-F.; Passaleva, G.; Patricelli, S.; Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pieri, M.; Pioppi, M.; Piroué, P. A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofiev, D.; Quartieri, J.; Qing, C. R.; Rahal-Callot, G.; Rahaman, M. A.; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P. G.; Ranieri, R.; Raspereza, A.; Ravindran, K. C.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Rewiersma, P.; Riemann, S.; Riles, K.; Roe, B. P.; Rojkov, A.; Romero, L.; Rosca, A.; Rosemann, C.; Rosier-Lees, S.; Rosenbleck, C.; Roth, S.; Rubio, J. A.; Ruggiero, G.; Rykaczewski, H.; Saidi, R.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schäfer, C.; Schegelsky, V.; Schmitt, V.; Schoeneich, B.; Schopper, H.; Schotanus, D. J.; Sciacca, C.; Servoli, L.; Shen, C. Q.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D. P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sulanke, H.; Sultanov, G.; Sun, L. Z.; Sushkov, S.; Suter, H.; Swain, J. D.; Szillasi, Z.; Tang, X. W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, C.; Ting, Samuel C. C.

2005-05-01

195

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

196

New estimation of the spectral index of high-energy cosmic rays as determined by the Compton-Getting anisotropy  

E-print Network

The amplitude of the Compton-Getting (CG) anisotropy contains the power-law index of the cosmic-ray energy spectrum. Based on this relation and using the Tibet air-shower array data, we measure the cosmic-ray spectral index to be $-3.03 \\pm 0.55_{stat} \\pm < 0.62_{syst}$ between 6 TeV and 40 TeV, consistent with $-$2.7 from direct energy spectrum measurements. Potentially, this CG anisotropy analysis can be utilized to confirm the astrophysical origin of the ``knee'' against models for non-standard hadronic interactions in the atmosphere.

M. Amenomori; X. J. Bi; D. Chen; S. W. Cui; Danzengluobu; L. K. Ding; X. H. Ding; C. Fan; 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; T. Y. Saito; M. Sakata; T. K. Sako; M. Shibata; A. Shiomi; T. Shirai; H. Sugimoto; M. Takita; Y. H. Tan; N. Tateyama; S. Torii; H. Tsuchiya; S. Udo; B. Wang; H. Wang; X. Wang; Y. 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; for The Tibet ASgamma Collaboration

2007-11-13

197

Energy Spectrum of Ultra-High Energy Cosmic Rays Observed with the Telescope Array Using a Hybrid Technique  

E-print Network

We measure the spectrum of cosmic rays with energies greater than $10^{18.2}$ 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; 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; 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

2013-01-01

198

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

E-print Network

at the Pierre Auger Observatory This article has been downloaded from IOPscience. Please scroll down to see energy cosmic rays recorded at the Pierre Auger Observatory The Pierre Auger collaboration P. Abreu,75 M P. Gouffon,20 E. Grashorn,100 S. Grebe,69,71 N. Griffith,100 M. Grigat,44 A.F. Grillo,59 Y

199

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. Bäcker; M. Balzer; K. B. Barber; A. F. Barbosa; R. Bardenet; S. L. C. Barroso; B. Baughman; J. Bäuml; J. J. Beatty; B. R. Becker; K. H. Becker; A. Bellétoile; J. A. Bellido; S. BenZvi; C. Berat; X. Bertou; P. L. Biermann; P. Billoir; F. Blanco; M. Blanco; H. Blümer; M. Bohá?ová; 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. 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; S. Fliescher; C. E. Fracchiolla; U. Fröhlich; B. Fuchs; R. Gaior; R. F. Gamarra; S. Gambetta; B. Garc?´a; D. Garc?´a Gámez; D. García Gámez; A. Gascon; H. Gemmeke; K. Gesterling; P. L. Ghia; U. Giaccari; M. Giller; H. Glass; M. S. Gold; G. Golup; F. Gomez Albarracin; M. Gómez Berisso; P. Gonçalves; D. Gonzalez; J. G. Gonzalez; B. Gookin; D. Góra; 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. Hörandel; A. Horneffer; M. Hrabovský; T. Huege; A. Insolia; F. Ionita; A. Italiano; C. Jarne; S. Jiraskova; K. Kadija; K. H. Kampert; P. Karhan; B. Kégl; 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. Krömer; D. Kruppke-Hansen; F. Kuehn; D. Kuempel; J. K. Kulbartz; N. Kunka; G. La Rosa; C. Lachaud; P. Lautridou; M. S. A. B. Leão; D. Lebrun; P. Lebrun; M. A. Leigui de Oliveira; A. Letessier-Selvon; I. Lhenry-Yvon; K. Link; R. López; A. Lopez Agüera; 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. Mostafá; C. A. Moura; S. Mueller; M. A. Muller; G. Müller; M. Münchmeyer; 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. Nožka; M. Nyklicek; J. Oehlschläger; 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. Rouillé-d’Orfeuil; E. Roulet; A. C. Rovero; F. Salamida; H. Salazar; G. Salina; F. Sánchez; 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

200

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

201

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-Muñiz; 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. Bäcker; M. Balzer; K. B. Barber; A. F. Barbosa; R. Bardenet; S. L. C. Barroso; B. Baughman; J. Bäuml; J. J. Beatty; B. R. Becker; K. H. Becker; A. Bellétoile; J. A. Bellido; S. BenZvi; C. Berat; X. Bertou; P. L. Biermann; P. Billoir; F. Blanco; M. Blanco; C. Bleve; H. Blümer; M. Bohácová; 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. Conceição; 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. Díaz 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. Fröhlich; B. Fuchs; R. Gaior; R. F. Gamarra; S. Gambetta; B. García; D. García Gámez; 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. Gómez Berisso; P. Gonçalves; D. Gonzalez; J. G. Gonzalez; B. Gookin; D. Góra; 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. Hörandel; A. Horneffer; M. Hrabovský; T. Huege; A. Insolia; F. Ionita; A. Italiano; C. Jarne; S. Jiraskova; K. Kadija; K. H. Kampert; P. Karhan; P. Kasper; B. Kégl; 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. Krömer; D. Kruppke-Hansen; F. Kuehn; D. Kuempel; J. K. Kulbartz; N. Kunka; G. La Rosa; C. Lachaud; P. Lautridou; M. S. A. B. Leão; D. Lebrun; P. Lebrun; M. A. Leigui de Oliveira; A. Lemiere; A. Letessier-Selvon; I. Lhenry-Yvon; K. Link R. López; A. Lopez Agüera; 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. Martínez 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. Mostafá; C. A. Moura; S. Mueller; M. A. Muller; G. Müller; M. Münchmeyer; 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. Oehlschläger; 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. Rodríguez-Frías; G. Ros; J. Rosado; T. Rossler; M. Roth; B. Rouillé-d'Orfeuil; E. Roulet; A. C. Rovero; C. Rühle; F. Salamida; H. Salazar; G. Salina

2011-01-01

202

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

203

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

204

A Model for Non High Energy Gamma Ray Bursts and Sources of Ultra High Energy Cosmic Rays --- Super Strongly Magnetized Milli-Second Pulsar Formed from a (C + O) Star and a Neutron Star (Black Hole) Close Binary System ---  

NASA Astrophysics Data System (ADS)

As a progenitor of NHE (Non High Energy) GRBs (Gamma Ray Bursts), we propose a (C + O) star and a neutron star (black hole) close binary system with separation ~ 0.2 Rodot. Since the (C + O) star is tidally locked, the collapsing core should have a spin angular momentum ~ 6 × 1048 cgs, so that a new-born pulsar should be a milli-second pulsar (MSP) (P ~ 1 ms). An ? - ? dynamo in the first 10 s after the bounce of the core will generate a super strong magnetic field (B ~ 1016 G). The beam of energy from a super strongly magnetized milli-second pulsar (SSM-MSP) can punch a hole in the supernova ejecta . Then the beam of gamma rays flows out of the ejecta for ~ 10 s with a total energy up to ~ 2 × 1051 erg. If we observe this beam from the lateral direction, the energy of gamma rays should be smaller than 500 keV due to the electron scattering and the total energy of gamma rays should be much smaller than ~ 2 × 1051 erg, which are the very characteristics of NHE-GRBs. In the SSM-MSP model of NHE-GRB, GRB events should be associated with Type Ib/Ic supernova, like GRB980425/SN1998bw. If a SSM-MSP is produced in a fraction (~ a few %) of Type Ib/Ic supernovae, the event rate as well as the isotropic and homogeneous distribution of NHE-GRBs can also be explained. According to this model a pulsar with a spin period P ~ 1.4 s (B/1016) (t/4 month)1/2 should exist in SN1998bw, so that the search for this pulsar in all the wave length is urgent. SSM-MSPs can accelerate protons up to ~ 3 × 1022 (P/1 ms)-2 (B/1016 G)eV. If a few % (~ 1050 erg) of the beam energy of SSM-MSP in NHE-GRB event (> 5 × 1051 erg) is in the form of high energy protons of energy ~ 1020 eV, the flux of the observed UHECRs (Ultra High Energy Cosmic Rays) can be explained. Then it should be possible to find a supernova remnant along the direction of each UHECR. As a natural implication of our model, it is suggested that a NHE-GRB is a part of the progenitor of a soft gamma ray repeater which also has a superstrong magnetic field (B ~ 1015 G) and is in a supernova remnant.

Nakamura, T.

1998-11-01

205

Ultra-High Energy Cosmic Neutrinos  

NASA Astrophysics Data System (ADS)

Astrophysical processes appear to produce particles with energies of at least 10^19-20 eV. Yet extra-galactic astronomy appears to be limited for photons with energies above 10^14 eV due to absorption. Neutrino astronomy offers the possibility to perform extra-galactic astronomy to these energies and beyond without an absorption cutoff. In addition, the interactions of ultra-high energy (UHE) neutrinos of cosmic origin with local matter may reveal exotic new physics processes that are unavailable to modern accelerators. UHE neutrino telescopes based on optical detection techniques that are currently operating and under construction will soon have apertures on the scale of 10 km^3-sr with excellent thresholds. Radio and acoustic detection techniques have been demonstrated in laboratory experiments and are being used to instrument apertures from 10 to to 10,000 km^3-sr for neutrinos with energies above 10^16 eV. Neutrino telescopes based on radio detection include the RICE detectors placed on the Amanda strings at the South Pole. The GLUE antennas pointed at the Moon have set limits on the neutrino intensity at higher energies. The best sensitivity at the highest energies comes from the FORTE satellite which looked for interactions in Greenland ice. The upcoming ANITA long-duration balloon flights over Antarctica will be sensitive to neutrinos produced by the interactions of cosmic rays with the cosmic microwave background radiation. Using the acoustic technique, the SAUND collaboration recently performed a UHE neutrino search using hydrophones in the deep sea near the Bahamas. Investigations for even larger apertures include several other detection possibilities, including placing radio and acoustic sensors in large underground salt formations. The acoustic technique may find promise in solid media currently under investigation. The neutrino sensitivity of current and proposed telescopes based on optical, radio, acoustic techniques will be compared for both specific models and in a model-independent fashion.

Saltzberg, David

2006-04-01

206

High energy solar cosmic rays detection by the Baksan air shower arrays, Andyrchy and Carpet , during 23rd solar cycle  

NASA Astrophysics Data System (ADS)

Total counting rate of two scintillation Baksan air shower arrays "Andyrchy" and "Carpet" was examined during Ground Level Enhancements (GLEs) observed in the 23rd cycle of solar activity. Significant excesses above the galactic cosmic ray background have been found during several GLE events. The magnitude of increases at the peak of intensity-time profiles during different GLEs amounts to 4-14 st.dev. (0.12-0.44% excess) by the 15-min data of "Andyrchy". The "Carpet" array has two times higher statistical accuracy than "Andyrchy" under the same observation conditions. The data of both Baksan shower arrays are compared with the neutron monitors data at Apatity and Moscow. The total counting rate of both arrays consists mainly of single detector events(one-fold). The counting rate of two-fold, three-fold and greater events are few percents of total one. One-fold component is produced by secondary single muons and by small local air showers (electrons and gamma rays). The energy of primary hadrons caused one- fold component is higher than that for neutron monitors and amounts a few tens of GeV. The data of two air shower arrays, "Andyrchy" and "Carpet", open a new interesting possibility to study solar cosmic rays in the energy range of few tens of GeV.

Alekseenko, V.; Karpov, S.; Karpova, Z.; Khaerdinov, N.; Petkov, V.; Poddubny, V.; Zaichenko, A.

207

Power-law partition and entropy production of high-energy cosmic rays: Knee-ankle structure of the all-particle spectrum  

NASA Astrophysics Data System (ADS)

A statistical description of the all-particle cosmic-ray spectrum is given in the 10^{14}\\ \\text{eV} to 10^{20}\\ \\text{eV} interval. The high-energy cosmic-ray flux is modeled as an ultra-relativistic multi-component plasma, whose components constitute a mixture of nearly ideal but nonthermal gases of low density and high temperature. Each plasma component is described by an ultra-relativistic power-law density manifested as spectral peak in the wideband fit. The “knee” and “ankle” features of the high- and ultra-high-energy spectrum turn out to be the global and local extrema of the double-logarithmic E3-scaled flux representation in which the spectral fit is performed. The all-particle spectrum is covered by recent data sets from several air shower arrays, and can be modeled as three-component plasma in the indicated energy range extending over six decades. The temperature, specific number density, internal energy and entropy of each plasma component are extracted from the partial fluxes in the broadband fit. The grand partition function and the extensive entropy functional of a non-equilibrated gas mixture with power-law components are derived in phase space by ensemble averaging.

Tomaschitz, Roman

2013-10-01

208

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

209

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

210

A reexamination of the cosmic-ray helium spectrum and the He-3/He-4 ratio at high energies  

NASA Technical Reports Server (NTRS)

Cosmic ray He spectral data collected by satellites in earth orbit were used to examine a recent measurement of He-3 of about 6 GeV/nucleon, an overabundance compared to predictions made with a leaky box approach. The spectral rigidity index at the time of the measurement was no more than 2.55, indicating a near-earth He-3/He-4 ratio of 0.17, although an index in the range 10-20 GV and a ratio of close to 0.24 is the usual value. New magnetic spectrometer data, however, show that a single spectral rigidity value for the near-earth He-3/He-4 ratio cannot be correct. The Fokker-Planck equation is used to demonstrate that solar modulation of the He flux yields an energy/abundance distribution close to observational data.

Webber, W. R.; Golden, R. L.; Mewaldt, R. A.

1987-01-01

211

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

E-print Network

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 $Z$, 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 $E_{th}/Z$ (for illustrative values of $Z=6,\\ 13,\\ 26$). If the anisotropies above $E_{th}$ 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; Ahn, E J; Albuquerque, I F M; Allard, D; Allekotte, I; Allen, J; Allison, P; Castillo, J Alvarez; Alvarez-Muñiz, 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; Bäcker, T; Balzer, M; Barber, K B; Barbosa, A F; Bardenet, R; Barroso, S L C; Baughman, B; Bäuml, J; Beatty, J J; Becker, B R; Becker, K H; Bellétoile, A; Bellido, J A; BenZvi, S; Berat, C; Bertou, X; Biermann, P L; Billoir, P; Blanco, F; Blanco, M; Bleve, C; Blümer, H; Bohá?ová, 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; Conceição, R; Contreras, F; Cook, H; Cooper, M J; Coppens, J; Cordier, A; Cotti, U; 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; Deligny, O; Dembinski, H; Dhital, N; Di Giulio, C; Diaz, J C; Castro, M L Díaz; 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; 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; Fröhlich, U; Fuchs, B; Gaior, R; Gamarra, R F; Gambetta, S; García, B; Gámez, D García; 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 Gómez; Gonçalves, P; Gonzalez, D; Gonzalez, J G; Gookin, B; Góra, 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; Hörandel, J R; Horneffer, A; Hrabovský, M; Huege, T; Insolia, A; Ionita, F; Italiano, A; Jarne, C; Jiraskova, S; Kadija, K; Kampert, K H; Karhan, P; Kasper, P; Kégl, 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; Krömer, O; Kruppke-Hansen, D; Kuehn, F; Kuempel, D; Kulbartz, J K; Kunka, N; La Rosa, G; Lachaud, C; Lautridou, P; Leão, M S A B; Lebrun, D; Lebrun, P; de Oliveira, M A Leigui; Lemiere, A; Letessier-Selvon, A; Lhenry-Yvon, I; López, K Link R; Agüera, A Lopez; Louedec, K; Bahilo, J Lozano; 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 Martínez; 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; Mollerach, S; Monasor, M; Ragaigne, D Monnier; Montanet, F; Morales, B; Morello, C; Moreno, E; Moreno, J C; Morris, C; Mostafá, M; Moura, C A; Mueller, S; Muller, M A; Müller, G; Münchmeyer, M; Mussa, R; Navarra, G; Navarro, J L; Navas, S; Necesal, P; Nellen, L; Nelles, A; Nhung, P T; Niemietz, L; Nierstenhoefer, N; Nitz, D; Nosek, D; Nožka, L; Nyklicek, M; Oehlschläger, 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; Rodríguez-Frías, M D; Ros, G; Rosado, J; Rossler, T; Roth, M; Rouillé-d'Orfeuil, B; Roulet, E; Rovero, A C; Rühle, C; Salamida, F; Salazar, H; Salina, G; Sánchez, F; Santander, M; Santo, C E; Santos, E

2011-01-01

212

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

NASA Astrophysics Data System (ADS)

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 n - N s )/( N n + N 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.; Adriani, O.; Barbarino, G. C.; Bazilevskaya, G. A.; Bellotti, R.; Boezio, M.; Bogomolov, E. A.; Bonechi, L.; Bongi, M.; Bonvicini, V.; Bottai, S.; Bruno, A.; Vacchi, A.; Vannuccini, E.; Vasilyev, G. I.; Voronov, S. A.; Galper, A. M.; Danilchenko, I. A.; De Donato, C.; De Santis, C.; De Simone, N.; Di Felice, V.; Zverev, V. G.; Zampa, G.; Zampa, N.; Cafagna, F.; Campana, D.; Carbone, R.; Carlson, P.; Casolino, M.; Castellini, G.; Kvashnin, A. N.; Koldashov, S. V.; Koldobskiy, S. A.; Krutkov, S. Y.; Leonov, A. A.; Malvezzi, V.; Marcelli, L.; Martucci, M.; Mayorov, A. G.; Malakhov, V. V.; Menn, W.; Merge, M.; Mikhailov, V. V.; Mocchiutti, E.; Monaco, A.; Mori, N.; Osteria, G.; Palma, F.; Papini, P.; Pearce, M.; Picozza, P.; Pizzolotto, C.; Ricci, M.; Ricciarini, S. B.; Runtso, M. F.; Sarkar, R.; Simon, M.; Sparvoli, R.; Spillantini, P.; Yurkin, Y. T.

2013-08-01

213

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

2006-02-22

214

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

215

The energy spectrum of ultra-high-energy cosmic rays measured by the Telescope Array FADC fluorescence detectors in monocular mode  

NASA Astrophysics Data System (ADS)

We present a measurement of the energy spectrum of ultra-high-energy cosmic rays performed by the Telescope Array experiment using monocular observations from its two new FADC-based fluorescence detectors. After a short description of the experiment, we describe the data analysis and event reconstruction procedures. Since the aperture of the experiment must be calculated by Monte Carlo simulation, we describe this calculation and the comparisons of simulated and real data used to verify the validity of the aperture calculation. Finally, we present the energy spectrum calculated from the merged monocular data sets of the two FADC-based detectors, and also the combination of this merged spectrum with an independent, previously published monocular spectrum measurement performed by Telescope Array's third fluorescence detector [T. Abu-Zayyad et al., The energy spectrum of Telescope Array's middle drum detector and the direct comparison to the high resolution fly's eye experiment, Astroparticle Physics 39 (2012) 109-119, http://dx.doi.org/10.1016/j.astropartphys.2012.05.012, Available from: ]. This combined spectrum corroborates the recently published Telescope Array surface detector spectrum [T. Abu-Zayyad, et al., The cosmic-ray energy spectrum observed with the surface detector of the Telescope Array experiment, ApJ 768 (2013) L1, http://dx.doi.org/10.1088/2041-8205/768/1/L1, Available from: ] with independent systematic uncertainties.

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.; Myers, I.; Minamino, M.; Miyata, K.; Murano, Y.; Nagataki, S.; Nakamura, T.; Nam, S. W.; Nonaka, T.; Ogio, S.; Ogura, J.; 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.; Sonley, T. J.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; 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.; Vasiloff, G.; Wada, Y.; Wong, T.; Yamakawa, Y.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.

2013-08-01

216

Study of Ultra-High Energy Cosmic Ray Composition Using Telescope Array's Middle Drum Detector and Surface Array in Hybrid Mode  

E-print Network

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 methodology to PAO, and good agreement is evident between data and a light, largely protonic composition using simulations from a variety of hadronic models for the comparison of both elongation rate and shower fluctuations. This is in good agreement with the HiRes results. This analysis is presented using two methods: data cuts using simple geometrical variables and a new pattern recognition technique.

Abbasi, R U; 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; Yoshiia, H; Zollinger, R; Zundel, Z

2014-01-01

217

Search for correlations of the arrival directions of ultra-high energy cosmic ray with extragalactic objects as observed by the telescope array experiment  

E-print Network

We search for correlations between positions of extragalactic objects and arrival directions of Ultra-High Energy Cosmic Rays (UHECRs) with primary energy $E \\ge 40$ EeV as observed by the surface detector array of the Telescope Array (TA) experiment during the first 40 months of operation. We examined several public astronomical object catalogs, including the Veron-Cetty and Veron catalog of active galactic nuclei. We counted 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 combinations of these parameters which maximize the correlations, and calculate the chance probabilities 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...

Abu-Zayyad, T; 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; 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

2013-01-01

218

Cosmic rays  

SciTech Connect

The fundamental characteristics of cosmic rays (CRs) and the history of CR studies are discussed in a general review. Chapters are devoted to the early days of CR observations, the identification of CRs, the effect of the geomagnetic field, solar particles, Galactic CRs, the CR energy spectrum, and clues from subatomic physics. Consideration is given to the origin of CRs, CRs with little or no mass, the subnuclear world, and applications of CR research (C-14 dating and studies of interplanetary dust particles). Diagrams, drawings, graphs, and photographs are provided. 17 refs.

Friedlander, M.W.

1989-01-01

219

Interacting Cosmic Rays with Molecular Clouds: A Bremsstrahlung Origin of Diffuse High-energy Emission from the Inner 2°×1° 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

220

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

221

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 ...

Zhang, Shuo

222

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

2009-11-13

223

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

224

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

225

Science with the new generation high energy gamma- ray experiments  

Microsoft Academic Search

This Conference is the fifth of a series of Workshops on High Energy Gamma- ray Experiments, following the Conferences held in Perugia 2003, Bari 2004, Cividale del Friuli 2005, Elba Island 2006. This year the focus was on the use of gamma-ray to study the Dark Matter component of the Universe, the origin and propagation of Cosmic Rays, Extra Large

M. Alvarez; D. D'Armiento; G. Agnetta; A. Alberdi; A. Antonelli; A. Argan; P. Assis; E. A. Baltz; C. Bambi; G. Barbiellini; H. Bartko; M. Basset; D. Bastieri; P. Belli; G. Benford; L. Bergstrom; R. Bernabei; G. Bertone; A. Biland; B. Biondo; F. Bocchino; E. Branchini; M. Brigida; T. Bringmann; P. Brogueira; A. Bulgarelli; J. A. Caballero; G. A. Caliandro; P. Camarri; F. Cappella; P. Caraveo; R. Carbone; M. Carvajal; S. Casanova; A. J. Castro-Tirado; O. Catalano; R. Catena; F. Celi; A. Celotti; R. Cerulli; A. Chen; R. Clay; V. Cocco; J. Conrad; E. Costa; A. Cuoco; G. Cusumano; C. J. Dai; B. Dawson; B. De Lotto; G. De Paris; A. de Ugarte Postigo; E. Del Monte; C. Delgado; A. Di Ciaccio; G. Di Cocco; S. Di Falco; G. Di Persio; B. L. Dingus; A. Dominguez; F. Donato; I. Donnarumma; M. Doro; J. Edsjo; J. M. Espino Navas; M. C. Espirito Santo; Y. Evangelista; C. Evoli; D. Fargion; C. Favuzzi; M. Feroci; M. Fiorini; L. Foggetta; N. Fornengo; T. Froysland; M. Frutti; F. Fuschino; J. L. Gomez; M. Gomez; D. Gaggero; N. Galante; M. I. Gallardo; M. Galli; J. E. Garcia; M. Garczarczyk; F. Gargano; M. Gaug; F. Gianotti; S. Giarrusso; B. Giebels; N. Giglietto; P. Giommi; F. Giordano; A. Giuliani; J. Glicenstein; P. Goncalves; D. Grasso; M. Guerriero; H. L. He; A. Incicchitti; J. Kirk; H. H. Kuang; A. La Barbera; G. La Rosa; C. Labanti; G. Lamanna; I. Lapshov; F. Lazzarotto; S. Liberati; F. Liello; P. Lipari; F. Longo; F. Loparco; M. Lozano; P. G. Lucentini De Sanctis; J. M. Ma; M. C. Maccarone; L. Maccione; V. Malvezzi; A. Mangano; M. Mariotti; M. Marisaldi; I. Martel; A. Masiero; E. Massaro; M. Mastropietro; E. Mattaini; F. Mauri; M. N. Mazziotta; S. Mereghetti; T. Mineo; S. Mizobuchi; A. Moiseev; M. Moles; C. Monte; F. Montecchia; E. Morelli; A. Morselli; I. Moskalenko; F. Nozzoli; J. F. Ormes; M. A. Peres-Torres; L. Pacciani; A. Pellizzoni; F. Perez-Bernal; F. Perotti; P. Picozza; L. Pieri; M. Pietroni; M. Pimenta; A. Pina; C. Pittori; C. Pontoni; G. Porrovecchio; F. Prada; M. Prest; D. Prosperi; R. Protheroe; G. Pucella; J. M. Quesada; J. M. Quintana; J. R. Quintero; S. Raino; M. Rapisarda; M. Rissi; J. Rodriguez; E. Rossi; G. Rowell; A. Rubini; F. Russo; M. Sanchez-Conde; B. Sacco; V. Scapin; M. Schelke; A. Segreto; A. Sellerholm; X. D. Sheng; A. Smith; P. Soffitta; R. Sparvoli; P. Spinelli; V. Stamatescu; L. S. Stark; M. Tavani; G. Thornton; L. G. Titarchuk; B. Tome; A. Traci; M. Trifoglio; A. Trois; P. Vallania; E. Vallazza; S. Vercellone; S. Vernetto; V. Vitale; N. Wild; Z. P. Ye; A. Zambra; F. Zandanel; D. Zanello

2007-01-01

226

Extremely high energy neutrinos from cosmic strings  

SciTech Connect

Superstring theory and other supersymmetric theories predict the existence of relatively light, weakly interacting scalar particles, called moduli, with a universal form of coupling to matter. Such particles can be emitted from cusps of cosmic strings, where extremely large Lorentz factors are achieved momentarily. Highly boosted modulus bursts emanating from cusps subsequently decay into gluons; they generate parton cascades which in turn produce large numbers of pions and then neutrinos. Because of very large Lorentz factors, extremely high energy neutrinos, up to the Planck scale and above, are produced. For some model parameters, the predicted flux of neutrinos with energies > or approx. 10{sup 21} eV is observable by JEM-EUSO and by the future large radio detectors LOFAR and SKA.

Berezinsky, Veniamin [INFN, Laboratori Nazionali del Gran Sasso, I-67010 Assergi (AQ) (Italy); Sabancilar, Eray; Vilenkin, Alexander [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 (United States)

2011-10-15

227

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

E-print Network

Satellite-detected Gamma- ray Bursts using Milagro P. M. SAZ PARKINSON & B. L. DINGUS ¡ FOR THE MILAGRO@scipp.ucsc.edu; dingus@lanl.gov Abstract: Gamma-ray bursts (GRBs) have been detected up to GeV energies and are predicted

California at Santa Cruz, University of

228

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

229

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

230

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

231

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

232

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

233

A Simplified Model for the Acceleration of Cosmic Ray Particles  

ERIC Educational Resources Information Center

Two important questions concerning cosmic rays are: Why are electrons in the cosmic rays less efficiently accelerated than nuclei? How are particles accelerated to great energies in ultra-high energy cosmic rays? In order to answer these questions we construct a simple model of the acceleration of a charged particle in the cosmic ray. It is not…

Gron, Oyvind

2010-01-01

234

The ?-ray and cosmic ray connection: Ulysses HET secondary radioisotope measurements and cosmic ray propagation  

NASA Astrophysics Data System (ADS)

Cosmic rays constitute a super-thermal gas of charged particles magnetically confined within the Galaxy. Cosmic ray nuclei and electrons are a principal source of the diffuse ?-ray background in the Galaxy. Thus, understanding diffuse ?-ray production is directly related to understanding cosmic ray propagation in the Galaxy. While propagating though the interstellar medium (ISM), cosmic ray nuclei undergo nuclear spallation reactions, producing both stable and unstable secondary nuclei. Measurements of secondary radioisotopes are crucial tests of cosmic ray propagation. The abundances of some radioactive secondary isotopes (10Be, 26Al, 36Cl, etc.) measure the average density of material cosmic rays traverse and relate to the confinement times of cosmic rays in the Galaxy. The abundances of electron capture isotopes and their daughter nuclei (for example, 49V and 51V) test the role of cosmic ray reacceleration. The Ulysses High Energy Telescope (HET) is a cosmic ray isotope spectrometer with sufficient mass resolution (~0.28 u at Fe) and collecting area to measure these rare isotopes. The latest HET measurements of the radioactive secondary cosmic ray isotopes are given, and the implications for cosmic ray propagation and diffuse ?-ray production are discussed. .

Connell, J. J.; Simpson, J. A.

2000-04-01

235

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...

236

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

237

Science with the new generation high energy gamma- ray experiments  

E-print Network

This Conference is the fifth of a series of Workshops on High Energy Gamma- ray Experiments, following the Conferences held in Perugia 2003, Bari 2004, Cividale del Friuli 2005, Elba Island 2006. This year the focus was on the use of gamma-ray to study the Dark Matter component of the Universe, the origin and propagation of Cosmic Rays, Extra Large Spatial Dimensions and Tests of Lorentz Invariance.

M. Alvarez; D. D'Armiento; G. Agnetta; A. Alberdi; A. Antonelli; A. Argan; P. Assis; E. A. Baltz; C. Bambi; G. Barbiellini; H. Bartko; M. Basset; D. Bastieri; P. Belli; G. Benford; L. Bergstrom; R. Bernabei; G. Bertone; A. Biland; B. Biondo; F. Bocchino; E. Branchini; M. Brigida; T. Bringmann; P. Brogueira; A. Bulgarelli; J. A. Caballero; G. A. Caliandro; P. Camarri; F. Cappella; P. Caraveo; R. Carbone; M. Carvajal; S. Casanova; A. J. Castro-Tirado; O. Catalano; R. Catena; F. Celi; A. Celotti; R. Cerulli; A. Chen; R. Clay; V. Cocco; J. Conrad; E. Costa; A. Cuoco; G. Cusumano; C. J. Dai; B. Dawson; B. De Lotto; G. De Paris; A. de Ugarte Postigo; E. Del Monte; C. Delgado; A. Di Ciaccio; G. Di Cocco; S. Di Falco; G. Di Persio; B. L. Dingus; A. Dominguez; F. Donato; I. Donnarumma; M. Doro; J. Edsjo; J. M. Espino Navas; M. C. Espirito Santo; Y. Evangelista; C. Evoli; D. Fargion; C. Favuzzi; M. Feroci; M. Fiorini; L. Foggetta; N. Fornengo; T. Froysland; M. Frutti; F. Fuschino; J. L. Gomez; M. Gomez; D. Gaggero; N. Galante; M. I. Gallardo; M. Galli; J. E. Garcia; M. Garczarczyk; F. Gargano; M. Gaug; F. Gianotti; S. Giarrusso; B. Giebels; N. Giglietto; P. Giommi; F. Giordano; A. Giuliani; J. Glicenstein; P. Goncalves; D. Grasso; M. Guerriero; H. L. He; A. Incicchitti; J. Kirk; H. H. Kuang; A. La Barbera; G. La Rosa; C. Labanti; G. Lamanna; I. Lapshov; F. Lazzarotto; S. Liberati; F. Liello; P. Lipari; F. Longo; F. Loparco; M. Lozano; P. G. Lucentini De Sanctis; J. M. Ma; M. C. Maccarone; L. Maccione; V. Malvezzi; A. Mangano; M. Mariotti; M. Marisaldi; I. Martel; A. Masiero; E. Massaro; M. Mastropietro; E. Mattaini; F. Mauri; M. N. Mazziotta; S. Mereghetti; T. Mineo; S. Mizobuchi; A. Moiseev; M. Moles; C. Monte; F. Montecchia; E. Morelli; A. Morselli; I. Moskalenko; F. Nozzoli; J. F. Ormes; M. A. Peres-Torres; L. Pacciani; A. Pellizzoni; F. Perez-Bernal; F. Perotti; P. Picozza; L. Pieri; M. Pietroni; M. Pimenta; A. Pina; C. Pittori; C. Pontoni; G. Porrovecchio; F. Prada; M. Prest; D. Prosperi; R. Protheroe; G. Pucella; J. M. Quesada; J. M. Quintana; J. R. Quintero; S. Raino; M. Rapisarda; M. Rissi; J. Rodriguez; E. Rossi; G. Rowell; A. Rubini; F. Russo; M. Sanchez-Conde; B. Sacco; V. Scapin; M. Schelke; A. Segreto; A. Sellerholm; X. D. Sheng; A. Smith; P. Soffitta; R. Sparvoli; P. Spinelli; V. Stamatescu; L. S. Stark; M. Tavani; G. Thornton; L. G. Titarchuk; B. Tome; A. Traci; M. Trifoglio; A. Trois; P. Vallania; E. Vallazza; S. Vercellone; S. Vernetto; V. Vitale; N. Wild; Z. P. Ye; A. Zambra; F. Zandanel; D. Zanello

2007-12-04

238

Cosmic-ray detectors on the Moon  

NASA Technical Reports Server (NTRS)

The state of cosmic ray physics is reviewed. It is concluded that the nonexistent lunar magnetic field, the low lunar radiation background, and the lack of an atmosphere on the Moon provide an excellent environment for the study of high energy primary cosmic rays.

Linsley, John

1988-01-01

239

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

240

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

241

Pion-to-proton ratio for unaccompanied high-energy cosmic-ray hadrons at mountain altitude using transition-radiation detector  

NASA Astrophysics Data System (ADS)

A transition-radiation (TR) detector, consisting of 24 modules of styrofoam radiators and multiwire proportional chambers, and an ionization calorimeter have been used to measure the pion-to-proton ratio among the unaccompanied cosmic-ray hadrons at a mountain altitude of 730 g cm-2. Using the characteristics of the TR detector obtained from calibrations with particle beams at accelerators, the ?p ratio has been determined for cosmic-ray hadrons as ?p=0.96+/-0.15 for hadron energy = 400-800 GeV, and ?p=0.45+/-0.25 for energy > 800 GeV. Monte Carlo simulations of hadron cascades in the atmosphere using the approximate criterion of unaccompaniment suggest that the observed ?p ratio as well as the previously reported neutral-to-charge ratio can be understood by assuming a value of about 13 for the charge exchange in nucleon-air-nucleus inelastic interactions at energies above 400 GeV.

Ellsworth, R. W.; Ito, A. S.; MacFall, J. R.; Siohan, F.; Streitmatter, R. E.; Tonwar, S. C.; Viswanath, P. R.; Yodh, G. B.

1983-05-01

242

Pion-to-proton ratio for unaccompanied high-energy cosmic-ray hadrons at mountain altitude using transition-radiation detector  

Microsoft Academic Search

A transition-radiation (TR) detector, consisting of 24 modules of styrofoam radiators and multiwire proportional chambers, and an ionization calorimeter have been used to measure the pion-to-proton ratio among the unaccompanied cosmic-ray hadrons at a mountain altitude of 730 g cm-2. Using the characteristics of the TR detector obtained from calibrations with particle beams at accelerators, the pip ratio has been

R. W. Ellsworth; A. S. Ito; J. R. MacFall; F. Siohan; R. E. Streitmatter; S. C. Tonwar; P. R. Viswanath; G. B. Yodh

1983-01-01

243

Review of the Second School on Cosmic Rays and Astrophysics  

NASA Astrophysics Data System (ADS)

The Second School on Cosmic Rays and Astrophysics was held in Puebla, Mexico, on August 30 to September 8, 2006. It included subjects like experimental techniques, primary spectrum and composition of cosmic rays, high-energy interactions, gamma ray astronomy, neutrino astrophysics, cosmic ray detectors, etc. I present a very short review of some of the lectures given there.

Martínez, Humberto

2009-04-01

244

Search for correlations of GRB and cosmic rays  

NASA Astrophysics Data System (ADS)

It is possible that violent processes resulting in Gamma Ray Bursts produce also high energy photons and cosmic rays. The possible correlations of very short GRB with, e.g., CMB, cosmic rays is briefly discussed. We have also begun preparation of the experiment correlating in real time data from Maze cosmic ray detector and Pi of the Sky robotic telescope.

J?drzejczak, K.; Kasztelan, M.; Mankiewicz, L.; Molak, M.; Nawrocki, K.; Piotrowski, L. W.; Soko?owski, M.; Szabelska, B.; Szabelski, J.; Wibig, T.; Wolfendale, A. W.; Wrochna, G.

2007-06-01

245

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

246

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

247

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

248

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

249

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)."

250

Cosmic Ray Muons in QCD  

NASA Astrophysics Data System (ADS)

Despite 100 years of effort, many aspects of cosmic rays are still not well understood. Studies of high-energy muons produced in cosmic ray air showers are an important part of this effort. These muons are produced by the decays of pions and kaons at lower energies, and by charm quarks above about 1 TeV. Measurement of these muons can be used to determine the composition of cosmic rays. Moreover, the muons are produced at far-forward rapidities and are an excellent complement to data collected by accelerators at lower rapidity. Underground detectors have studied cosmic ray muons and measured lateral separations ranging from the meter scale to hundreds of meters. For larger separations, the muon transverse momentum is in excess of 6 GeV/c and muon interactions can be characterized using perturbative QCD. These measurements can be used to extend accelerator measurements to higher center of mass energies and rapidities, and have important implications for charm production as well as cosmic ray composition.

Gerhardt, Lisa

2012-03-01

251

Detection of cosmic neutrino clustering by cosmic ray spectra  

E-print Network

We propose a method to investigate the scenario that cosmic relic neutrinos are highly clustered around stars and galaxies, or dark-matter clusters, rather than uniformly distributed in the universe. Such a scenario can be detected or constrained by the interaction of high energy cosmic ray protons and nuclei with the cosmic neutrinos. There should be observable signature in the energy spectra of cosmic ray protons and nuclei for a neutrino clustering factor beyond $10^{13}$. We provide a relation on the signature onset positions between proton and nuclei spectra, and discuss possible support from existing experiments. It is also suggested that the relative abundance of cosmic ray nuclei may detect or constrain the cosmic neutrinos with smaller clustering.

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

2005-02-18

252

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

253

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

254

High-energy emission in gamma-ray bursts  

NASA Technical Reports Server (NTRS)

Between February 1980 and August 1983 the Gamma-Ray Spectrometer on the Solar Maximum Mission Satellite (SMM) detected 72 events identified as being of cosmic origin. These events are an essentially unbiased subset of all gamma-ray bursts. The measured spectra of these events show that high energy (greater than 1 MeV) emission is a common and energetically important feature. There is no evidence for a general high-energy cut-off or a distribution of cut-offs below about 6 MeV. These observations imply a limit on the preferential beaming of high energy emission. This constraint, combined with the assumption of isotropic low energy emission, implies that the typical magnetic field strength at burst radiation sites is less than 1 x 10 to the 12th gauss.

Matz, S. M.; Forrest, D. J.; Vestrand, W. T.; Chupp, E. L.; Share, G. H.; Rieger, E.

1985-01-01

255

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

256

Cosmic Rays: What Gamma Rays Can Say  

E-print Network

We will review the main channels of gamma ray emission due to the acceleration and propagation of cosmic rays, discussing the cases of both galactic and extra-galactic cosmic rays and their connection with gamma rays observations.

Aloisio, Roberto

2014-01-01

257

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

258

Ultrahigh Energy Cosmic Rays  

E-print Network

This is a review of the most resent results from the investigation of the Ultrahigh Energy Cosmic Rays, particles of energy exceeding 10$^{18}$ eV. After a general introduction to the topic and a brief review of the lower energy cosmic rays and the detection methods, the two most recent experiments, the High Resolution Fly's Eye (HiRes) and the Southern Auger Observatory are described. We then concentrate on the results from these two experiments on the cosmic ray energy spectrum, the chemical composition of these cosmic rays and on the searches for their sources. We conclude with a brief analysis of the controversies in these results and the projects in development and construction that can help solve the remaining problems with these particles.

Letessier-Selvon, Antoine

2011-01-01

259

Ultrahigh energy cosmic rays  

NASA Astrophysics Data System (ADS)

This is a review of the most resent results from the investigation of the ultrahigh energy cosmic rays, particles of energy exceeding 1018eV. After a general introduction to the topic and a brief review of the lower energy cosmic rays and the detection methods, the two most recent experiments, the High Resolution Fly’s Eye and the Southern Auger Observatory, are described. Results from these two experiments on the cosmic ray energy spectrum, the chemical composition of these cosmic rays, and searches for their sources are presented. An analysis of the controversies in these results and the projects in development and construction that can help solve the remaining problems with these particles is also presented.

Letessier-Selvon, Antoine; Stanev, Todor

2011-07-01

260

Cosmic Rays and Climate  

NASA Astrophysics Data System (ADS)

Palaeoclimatic data provide extensive evidence for solar/cosmic ray forcing of Earth's climate on all timescales, but the underlying mechanism remains a mystery. However, satellite data suggest that clouds may be influenced by galactic cosmic rays, which are modulated by the solar wind, by the geomagnetic field and, on longer timescales, by galactic variations. Physical mechanisms to explain the cloud observations have been proposed and modelled. Although these are supported by recent atmospheric observations, definitive mechanistic experiments are lacking. In order to test whether cosmic rays and clouds are causally linked, a novel experiment known as CLOUD has been proposed using a beam from a CERN particle accelerator. This paper presents an overview of the palaeoclimatic evidence for cosmic ray forcing of Earth's climate, and reviews the possible physical mechanisms and the experimental prospects.

Kirkby, J.

2005-12-01

261

Highest Energy Cosmic Rays  

E-print Network

It is proposed that the highest energy $\\sim 10^{20}$eV cosmic ray primaries are protons, decay products of a long-lived progenitor whose high kinetic energy arises from decay of a distant (cosmological) superheavy particle, G. Such a scenario can occur in e.g. SU(15) grand unification and in some preon models, but is more generic; if true, these unusual cosmic rays provide a window into new physics.

Paul H. Frampton

1998-04-22

262

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

263

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

264

Cosmic Rays and Climate  

NASA Astrophysics Data System (ADS)

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 field and by the galactic environment of Earth. Two different classes of microphysical mechanisms have been proposed to connect cosmic rays with clouds: firstly, an influence of cosmic rays on the production of cloud condensation nuclei and, secondly, an influence of cosmic rays on the global electrical circuit in the atmosphere and, in turn, on ice nucleation and other cloud microphysical processes. Considerable progress on understanding ion aerosol cloud processes has been made in recent years, and the results are suggestive of a physically-plausible link between cosmic rays, clouds and climate. However, a concerted effort is now required to carry out definitive laboratory measurements of the fundamental physical and chemical processes involved, and to evaluate their climatic significance with dedicated field observations and modelling studies.

Kirkby, Jasper

2007-11-01

265

Study of the chemical composition of high energy cosmic rays using the muon LDF of EAS between $10^{17.25}$ eV and $10^{17.75}$ eV  

E-print Network

We explore the feasibility of estimating primary cosmic ray composition at high energies from the study of two parameters of Extensive Air Showers (EAS) at ground and underground level with Monte Carlo simulations using the new EPOS and QGSJETII hadronic models tuned with LHC data. Namely, the slope and density at a given distance of the muon lateral distribution function are analysed in this work. The power to discriminate primary masses is quantified in terms of merit factor for each parameter. The analysis considers three different primary particles (proton, iron and gamma), four different zenith angles (0$^{\\circ}$, 15$^{\\circ}$, 30$^{\\circ}$ and 45$^{\\circ}$) and primary energies of $10^{17.25}$ eV, $10^{17.50}$ eV and $10^{17.75}$ eV.

Tapia, A; Sánchez, F; Croce, A Sedoski; Figueira, J M; García, B; González, N; Josebachuili, M; Ravignani, D; Wundheiler, B; Etchegoyen, A

2015-01-01

266

Study of Celestial Objects with Very High Energy Gamma Rays CANGAROO III  

E-print Network

Study of Celestial Objects with Very High Energy Gamma Rays CANGAROO III Project Description Collaboration between Australia and Nippon for a GAmma Ray Observatory in the Outback Institute for Cosmic Ray Energy Universe'' Gamma () rays are the highest energy band of electromagnetic radiation; located

Enomoto, Ryoji

267

Cosmic ray recipes  

E-print Network

Cosmic rays represent one of the most fascinating research themes in modern astronomy and physics. After almost a century since their discovery, a huge amount of scientific literature has been written on this topic and it is not always easy to extract from it the necessary information for somebody who approaches the subject for the first time. This has been the main motivation for preparing this article, which is a concise and self-contained review for whoever is interested in studying cosmic rays. The priority has been given here to well established facts, which are not at risk to get obsolete in a few years due to the fast progress of the research in this field. Also many data are presented, which are useful to characterize the doses of ionizing radiation delivered to organisms living on the Earth due to cosmic rays. The technical terms which are often encountered in the scientific literature are explained in a separate appendix.

Franco Ferrari; Ewa Szuszkiewicz

2006-01-08

268

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

269

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.

270

Computations of cosmic ray propagation in the Earth's atmosphere, towards a GLE analysis  

E-print Network

Computations of cosmic ray propagation in the Earth's atmosphere, towards a GLE analysis A Mishev 1 measurements. In this study a simulation of cosmic ray atmospheric cascade is carried out with PLANETOCOSMICS. Introduction The Earth is constantly hit by high energy particles - cosmic ray. The primary cosmic ray (CR

Usoskin, Ilya G.

271

Educational Cosmic Ray Arrays  

NASA Astrophysics Data System (ADS)

In the last decade a great deal of interest has arisen in using sparse arrays of cosmic ray detectors located at schools as a means of doing both outreach and physics research. This approach has the unique advantage of involving grade school students in an actual ongoing experiment, rather then a simple teaching exercise, while at the same time providing researchers with the basic infrastructure for installation of cosmic ray detectors. A survey is made of projects in North America and Europe and in particular the ALTA experiment at the University of Alberta which was the first experiment operating under this paradigm.

Soluk, R. A.

2006-04-01

272

Distributed reacceleration of cosmic rays  

NASA Technical Reports Server (NTRS)

We develop a model in which cosmic rays, in addition to their initial acceleration by a strong shock, are continuously reaccelerated (e.g., by weak shocks) while propagating through the galaxy. The equations describing this acceleration scheme are solved analytically (approximating ionization losses by a cutoff) and numerically. Solutions for the spectra of primary and secondary cosmic rays are given in a closed analytic form, and they allow a rapid search in parameter space for viable propagation models with distributed reacceleration included. The observed boron-to-carbon ratio can be reproduced by the reacceleration theory over a range of escape parameters, some of them quite different from the standard "leaky box" model. It is also shown that even a very modest amount of reacceleration by strong shocks causes the boron-to carbon ratio to level off at sufficiently high energies, and this effect may be observed in the CRNE data. Several other curiosities in the data may be explained naturally if a modest amount of distributed reacceleration is invoked, including (a) the apparent truncation at low energy in the otherwise exponential pathlength distribution associated with the leaky box model, (b) the sub-iron isotopic anomalies and other effects noted by Silberberg et al., and (c) the discrepancy between the reported 10Be lifetime and the lifetime of cosmic rays in the dense strata of the galactic disk.

Wandel, A.; Eichler, D.; Letaw, J. R.; Silberberg, R.; Tsao, C. H.

1987-01-01

273

Cosmic Ray Energetics And Mass  

NASA Astrophysics Data System (ADS)

The balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment was flown for ~161 days in six flights over Antarctica. High energy cosmic-ray data were collected over a wide energy range from ~ 10^10 to > 10^14 eV at an average altitude of ~38.5 km with ~3.9 g/cm2 atmospheric overburden. Cosmic-ray elements from protons (Z = 1) to iron nuclei (Z = 26) are separated with excellent charge resolution. Building on success of the balloon flights, the payload is being reconfigured for exposure on the International Space Station (ISS). This ISS-CREAM instrument is configured with the CREAM calorimeter for energy measurements, and four finely segmented Silicon Charge Detector layers for precise charge measurements. In addition, the Top and Bottom Counting Detectors (TCD and BCD) and Boronated Scintillator Detector (BSD) have been newly developed. The TCD and BCD are scintillator based segmented detectors to separate electrons from nuclei using the shower profile differences, while BSD distinguishes electrons from nuclei by detecting thermal neutrons that are dominant in nuclei induced showers. An order of magnitude increase in data collecting power is possible by utilizing the ISS to reach the highest energies practical with direct measurements. The project status including results from on-going analysis of existing data and future plans will be discussed.

Seo, Eun-Suk

2014-08-01

274

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; Mészáros, Peter; Waxman, Eli

275

Accelerator Data for Cosmic Ray Physics  

E-print Network

I present selected examples of accelerator data, mainly from hadron colliders, that are relevant for understanding cosmic ray showers. I focus on the forward region, $x_{Feynman} > 0.05$, where high energy data are scarce, since the emphasis in collider physics became high-$p_T$ phenomena.

M. G. Albrow

2010-09-21

276

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

277

Title of dissertation: A SEARCH FOR BURSTS OF VERY HIGH ENERGY GAMMA RAYS  

E-print Network

ABSTRACT Title of dissertation: A SEARCH FOR BURSTS OF VERY HIGH ENERGY GAMMA RAYS WITH MILAGRO by cosmic gamma rays of energies E 100 GeV . The effective area of Milagro peaks at energies E 10 Te though the search was optimized primarily for detecting the emission from Gamma-Ray Bursts (GRBs

California at Santa Cruz, University of

278

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

279

In Search of Cosmic Rays  

NSDL National Science Digital Library

The authors discuss the Cosmic Ray Observatory Project (CROP), focusing on their high school's participation in the project. Students build and monitor cosmic ray detectors to count and study cosmic rays and to determine whether or not the time of day inf

Derek Streich

2001-11-01

280

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

281

Signatures of cosmic-ray interactions on the solar surface  

NASA Technical Reports Server (NTRS)

The fluxes of neutrinos, gamma rays, antiprotons, neutrons, and antineutrons that result from collisions of high-energy Galactic cosmic rays with the solar atmosphere are estimated. The results are sensitive to assumptions about cosmic-ray transport in the magnetic fields of the inner solar system. The high-energy photon flux should be observable by the Gamma Ray Observatory. The neutrino flux should produce less than one event per year in the next generation of neutrino telescopes. The antiproton flux is unobservable against the Galactic background. The neutron and antineutron fluxes are detectable only if neutrons produced in terrestrial cosmic-ray events may be discriminated against.

Seckel, D.; Stanev, Todor; Gaisser, T. K.

1991-01-01

282

Possible High-energy neutrinos from the cosmic accelerator RXJ1713.7-3946  

E-print Network

The observation of TeV-gamma rays of neutral pion origin from the supernova remnant RX J1713.7-3946 might have revealed the first specific site where protons are accelerated to energies typical of the main component of the cosmic rays. In this letter we calculate the high-energy neutrino flux associated with this source to be at least 40 muon-type neutrinos per kilometer-squared per year. We perform the same calculations for other known sources of TeV-gamma rays and show how neutrino observations can establish whether the TeV-gamma rays emitted by blazars and supernova remnants are the decay products of neutral pions and thus unequivocally establish the sources as cosmic accelerators.

Jaime Alvarez-Muñiz; Francis Halzen

2002-09-26

283

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

284

Interactions of Cosmic Ray Nuclei  

E-print Network

We present convenient formulae for the energy losses of energetic atomic nuclei over the entire energy range relevant to the physics of cosmic rays. Results are applied to a leaky-box equation with a complete loss term. Thereby we derive the equilibrium spectrum of cosmic rays in various types of galaxies. We emphasize a spectral break energy at 450 MeV independent of the matter density, resulting from the transition from Coulomb and ionization losses to pion production losses as the relevant cooling process for the cosmic ray nuclei . We comment on the possible cosmic ray origin of the cosmic gamma ray background.

K. Mannheim; R. Schlickeiser

1994-02-16

285

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

286

Highest-Energy Cosmic Rays and Hilbertian Repulsive Effect  

E-print Network

We point out that an important portion of the high energy of the cosmic rays from extragalactic sources can be attributed to a Hilbertian repulsive effect, which is a consequence of Einstein equations without cosmological term.

Angelo Loinger; Tiziana Marsico

2007-12-22

287

Discovery of Very-High-Energy Gamma-Rays from the Galactic Centre Ridge  

E-print Network

The origin of Galactic cosmic rays (with energies up to 10^15 eV) remains unclear, though it is widely believed that they originate in the shock waves of expanding supernova remnants. Currently the best way to investigate their acceleration and propagation is by observing the gamma-rays produced when cosmic rays interact with interstellar gas. Here we report observations of an extended region of very high energy (VHE, >100 GeV) gamma-ray emission correlated spatially with a complex of giant molecular clouds in the central 200 pc of the Milky Way. The hardness of the gamma-ray spectrum and the conditions in those molecular clouds indicate that the cosmic rays giving rise to the gamma-rays are likely to be protons and nuclei rather than electrons. The energy associated with the cosmic rays could have come from a single supernova explosion around 10,000 years ago.

The H. E. S. S. Collaboration; :; F. A. Aharonian

2006-03-01

288

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

289

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

2006-10-09

290

Origin of cosmic rays  

NASA Astrophysics Data System (ADS)

It is argued that there are three 'origins' of cosmic rays; the origin of the particles, the origin of the energy, and the site of the acceleration. The evidence for each origin is discussed and a plausible synthesis outlined for the particles of Galactic origin where the energy comes mainly (but not exclusively) from supernova explosions, the site of the acceleration is at strong collisionless shock waves, and the accelerated particles come from the interstellar and circumstellar material swept over by these shocks. If these shocks are capable (as indicated by recent observations and theoretical work) of significantly amplifying magnetic fields this picture appears capable of explaining the cosmic ray particles at all energies below the 'ankle' at 3 × 1018 eV. The particles above this energy are generally taken to be of extra-galactic origin and possible acceleration sites for these UHE particles are briefly discussed.

Drury, Luke O.'C.

2012-12-01

291

Cosmic ray albedo gamma rays from the quiet sun  

NASA Technical Reports Server (NTRS)

We estimate the flux of gamma-rays that result from collisions of high energy galactic cosmic rays with the solar atmosphere. An important aspect of our model is the propagation of cosmic rays through the magnetic fields of the inner solar systems. We use diffusion to model propagation down to the bottom of the corona. Below the corona we trace particle orbits through the photospheric fields to determine the location of cosmic ray interactions in the solar atmosphere and evolve the resultant cascades. For our nominal choice of parameters, we predict an integrated flux of gamma rays (at 1 AU) of F(E(sub gamma) greater than 100 MeV) approximately = 5 x 10(exp -8)/sq cm sec. This can be an order of magnitude above the galactic background and should be observable by the Energetic Gamma Ray experiment telescope (EGRET).

Seckel, D.; Stanev, T.; Gaisser, T. K.

1992-01-01

292

Invariance Violation Extends the Cosmic Ray Horizon ?  

E-print Network

We postulate in the present paper that the energy-momentum relation is modified for very high energy particles to violate Lorentz invariance and the speed of photon is changed from the light velocity c. The violation effect is amplified, in a sensitive way to detection, through the modified kinematical constraints on the conservation of energy and momentum, in the absorption process of gamma-rays colliding against photons of longer wavelengths and converting into an electron-positron pair. For gamma-rays of energies higher than 10 TeV, the minimum energy of the soft photons for the reaction and then the absorption mean free path of gamma-rays are altered by orders of magnitude from the ones conventionally estimated. Consideration is similarly applied to high energy cosmic ray protons. The consequences may require the standard assumptions on the maximum distance that very high energy radiation can travel from to be revised.

T. Kifune

1999-04-13

293

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

294

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

295

Cosmic Rays above the Knee  

Microsoft Academic Search

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

Michael Unger

2008-01-01

296

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).

2012-08-03

297

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

298

Cosmic Rays and Climate Change  

NASA Astrophysics Data System (ADS)

A survey is made of the evidence for and against the hypothesis that cosmic rays affect cloud cover and thereby surface temperature. The analysis is made for the troposphere in the main and it includes correlations of cloud cover with cosmic ray intensity, Forbush decreases, cosmic ray short period increases and eleven year changes; also included are the electrical effects associated with cosmic rays. A complementary study comprises a search for extra cloud cover associated with terrestrial radon emissions, the Chernobyl accident and nuclear bomb tests. It is concluded that the best estimate of the fraction of (low) cloud cover attributable to a 2% change in cosmic ray intensity is about 0.02%. Insofar as the maximum change in average cosmic ray intensity over the last 50 years is about 0.2%, no more than 0.01% of cloud cover change in this period can have been caused by cosmic rays; their contribution to Global Warming is thus considered to be negligible. Not surprisingly, we find that the effect of cosmic rays on stratospheric cloud is bigger, by a factor of at least ten. In both the troposphere and the stratosphere the cosmic ray effects at the Poles are bigger than average.

Erlykin, A. D.; Laken, B. A.; Sloan, T.; Wolfendale, A. W.

2010-09-01

299

Albedo gamma-rays from cosmic ray interactions on the solar surface  

NASA Technical Reports Server (NTRS)

We estimate the flux of gamma-rays that result from collisions of high energy galactic cosmic rays with the solar atmosphere. The high energy photon flux should be observable by the GRO, although details of our results are sensitive to assumptions about cosmic ray propagation through the magnetic fields of the inner solar system. We also estimate the neutrino and neutron fluxes resulting from the same process.

Seckel, D.; Stanev, T.; Gaisser, T. K.

1991-01-01

300

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

301

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

2010-11-22

302

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

303

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.

Brandenberger, Robert; Xue, Wei; Zhang, Xinmin

2009-01-01

304

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

2009-01-22

305

Cosmic gamma-ray bursts  

NASA Technical Reports Server (NTRS)

A review of the cosmic gamma-ray burst phenomenon is presented. Both the light curves and the energy spectra of these short transient events display a great diversity. However, rapid rise times and periodicities sometimes observed in the light curves suggest a compact object origin. Similarly, absorption and emission features in the energy spectra argue strongly in favor of this interpretation. Counterparts to gamma-bursters in other energy ranges, such as optical and sort x-ray, have still not been identified, however, leading to a large uncertainty in the distances to bursters. Although gamma-ray burst sources have not yet been observed to repeat, numerous bursts from three objects which may be related to the gamma-bursters, called Soft Gamma Repeaters, have been recorded; there is weak evidence that they may be relatively distant on a galactic scale. Future missions, particularly those emphasizing high energy, time, and/or spatial resolution, as well as a multiwavelength approach, are likely to advance our understanding of this enigmatic phenomenon.

Hurley, K.

1991-01-01

306

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

307

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

308

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

309

24. Cosmic rays 1 24. COSMIC RAYS  

E-print Network

on gyroradius or magnetic rigidity, R, which is gyroradius multiplied by the magnetic field strength: R = p c Z particles are "modulated" by the solar wind, the expanding magnetized plasma generated by the Sun, which per unit rigidity. Propagation (and probably also acceleration) through cosmic magnetic fields depends

310

26. Cosmic rays 1 26. COSMIC RAYS  

E-print Network

on gyroradius or magnetic rigidity, R, which is gyroradius multiplied by the magnetic field strength: R = p c Z particles are "modulated" by the solar wind, the expanding magnetized plasma generated by the Sun, which per unit rigidity. Propagation (and probably also acceleration) through cosmic magnetic fields depends

311

Physics of solar cosmic rays  

NASA Technical Reports Server (NTRS)

A review of the historical development of solar cosmic ray research is presented and details concerning the solar atmosphere, the interplanetary space, and solar activity are considered, giving attention to solar-atmosphere structure, problems of radiative transfer, questions of solar magnetism, solar wind, and interplanetary plasmas. Solar flares and associated phenomena are discussed along with the generation of solar cosmic ray events, the mechanism of solar flares, the acceleration process of solar cosmic rays, the propagation of solar cosmic rays, and relations between the flow of energetic protons and solar active regions. Questions regarding the origin theory of cosmic rays are also explored, taking into account the solar origin theory and problems of flare stars.

Sakurai, K.

1974-01-01

312

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

313

Cosmic-ray acceleration in supernova shocks  

E-print Network

Galactic cosmic rays are widely believed to be accelerated in expanding shock waves initiated by supernova explosions. The theory of diffusive shock acceleration of cosmic rays is now well established, but two fundamental questions remain partly unanswered: what is the acceleration efficiency, i.e. the fraction of the total supernova energy converted to cosmic-ray energy, and what is the maximum kinetic energy achieved by particles accelerated in supernova explosions? Recent observations of supernova remnants, in X-rays with the Chandra and XMM-Newton satellites and in very-high-energy gamma rays with several ground-based atmospheric Cerenkov telescopes, have provided new pieces of information concerning these two questions. After a review of these observations and their current interpretations, I show that complementary information on the diffusive shock acceleration process can be obtained by studying the radio emission from extragalactic supernovae. As an illustration, a nonlinear model of diffusive shock acceleration is applied to the radio light curves of the supernova SN 1993J, which exploded in the nearby galaxy M81. The results of the model suggest that most of the Galactic cosmic rays may be accelerated during the early phase of interaction between the supernova ejecta and the wind lost from the progenitor star.

Vincent Tatischeff

2008-04-07

314

Observations of the Large Magellanic Cloud in high-energy gamma rays  

NASA Technical Reports Server (NTRS)

The LMC provides a valuable site to study gamma-ray production, intensity, and distribution in an external galaxy. Using 4 weeks of data from the Energetic Gamma Ray Experiment Telescope (EGRET) aboard the Compton Gamma Ray Observatory, high-energy gamma-ray emission was detected for the first time from the LMC region. These gamma rays are believed to be produced primarily through the interaction of cosmic rays with interstellar matter. Hence, combined with a knowledge of the interstellar matter distribution, they can provide a direct measure of the cosmic-ray density in an external galaxy. The results obtained from EGRET observations indicate that the level of cosmic rays in the LMC is comparable to that in our Galaxy. The integrated flux above 100 MeV is (1.9 +/- 0.4) x 10 exp -7 photons/(sq cm s). The measured flux suggests a cosmic-ray density level consistent with that expected from a quasi-stable equilibrium model. This is the first detection of a normal galaxy outside the Milky Way in high-energy gamma rays.

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

1992-01-01

315

High-energy gamma-ray observations of active galaxies  

NASA Technical Reports Server (NTRS)

During the period from 1992 May to early 1992 November, the Energetic Gamma-Ray Experiment Telescope (EGRET) on board the Compton Gamma Ray Observatory obtained high-energy gamma-ray data for most of the sky. A total of 18 active galaxies have been seen with high certainty, and it is expected that more will be found in the data when a more thorough analysis is complete. All of those that have been seen are radio-loud quasars or BL Lacertae objects; most have already been identified as blazars. No Seyfert galaxies have been found thus far. If the spectra are represented as a power law in energy, spectral slopes ranging from approximately -1.7 to -2.4 are found. A wide range of z-values exits in the observed sample, eight having values in excess of 1.0. Time variations have been seen, with the timescale for a significant change being as short as days in at least one case. These results imply the existence of very large numbers of relativistic particles, probably close to the central object. Although a large extrapolation is required, their existence also suggests that these active galactic nuclei may be the source of the extragalactic cosmic rays.

Fichtel, Carl E.

1994-01-01

316

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

317

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

318

How to Detect Cosmic Rays Learning Objectives  

E-print Network

1 CRaTER: How to Detect Cosmic Rays Learning Objectives: · The students will be able to explain two examples of a cosmic ray detector. · Students will learn how cosmic rays can affect us here on Earth. The sources of particle radiation can be radioactive materials, like uranium, or cosmic rays. (See picture

Christian, Eric

319

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

320

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; Demítrio Gonzalez Alarcon, Walter; Munakata, Kazuoki; Kuwabara, Takao; Kato, Chihiro; Bieber, John W.

321

Pulsars, supernovae, and ultrahigh energy cosmic rays  

NASA Astrophysics Data System (ADS)

The acceleration of ultrahigh energy nuclei in fast spinning newborn pulsars can explain the observed spectrum of ultrahigh energy cosmic rays and the trend towards heavier nuclei for energies above 10^{19} eV as indicated by air shower studies reported by the Auger Observatory. By assuming a normal distribution of pulsar birth periods centered at 300 ms, we show that the contribution of extragalactic pulsar births to the ultrahigh energy cosmic ray spectrum naturally gives rise to a contribution to very high energy cosmic rays (VHECRs, between 10^{16} and 10^{18} eV) by Galactic pulsar births. The required injected composition to fit the observed spectrum depends on the absolute energy scale, differing considerably between the energy scale used by Auger and that used by the Telescope Array. Depending on the composition of the cosmic rays that escape the supernova remnant and the diffusion behavior of VHECRs in the Galaxy, the contribution of Galactic pulsar births can also bridge the gap between predictions for cosmic ray acceleration in supernova remnants and the observed spectrum below the ankle. Fast spinning newborn pulsars that could produce UHECRs would be born in supernovae that could present interesting specific radiative features, due to the interaction of the pulsar wind with the surrounding ejecta. The resulting supernova lightcurves could present a high luminosity plateau over a few years, and a bright X-ray and gamma-ray peak around one or two years after the onset of the explosion. If such signatures were observed, they could have important implications both for UHECR astrophysics and for the understanding of core-collapse supernovae.

Kotera, K.; Fang, K.; Olinto, A. V.; Phinney, E. S.

2012-12-01

322

Cosmic Rays and Global Warming  

E-print Network

It has been claimed by others that observed temporal correlations of terrestrial cloud cover with `the cosmic ray intensity' are causal. The possibility arises, therefore, of a connection between cosmic rays and Global Warming. If true, the implications would be very great. We have examined this claim to look for evidence to corroborate it. So far we have not found any and so our tentative conclusions are to doubt it. Such correlations as appear are more likely to be due to the small variations in solar irradiance, which, of course, correlate with cosmic rays. We estimate that less than 15% of the 11-year cycle warming variations are due to cosmic rays and less than 2% of the warming over the last 35 years is due to this cause.

T. Sloan; A W Wolfendale

2007-06-28

323

Models for cosmic ray interactions  

E-print Network

Contemporary models of hadronic interactions are reviewed. Basic phenomenological approaches are compared, with an emphasizes on the predicted air shower characteristics. Special attention is payed to the remaining discrepancies between present hadronic MC generators and cosmic ray data. Finally, future prospects concerning model improvements are discussed, in particular, regarding the possibilities to discriminate between different models on the basis of accelerator or cosmic ray measurements.

S. Ostapchenko

2006-01-27

324

Cosmic ray nuclei from extragalactic and galactic pulsars  

NASA Astrophysics Data System (ADS)

In an extragalactic newly-born pulsar, nuclei striped off the star surface can be accelerated to extreme energies and leave the source through dense supernova surroundings. The escaped ultrahigh energy cosmic rays can explain both UHE energy spectral and atmospheric depth observations. In addition, assuming that Galactic pulsars accelerate cosmic rays with the same injection composition, very high energy cosmic rays from local pulsars can meet the flux measurements from above the knee to the ankle, and at the same time, agree with the detected composition trend.

Fang, Ke

2013-02-01

325

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

326

Cosmic ray driven outflows  

E-print Network

We present simulations of the magnetized interstellar medium (ISM) in models of massive star forming (40 Msun / yr) disk galaxies with high gas surface densities (~100 Msun / pc^2) similar to observed star forming high-redshift disks. We assume that type II supernovae deposit 10 per cent of their energy into the ISM as cosmic rays and neglect the additional deposition of thermal energy or momentum. With a typical Galactic diffusion coefficient for CRs (3e28 cm^2 / s) we demonstrate that this process alone can trigger the local formation of a strong low density galactic wind maintaining vertically open field lines. Driven by the additional pressure gradient of the relativistic fluid the wind speed can exceed 1000 km/s, much higher than the escape velocity of the galaxy. The global mass loading, i.e. the ratio of the gas mass leaving the galactic disk in a wind to the star formation rate becomes of order unity once the system has settled into an equilibrium. We conclude that relativistic particles accelerated i...

Hanasz, Michal; Naab, Thorsten; Gawryszczak, Artur; Kowalik, Kacper; Wólta?ski, Dominik

2013-01-01

327

ANTARES proposal Towards a large scale high energy cosmic neutrino undersea detector  

E-print Network

The ANTARES collaboration propose to observe high energy cosmic neutrinos using a deep sea Cherenkov detector. The sky survey with high energy neutrinos is complementary to the observations with photons and will shed a new light on the understanding of the origin of cosmics rays. We propose to explore the possibility of a km-scale detector to be installed in a deep site in the Mediterranean sea, for which a broad collaboration will be needed. With the help of collaborators and partners which have experience in sea science engineering (COM, CSTN, CTME, IFREMER, France Télécom Câbles, INSU-CNRS...) we will test the sea engineering part of a detector including test deployments close to the Toulon coast (France) where technical support is available and where several sites at depths down to 2500~m are easily accessible. We propose to build and install a demonstrator (a fully equipped 3-dimensional test array) the design of which can be extended to a km-scale detector. During the same time, autonomous systems al...

Amram, P; Aslanides, Elie; Aubert, Jean-Jacques; Azoulay, R; Bailey, D; Basa, S; Berthier, R; Bertin, V; Billault, M; Biller, S D; Blanc, F; Blanc, P E; Blondeau, F; Boulesteix, J; Brooks, B; Calzas, A; Cârloganu, C; Carr, J; Carton, P H; Cases, R; Cribier, Michel; De Botton, N R; Desages, F E; Destelle, J J; Dispau, G; Drogou, J F; Feinstein, F; Festy, D; Fuda, J L; Galumian, P I; Goret, P; Gosset, L G; Gournay, J F; Hernández, J J; Herrouin, G; Hubaut, F; Jelley, N A; Kajfasz, E; Lachartre, D; Lamare, P; Languillat, J C; Laubier, L; Laugier, J P; Le Gac, R; Le Provost, H; Le Van-Suu, A; Lemoine, L; Loiseau, D; Loucatos, Sotirios S; Magnier, P; Marcelin, M; Martin, L; Mazéas, F; Mazure, A; McNutt, J R; Meessen, C; Millot, C; Mols, P; Montanet, François; Moorhead, M E; Moscoso, L; Navas, S; Olivetto, C; Payre, P; Perrin, P; Poinsignon, J; Potheau, R; Raymond, M; Sacquin, Yu; Schuller, J P; Soirat, J P; Tabary, A; Talby, M; Triay, R; Valdy, P; Velasco, J; Vigeolas, E; Vignaud, D; Vilanova, D; Wark, D; Zúñiga, J

1997-01-01

328

Ultra-high energy gamma rays  

NASA Technical Reports Server (NTRS)

The production of ultrahigh energy gamma rays by proton interactions with relicit radiation, propagation of gamma rays through the universe, and proton cascading in the presence and absence of galactic magnetic fields is discussed. Detailed data are given on proton spectrum link, gamma ray intensity, and energy spectra of gamma rays on production.

Strong, A. W.; Wdowczyk, J.; Wolfendale, A. W.

1973-01-01

329

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

330

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

331

Very High Energy ?-Ray Afterglow Emission of Nearby Gamma-Ray Bursts  

NASA Astrophysics Data System (ADS)

The synchrotron self-Compton (SSC) emission from gamma-ray burst (GRB) forward shock can extend to the very high energy (VHE; E ? > 100 GeV) range. Such high energy photons are rare and are attenuated by the cosmic infrared background before reaching us. In this work, we discuss the prospect to detect these VHE photons using the current ground-based Cherenkov detectors. Our calculated results are consistent with the upper limits obtained with several Cherenkov detectors for GRB 030329, GRB 050509B, and GRB 060505 during the afterglow phase. For five bursts in our nearby GRB sample (except for GRB 030329), current ground-based Cherenkov detectors would not be expected to detect the modeled VHE signal. Only for those very bright and nearby bursts like GRB 030329, detection of VHE photons is possible under favorable observing conditions and a delayed observation time of lsim10 hr.

Xue, R. R.; Tam, P. H.; Wagner, S. J.; Behera, B.; Fan, Y. Z.; Wei, D. M.

2009-09-01

332

An Absence of Neutrinos Associated with Cosmic Ray Acceleration in Gamma-Ray Bursts  

E-print Network

Gamma-Ray Bursts (GRBs) have been proposed as a leading candidate for acceleration of ultra high-energy cosmic rays, which would be accompanied by emission of TeV neutrinos produced in proton-photon interactions during acceleration in the GRB fireball. Two analyses using data from two years of the IceCube detector produced no evidence for this neutrino emission, placing strong constraints on models of neutrino and cosmic-ray production in these sources.

Abbasi, R; Abu-Zayyad, T; Ackermann, M; Adams, J; Aguilar, J A; Ahlers, M; Altmann, D; Andeen, K; Auffenberg, J; Bai, X; Baker, M; Barwick, S W; Bay, R; Alba, J L Bazo; Beattie, K; Beatty, J J; Bechet, S; Becker, J K; Becker, K -H; Bell, M; Benabderrahmane, M L; BenZvi, S; Berdermann, J; Berghaus, P; Berley, D; Bernardini, E; Besson, D Bertrand D Z; Bindig, D; Bissok, M; Blaufuss, E; Blumenthal, J; Boersma, D J; Bohm, C; Bose, D; Böser, S; Botner, O; Brayeur, L; Brown, A M; Buitink, S; Caballero-Mora, K S; Carson, M; Casier, M; Chirkin, D; Christy, B; Clevermann, F; Cohen, S; Colnard, C; Cowen, D F; Silva, A H Cruz; D'Agostino, M V; Danninger, M; Daughhetee, J; Davis, J C; De Clercq, C; Degner, T; Descamps, F; Desiati, P; de Vries-Uiterweerd, G; DeYoung, T; Díaz-Vélez, J C; Dierckxsens, M; Dreyer, J; Dumm, J P; Dunkman, M; Eisch, J; Ellsworth, R W; Engdegård, O; 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; Franke, R; Gaisser, T K; Gallagher, J; Gerhardt, L; Gladstone, L; Glüsenkamp, T; Goldschmidt, A; Goodman, J A; Góra, D; Grant, D; Griesel, T; Groß, A; Grullon, S; Gurtner, M; Ha, C; Ismail, A Haj; Hallgren, A; Halzen, F; Han, K; Hanson, K; Heereman, D; Heinen, D; Helbing, K; Hellauer, R; Hickford, S; Hill, G C; Hoffman, K D; Hoffmann, B; Homeier, A; Hoshina, K; Huelsnitz, W; Hül?, J -P; Hulth, P O; Hultqvist, K; Hussain, S; Ishihara, A; Jacobi, E; Jacobsen, J; Japaridze, G S; Johansson, H; Kappes, A; Karg, T; Karle, A; Kiryluk, J; Kislat, F; Klein, S R; Köhne, J -H; Kohnen, G; Kolanoski, H; Köpke, L; Kopper, S; Koskinen, D J; Kowalski, M; Kowarik, T; Krasberg, M; Kroll, G; Kunnen, J; Kurahashi, N; Kuwabara, T; Labare, M; Laihem, K; Landsman, H; Larson, M J; Lauer, R; Lünemann, J; Madsen, J; Marotta, A; Maruyama, R; Mase, K; Matis, H S; Meagher, K; Merck, M; Mészáros, P; Meures, T; Miarecki, S; Middell, E; Milke, N; Miller, J; Montaruli, T; Morse, R; Movit, S M; Nahnhauer, R; Nam, J W; Naumann, U; Nowicki, S C; Nygren, D R; Odrowski, S; Olivas, A; Olivo, M; O'Murchadha, A; Panknin, S; Paul, L; Heros, C Pérez de los; Piegsa, A; Pieloth, D; Posselt, J; Price, P B; Przybylski, G T; Rawlins, K; Redl, P; Resconi, E; Rhode, W; Ribordy, M; Richman, M; Riedel, B; Rizzo, A; Rodrigues, J P; Rothmaier, F; Rott, C; Ruhe, T; Rutledge, D; Ruzybayev, B; Ryckbosch, D; Sander, H -G; Santander, M; Sarkar, S; Schatto, K; Schmidt, T; Schöneberg, S; Schönwald, A; Schukraft, A; Schulte, L; Schultes, A; Schulz, O; Schunck, M; Seckel, D; Semburg, B; Seo, S H; Sestayo, Y; Seunarine, S; Silvestri, A; Smith, M W E; Spiczak, G M; Spiering, C; Stamatikos, M; Stanev, T; Stezelberger, T; Stokstad, R G; Stößl, A; Strahler, E A; Ström, R; Stüer, M; Sullivan, G W; Taavola, H; Taboada, I; Tamburro, A; Ter-Antonyan, S; Tilav, S; Toale, P A; Toscano, S; Tosi, D; van Eijndhoven, N; Van Overloop, A; van Santen, J; Vehring, M; Voge, M; Walck, C; Waldenmaier, T; Wallraff, M; Walter, M; Wasserman, R; Weaver, Ch; Wendt, C; Westerhoff, S; Whitehorn, N; Wiebe, K; Wiebusch, C H; Williams, D R; Wischnewski, R; Wissing, H; Wolf, M; Wood, T R; Woschnagg, K; Xu, C; Xu, D L; Xu, X W; Yanez, J P; Yodh, G; Yoshida, S; Zarzhitsky, P; Zoll, M

2012-01-01

333

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

334

Underground cosmic-ray experiment EMMA  

NASA Astrophysics Data System (ADS)

EMMA (Experiment with MultiMuon Array) is a new approach to study the composition of cosmic rays at the knee region (1 - 10 PeV). The array will measure the multiplicity and lateral distribution of the high-energy muon component of an air shower and its arrival direction on an event-by-event basis. The array operates in the Pyhäsalmi Mine, Finland, at a depth of 75 metres (or 210 m.w.e) corresponding to the cut-off energy of approximately 50 GeV for vertical muons. The data recording with a partial array has started and preliminary results of the first test runs are presented.

Kuusiniemi, P.; Bezrukov, L.; Enqvist, T.; Fynbo, H.; Inzhechik, L.; Joutsenvaara, J.; Kalliokoski, T.; Loo, K.; Lubsandorzhiev, B.; Monto, T.; Petkov, V.; Räihä, T.; Sarkamo, J.; Slupecki, M.; Trzaska, W. H.; Virkajärvi, A.

2013-02-01

335

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

336

Coherence length of cosmic background radiation enlarges the attenuation length of the ultra-high energy proton  

E-print Network

It is pointed out that an agreement of the one particle energy spectrum of the cosmic background radiation (CMBR) with Plank distribution of 2.725 [K] does not give a strong constraint on the coherence length of CMBR if the mean free path of CMBR is very long. The coherence length in this situation is estimated as a few times of $k_BT$. Due to this finite coherence length, the attenuation length of ultra-high energy cosmic rays (UHECR) is reduced in the $\\Delta $ resonance region,i.e., around $10^{20}$ [eV]. The small attenuation length makes the suppression of the flux of cosmic rays in this energy region less prominent than the naive estimation

Kenzo Ishikawa; Yutaka Tobita

2010-03-09

337

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

338

The EGRET high energy gamma ray telescope  

NASA Technical Reports Server (NTRS)

The Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (GRO) is sensitive in the energy range from about 20 MeV to about 30,000 MeV. Electron-positron pair production by incident gamma photons is utilized as the detection mechanism. The pair production occurs in tantalum foils interleaved with the layers of a digital spark chamber system; the spark chamber records the tracks of the electron and positron, allowing the reconstruction of the arrival direction of the gamma ray. If there is no signal from the charged particle anticoincidence detector which surrounds the upper part of the detector, the spark chamber array is triggered by two hodoscopes of plastic scintillators. A time of flight requirement is included to reject events moving backward through the telescope. The energy of the gamma ray is primarily determined by absorption of the energies of the electron and positron in a 20 cm deep NaI(Tl) scintillator.

Hartman, R. C.; Bertsch, D. L.; Fichtel, C. E.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.; Mayer-Hasselwander, H. A.

1992-01-01

339

The high energy X-ray universe.  

PubMed

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

2010-04-20

340

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

341

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.

Higley, Susan

342

Cosmic Rays and Global Warming  

SciTech Connect

Some workers have claimed that the observed temporal correlations of (low level) terrestrial cloud cover with the cosmic ray intensity changes, due to solar modulation, are causal. The possibility arises, therefore, of a connection between cosmic rays and Global Warming. If true, the implications would be very great. We have examined this claim in some detail. So far, we have not found any evidence in support and so our conclusions are to doubt it. From the absence of corroborative evidence we estimate that less than 15% at the 95% confidence level, of the 11-year cycle warming variations are due to cosmic rays and less than 2% of the warming over the last 43 years is due to this cause. The origin of the correlation itself is probably the cycle of solar irradiance although there is, as yet, no certainty.

Sloan, T. [Physics Department, University of Lancaster, Lancaster, UK (United Kingdom); Wolfendale, A. W. [Physics Department, Durham University, Durham (United Kingdom)

2008-01-24

343

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

344

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 ray–wave 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

345

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

346

Pionic Photons and Neutrinos from Cosmic Ray Accelerators  

E-print Network

Identifying the accelerators that produce the Galactic and extragalactic cosmic rays has been a priority mission of several generations of high energy gamma ray and neutrino telescopes; success has been elusive so far. Detecting the gamma-ray and neutrino fluxes associated with cosmic rays reaches a new watershed with the completion of IceCube, the first neutrino detector with sensitivity to the anticipated fluxes, and the construction of CTA, a ground-based gamma ray detector that will map and study candidate sources with unprecedented precision. In this paper, we revisit the prospects for revealing the sources of the cosmic rays by a multiwavelength approach; after reviewing the methods, we discuss supernova remnants, gamma ray bursts, active galaxies and GZK neutrinos in some detail.

Francis Halzen

2011-11-04

347

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

348

High energy particle astronomy.  

NASA Technical Reports Server (NTRS)

Discussion of techniques currently used in high energy particle astronomy for measuring charged and neutral cosmic rays and their isotope and momentum distribution. Derived from methods developed for accelerator experiments in particle physics, these techniques help perform important particle astronomy experiments pertaining to nuclear cosmic ray and gamma ray research, electron and position probes, and antimatter searches.

Buffington, A.; Muller, R. A.; Smith, L. H.; Smoot, G. F.

1972-01-01

349

High energy X-ray computed tomography for industrial applications  

Microsoft Academic Search

A high-energy X-ray computed tomography system with an electron linear accelerator was developed to image cross-sections of large-scale and high-density materials. An electron linear accelerator is used for the X-ray source. The maximum X-ray energy is 12 MeV and the average energy is around 4 MeV. The intensity of an X-ray fan beam passing through the test object is measured

S. Izumi; S. Kamata; K. Satoh; H. Miyai

1991-01-01

350

High energy X-ray computed tomography for industrial applications  

Microsoft Academic Search

A high energy X-ray computed tomography (CT) system with an electron linear accelerator was developed to image cross-sections of large-scale and high-density materials. An electron linear accelerator is used as the X-ray source. The maximum X-ray energy is 12 MeV, and the average energy is around 4 MeV. The intensity of the X-ray fan beam passing through the test object

S. Izumi; S. Kamata; K. Satoh; H. Miyai

1993-01-01

351

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

352

Multimessenger approach to search for cosmic ray anisotropies  

NASA Astrophysics Data System (ADS)

The origin of the highest energy cosmic rays is still unknown. The discovery of their sources will reveal the workings of the most energetic astrophysical accelerators in the universe. Recent international efforts have brought us closer to unveiling this mystery. Possible ultra-high energy cosmic ray sources have been narrowed down with the confirmation of an "ankle" and the GZK-like spectral feature at the high-end of the energy spectrum. A clear resolution of the ultra-high energy mystery calls for the search of anisotropies in the distribution of arrival directions of cosmic rays. In this thesis, we adopt the so-called "multi-messenger" approach to search for both large-scale and point-like source anisotropic features, using data collected with the Pierre Auger Observatory.

Buroker, Larry

353

Measuring Cosmic Rays at 1 PeV and Above  

NASA Astrophysics Data System (ADS)

High energy cosmic rays arrive at Earth's upper atmosphere from all directions with a remarkably smooth power-law spectrum. Structures in this otherwise smooth spectrum (such as changes in slope or in chemical composition) give clues as to the sources, acceleration, and propagation of these particles. At energies beyond 1 PeV, as cosmic rays become too rare for direct measurements to be practical, large ground-based experiments make indirect measurements of cosmic ray air showers. They employ a wide range of detection technologies and techniques, exploring known features in the spectrum such as the "knee" and the "ankle", as well as searching for new clues in the energy spectrum, chemical composition, and anisotropy in arrival directions of these particles. This talk will overview the broad landscape of ground-based cosmic ray detector arrays, and will focus on the IceCube Observatory at the South Pole.

Rawlins, Katherine

2012-05-01

354

A New View of the High Energy Gamma-Ray Sky with the Ferrni Gamma-Ray Space Telescope  

NASA Technical Reports Server (NTRS)

Following its launch in June 2008, high energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have opened a new and important window on a wide variety of phenomena, including pulsars, black holes and active galactic nuclei, gamma-ray bursts, supernova remnants and the origin of cosmic rays, and searches for hypothetical new phenomena such as super symmetric dark matter annihilations. In this talk I will describe the current status of the Fermi observatory and review the science highlights from the first year of observations.

McEnery, Julie

2009-01-01

355

30TH INTERNATIONAL COSMIC RAY CONFERENCE Numerical Model of Cosmic Ray Induced Ionization in the Atmosphere  

E-print Network

30TH INTERNATIONAL COSMIC RAY CONFERENCE Numerical Model of Cosmic Ray Induced Ionization.usoskin@oulu.fi Abstract: We present a full numerical model to calculate cosmic ray induced ionization in the at- mosphere practical applications are discussed. Introduction Energetic galactic cosmic rays (CR) form an im- portant

Usoskin, Ilya G.

356

28th International Cosmic Ray Conference 3905 Galactic Cosmic Ray Fluctuations: Long-term Modulation  

E-print Network

28th International Cosmic Ray Conference 3905 Galactic Cosmic Ray Fluctuations: Long study the time evolution of power spectra of galac- tic cosmic ray fluctuations during the last three monitors, Tixie Bay (Russia) and Oulu (Finland). We have shown that the power spectrum of cosmic ray

Usoskin, Ilya G.

357

28th International Cosmic Ray Conference 3473 REal-time COsmic Ray Database (RECORD)  

E-print Network

28th International Cosmic Ray Conference 3473 REal-time COsmic Ray Database (RECORD) Valery Kozlov, Moscow region, Russia. Abstract In this paper we present a first distributed REal-time COsmic Ray methods. The database contains not only original cosmic ray data but also auxiliary data necessary

Usoskin, Ilya G.

358

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.

359

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

360

Search for ultra-high-energy cosmic neutrinos with the IceCube neutrino observatory  

NASA Astrophysics Data System (ADS)

A search for extremely-high-energy (EHE) neutrinos with energies greater than 106 GeV has been performed using the data taken with the IceCube detector at the South Pole between May 2010 and May 2012. Two neutrino-induced cascade events are observed passing all the signal search criteria over an expected background of 0.06 events. Energies of the observed two events are estimated to be in the range of 106 ˜ 107 GeV. We find no events with energies above 109 GeV in the sample of accumulated effective all-flavor-sum neutrino detection exposure of ? 4.8 × 1016 cm2 sec sr. An upper limit on the neutrino flux in the energy range above 106 GeV is obtained from the observations. The present IceCube data disfavors strong cosmological evolutions of ultra-high-energy cosmic-ray sources such as AGNs associated with radio-loud jets.

Yoshida, Shigeru

2013-05-01

361

The highest energy cosmic rays: Observations  

NASA Astrophysics Data System (ADS)

Observations of cosmic ray air showers with energies above 0.1 EeV (1017 eV) are key to understanding where the highest energy cosmic rays originate, how they acquire their energy, what types of particles they are, and also the nature of their ultra-high-energy hadronic interactions at the top of the atmosphere. Prominent features of the energy spectrum have now been established, although some difference remains in energy normalization between results from different observatories. A distinct ankle is present near 4 EeV, and a GZK-like downturn is evident above about 30 EeV. Well above that GZK threshold, there have been tantalizing indications of clustering of arrival directions and correlation with catalogs of local matter, but no anisotropy has been independently confirmed so far at any energy above 0.1 EeV. With 99% confidence, the dipole anisotropy is less than 2% for energies just below 1 EeV, as measured in right ascension from the southern hemisphere. Moreover, no discrete source of neutral particles has been discovered and astrophysically interesting upper limits have been derived. Although the present upper limits on the diffuse intensities of photons and neutrinos do not constrain typical models of GZK production, they have eliminated most top-down models in which cosmic rays originate through the annihilation or decay of supermassive particles. The vast majority of cosmic rays must be protons and other charged nuclei. Data from different observatories have led to inconsistent inferences about the relative abundances of primary mass groups and the dependence of the composition on energy. The effective proton-air interaction cross section has been measured at EeV energies and is in agreement with conventional extrapolations obtained from measurements at collider energies.

Sommers, Paul

2013-02-01

362

Lunar/Solar effects on Cosmic Rays  

E-print Network

Lunar/Solar effects on Cosmic Rays By: Sophia Bauer & Jenna Valdez #12;Introduction When cosmic rays travel through the moon they will decay because of the mass of the moon. Therefore there should be less cosmic rays coming into the earth's atmosphere from the direction of the moon. We were interested

California at Santa Cruz, University of

363

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

364

Galactic cosmic rays M.-B. Kallenrode  

E-print Network

Galactic cosmic rays M.-B. Kallenrode University of L¨uneburg, 21332 L¨uneburg, Germany Camera.: ??? First author: Kallenrode 1 Galactic cosmic rays M.-B. Kallenrode University of L¨uneburg, 21332 L¨uneburg, Germany This presentation gives a brief review of galactic cosmic rays. It starts with observations made

Steinhoff, Heinz-Jürgen

365

LATERAL DISTRIBUTION OF COSMIC RAY MUONS UNDERGROUND  

E-print Network

LATERAL DISTRIBUTION OF COSMIC RAY MUONS UNDERGROUND: Results from the CosmoALEPH ExperimentË?at Siegen Siegen 2006 #12; LATERAL DISTRIBUTION OF COSMIC RAY MUONS UNDERGROUND: Results from the Cosmo; ABSTRACT LATERAL DISTRIBUTION OF COSMIC RAY MUONS UNDERGROUND: Results from the CosmoALEPH Experiment

Siegen, Universität

366

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

367

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

368

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

369

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

370

Cosmic Gamma-ray Background Radiation  

E-print Network

The cosmic gamma-ray background radiation is one of the most fundamental observables in the gamma-ray band. Although the origin of the cosmic gamma-ray background radiation has been a mystery for a long time, the Fermi gamma-ray space telescope has recently measured it at 0.1-820 GeV and revealed that the cosmic GeV gamma-ray background is composed of blazars, radio galaxies, and star-forming galaxies. However, Fermi still leaves the following questions. Those are dark matter contribution, origins of the cosmic MeV gamma-ray background, and the connection to the IceCube TeV-PeV neutrino events. In this proceeding, I will review the current understandings of the cosmic gamma-ray background and discuss future prospects of cosmic gamma-ray background radiation studies. I also briefly review the current status of cosmic infrared/optical background radiation studies.

Inoue, Yoshiyuki

2014-01-01

371

OG 1.2.18 1 Single hadrons in Milagro and the Spectrum of Cosmic Ray  

E-print Network

OG 1.2.18 1 Single hadrons in Milagro and the Spectrum of Cosmic Ray Protons Gaurang B. Yodh 1 of the Technique: At high energies (energies above a few TeV) most cosmic rays produce air showers at the Milagro of the incident cosmic ray are located within few meters of the core of the shower. A fraction exp( \\Gammax â??(E

California at Santa Cruz, University of

372

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

373

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

374

A search for high-energy gamma-ray bursts  

NASA Astrophysics Data System (ADS)

The ground-based extensive air shower array ``Andyrchy'' of the Baksan Neutrino Observatory was used for the search of high-energy gamma-ray bursts as well as the high-energy radiation (E_{gamma} ? 10 GeV) within the gamma-ray bursts, which have been recorded in the low-energy range (E_{gamma} ? 30-50 keV) on the BATSE. The results obtained in 1996-2000 in the sky survey and in coincidence with the BATSE events are presented.

Petkov, V. B.; Alekseenko, V. V.; Volchenko, V. I.; Zaichenko, A. N.; Karpov, S. N.; Poddubny, V. Ya.; Radchenkov, A. V.; Smirnov, D. V.; Khaerdinov, N. S.; Chernyaev, A. B.; Yanin, A. F.

2003-04-01

375

The very-high-energy gamma-ray sky.  

PubMed

Over the past few years, very-high-energy gamma-ray astronomy has emerged as a truly observational discipline, with many detected sources representing different galactic and extragalactic source populations-supernova remnants, pulsar wind nebulae, giant molecular clouds, star formation regions, compact binary systems, and active galactic nuclei. It is expected that observations with the next generation of stereoscopic arrays of imaging atmospheric Cherenkov telescopes over a very broad energy range from 10(10) to 10(15) electron volts will dramatically increase the number of very-high-energy gamma-ray sources, thus having a huge impact on the development of astrophysics, cosmology, and particle astrophysics. PMID:17204642

Aharonian, Felix

2007-01-01

376

Very-High-Energy Gamma-Ray Observations of M 31 with VERITAS  

NASA Astrophysics Data System (ADS)

VERITAS, an array of 12 m imaging atmospheric Cherenkov telescopes in southern Arizona, is one of the world's most sensitive detectors of astrophysical very-high-energy (VHE, > 100 GeV) gamma rays. We present the current status of the VERITAS observations of M 31 (Andromeda Galaxy) including an upper limit on the VHE flux and a comparison with theoretical predictions. The dominant mechanism for the formation of diffuse gamma rays is expected to be through the inelastic collision of high-energy cosmic rays with the interstellar medium (ISM). M 31 provides an opportunity to probe this mechanism due to its proximity and spatial extent, with the VERITAS point-spread function sufficient to resolve the ISM dense star-forming ring and the galaxy core with its multiple supernova remnants.

Bird, R.

2014-07-01

377

30th International Cosmic Ray Conference Hybrid Performance of the Pierre Auger Observatory  

E-print Network

calculable aper- ture. The FD provides the conversion between S(1000) and the cosmic ray primary energy, #12- ditional FD direction fitting method with the arrival time of the shower at the ground mea- sured design, in which ultra high energy cosmic rays are detected simultaneously by fluorescence telescopes

378

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 electron–positron pairs in the shower as they move through the geomagnetic field. This should allow one to

Heino Falcke; Peter Gorham

2003-01-01

379

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

380

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

381

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

382

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

383

An overview of cosmic ray research - Composition, acceleration and propagation  

NASA Technical Reports Server (NTRS)

An overview of cosmic ray (CR) research and its relationship to other areas of high-energy astrophysics is presented. Research being conducted on the composition of cosmic rays (CRs) is examined, including the study of the solar system 'template' for CRs, CR abundances at earth, solar energetic particles, the CR elements beyond zinc, and the study of electrons, positrons, antinuclei, and of isotopic composition of CRs. Research on the CR energy spectrum and anisotropy is briefly reviewed. The study of acceleration processes, particle confinement, and propagation of CRs is addressed. Finally, the investigation of source abundances in CRs is discussed.

Wefel, John P.

1988-01-01

384

A Simple Cosmic Ray Muon Detector At High Cutoff Rigidity  

NASA Astrophysics Data System (ADS)

A small cosmic ray detector (area of 0.5 m2),using plastic scintillator, was constructed and being in operation in Riyadh (Rc=13 GeV) since September 2013. The objective of this detector is to study high energy cosmic ray muons on different time scales and investigate their correlations with environmental parameters. In this study, the technical aspects, the construction works of the system, and some of the calibration procedures will be briefly given. Preliminarily results obtained by the detector will be summarized. This includes the observations of three Forbush decreases occurred during the study period.

Maghrabi, Abdullrahman; Alghamdi, Abdulrahman S.; Almoteri, MR. M.; Rakan Alotaibi, MR.; Garawi, M. S. Al

385

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

2007-10-25

386

High resolution, large area, high energy x-ray tomography  

SciTech Connect

An x-ray tomography system is being developed for high resolution inspection of large objects. The goal is to achieve 25 micron resolution over object sizes that are tens of centimeters in extent. Typical objects will be metal in composition and therefore high energy, few MeV x-rays will be required. A proof-of-principle system with a limited field of view has been developed. Preliminary results are presented.

Trebes, J.E.; Dolan, K.W.; Haddad, W.S.; Haskins, J.J.; Lerche, R.A.; Logan, C.M.; Perkins, D.E.; Schneberk, D.J.; Rikard, R.D.

1997-08-01

387

Particle astrophysics and cosmic ray studies from a lunar base  

NASA Astrophysics Data System (ADS)

The major advantages that lunar-base detectors would have over the earth-based and the earth-orbiting detectors for various particle-astrophysics and cosmic-ray studies include the lack of an atmosphere, a low magnetic field, the stability of a lunar-surface platform, the possibility of using lunar material, and the presence of an already existing lunar base. The paper discusses studies that would benefit from lunar-base detectors, which include measurements of the cosmic ray spectrum and composition in the 10 14-16 eV per nucleus region; observations of heavy neutrinos or the products of WIMP annihilations; studies of ultraheavy cosmic rays, isotopes, and antimatter; and observations of high-energy gamma-ray sources in the currently unexplored 5-200 GeV window.

Cherry, Michael L.

1990-07-01

388

Ionisation as indicator for cosmic ray acceleration  

NASA Astrophysics Data System (ADS)

Astrospheres and wind bubbles of massive stars are believed to be sources of cosmic rays with energies E ? 1 TeV. These particles are not directly detectable, but their impact on surrounding matter, in particular ionisation of atomic and molecular hydrogen, can lead to observable signatures. A correlation study of both gamma ray emission, induced by proton-proton interactions of cosmic ray protons with kinetic energies Ep ? 280 MeV with ambient hydrogen, and ionisation induced by cosmic ray protons of kinetic energies Ep < 280 MeV can be performed in order to study potential sources of (sub)TeV cosmic rays.

Schuppan, F.; Röken, C.; Fedrau, N.; Becker Tjus, J.

2014-06-01

389

Measurement of C-12, O-16, and Fe-56 charge changing cross sections in helium at high energy, comparison with cross sections in hydrogen, and application to cosmic-ray propagation  

NASA Technical Reports Server (NTRS)

We present measurements of the spallation cross sections of carbon, oxygen, and iron in helium and hydrogen, at beam energies from 540 to 1600 MeV/nucleon, performed by exposing liquid helium, CH2, and C targets. Charge changing cross sections are reported for fragments down to Ne for Fe + alpha and Fe + p reactions, and down to B for O + alpha, O + p, C + alpha, and C + p reactions. Alpha- to p-induced cross section ratios (sigma(sub alpha)/sigma(sub p)) are determined at the same energy per nucleon. From these measurements an empirical formula for the (sigma(sub alpha)/sigma(sub p)) ratios is derived and is found in good agreement with available isotopic cross sections data from radioactivity and radiochemical techniques. These results are applied to the propagation of heavy charged cosmic rays in an interstellar medium with a helium to hydrogen abundance ratio of 0.10. It is shown that the Sc-Mn/Fe ratio prediction is decreased relative to the B/C ratio when compared to propagation calculations in a pure hydrogen interstellar medium.

Ferrando, P.; Webber, W. R.; Goret, P.; Kish, J. C.; Schrier, D. A.; Soutoul, A.; Testard, O.

1988-01-01

390

X-ray Production By Cosmic Muons  

NASA Astrophysics Data System (ADS)

Muons have a small cross section for interactions and high energy, so they are very penetrating and give the significant contribution to the gamma spectra of Ge detectors, even in deep underground laboratories. One of the muon interaction effects with material is X-rays production. Having in mind that gold is often used as a detectors component, in this paper the production of X-rays in gold sample is analyzed by using an coincidence system based on plastic scintillation detector and Ge detector. The Au disc-shaped sample with mass of 40.6 g, radius 3.34 cm and 0.06 cm thickness was inside 12 cm thick lead shield of extended range HPGe detector. The plastic detector of 0.5 × 0.5 × 0.05 m dimensions was placed above the lead shield at the distance of 32 cm from detector endcap. The producing rate of K? rays per Au mass unit from coincidence gamma spectrum is determined as R ~7.1 × 10-4 g-1s-1. Taking in account the measured muon flux of ?=54 s-1m-2, the muon cross section ?K?~ 43 Barn, for Au K? X-rays production is calculated. Also, the cross sections of X-ray production by cosmic muons in lead and tungsten are measured. Unexpectedly, the results obtained did not reveal Z dependence in the Z= 74-82 region.

Mrdja, D.; Bikit, I.; Ani?in, I.; Veskovi?, M.; Forkapi?, S.

2007-04-01

391

High Energy Gamma Ray Lines from Solar Flares  

NASA Technical Reports Server (NTRS)

A number of nuclear states have been identified as possible candidates for producing high-energy gamma-ray line emission in solar flares. For one high-energy line, resulting from the decay of C-12 (15.11 MeV), the excitation cross sections and branching radios have been studied extensively. In a solar flare, the ratio of the flux of 15. 11 -MeV gamma rays to the flux of 4.44-MeV gamma rays depends critically on the spectral index of the flare-accelerated protons. Prospects for being able to determine that spectral index using results from HESSI observations together with the analytic results of Crannell, Crannell, and Ramaty (1979) will be presented.

Crannell, Carol Jo

2000-01-01

392

Transport and acceleration of anomalous cosmic rays  

NASA Astrophysics Data System (ADS)

Anomalous cosmic rays are produced from interstellar pickup ions by heliospheric plasma processes. The solar wind termination shock was believed to be the source of these high-energy ions before the Voyagers' shock encounter. Because ACR spectra were observed to be modulated at the shock, several different acceleration cites and mechanisms were proposed. These included termination shock locations not visited by the Voyagers, the inner helioshgeath, and regions near the heliopause. I will review and compare the current generation of ACR transport models, including an update on the Huntsville model. A need to accommodate a physically realistic geometry of the termination shock and heliosheath for ACR modeling is emphasized. I also discuss recent ACR flux decreases as a sign of Voyager's proximity to the heliopause.

Florinski, Vladimir; Senanayake, Udara

2012-07-01

393

Cosmic Rays: The Second Knee and Beyond  

E-print Network

We conduct a review of experimental results on Ultra-High Energy Cosmic Rays (UHECR's) including measurements of the features of the spectrum, the composition of the primary particle flux and the search for anisotropy in event arrival direction. We find that while there is a general consensus on the features in the spectrum -- the Second Knee, the Ankle, and (to a lesser extent) the GZK Cutoff -- there is little consensus on the composition of the primaries that accompany these features. This lack of consensus on the composition makes interpretation of the agreed upon features problematic. There is also little direct evidence about potential sources of UHECRs, as early reports of arrival direction anisotropies have not been confirmed in independent measurements.

Douglas R Bergman; John W. Belz

2007-04-27

394

The isotopic composition of cosmic-ray beryllium and its implication for the cosmic ray's age  

NASA Technical Reports Server (NTRS)

We report a new measurement of the cosmic-ray isotopic composition of beryllium in the low-energy range from 35 to 113 MeV per nucleon. This measurement was made using the High Energy Telescope of the CRS experiment on the Voyager 1 and 2 spacecraft during the time period from 1977 to 1991. In this overall time period of 14 years the average solar modulation level was about 500 MV. The cosmic-ray beryllium isotopes were completely separated with an average mass resolution sigma of 0.185 amu. The isotope fractions of Be-7, Be-9, and Be-10 obtained are 52.4 +/- 2.9%, 43.3 +/- 3.7%, and 4.3 +/- 1.5%, respectively. The measured cosmic-ray abundances of Be-7 and Be-9 are found to be in agreement with calculations based on standard Leaky-Box model for the interstellar propagation of cosmic-ray nuclei using the recent cross sections of the New Mexico-Saclay collaboration. From our observed ratio Be-10/Be = 4.3 +/- 1.5% we deduce an average interstellar density of about 0.28 (+0.14, -0.11) atoms/cu cm, and acosmic-ray lifetime for escape of 27 (+19, -9) x 10(exp 6) years. The surviving fraction of Be-10 is found to be 0.19 +/- 0.07. Modifications to the conclusions of the Leaky-Box model when a diffusion + convection halo model for propagation is used are also considered.

Lukasiak, A.; Ferrando, P.; Mcdonald, F. B.; Webber, W. R.

1994-01-01

395

The H.E.S.S. measurement of the cosmic-ray electron spectrum  

NASA Astrophysics Data System (ADS)

The measurement of very-high-energy cosmic-ray electrons is intrinsically difficult due to their very steep spectrum with low fluxes and an enormous background of hadronic cosmic rays. The large collection areas needed for such a measurement can be provided by ground-based imaging atmospheric Cherenkov telescopes. The High Energy Stereoscopic System (H.E.S.S.) has performed the first ground-based cosmic-ray electron measurement and thereby extended the measured range of the spectrum to several TeV.

Egberts, Kathrin; Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Barres de Almeida, U.; Bazer-Bachi, A. R.; Becherini, Y.; Behera, B.; Bernlühr, K.; Bochow, A.; Boisson, C.; Bolmont, J.; Borrel, V.; Brucker, J.; Brun, F.; Brun, P.; Bühler, R.; Bulik, T.; Büsching, I.; Boutelier, T.; Chadwick, P. M.; Charbonnier, A.; Chaves, R. C. G.; Cheesebrough, A.; Conrad, J.; Chounet, L.-M.; Clapson, A. C.; Coignet, G.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; Dickinson, H. J.; Domainko, A. Djannati-Ataü W.; Drury, L. O'c.; Dubois, F.; Dubus, G.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fiasson, A.; Fürster, A.; Fontaine, G.; Füssling, M.; Gabici, S.; Gallant, Y. A.; Gérard, L.; Gerbig, D.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Goret, P.; Güring, D.; Hampf, D.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hoffmann, A.; Hofmann, W.; Hofverberg, P.; Holleran, M.; Hoppe, S.; Horns, D.; Jacholkowska, A.; de Jager, O. C.; Jahn, C.; Jung, I.; Katarzynski, K.; Katz, U.; Kaufmann, S.; Kerschhaggl, M.; Khangulyan, D.; Khálifi, B.; Keogh, D.; Klochkov, D.; Kluzniak, W.; Kneiske, T.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Lamanna, G.; Lenain, J.-P.; Lohse, T.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maurin, D.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Moderski, R.; Moulin, E.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nekrassov, D.; Nguyen, N.; Nicholas, B.; Niemiec, J.; Nolan, S. J.; Ohm, S.; Olive, J.-F.; de Ona Wilhelmi, E.; Opitz, B.; Orford, K. J.; Ostrowski, M.; Panter, M.; Paz Arribas, M.; Pedaletti, G.; Pelletier, G.; Petrucci, P.-O.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raubenheimer, B. C.; Raue, M.; Rayner, S. M.; Reimer, O.; Renaud, M.; de Los Reyes, R.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Ruppel, J.; Ryde, F.; Sahakian, V.; Santangelo, A.; Schlickeiser, R.; Schück, F. M.; Schünwald, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Shalchi, A.; Sushch, I.; Sikora, M.; Skilton, J. L.; Sol, H.; Stawarz, L.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Szostek, A.; Tam, P. H.; Tavernet, J.-P.; Terrier, R.; Tibolla, O.; Tluczykont, M.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Venter, L.; Vialle, J. P.; Viana, A.; Vincent, P.; Vivier, M.; Vülk, H. J.; Volpe, F.; Vorobiov, S.; Wagner, S. J.; Ward, M.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

396

Cosmic rays and terrestrial life: A brief review  

NASA Astrophysics Data System (ADS)

“The investigation into the possible effects of cosmic rays on living organisms will also offer great interest.” - Victor F. Hess, Nobel Lecture, December 12, 1936 High-energy radiation bursts are commonplace in our Universe. From nearby solar flares to distant gamma ray bursts, a variety of physical processes accelerate charged particles to a wide range of energies, which subsequently reach the Earth. Such particles contribute to a number of physical processes occurring in the Earth system. A large fraction of the energy of charged particles gets deposited in the atmosphere, ionizing it, causing changes in its chemistry and affecting the global electric circuit. Remaining secondary particles contribute to the background dose of cosmic rays on the surface and parts of the subsurface region. Life has evolved over the past ?3 billion years in presence of this background radiation, which itself has varied considerably during the period [1-3]. As demonstrated by the Miller-Urey experiment, lightning plays a very important role in the formation of complex organic molecules, which are the building blocks of more complex structures forming life. There is growing evidence of increase in the lightning rate with increasing flux of charged particles. Is there a connection between enhanced rate of cosmic rays and the origin of life? Cosmic ray secondaries are also known to damage DNA and cause mutations, leading to cancer and other diseases. It is now possible to compute radiation doses from secondary particles, in particular muons and neutrons. Have the variations in cosmic ray flux affected the evolution of life on earth? We describe the mechanisms of cosmic rays affecting terrestrial life and review the potential implications of the variation of high-energy astrophysical radiation on the history of life on earth.

Atri, Dimitra; Melott, Adrian L.

2014-01-01

397

Cloud chamber visualization of primary cosmic rays  

SciTech Connect

From 1948 until 1963, cloud chambers were carried to the top of the atmosphere by balloons. From these flights, which were begun by Edward P. Ney at the University of Minnesota, came the following results: discovery of heavy cosmic ray nuclei, development of scintillation and cherenkov detectors, discovery of cosmic ray electrons, and studies of solar proton events. The history of that era is illustrated here by cloud chamber photographs of primary cosmic rays.

Earl, James A. [Department of Astronomy, University of Maryland, College Park MD (United States)

2013-02-07

398

Very-high energy gamma-ray astronomy. A 23-year success story in high-energy astroparticle physics  

NASA Astrophysics Data System (ADS)

Very-high energy (VHE) gamma quanta contribute only a minuscule fraction - below one per million - to the flux of cosmic rays. Nevertheless, being neutral particles they are currently the best "messengers" of processes from the relativistic/ultra-relativistic Universe because they can be extrapolated back to their origin. The window of VHE gamma rays was opened only in 1989 by the Whipple collaboration, reporting the observation of TeV gamma rays from the Crab nebula. After a slow start, this new field of research is now rapidly expanding with the discovery of more than 150 VHE gamma-ray emitting sources. Progress is intimately related with the steady improvement of detectors and rapidly increasing computing power. We give an overview of the early attempts before and around 1989 and the progress after the pioneering work of the Whipple collaboration. The main focus of this article is on the development of experimental techniques for Earth-bound gamma-ray detectors; consequently, more emphasis is given to those experiments that made an initial breakthrough rather than to the successors which often had and have a similar (sometimes even higher) scientific output as the pioneering experiments. The considered energy threshold is about 30 GeV. At lower energies, observations can presently only be performed with balloon or satellite-borne detectors. Irrespective of the stormy experimental progress, the success story could not have been called a success story without a broad scientific output. Therefore we conclude this article with a summary of the scientific rationales and main results achieved over the last two decades.

Lorenz, E.; Wagner, R.

2012-08-01

399

Propagation of cosmic rays in the galaxy  

NASA Technical Reports Server (NTRS)

The characteristics of a model for analyzing the propagation of cosmic rays are discussed. The requirements for analyzing the relevant observational data on cosmic rays are defines as: (1) the chemical and isotopic composition of cosmic rays as a function of energy, (2) the flux and energy spectrum of the individual nucleonic components, (3) the flux and energy spectrum of the electronic component, (4) the cosmic ray prehistory, and (5) the degree of isotropy in their arrival directions as a function of energy. It is stated that the model which has been able to bring to pass the greatest measure of success is the galactic confinement model.

Daniel, R. R.; Stephens, S. A.

1974-01-01

400

A hysteresis effect in cosmic ray modulation  

NASA Technical Reports Server (NTRS)

The rigidity dependence is investigated in the modulation of cosmic ray protons and alphas at intermediate (2-13 Gv) rigidities during the declines and recoveries of the cosmic ray flux near cosmic ray minimum. The results include the finding that sudden changes in the modulation of the primary cosmic rays are initiated by large solar particle outflow and begin as type I Forbush decreases. Typically, the modulation spectrum becomes flatter at intermediate rigidity below 13 Gv and steeper at rigidities above 13 Gv during early recovery.

Verschell, H. J.; Mendell, R. B.; Korff, S. A.

1974-01-01

401

The Interstellar Transport of Galactic Cosmic Rays.  

E-print Network

??Using the Cosmic Ray Isotope Spectrometer: CRIS) onboard the Advanced Composition Explorer: ACE) spacecraft, new and improved high-precision measurements of the elemental composition and energy… (more)

Lave, Kelly

2012-01-01

402

Radiation processing with high-energy X-rays  

NASA Astrophysics Data System (ADS)

The radiation processing of materials and commercial products with high-energy X-rays, which are also identified by the German term bremsstrahlung, can produce beneficial changes that are similar to those obtained by irradiation with nuclear gamma rays emitted by cobalt-60 sources. Both X-rays and gamma rays are electromagnetic radiations with short wavelengths and high photon energies that can stimulate chemical reactions by creating ions and free radicals in irradiated materials. Nevertheless, there are some physical differences in these energy sources that can influence the choice for practical applications. The English translation of bremsstrahlung is braking radiatiorn or deceleration radiation. It is produced when energetic electrons are deflected by the strong electric field near an atomic nucleus. The efficiency for producing this kind of electromagnetic energy increases with the kinetic energy of the electrons and the atomic number of the target material. The energy spectrum of the emitted X-ray photons is very broad and extends up to the maximum energy of the incident electrons. In contrast, a cobalt-60 nucleus emits two gamma rays simultaneously, which have well-defined energies. Another significant difference is the angular distribution of the radiation. Nuclear gamma rays are emitted in all directions, but high-energy bremsstrahlung photons are concentrated in the direction of the incident electrons when they strike the target material. This property enables an X-ray processing facility to be more compact than a gamma-ray processing facility with similar throughput capacity, and it increases the penetration and the efficiency for absorbing the emitted X-ray energy in the irradiated material. Recent increases in the electron energy and the electron beam power from modern industrial accelerators have increased the throughput rates in X-ray processing facilities, so that this irradiation method is now economically competitive with large cobalt-60 facilities. Several industrial facilities are now equipped to provide radiation processing with X-rays. This paper describes the characteristics of high-energy, high-power X-rays, and some practical applications in curing polymeric materials with this kind of radiation.

Cleland, Marshall R.; Stichelbaut, Frédéric

2013-03-01

403

Cosmic ray diffusion: Report of the Workshop in Cosmic Ray Diffusion Theory  

NASA Technical Reports Server (NTRS)

A workshop in cosmic ray diffusion theory was held at Goddard Space Flight Center on May 16-17, 1974. Topics discussed and summarized are: (1) cosmic ray measurements as related to diffusion theory; (2) quasi-linear theory, nonlinear theory, and computer simulation of cosmic ray pitch-angle diffusion; and (3) magnetic field fluctuation measurements as related to diffusion theory.

Birmingham, T. J.; Jones, F. C.

1975-01-01

404

Gamma and cosmic-ray tests of special relativity  

NASA Astrophysics Data System (ADS)

Lorentz symmetry violation (LSV) at Planck scale can be tested (see e.g. physics/0003080) through ultra-high energy cosmic rays (UHECR). In a deformed Lorentz symmetry (DLS) pattern where the effective LSV parameter varies like the square of the momentum scale (quadratically deformed relativistic kinematics, QDRK), a ~10-6 LSV at Planck scale would be enough to produce observable effects on the properties of cosmic rays at the ~1020 eV scale: absence of GZK cutoff, stability of unstable particles, lower interaction rates, kinematical failure of any parton model and of standard formulas for Lorentz contraction and time dilation... . Its phenomenological implications are compatible with existing data. If the effective LSV parameter is taken to vary linearly with the momentum scale (linearly deformed relativistic kinematics, LDRK), a LSV at Planck scale larger than ~10-7 seems to lead to contradictions with data above ~ TeV energies. Consequences are important for high-energy gamma-ray experiments, as well as for high-energy cosmic rays and gravitational waves. .

Gonzalez-Mestres, Luis

2001-04-01

405

Lunar monitoring outpost of cosmic rays  

NASA Astrophysics Data System (ADS)

The basic purpose of the planned NEUTRONIUM-100 experiment considers expansion of the direct measurements of cosmic rays spectra and anisotropy to the energy range of ~1017 eV with element-by-element resolution of the nuclear component. These measurements will make it possible to solve the problem of the “knee” of the spectrum and to make choice between the existing models of the cosmic rays origin and propagation. The proposed innovative method of energy measurements is based on the simultaneous detection of different components of back scattered radiation generated by showers produced by the primary particle in the regolyth (neutrons, gamma rays and radio waves). A multi-module system disposed on the Moon's surface is proposed for particles registration. Each module consists of a radio antenna, contiguous to the regolyth, scintillation detectors with gadolinium admixture and silicon charge detectors. Scintillation detectors record electrons and gamma-rays of back scattered radiation and delayed neutrons. The area of the experimental facility will be at least ~100 m2, suitable for upgrading. Average density of the detecting equipment is evaluated as 10-20 g/m2. Taking into account the weight of the equipment delivered from the Earth will be about 10 tons it is possible to compose an eqperimental facility with geometric factor of 150-300 m2sr. The Moon provides unique conditions for this experiment due to presence of the absorbing material and absence of atmosphere. The experiment will allow expansion of the measurements up to ~1017 eV with element-by-element resolution of the nuclear component. Currently direct measurements reach energy range of up to ~1015 eV, and Auger shower method does not provide information about the primary particle's charge. It is expected that ~15 particles with energy >1017 eV will be detected by the proposed experimental equipment per year. It will provide an opportunity to solve the problems of the current high-energy astrophysics.

Panasyuk, Mikhail; Kalmykov, Nikolai; Turundaevskiy, Andrey; Chubenko, Alexander; Podorozhny, Dmitry; Mukhamedshin, Rauf; Sveshnikova, Lubov; Tkachev, Leonid; Konstantinov, Andrey

406

Cosmic Rays and the Search for a Lorentz Invariance Violation  

E-print Network

This is an introductory review about the on-going search for a signal of Lorentz Invariance Violation (LIV) in cosmic rays. We first summarise basic aspects of cosmic rays, focusing on rays of ultra high energy (UHECRs). We discuss the Greisen-Zatsepin-Kuz'min (GZK) energy cutoff for cosmic protons, which is predicted due to photopion production in the Cosmic Microwave Background (CMB). This is a process of modest energy in the proton rest frame. It can be investigated to a high precision in the laboratory, if Lorentz transformations apply even at factors $\\gamma \\sim O(10^{11})$. For heavier nuclei the energy attenuation is even faster due to photo-disintegration, again if this process is Lorentz invariant. Hence the viability of Lorentz symmetry up to tremendous gamma-factors - far beyond accelerator tests - is a central issue. Next we comment on conceptual aspects of Lorentz Invariance and the possibility of its spontaneous breaking. This could lead to slightly particle dependent ``Maximal Attainable Velocities''. We discuss their effect in decays, Cerenkov radiation, the GZK cutoff and neutrino oscillation in cosmic rays. We also review the search for LIV in cosmic gamma-rays. For multi TeV gamma-rays we possibly encounter another puzzle related to the transparency of the CMB, similar to the GZK cutoff. The photons emitted in a Gamma Ray Burst occur at lower energies, but their very long path provides access to information not far from the Planck scale. No LIV has been observed so far. However, even extremely tiny LIV effects could change the predictions for cosmic ray physics drastically. An Appendix is devoted to the recent hypothesis by the Pierre Auger Collaboration, which identifies nearby Active Galactic Nuclei - or objects next to them - as probable UHECR sources.

Wolfgang Bietenholz

2008-06-23

407

A search for high energy gamma-ray bursts  

NASA Astrophysics Data System (ADS)

For the purpose to register high energy gamma-ray bursts (with gammas energy above 10 GeV) the single counting rate of the EAS "Andyrchy" array was used. The independent sky survey for 1996-2001 years is performed by searching for short increases of counting rate. The results of a search for coincident events at the time of GRBs detected by BATSE are presented.

Alekseenko, V.; Chernyaev, A.; Petkov, V.; Poddubny, V.; Radchenkov, A.; Zaichenko, A.

408

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 w...

Widom, A; Srivastava, Y N

2014-01-01

409

Cosmic-ray neutron simulations and measurements in Taiwan.  

PubMed

This study used simulations of galactic cosmic ray in the atmosphere to investigate the neutron background environment in Taiwan, emphasising its altitude dependence and spectrum variation near interfaces. The calculated results were analysed and compared with two measurements. The first measurement was a mobile neutron survey from sea level up to 3275 m in altitude conducted using a car-mounted high-sensitivity neutron detector. The second was a previous measured result focusing on the changes in neutron spectra near air/ground and air/water interfaces. The attenuation length of cosmic-ray neutrons in the lower atmosphere was estimated to be 163 g cm(-2) in Taiwan. Cosmic-ray neutron spectra vary with altitude and especially near interfaces. The determined spectra near the air/ground and air/water interfaces agree well with measurements for neutrons below 10 MeV. However, the high-energy portion of spectra was observed to be much higher than our previous estimation. Because high-energy neutrons contribute substantially to a dose evaluation, revising the annual sea-level effective dose from cosmic-ray neutrons at ground level in Taiwan to 35 ?Sv, which corresponds to a neutron flux of 5.30 × 10(-3) n cm(-2) s(-1), was suggested. PMID:24573968

Chen, Wei-Lin; Jiang, Shiang-Huei; Sheu, Rong-Jiun

2014-10-01

410

High energy neutrino absorption and its effects on stars in close x-ray binaries  

SciTech Connect

The physics and astrophysics of high energy neutrino production and interactions in close x-ray binary systems are studied. These studies were stimulated by recent observations of ultrahigh energy gamma rays and possibly other ultrahigh energy particles coming from the directions of Cygnus X-3 and other binary systems and possessing the periodicity characteristics of these systems. Systems in which a compact object, such as a neutron star, is a strong source of high energy particles which, in turn, produce photons, neutronos and other secondary particles by interactions in the atmosphere of the companion star were considered. The highest energy neutrinos are absorbed deep in the companion and the associated energy deposition may be large enough to effect its structure or lead to its ultimate disruption. This neutrino heating was evaluated, starting with a detailed numerical calculation of the hadronic cascade induced in the atmosphere of the companion star. For some theoretical models, the resulting energy deposition from neutrino absorption may be so great as to disrupt the companion star over an astronomically small timescale of the order of 10,000 years. Even if the energy deposition is smaller, it may still be high enough to alter the system substantially, perhaps leading to quenching of high energy signals from the source. Given the cosmic ray luminosities required to produce the observed gamma rays from cygnus X-3 and LMX X-4, such a situation may occur in these sources.

Gaisser, T.K.; Stecker, F.W.

1986-07-01

411

High energy neutrino absorption and its effects on stars in close X-ray binaries  

NASA Technical Reports Server (NTRS)

The physics and astrophysics of high energy neutrino production and interactions in close X-ray binary systems are studied. These studies were stimulated by recent observations of ultrahigh energy gamma-rays and possibly other ultrahigh energy particles coming from the directions of Cygnus X-3 and other binary systems and possessing the periodicity characteristics of these systems. Systems in which a compact object, such as a neutron star, is a strong source of high energy particles which, in turn, produce photons, neutronos and other secondary particles by interactions in the atmosphere of the companion star were considered. The highest energy neutrinos are absorbed deep in the companion and the associated energy deposition may be large enough to effect its structure or lead to its ultimate disruption. This neutrino heating was evaluated, starting with a detailed numerical calculation of the hadronic cascade induced in the atmosphere of the companion star. For some theoretical models, the resulting energy deposition from neutrino absorption may be so great as to disrupt the companion star over an astronomically small timescale of the order of 10,000 years. Even if the energy deposition is smaller, it may still be high enough to alter the system substantially, perhaps leading to quenching of high energy signals from the source. Given the cosmic ray luminosities required to produce the observed gamma rays from cygnus X-3 and LMX X-4, such a situation may occur in these sources.

Gaisser, T. K.; Stecker, F. W.

1986-01-01

412

Very high energy gamma-ray emission from Tycho's supernova remnant  

NASA Astrophysics Data System (ADS)

Supernova remnant (SNR) G120.1+1.4 (also known as Tycho's SNR) is the remnant of one of only five confirmed historical supernovae. As such, it has been well studied across the electromagnetic spectrum. This thesis describes the first statistically significant detection of very high energy (VHE) (˜ 100 GeV to 100 TeV) gamma rays from Tycho's SNR, reported in 2011 by the VERITAS collaboration. The analysis that led to that detection was performed by this author, and this dissertation will discuss the process in detail. Subsequently, a statistically significant detection in high energy (HE) (˜ 30 MeV to 100 GeV) gamma rays was reported by other authors using data from the Fermi Gamma-Ray Space Telescope. Comparison of models to the spectral energy distribution of the photon flux from this remnant in HE and VHE gamma rays favors a hadronic origin for the emission, particularly when combined with current X-ray data, although a leptonic origin cannot be ruled out at this time. This is significant because a confirmed hadronic origin for the gamma-ray emission would identify this SNR as a site of cosmic ray acceleration, providing observational evidence for the idea that SNRs are the source of the Galactic cosmic ray population. Chapter 1 of this dissertation will provide historical background on Tycho's SNR, along with a summary of modern observations of the remnant across the electromagnetic spectrum. Chapter 2 is a discussion of the role played by SNRs in the process of cosmic ray acceleration, including both theoretical underpinnings and observational evidence. Chapter 3 provides an overview of the field of VHE gamma-ray astronomy, with discussions of gamma-ray production mechanisms and gamma-ray source classes. Chapter 4 describes the instruments used to observe HE and VHE gamma rays. Chapter 5 is a discussion of general analysis methods and techniques for data from Imaging Atmospheric Cherenkov Telescopes (IACTs). Chapter 6 provides details about the specific analysis I completed on VERITAS data on Tycho's SNR. Lastly, Chapter 7 discusses the modeling and interpretation of the VHE Tycho detection in the context of current multiwavelength observational results.

Saxon, Dana Boltuch

413

CHEMICAL COMPOSITION AND MAXIMUM ENERGY OF GALACTIC COSMIC RAYS  

SciTech Connect

A model of the cosmic-ray energy spectrum is proposed that assumes various acceleration limits at multiple sources. The model describes the broken power-law energy spectrum of cosmic rays by superposition of multiple sources; a diffusive shock acceleration mechanism plays an essential role. The maximum energy of galactic cosmic rays is discussed based on a comparison of experimental data with calculations done using the proposed model. The model can describe the energy spectrum at very high energies of up to several times 10{sup 18} eV, but the observed highest-energy cosmic rays deviate from the model predictions, indicating a different origin, such as an extragalactic source. This model describes the steepening of the power index at the so-called knee. However, it was found that additional assumptions are needed to explain the sharpness of the knee. Two possible explanations for the structure of the knee are discussed in terms of nearby source(s) and the hard energy spectrum suggested by nonlinear effects of cosmic-ray acceleration mechanisms.

Shibata, M.; Katayose, Y. [Department of Physics, Yokohama National University, Yokohama 240-8501 (Japan); Huang, J. [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Chen, D., E-mail: mshibata@ynu.ac.j [Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582 (Japan)

2010-06-20

414

Simulation of Cosmic Ray neutrinos Interactions in Water  

E-print Network

The program CORSIKA, usually used to simulate extensive cosmic ray air showers, has been adapted to a water medium in order to study the acoustic detection of ultra high energy neutrinos. Showers in water from incident protons and from neutrinos have been generated and their properties are described. The results obtained from CORSIKA are compared to those from other available simulation programs such as Geant4.

T. Sloan

2006-10-09

415

Radiographic Images Produced by Cosmic-Ray Muons  

SciTech Connect

An application of high energy physics instrumentation is to look for structure or different densities (materials) hidden in a matrix (tons) of material. By tracing muons produced by primary Cosmic Rays, it has been possible to generate a kind of radiographs which shows the inner structure of dense containers, monuments or mountains. In this paper I review the basics principles of such techniques with emphasis in the Sun Pyramid project, carried out by IFUNAM in collaboration with Instituto Nacioanal de Antropologia e Historia.

Alfaro, Ruben [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, 01000, Mexico D.F. (Mexico)

2006-09-25

416

Very high energy gamma ray extension of GRO observations  

NASA Technical Reports Server (NTRS)

This has been an exiciting year for high energy gamma-ray astronomy, both from space and from ground-based observatories. It has been a particularly active period for the Whipple Observatory gamma-ray group. In phase 1 of the Compton Gamma Ray Observatory (GRO), there has not been too much opportunity for overlapping observations with the Energetic Gamma Ray Experiment Telescope (EGRET) and the other GRO telescopes; however, significant progress was made in the development of data analysis techniques and in improving the sensitivity of the technique which will have direct application in correlative observations in phase 2. Progress made during the period 1 Jul. 1991 - 31 Dec. 1991 is presented.

Weekes, Trevor C.

1992-01-01

417

PeV neutrinos from intergalactic interactions of cosmic rays emitted by active galactic nuclei.  

PubMed

The observed very high energy spectra of distant blazars are well described by secondary gamma rays produced in line-of-sight interactions of cosmic rays with background photons. In the absence of the cosmic-ray contribution, one would not expect to observe very hard spectra from distant sources, but the cosmic ray interactions generate very high energy gamma rays relatively close to the observer, and they are not attenuated significantly. The same interactions of cosmic rays are expected to produce a flux of neutrinos with energies peaked around 1 PeV. We show that the diffuse isotropic neutrino background from many distant sources can be consistent with the neutrino events recently detected by the IceCube experiment. We also find that the flux from any individual nearby source is insufficient to account for these events. The narrow spectrum around 1 PeV implies that some active galactic nuclei can accelerate protons to EeV energies. PMID:23931348

Kalashev, Oleg E; Kusenko, Alexander; Essey, Warren

2013-07-26

418