Sample records for cosmic ray detection

  1. Ultrahigh Energy Cosmic Rays Detection

    E-print Network

    Carla Aramo

    2005-09-06

    The paper describes methods used for the detection of cosmic rays with energies above 10^18 eV (UHECR, UltraHigh Energy Cosmic Rays). It had been anticipated there would be a cutoff in the energy spectrum of primary cosmic rays around 3 10^19 eV induced by their interaction with the 2.7 K primordial photons. This has become known as the GZK cutoff. However, several showers have been detected with estimated primary energy exceeding this limit.

  2. 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).

  3. Research Concerning Detection of Cosmic Rays

    Microsoft Academic Search

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

    2010-01-01

    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

  4. Research Concerning Detection of Cosmic Rays

    NASA Astrophysics Data System (ADS)

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

    2010-02-01

    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. )

  5. Cosmic Ray Muon Radiography for Contraband Detection.

    SciTech Connect

    Schultz, Larry J.; Borozdin, Konstantin N.; Gomez, John J.; Hogan, Gary E.; Morris, Chris L.; Priedhorsky, William C.; Saunders, Alexander

    2003-07-11

    The threat of the detonation of a nuclear device in a major US city has prompted research aimed at providing more robust border surveillance for contraband nuclear material. Existing radiographic techniques are inefficient for the detection of shielded material. These techniques also involve radiation hazards, real and perceived. We have invented a new technique which is capable of passively detecting small quantities of shielded SNM in a short time by using the multiple scattering of cosmic ray muons as a radiographic probe. A chief advantage of this technique is that no artificial dose is applied to the object being radiographed. We describe the technique and discuss experimental and simulated results.

  6. Fibre laser hydrophones for cosmic ray particle detection

    NASA Astrophysics Data System (ADS)

    Buis, E. J.; Doppenberg, E. J. J.; Nieuwland, R. A.; Toet, P. M.

    2014-03-01

    The detection of ultra high energetic cosmic neutrinos provides a unique means to search for extragalactic sources that accelerate particles to extreme energies. It allows to study the neutrino component of the GZK cut-off in the cosmic ray energy spectrum and the search for neutrinos beyond this limit. Due to low expected flux and small interaction cross-section of neutrinos with matter large experimental set-ups are needed to conduct this type of research. Acoustic detection of cosmic rays may provide a means for the detection of ultra-high energetic neutrinos. Using relative low absorption of sound in water, large experimental set-ups in the deep sea are possible that are able to detect these most rare events, but it requires highly sensitive hydrophones as the thermo-acoustic pulse originating from a particle shower in water has a typical amplitude as low as a mPa. It has been shown in characterisation measurements that the fibre optic hydrophone technology as designed and realised at TNO provides the required sensitivity. Noise measurements and pulse reconstruction have been conducted that show that the hydrophone is suited as a particle detector.

  7. Student Projects in Cosmic Ray Detection

    ERIC Educational Resources Information Center

    Brouwer, W.; Pinfold, J.; Soluk, R.; McDonough, B.; Pasek, V.; Bao-shan, Zheng

    2009-01-01

    The Alberta Large-area Time-coincidence Array (ALTA) study has been in existence for about 10 years under the direction of Jim Pinfold of the Centre for Particle Physics at the University of Alberta. The purpose of the ALTA project is to involve Alberta high schools, and primarily their physics classes, to assist in the detection of the presence…

  8. The Renaissance of Radio Detection of Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Huege, Tim

    2014-10-01

    Nearly 50 years ago, the first radio signals from cosmic ray air showers were detected. After many successful studies, however, research ceased not even 10 years later. Only a decade ago, the field was revived with the application of powerful digital signal processing techniques. Since then, the detection technique has matured, and we are now in a phase of transition from small-scale experiments accessing energies below 10 18 eV to experiments with a reach for energies beyond 10 19 eV. We have demonstrated that air shower radio signals carry information on both the energy and the mass of the primary particle, and current experiments are in the process of quantifying the precision with which this information can be accessed. All of this rests on solid understanding of the radio emission processes which can be interpreted as a coherent superposition of geomagnetic emission, Askaryan charge-excess radiation, and Cherenkov-like coherence effects arising in the density gradient of the atmosphere. In this article, I highlight the "state of the art" of radio detection of cosmic rays and briefly discuss its perspectives for the next few years.

  9. Cosmic Ray Inspection and Passive Tomography for SNM Detection

    SciTech Connect

    Armitage, John; Oakham, Gerald [Department of Physics, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6 (Canada); Bryman, Douglas [Advanced Applied Physics Solutions, 4004 Westbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Cousins, Thomas; Noeel, Scott [International Safety Research, 38 Colonnade Rd. N. Ottawa, ON, K2E 7J6 (Canada); Gallant, Grant [Canadian Border Services Agency, Laboratory and Scientific Services Directorate, 79 Bentley Avenue, Ottawa, ON, K2E 6T7 (Canada); Jason, Andrew [Los Alamos National Laboratories, MS H817, Los Alamos National Laboratory, Los Alamos, NM, USA 87544 (United States); Jonkmans, Guy [Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, ON, K0J 1J0 (Canada); Stocki, Trevor J. [Radiation Protection Bureau, Health Canada, 775 BrookfieldRd, A.L. 6302D1, Ottawa, ON, K1A 1C1 (Canada); Waller, David [Defence Research and Development Canada-Ottawa, 3701 Carling Avenue, Ottawa, ON, K1A 0Z4 (Canada)

    2009-12-02

    The Cosmic Ray Inspection and Passive Tomography (CRIPT) project has recently started investigating the detection of illicit Special Nuclear Material in cargo using cosmic ray muon tomography and complementary neutron detectors. We are currently performing simulation studies to help with the design of small scale prototypes. Based on the prototype tests and refined simulations, we will determine whether the muon tracking system for the full scale prototype will be based on drift chambers or extruded scintillator trackers. An analysis of the operations of the Port of Montreal has determined how long muon scan times should take if all or a subset of the cargo is to be screened. As long as the throughput of the muon system(s) is equal to the rate at which containers are unloaded from ships, the impact on port operations would not be great if a muon scanning stage were required for all cargo. We also show preliminary simulation results indicating that excellent separation between Al, Fe and Pb is possible under ideal conditions. The discrimination power is reduced but still significant when realistic momentum resolution measurements are considered.

  10. Cosmic rays detected with the Auger Engineering Radio Array

    NASA Astrophysics Data System (ADS)

    Schoorlemmer, H.

    2012-08-01

    At the Pierre Auger Observatory in Argentina, the first stage of the Auger Engineering Radio Array (AERA) has been deployed. It is located close to the low-energy enhancements of the observatory and currently consists of 24 autonomous radio detector stations. In the coming years, the number of detection stations will grow to 160 units covering almost 20 km2. Since April of this year AERA is measuring radio emission from cosmic-ray induced air showers. These measurements are confirmed by simultaneous measurements of the particle detectors and the fluorescence telescopes of the observatory. AERA will provide us with new insights on the radio emission mechanisms of air showers with energies above 1017 eV.

  11. Feasibility of cosmic-ray muon intensity measurements for tunnel detection

    Microsoft Academic Search

    Aivars Celmins

    1990-01-01

    Subsurface cosmic-ray muon intensity depends on the amount of material above the point of reference and is therefore influenced by anomalies in rock density. Because such anomalies might be caused by geological structures (e.g. ore bodies), cosmic-ray intensity measurements have been used for geophysical exploration. Recently, cosmic-ray muon intensity measurements have been also proposed as a method to detect tunnels.

  12. The renaissance of radio detection of cosmic rays

    E-print Network

    Huege, Tim

    2013-01-01

    Nearly 50 years ago, the first radio signals from cosmic ray air showers were detected. After many successful studies, however, research ceased not even 10 years later. Only a decade ago, the field was revived with the application of powerful digital signal processing techniques. Since then, the detection technique has matured, and we are now in a phase of transition from small-scale experiments accessing energies below 1018 eV to experiments with a reach for energies beyond 1019 eV. We have demonstrated that air shower radio signals carry information on both the energy and the mass of the primary particle, and current experiments are in the process of quantifying the precision with which this information can be accessed. All of this rests on a solid understanding of the radio emission processes which can be interpreted as a coherent superposition of geomagnetic emission, Askaryan charge-excess radiation, and Cherenkov-like coherence effects arising in the density gradient of the atmosphere. In this article, ...

  13. COSMIC-RAY MUON TOMOGRAPHY AND ITS APPLICATION TO THE DETECTION OF HIGH-Z MATERIALS

    E-print Network

    Kurien, Susan

    COSMIC-RAY MUON TOMOGRAPHY AND ITS APPLICATION TO THE DETECTION OF HIGH-Z MATERIALS Konstantin University of South Carolina, 712 Main Street, Columbia, SC 29208 ABSTRACT Each minute, about 10000 muons rays striking the upper atmosphere. Millions of highly penetrative muons pass through our bodies, cars

  14. Measurement of Cosmic-Ray Muon-Capture X-Rays and Application to Nuclear Material Detection

    NASA Astrophysics Data System (ADS)

    Shimbara, Y.; Matsuzaki, T.; Abe, K.; Haga, K.; Homma, A.; Kikukawa, N.; Murooka, D.; Nagashima, M.; Nakamura, Y.; Ogura, T.; Sakai, T.; Sera, D.; Tashiro, K.; Goto, J.; Ito, J.; Kato, S.; Ohtsubo, T.; Ohya, S.; Takeda, K.; Tsurumaki, Y.; Yajima, A.; Yoshikawa, T.; Itoh, T.; Tanaka, M.; Suzuki, S.; Yanagi, K.

    2015-10-01

    Muonic X-ray measurement by the use of cosmic muon has a potential to identify nuclear material in containers. We performed a feasibility study by using an iron target. Two plastic scintillators detected incoming cosmic-ray muons and a veto scintillator identified muons stopped in the target. Germanium detectors in coincidence with the scintillators measured muonic X-ray energies. We clearly observed muonic X-ray peaks in the photon spectrum, of which the energies were consistent with known muonic X-ray energies. By using the obtained spectrum, input parameters of the Monte-Carlo simulation were checked. The simulation for uranium target showed that this method is promising.

  15. FPGA Based Wavelet Trigger in Radio Detection of Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Szadkowski, Zbigniew; Szadkowska, Anna

    2014-09-01

    Experiments which show coherent radio emission from extensive air showers induced by ultra-high-energy cosmic rays are designed for a detailed study of the development of the electromagnetic part of air showers. Radio detectors can operate with 100 % up time as, e.g., surface detectors based on water-Cherenkov tanks. They are being developed for ground-based experiments (e.g., the Pierre Auger Observatory) as another type of air-shower detector in addition to fluorescence detectors, which operate with only ˜10 % of duty on dark nights. The radio signals from air showers are caused by coherent emission from geomagnetic radiation and charge-excess processes. The self-triggers in radio detectors currently in use often generate a dense stream of data, which is analyzed afterwards. Huge amounts of registered data require significant manpower for off-line analysis. Improvement of trigger efficiency is a relevant factor. The wavelet trigger, which investigates on-line the power of radio signals (˜V2/R), is promising; however, it requires some improvements with respect to current designs. In this work, Morlet wavelets with various scaling factors were used for an analysis of real data from the Auger Engineering Radio Array and for optimization of the utilization of the resources in an FPGA. The wavelet analysis showed that the power of events is concentrated mostly in a limited range of the frequency spectrum (consistent with a range imposed by the input analog band-pass filter). However, we found several events with suspicious spectral characteristics, where the signal power is spread over the full band-width sampled by a 200 MHz digitizer with significant contribution of very high and very low frequencies. These events may not originate from cosmic ray showers but could be the result of human contamination. The engine of the wavelet analysis can be implemented in the modern powerful FPGAs and can remove suspicious events on-line to reduce the trigger rate.

  16. FPGA Based Wavelet Trigger in Radio Detection of Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Szadkowski, Zbigniew; Szadkowska, Anna

    2014-12-01

    Experiments which show coherent radio emission from extensive air showers induced by ultra-high-energy cosmic rays are designed for a detailed study of the development of the electromagnetic part of air showers. Radio detectors can operate with 100 % up time as, e.g., surface detectors based on water-Cherenkov tanks. They are being developed for ground-based experiments (e.g., the Pierre Auger Observatory) as another type of air-shower detector in addition to fluorescence detectors, which operate with only ˜10 % of duty on dark nights. The radio signals from air showers are caused by coherent emission from geomagnetic radiation and charge-excess processes. The self-triggers in radio detectors currently in use often generate a dense stream of data, which is analyzed afterwards. Huge amounts of registered data require significant manpower for off-line analysis. Improvement of trigger efficiency is a relevant factor. The wavelet trigger, which investigates on-line the power of radio signals (˜ V2/ R), is promising; however, it requires some improvements with respect to current designs. In this work, Morlet wavelets with various scaling factors were used for an analysis of real data from the Auger Engineering Radio Array and for optimization of the utilization of the resources in an FPGA. The wavelet analysis showed that the power of events is concentrated mostly in a limited range of the frequency spectrum (consistent with a range imposed by the input analog band-pass filter). However, we found several events with suspicious spectral characteristics, where the signal power is spread over the full band-width sampled by a 200 MHz digitizer with significant contribution of very high and very low frequencies. These events may not originate from cosmic ray showers but could be the result of human contamination. The engine of the wavelet analysis can be implemented in the modern powerful FPGAs and can remove suspicious events on-line to reduce the trigger rate.

  17. Cosmic Rays

    NSDL National Science Digital Library

    Mendez, J.

    This series of web pages, authored and curated by David P. Stern, 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.

  18. Detecting Radio Emission from Cosmic Ray Air Showers and Neutrinos with a Digital Radio Telescope

    E-print Network

    Heino Falcke; Peter Gorham

    2002-07-10

    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 use the radio emission as a useful diagnostic tool for cosmic ray research. A new generation of digital telescopes will make it possible to study this radio emission in greater detail. For example, the planned Low-Frequency Array (LOFAR), operating at 10-200 MHz, will be an instrument uniquely suited to study extensive air showers and even detect neutrino-induced showers on the moon. We discuss sensitivities, count rates and possible detection algorithms for LOFAR and a currently funded prototype station LOPES. This should also be applicable to other future digital radio telescopes such as the Square-Kilometer-Array (SKA). LOFAR will be capable of detecting air-shower radio emission from >2*10^14 eV to ~10^20 eV. The technique could be easily extended to include air shower arrays consisting of particle detectors (KASCADE, Auger), thus providing crucial additional information for obtaining energy and chemical composition of cosmic rays. It also has the potential to extend the cosmic ray search well beyond an energy of 10^21 eV if isotropic radio signatures can be found. Other issues that LOFAR can address are to determine the neutral component of the cosmic ray spectrum, possibly look for neutron bursts, and do actual cosmic ray astronomy.

  19. Feasibility of cosmic-ray-muon intensity measurements for tunnel detection. Final report, February 1989February 1990

    Microsoft Academic Search

    Celmins

    1990-01-01

    Subsurface cosmic-ray muon intensity depends on the amount of material above the point of reference and is therefore influenced by anomalies in rock density. Because such anomalies might be caused by geological structures (e.g. ore bodies), cosmic-ray intensity measurements have been used for geophysical exploration. Recently, cosmic-ray muon intensity measurements have been also proposed as a method to detect tunnels.

  20. Detecting X-ray Synchrotron Emission in Supernova Remnants: Implications for Abundances and Cosmic Rays

    E-print Network

    Kristy K. Dyer; Stephen P. Reynolds; Kazik J. Borkowski; Robert Petre

    2000-11-30

    The 10^51 ergs released in a supernova have far reaching consequences in the galaxy, determining elemental abundances, accelerating cosmic rays, and affecting the makeup of the interstellar medium. Recently the spectra of several supernova remnants have been found to be dominated by nonthermal emission. Separating the thermal and nonthermal components is important not only for the understanding of cosmic-ray acceleration and shock microphysics properties but for accurate assessment of the temperatures and line strengths. New models designed to model spatially resolved synchrotron X-rays from type Ia supernovae can contribute to the understanding of both the thermal physics (dynamics, abundances) and nonthermal physics (shock acceleration, magnetic-field amplification) of supernova remnants. I will describe model fits to SN 1006, emphasizing the physical constraints that can be placed on SNRs, abundances, and the cosmic-ray acceleration process.

  1. Lunar detection of ultra-high-energy cosmic rays and neutrinos with the Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    Bray, J.; Alvarez-Muniz, J.; Buitink, S.; Dagkesamanskii, R.; Ekers, R. D.; Falcke, H. D. E.; Gayley, K.; Huege, T.; James, C. W.; Mevius, M.; Mutel, R.; Protheroe, R. J.; Scholten, O.; Schroeder, F.; Spencer, R. E.; ter Veen, S.

    The origin of the most energetic particles in nature, the ultra-high-energy (UHE) cosmic rays, is still a mystery. Only the most energetic of these have sufficiently small angular deflections to be used for directional studies, and their flux is so low that even the 3,000 km^2 Pierre Auger detector registers only about 30 cosmic rays per year of these energies. A method to provide an even larger aperture is to use the lunar Askaryan technique, in which ground-based radio telescopes search for the nanosecond radio flashes produced when a cosmic ray interacts with the Moon's surface. The technique is also sensitive to UHE neutrinos, which may be produced in the decays of topological defects from the early universe. Observations with existing radio telescopes have shown that this technique is technically feasible, and established the required procedure: the radio signal should be searched for pulses in real time, compensating for ionospheric dispersion and filtering out local radio interference, and candidate events stored for later analysis. For the Square Kilometre Array (SKA), this requires the formation of multiple tied-array beams, with high time resolution, covering the Moon, with either SKA1-LOW or SKA1-MID. With its large collecting area and broad bandwidth, the SKA will be able to detect the known flux of UHE cosmic rays using the visible lunar surface - millions of square km - as the detector, providing sufficient detections of these extremely rare particles to address the mystery of their origin.

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

    E-print Network

    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

    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.

  3. Cosmic Rays and Experiment CZELTA

    SciTech Connect

    Smolek, Karel; Nyklicek, Michal [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Kovacikova, Petra [Faculty of Philosophy and Science, Silesian University in Opava, Bezrucovo namesti 13, 746 01 Opava (Czech Republic)

    2007-11-26

    This paper gives a review of the physics of cosmic rays with emphasis on the methods of detection and study. A summary is given of the Czech project CZELTA which is part of a multinational program to study cosmic rays with energies above 10{sup 14} eV.

  4. Detection and imaging of atmospheric radio flashes from cosmic ray air showers.

    PubMed

    Falcke, H; Apel, W D; Badea, A F; Bähren, L; Bekk, K; Bercuci, A; Bertaina, M; Biermann, P L; Blümer, J; Bozdog, H; Brancus, I M; Buitink, S; Brüggemann, M; Buchholz, P; Butcher, H; Chiavassa, A; Daumiller, K; de Bruyn, A G; de Vos, C M; Di Pierro, F; Doll, P; Engel, R; Gemmeke, H; Ghia, P L; Glasstetter, R; Grupen, C; Haungs, A; Heck, D; Hörandel, J R; Horneffer, A; Huege, T; Kampert, K-H; Kant, G W; Klein, U; Kolotaev, Y; Koopman, Y; Krömer, O; Kuijpers, J; Lafebre, S; Maier, G; Mathes, H J; Mayer, H J; Milke, J; Mitrica, B; Morello, C; Navarra, G; Nehls, S; Nigl, A; Obenland, R; Oehlschläger, J; Ostapchenko, S; Over, S; Pepping, H J; Petcu, M; Petrovic, J; Plewnia, S; Rebel, H; Risse, A; Roth, M; Schieler, H; Schoonderbeek, G; Sima, O; Stümpert, M; Toma, G; Trinchero, G C; Ulrich, H; Valchierotti, S; van Buren, J; van Cappellen, W; Walkowiak, W; Weindl, A; Wijnholds, S; Wochele, J; Zabierowski, J; Zensus, J A; Zimmermann, D

    2005-05-19

    The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10(20) eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within approximately 50 Mpc through interactions with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from unusual astrophysical sources to exotic string physics. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or gamma-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. Here we report the detection of radio flashes from cosmic-ray air showers using low-cost digital radio receivers. We show that the radiation can be understood in terms of the geosynchrotron effect. Our results show that it should be possible to determine the nature and composition of UHECRs with combined radio and particle detectors, and to detect the ultrahigh-energy neutrinos expected from flavour mixing. PMID:15902250

  5. LAT Perspectives in Detection of High Energy Cosmic Ray Electrons

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

    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.

  6. Radio detection of cosmic ray induced air showers at the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Fliescher, Stefan; Pierre Auger Collaboration

    2012-01-01

    AERA—the Auger Engineering Radio Array—is currently being set up at the southern site of the Pierre Auger Observatory. AERA will explore the potential of the radio-detection technique to cosmic ray induced air showers with respect to the next generation of large-scale surface detectors. As AERA is co-located with the low-energy enhancements of the Pierre Auger Observatory, the observation of air showers in coincidence with the Auger surface and fluorescence detector will allow to study the radio emission processes in detail and to calibrate the radio signal. Finally, the combined reconstruction of shower parameters with three independent techniques promises new insights into the nature of cosmic rays in the transition region from 1017 to 1019 eV.Besides the detection of coherent radiation in the MHz frequency range, the setups AMBER—Air-shower Microwave Bremsstrahlung Experimental Radiometer—and MIDAS—MIcrowave Detection of Air Showers—prepare to check the possibility to detect air showers due the emission of molecular bremsstrahlung in the GHz range at the Auger site.This article presents the status of the radio-detection setups and discusses their physics potential as well as experimental challenges. Special focus is laid on the first stage of AERA which is the startup to the construction of a 20 km2 radio array.

  7. Cosmic x ray physics

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  8. Cosmic x ray physics

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    The annual progress report on Cosmic X Ray Physics is presented. Topics studied include: the soft x ray background, proportional counter and filter calibrations, the new sounding rocket payload: X Ray Calorimeter, and theoretical studies.

  9. The no-reflection regime of radar detection of cosmic ray air showers

    NASA Astrophysics Data System (ADS)

    Bakunov, M. I.; Maslov, A. V.; Novokovskaya, A. L.; Kryemadhi, A.

    2015-05-01

    The ionization front of a cosmic ray air shower propagates in the atmosphere with almost the speed of light in vacuum, i.e., faster than a radio wave in the air. There can be no reflection of a radar signal from such a front. Instead, an additional transmitted wave, which travels behind the front in the backward direction, is generated. We study the frequencies, propagation directions, and amplitudes for the waves excited at the front and discuss their use for radar detection of air showers.

  10. Cosmic Ray Astronomy

    E-print Network

    Paul Sommers; Stefan Westerhoff

    2008-02-09

    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.

  11. Cosmic Rays in Thunderstorms

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  12. How Cosmic Rays Affect Humans

    NSDL National Science Digital Library

    2012-08-03

    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)."

  13. Detection of the Cosmic ?-Ray Horizon From Multiwavelength Observations of Blazars

    DOE PAGESBeta

    Dominguez, A.; Finke, J. D.; Prada, F.; Primack, J. R.; Kitaura, F. S.; Siana, B.; Paneque, D.

    2013-05-24

    The first statistically significant detection of the cosmic ?-ray horizon (CGRH) that is independent of any extragalactic background light (EBL) model is presented. The CGRH is a fundamental quantity in cosmology. It gives an estimate of the opacity of the Universe to very high energy (VHE) ?-ray photons due to photon-photon pair production with the EBL. The only estimations of the CGRH to date are predictions from EBL models and lower limits from ?-ray observations of cosmological blazars and ?-ray bursts. Here, we present homogeneous synchrotron/synchrotron self-Compton (SSC) models of the spectral energy distributions of 15 blazars based on (almost)more »simultaneous observations from radio up to the highest energy ?-rays taken with the Fermi satellite. These synchrotron/SSC models predict the unattenuated VHE fluxes, which are compared with the observations by imaging atmospheric Cherenkov telescopes. This comparison provides an estimate of the optical depth of the EBL, which allows a derivation of the CGRH through a maximum likelihood analysis that is EBL-model independent. We find that the observed CGRH is compatible with the current knowledge of the EBL.« less

  14. Radio emission from extensive air showers as a method for cosmic-ray detection

    SciTech Connect

    Kalmykov, N. N.; Konstantinov, A. A., E-mail: elan1980@mail.r [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation); Engel, R. [Karlsruhe Institute of Technology (Germany)

    2010-07-15

    At the present time, radio emission from extensive air showers (EASs) is being considered as a new promising method for detecting cosmic rays of energy in the region E{sub 0} > 5 x 10{sup 16} eV. Radio emission from an EAS whose development is simulated by the Monte Carlo method is calculated here. The field of radio emission from an EAS is calculated on the basis of two representations of a shower: that as a set of individual particles and that as a continuous set of currents. The sensitivity of radio emission to EAS parameters in the frequency range 10-100 MHz is investigated. The results can be used to analyze experiments that being presently performed (CODALEMA and LOPES) and those that are being planned for the future.

  15. Development of a two-fold segmented detection system for near horizontally cosmic-ray muons to probe the internal structure of a volcano

    Microsoft Academic Search

    H. Tanaka; K. Nagamine; N. Kawamura; S. N. Nakamura; K. Ishida; K. Shimomura

    2003-01-01

    Very high-energy cosmic-ray muons penetrating through a mountain enable us to probe internal structure of volcanoes. An improved cosmic-ray muon detection system comprising two segmented detectors with multiplicity cut of the soft-component background of cosmic ray was developed. By applying to the measurement on internal structure of the volcano Mt. Asama, we proved that the volume occupancy in the region

  16. Radio detection of high-energy cosmic rays at the Pierre Auger Observatory

    SciTech Connect

    Berg, A.M.van den; Collaboration, for the Pierre Auger

    2007-08-01

    The southern Auger Observatory provides an excellent test bed to study the radio detection of extensive air showers as an alternative, cost-effective, and accurate tool for cosmic-ray physics. The data from the radio setup can be correlated with those from the well-calibrated baseline detectors of the Pierre Auger Observatory. Furthermore, human-induced radio noise levels at the southern Auger site are relatively low. We have started an R&D program to test various radio-detection concepts. Our studies will reveal Radio Frequency Interferences (RFI) caused by natural effects such as day-night variations, thunderstorms, and by human-made disturbances. These RFI studies are conducted to optimize detection parameters such as antenna design, frequency interval, antenna spacing and signal processing. The data from our initial setups, which presently consist of typically 3 - 4 antennas, will be used to characterize the shower from radio signals and to optimize the initial concepts. Furthermore, the operation of a large detection array requires autonomous detector stations. The current design is aiming at stations with antennas for two polarizations, solar power, wireless communication, and local trigger logic. The results of this initial phase will provide an important stepping stone for the design of a few tens kilometers square engineering array.

  17. A Cocoon of Freshly Accelerated Cosmic Rays Detected by Fermi in the Cygnus Superbubble

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bottacini, E.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; de Angelis, A.; de Palma, F.; Dermer, C. D.; do Couto e Silva, E.; Drell, P. S.; Dumora, D.; Favuzzi, C.; Fegan, S. J.; Focke, W. B.; Fortin, P.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hayashi, K.; Hays, E.; Jóhannesson, G.; Johnson, A. S.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kerr, M.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lee, S.-H.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Martin, P.; Mazziotta, M. N.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Parent, D.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pohl, M.; Prokhorov, D.; Rainò, S.; Rando, R.; Razzano, M.; Reposeur, T.; Ritz, S.; Parkinson, P. M. Saz; Sgrò, C.; Siskind, E. J.; Smith, P. D.; Spinelli, P.; Strong, A. W.; Takahashi, H.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Tramacere, A.; Troja, E.; Uchiyama, Y.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Zimmer, S.; Bontemps, S.

    2011-11-01

    The origin of Galactic cosmic rays is a century-long puzzle. Indirect evidence points to their acceleration by supernova shockwaves, but we know little of their escape from the shock and their evolution through the turbulent medium surrounding massive stars. Gamma rays can probe their spreading through the ambient gas and radiation fields. The Fermi Large Area Telescope (LAT) has observed the star-forming region of Cygnus X. The 1- to 100-gigaelectronvolt images reveal a 50-parsec-wide cocoon of freshly accelerated cosmic rays that flood the cavities carved by the stellar winds and ionization fronts from young stellar clusters. It provides an example to study the youth of cosmic rays in a superbubble environment before they merge into the older Galactic population.

  18. Detecting atmospheric cosmic ray induced muon showers with the NO ?A Far Detector

    NASA Astrophysics Data System (ADS)

    Sultana, Mehreen

    2015-04-01

    The research goals of Fermilab's NuMi Off-Axis Electron Neutrino Appearance (NO ?A) are to observe muon neutrino to electron neutrino oscillations, determine the ordering of neutrino masses, and explain violation of matter/anti-matter symmetry. However, NO ?A can also be used to study cosmic ray induced high energy extensive air showers. This poster describes the initial characterization of NO ?A as a cosmic ray detector. The detector has a combination of large size and high spatial resolution that will allow future studies of the hadronic cores of cosmic ray air showers. A large component of these showers are muons. Multiple parallel muon tracks seen in a single event with the NO ?A detectors result from the same primary cosmic ray collision in the upper atmosphere. In order to use these muon bundles to probe the cosmic ray physics involved, we determine event characteristics such as the multiplicity of observed multiple muons, the effective area of the detector, the angular resolution of the detector, the scattering of individual muons, and the effectiveness of identifying and isolating these parallel muon shower events from background and noise. NuMi Off-Axis Electron Neutrino Appearance Experiment.

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

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

  20. Direction identification in radio images of cosmic-ray air showers detected with LOPES and KASCADE

    E-print Network

    A. Nigl

    2008-09-16

    AIMS: We want to understand the emission mechanism of radio emission from air showers to determine the origin of high-energy cosmic rays. Therefore, we study the geometry of the air shower radio emission measured with LOPES and search for systematic effects between the direction determined on the radio signal and the direction provided by the particle detector array KASCADE. METHODS: We produce 4D radio images on time-scales of nanoseconds using digital beam-forming. Each pixel of the image is calculated for three spatial dimensions and as a function of time. The third spatial dimension is obtained by calculating the beam focus for a range of curvature radii fitted to the signal wave front. We search this multi-dimensional parameter space for the direction of maximum coherence of the air shower radio signal and compare it to the direction provided by KASCADE. RESULTS: The maximum radio emission of air showers is obtained for curvature radii being larger than 3 km. We find that the direction of the emission maximum can change when optimizing the curvature radius. Furthermore, we find a tentative increase of the curvature radius to lower elevations, where the air showers pass through a larger atmospheric depth. CONCLUSIONS: We conclude that the angular resolution of LOPES is sufficient to determine the direction which maximizes the observed electric field amplitude. However, the statistical uncertainty of the directions is not determined by the resolution of LOPES, but by the uncertainty of the curvature radius. We do not find any systematic deviation between the directions determined from the radio signal and from the detected particles. This result places a strong supportive argument for the use of the radio technique to study the origin of high-energy cosmic rays.

  1. Overview of radio detection of cosmic ray air showers in the MHz range, and prospects for a large scale experiment

    NASA Astrophysics Data System (ADS)

    Melissas, Maximilien; Pierre Auger Collaboration

    2011-06-01

    Since its revival in the last decade, radio detection of cosmic ray air showers has made tremendous progress. Today, several experiments are routinely detecting radio signals associated with air showers. Large cosmic ray observatories such as the Pierre Auger Observatory are also pursuing radio detection activities. As an introduction, in this article we will summarize the main results from the first generation of radio detection experiments: LOPES and CODALEMA. Then, we will show which questions concerning the radio emission mechanisms can be answered from larger-scale experiments like the Auger Engineering Radio Array (AERA), which is a 20 km2 antenna array under construction close to other enhancement devices at the Pierre Auger Observatory.

  2. Tracks of Cosmic Rays in Plastics

    Microsoft Academic Search

    R. L. Fleischer; P. B. Price; R. M. Walker; R. C. Filz; K. Fukui; M. W. Friedlander; E. Holeman; R. S. Rajan; A. S. Tamhane

    1967-01-01

    Cosmic ray nuclei have been observed with the use of plastic track-detecting solids in satellites and high-altitude balloon flights. Nuclear emulsions in the stacks of plastic sheets allowed the positive identification of cosmic ray nuclei as light as nitrogen. The most striking new information was the failure to observe relativistic iron nuclei, a result which has led to an advance

  3. PAMELA Cosmic Ray Observations

    NASA Astrophysics Data System (ADS)

    Boezio, Mirko

    2012-07-01

    On the 15th of June 2006, the PAMELA satellite-borne experiment was launched from the Baikonur cosmodrome and it has been collecting data since July 2006. The combination of a permanent magnet silicon strip spectrometer and a silicon-tungsten imaging calorimeter allows precision studies of the charged cosmic radiation to be conducted over a wide energy range with high statistics. The primary scientific goal is the measurement of the antiproton and positron energy spectrum from few tens of MeV up to hundreds of GeV in order to search for exotic sources, such as dark matter particle annihilations, and testing models of cosmic-ray propagation in the galaxy and in the heliosphere. PAMELA is also searching for primordial antinuclei (anti-helium) and testing cosmic-ray propagation models through precise measurements of light nuclei and their isotopes. We will present the status and main results of the PAMELA experiment after six years in orbit.

  4. In Search of Cosmic Rays

    NSDL National Science Digital Library

    Derek Streich

    2001-11-01

    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

  5. Frontiers in Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Anchordoqui, Luis A.; Dermer, Charles D.; Ringwald, Andreas

    2006-02-01

    This rapporteur review covers selected results presented in the Parallel Session HEA2 (High Energy Astrophysics 2) of the 10th Marcel Grossmann Meeting on General Relativity, held in Rio de Janeiro, Brazil, July 2003. The subtopics are: ultra high energy cosmic ray anisotropies, the possible connection of these energetic particles with powerful gamma ray bursts, and new exciting scenarios with a strong neutrino-nucleon interaction in the atmosphere.

  6. Frontiers in Cosmic Rays

    E-print Network

    Luis A. Anchordoqui; Charles D. Dermer; Andreas Ringwald

    2004-02-27

    This rapporteur review covers selected results presented in the Parallel Session HEA2 (High Energy Astrophysics 2) of the 10th Marcel Grossmann Meeting on General Relativity, held in Rio de Janeiro, Brazil, July 2003. The subtopics are: ultra high energy cosmic ray anisotropies, the possible connection of these energetic particles with powerful gamma ray bursts, and new exciting scenarios with a strong neutrino-nucleon interaction in the atmosphere.

  7. Nineteenth International Cosmic Ray Conference. OG Sessions, Volume 3

    NASA Technical Reports Server (NTRS)

    Jones, F. C. (compiler)

    1985-01-01

    Papers submitted for presentation at the 19th International Cosmic Ray Conference are compiled. This volume addresses cosmic ray sources and acceleration, interstellar propagation and nuclear interactions, and detection techniques and instrumentation.

  8. Cherenkov detection of cosmic rays in Hanoi: Response to low signals

    NASA Astrophysics Data System (ADS)

    Thao, N. T.; Anh, P. T.; Darriulat, P.; Diep, P. N.; Dong, P. N.; Hiep, N. V.; Hoai, D. T.; Nhung, P. T. T.

    2013-05-01

    A replica of one of the 1660 Cherenkov detectors used in the ground array of the Pierre Auger Cosmic Ray Observatory in Argentina has been constructed on the roof of the VATLY astrophysics laboratory in Ha Noi (Viet Nam). We report on measurements of low amplitude signals using the detector to study event pairs occurring within a small time window. The data include time autocorrelation and charge distributions.

  9. The AMY experiment to measure GHz radiation for Ultra-High Energy Cosmic Ray detection

    NASA Astrophysics Data System (ADS)

    Alvarez-Muniz, J.; Bohacova, M.; Cataldi, G.; Coluccia, M. R.; Creti, P.; De Mitri, I.; Di Giulio, C.; Engel, R.; Facal San Luis, P.; Iarlori, M.; Martello, D.; Monasor, M.; Perrone, L.; Petrera, S.; Privitera, P.; Riegel, M.; Rizi, V.; Rodriguez Fernandez, G.; Salamida, F.; Salina, G.; Settimo, M.; Smida, R.; Verzi, V.; Werner, F.; Williams, C.

    2013-02-01

    The Air Microwave Yield (AMY) project aims to measure the emission in the GHz regime from test-beam induced air-shower. The experiment is using the Beam Test Facility (BTF) of the Frascati INFN National Laboratories in Italy. The final purpose is to characterize a process to be used in a next generation of ultra-high energy cosmic rays (UHECRs) detectors. We describe the experimental apparatus and the first test performed in November 2011.

  10. Interactions of Cosmic Ray Nuclei

    E-print Network

    K. Mannheim; R. Schlickeiser

    1994-02-16

    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.

  11. Building a Cloud Chamber (Cosmic Ray Detector)

    NSDL National Science Digital Library

    In this activity, students learn about cosmic rays firsthand by building a cloud chamber to detect them. The comprehensive activity includes step-by-step directions for constructing and operating a cloud chamber and ideas for additional experiments.

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

    ERIC Educational Resources Information Center

    Friedlander, Michael

    1990-01-01

    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)

  13. Relativistic heavy cosmic rays

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

  14. Exploring design tradeoffs of a distributed algorithm for cosmic ray event detection

    NASA Astrophysics Data System (ADS)

    Yousaf, S.; Bakhshi, R.; van Steen, M.; Voulgaris, S.; Kelley, J. L.

    2013-03-01

    Many sensor networks, including large particle detector arrays measuring high-energy cosmic-ray air showers, traditionally rely on centralised trigger algorithms to find spatial and temporal coincidences of individual nodes. Such schemes suffer from scalability problems, especially if the nodes communicate wirelessly or have bandwidth limitations. However, nodes which instead communicate with each other can, in principle, use a distributed algorithm to find coincident events themselves without communication with a central node. We present such an algorithm and consider various design tradeoffs involved, in the context of a potential trigger for the Auger Engineering Radio Array (AERA).

  15. A Correlation Between the Highest Energy Cosmic Rays and Nearby Active Galactic Nuclei Detected by Fermi

    NASA Astrophysics Data System (ADS)

    Nemmen, Rodrigo S.; Bonatto, Charles; Storchi-Bergmann, Thaisa

    2010-10-01

    We analyze the correlation of the positions of ?-ray sources in the Fermi Large Area Telescope (LAT) First Source Catalog (1FGL) and the First LAT Active Galactic Nuclei (AGNs) Catalog (1LAC) with the arrival directions of ultra-high-energy cosmic rays (UHECRs) observed with the Pierre Auger Observatory, in order to investigate the origin of UHECRs. We find that Galactic sources and blazars identified in the 1FGL are not significantly correlated with UHECRs, while the 1LAC sources display a mild correlation (2.6? level) on an ?2fdg4 angular scale. When selecting only the 1LAC AGNs closer than 200 Mpc, we find a strong association (5.4?) between their positions and the directions of UHECRs on an ?17° angular scale; the probability of the observed configuration being due to an isotropic flux of cosmic rays is 5 × 10-8. There is also a 5? correlation with nearby 1LAC sources on a 6fdg5 scale. We identify seven "?-ray loud" AGNs which are associated with UHECRs within ?17° and are likely candidates for the production sites of UHECRs: Centaurus A, NGC 4945, ESO 323-G77, 4C+04.77, NGC 1218, RX J0008.0+1450, and NGC 253. We interpret these results as providing additional support to the hypothesis of the origin of UHECRs in nearby extragalactic objects. As the angular scales of the correlations are large, we discuss the possibility that intervening magnetic fields might be considerably deflecting the trajectories of the particles on their way to Earth.

  16. Cosmic Rays and Space Weather

    Microsoft Academic Search

    Lev I. Dorman

    2010-01-01

    \\u000a This lecture is an example how fundamental research in Cosmic Ray Astrophysics and Geophysics can be applied to very important\\u000a modern practical problem: monitoring by cosmic rays space weather and prediction by using on-line cosmic ray data space phenomena\\u000a dangerous for satellites electronics and astronauts health in the space, for crew and passengers health on commercial jets\\u000a in atmosphere, and

  17. Cosmic Rays and Climate Change

    NASA Astrophysics Data System (ADS)

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

    2010-09-01

    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.

  18. The Highest Energy Cosmic Rays and Gamma Rays

    Microsoft Academic Search

    S. F. Taylor; T. Abu-Zayyad; K. Belov; Z. Cao; G. Chen; M. A. Huang; C. C. H. Jui; D. B. Kieda; E. C. Loh; J. N. Matthews; M. Salamon; A. Salman; J. D. Smith; P. Sokolsky; P. Sommers; S. B. Thomas; L. R. Wiencke; D. J. Bird; R. W. Clay; B. R. Dawson; K. M. Simpson; C. R. Wilkinson; J. Boyer; E. J. Mannel; Y. Ho; W. Lee; T. O'Halloran; N. Hayashida; H. Hirasawa; F. Ishikawa; H. Lafoux; M. Nagano; D. Nishikawa; T. Ouchi; H. Ohoka; M. Ohnishi; N. Sakaki; M. Sasaki; H. Shimodaira; M. Teshima; R. Torii; T. Yamamoto; S. Yoshida; T. Yuda

    1998-01-01

    Taking advantage of the dark skies near Dugway, Utah, the University of Utah's Fly's Eye Detector has been observing cosmic rays with energies above 3x 10(16) eV by detecting light from the nitrogen fluorescence from the Extensive Air Showers produced by cosmic rays. The detection of an event measured to have 3x 10(20) eV raises the question of whether the

  19. Cosmic ray modulation by interplanetary disturbances

    Microsoft Academic Search

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

    2010-01-01

    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

  20. The Origin of Cosmic Rays

    ScienceCinema

    Pasquale Blasi

    2010-01-08

    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.

  1. Antiprotons in cosmic rays

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    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.

  2. A Bayesian self-clustering analysis of the highest energy cosmic rays detected by the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Khanin, Alexander; Mortlock, Daniel J.

    2014-10-01

    Cosmic rays are protons and atomic nuclei that flow into our Solar system and reach the Earth with energies of up to ˜1021 eV. The sources of ultrahigh energy cosmic rays (UHECRs) with E ? 1019 eV remain unknown, although there are theoretical reasons to think that at least some come from active galactic nuclei (AGNs). One way to assess the different hypotheses is by analysing the arrival directions of UHECRs, in particular their self-clustering. We have developed a fully Bayesian approach to analysing the self-clustering of points on the sphere, which we apply to the UHECR arrival directions. The analysis is based on a multistep approach that enables the application of Bayesian model comparison to cases with weak prior information. We have applied this approach to the 69 highest energy events recorded by the Pierre Auger Observatory, which is the largest current UHECR data set. We do not detect self-clustering, but simulations show that this is consistent with the AGN-sourced model for a data set of this size. Data sets of several hundred UHECRs would be sufficient to detect clustering in the AGN model. Samples of this magnitude are expected to be produced by future experiments, such as the Japanese Experiment Module Extreme Universe Space Observatory.

  3. Cosmic Ray Neutron Flux Measurements

    NASA Astrophysics Data System (ADS)

    Dayananda, Mathes

    2009-11-01

    Cosmic rays are high-energetic particles originating from outer space that bombard the upper atmosphere of the Earth. Almost 90% of cosmic ray particles consist of protons, electrons and heavy ions. When these particles hit the Earth's atmosphere, cascade of secondary particles are formed. The most abundant particles reach to the surface of the Earth are muons, electrons and neutrons. In recent years many research groups are looking into potential applications of the effects of cosmic ray radiation at the surface of the Earth [1, 2]. At Georgia State University we are working on a long-term measurement of cosmic ray flux distribution. This study includes the simultaneous measurement of cosmic ray muons, neutrons and gamma particles at the Earth surface in downtown Atlanta. The initial effort is focusing on the correlation studies of the cosmic ray particle flux distribution and the atmospheric weather conditions. In this presentation, I will talk about the development of a cosmic ray detector using liquid scintillator and the preliminary results. [4pt] [1] K.Borozdin, G.Hogan, C.Morris, W.Priedhorsky, A.Saunders, L.Shultz, M.Teasdale, ``Radiographic imaging with cosmic-ray muons'', Nature, Vol.422, p.277, Mar.2003[0pt] [2] Svensmark Henrik, Physical Review 81, 3, (1998)

  4. High-Energy Neutrinos from Cosmic Rays

    E-print Network

    F. Halzen

    2002-06-17

    We introduce neutrino astronomy from 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. We review the facts as well as the speculations about the sources. Among these gamma ray bursts and active galaxies represent well-motivated speculations because these are also the sources of the highest energy gamma rays, with emission observed up to 20 TeV, possibly higher. We discuss why cosmic accelerators are also expected to be cosmic beam dumps producing high-energy neutrino beams associated with the highest energy cosmic rays. Cosmic ray sources may produce neutrinos from MeV to EeV energy by a variety of mechanisms. 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. The technology for commissioning such instruments exists.

  5. Tomographic-spectral approach for dark matter detection in the cross-correlation between cosmic shear and diffuse ?-ray emission

    NASA Astrophysics Data System (ADS)

    Camera, S.; Fornasa, M.; Fornengo, N.; Regis, M.

    2015-06-01

    We recently proposed to cross-correlate the diffuse extragalactic ?-ray background with the gravitational lensing signal of cosmic shear. This represents a novel and promising strategy to search for annihilating or decaying particle dark matter (DM) candidates. In the present work, we demonstrate the potential of a tomographic-spectral approach: measuring the cross-correlation in separate bins of redshift and energy significantly improves the sensitivity to a DM signal. Indeed, the technique proposed here takes advantage of the different scaling of the astrophysical and DM components with redshift and, simultaneously of their different energy spectra and different angular extensions. The sensitivity to a particle DM signal is extremely promising even when the DM-induced emission is quite faint. We first quantify the prospects of detecting DM by cross-correlating the Fermi Large Area Telescope (LAT) diffuse ?-ray background with the cosmic shear expected from the Dark Energy Survey. Under the hypothesis of a significant subhalo boost, such a measurement can deliver a 5? detection of DM, if the DM particle is lighter than 300 GeV and has a thermal annihilation rate. We then forecast the capability of the European Space Agency Euclid satellite (whose launch is planned for 2020), in combination with an hypothetical future ?-ray detector with slightly improved specifications compared to current telescopes. We predict that the cross-correlation of their data will allow a measurement of the DM mass with an uncertainty of a factor of 1.5–2, even for moderate subhalo boosts, for DM masses up to few hundreds of GeV and thermal annihilation rates.

  6. Detection of primary and secondary cosmic ray particles aboard the ISS using SSNTD stacks.

    PubMed

    Pálfalvi, J K; Akatov, Yu; Szabó, J; Sajó-Bohus, L; Eördögh, I

    2006-01-01

    To study the radiation environment inside the International Space Station, solid state nuclear track detector stacks were used. Within the BRADOS experiments, Phase 1, seven stacks were exposed at different locations of the Russian segment 'Zvezda' for 248 days in 2001. It was supposed that the radiation field inside the ISS was composed from primary cosmic ray particles penetrating the wall of the ISS and secondaries, mainly neutrons induced by primaries in the wall and other structural materials surrounding the detectors. Based on the calibration made by utilising the high energy neutron reference field CERF at CERN (Geneva, Switzerland), the tracks induced by neutrons were separated from those induced by primary particles. Thus, the stacks, on one hand, provided the secondary neutron ambient dose equivalent. On the other hand, from the analysis of the rest of the tracks, the linear energy transfer spectra were computed and the flux and the dose of the primary particles were determined as shown in this paper. PMID:16735560

  7. Cosmic-Ray Positron Measurements

    NASA Astrophysics Data System (ADS)

    Schubnell, Michael

    Direct measurements of cosmic-ray electrons and positrons were first made in the early 1960s and since then a number of instruments were built to study this component of the cosmic radiation. The precise measurement of the intensities of CR electrons and positrons are key to our understanding of cosmic-ray origin and propagation. In addition the locally observed abundance of cosmic ray electrons and/or positrons may exhibit interesting spectral features. Observations confirm the almost exclusive secondary nature of positrons up to a few GeV but measurements by the HEAT-e instrument suggested as early as 1995 a possible primary positron component. More recent reports by the PAMELA team of a continued rise in the cosmic-ray positron fraction above about 10 GeV and of an excess of cosmic-ray electrons around a few hundred GeV by the ATIC collaboration have resulted in a flurry of publications interpreting these observations either as a possible dark matter signature or as a contribution from isolated astrophysical sources. While those interpretations are scientically exciting, the possibility that measurements are contaminated by misidentied cosmic-ray protons cannot be ignored. I will present a new analysis of low energy positron data taking into account modulation effects due to the solar cycle and I will take a critical look at current positron measurements and discuss theoretical interpretations from an experimentalist's point of view.

  8. Galactic Cosmic Rays: From Earth to Sources

    NASA Technical Reports Server (NTRS)

    Brandt, Theresa J.

    2012-01-01

    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.

  9. Astrophysics of Galactic charged cosmic rays

    E-print Network

    Antonella Castellina; Fiorenza Donato

    2011-10-13

    A review is given of the main properties of the charged component of galactic cosmic rays, particles detected at Earth with an energy spanning from tens of MeV up to about 10^19 eV. After a short introduction to the topic and an historical overview, the properties of cosmic rays are discussed with respect to different energy ranges. The origin and the propagation of nuclei in the Galaxy are dealt with from a theoretical point of view. The mechanisms leading to the acceleration of nuclei by supernova remnants and to their subsequent diffusion through the inhomogeneities of the galactic magnetic field are discussed and some clue is given on the predictions and observations of fluxes of antimatter, both from astrophysical sources and from dark matter annihilation in the galactic halo. The experimental techniques and instrumentations employed for the detection of cosmic rays at Earth are described. Direct methods are viable up to 10^14 eV, by means of experiments flown on balloons or satellites, while above that energy, due to their very low flux, cosmic rays can be studied only indirectly by exploiting the particle cascades they produce in the atmosphere. The possible physical interpretation of the peculiar features observed in the energy spectrum of galactic cosmic rays, and in particular the so-called "knee" at about 4x10^15 eV, are discussed. A section is devoted to the region between about 10^18 and 10^19 eV, which is believed to host the transition between galactic and extragalactic cosmic rays. The conclusion gives some perspectives on the cosmic ray astrophysics field. Thanks to a wealth of different experiments, this research area is living a very flourishing era. The activity is exciting both from the theoretical and the instrumental sides, and its interconnection with astronomy, astrophysics and particle physics experiences non-stop growth.

  10. Cosmic Rays and Global Warming

    E-print Network

    T. Sloan; A W Wolfendale

    2007-06-28

    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.

  11. Large-scale Distribution of Arrival Directions of Cosmic Rays Detected Above 1018 eV at the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Pierre Auger Collaboration; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Anti?i'c, T.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Bäuml, J.; Baus, C.; Beatty, J. J.; 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.; Brancus, I.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Buroker, L.; Burton, R. E.; Caballero-Mora, K. S.; Caccianiga, B.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chirinos Diaz, J.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Collica, L.; 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.; Daniel, B.; 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.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; del Río, M.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Díaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filip?i?, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Gitto, J.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gouffon, P.; Grashorn, E.; Grebe, S.; Griffith, N.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jansen, S.; Jarne, C.; Jiraskova, S.; Josebachuili, M.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Katkov, I.; 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.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; LaHurd, D.; Latronico, L.; Lauer, R.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Messina, S.; Meurer, C.; Meyhandan, R.; Mi'canovi'c, S.; Micheletti, M. I.; Minaya, I. A.; Miramonti, L.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nožka, L.; Oehlschläger, J.; Olinto, A.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Pastor, S.; Paul, T.

    2012-12-01

    A thorough search for large-scale anisotropies in the distribution of arrival directions of cosmic rays detected above 1018 eV at the Pierre Auger Observatory is presented. This search is performed as a function of both declination and right ascension in several energy ranges above 1018 eV, and reported in terms of dipolar and quadrupolar coefficients. Within the systematic uncertainties, no significant deviation from isotropy is revealed. Assuming that any cosmic-ray anisotropy is dominated by dipole and quadrupole moments in this energy range, upper limits on their amplitudes are derived. These upper limits allow us to test the origin of cosmic rays above 1018 eV from stationary Galactic sources densely distributed in the Galactic disk and predominantly emitting light particles in all directions.

  12. The potential of detecting intermediate-scale biomass and canopy interception in a coniferous forest using cosmic-ray neutron intensity measurements and neutron transport modeling

    NASA Astrophysics Data System (ADS)

    Andreasen, M.; Looms, M. C.; Bogena, H. R.; Desilets, D.; Zreda, M. G.; Sonnenborg, T. O.; Jensen, K. H.

    2014-12-01

    The water stored in the various compartments of the terrestrial ecosystem (in snow, canopy interception, soil and litter) controls the exchange of the water and energy between the land surface and the atmosphere. Therefore, measurements of the water stored within these pools are critical for the prediction of e.g. evapotranspiration and groundwater recharge. The detection of cosmic-ray neutron intensity is a novel non-invasive method for the quantification of continuous intermediate-scale soil moisture. The footprint of the cosmic-ray neutron probe is a hemisphere of a few hectometers and subsurface depths of 10-70 cm depending on wetness. The cosmic-ray neutron method offers measurements at a scale between the point-scale measurements and large-scale satellite retrievals. The cosmic-ray neutron intensity is inversely correlated to the hydrogen stored within the footprint. Overall soil moisture represents the largest pool of hydrogen and changes in the soil moisture clearly affect the cosmic-ray neutron signal. However, the neutron intensity is also sensitive to variations of hydrogen in snow, canopy interception and biomass offering the potential to determine water content in such pools from the signal. In this study we tested the potential of determining canopy interception and biomass using cosmic-ray neutron intensity measurements within the framework of the Danish Hydrologic Observatory (HOBE) and the Terrestrial Environmental Observatories (TERENO). Continuous measurements at the ground and the canopy level, along with profile measurements were conducted at towers at forest field sites. Field experiments, including shielding the cosmic-ray neutron probes with cadmium foil (to remove lower-energy neutrons) and measuring reference intensity rates at complete water saturated conditions (on the sea close to the HOBE site), were further conducted to obtain an increased understanding of the physics controlling the cosmic-ray neutron transport and the equipment used. Additionally, neutron transport modeling, using the extended version of the Monte Carlo N-Particle Transport Code, was conducted. The responses of the reference condition, different amounts of biomass, soil moisture and canopy interception on the cosmic-ray neutron intensity were simulated and compared to the measurements.

  13. Mapping the most energetic cosmic rays

    Microsoft Academic Search

    A. M. Hillas

    2009-01-01

    The Pierre Auger Collaboration has shown that the cosmic rays detected to August 2007, with estimated energies above 57 EeV, were mostly very close to the direction of a catalogued AGN within ˜75Mpc. The closeness of the sources to us, and their association with the locality of moderate Seyfert galaxies rather than the most striking radio galaxies, were surprising, leading

  14. Mapping the most energetic cosmic rays

    Microsoft Academic Search

    A. M. Hillas

    2009-01-01

    The Pierre Auger Collaboration has shown that the cosmic rays detected to August 2007, with estimated energies above 57EeV, were mostly very close to the direction of a catalogued AGN within ?75Mpc. The closeness of the sources to us, and their association with the locality of moderate Seyfert galaxies rather than the most striking radio galaxies, were surprising, leading some

  15. Radiation from Cosmic Ray Air Showers

    Microsoft Academic Search

    F. D. Kahn; I. Lerche

    1966-01-01

    Cosmic ray showers passing through the atmosphere produce electromagnetic disturbances. It has been suggested that these can be detected by means of a radio telescope. We set up a simple model for a shower and find that the time-integrated energy flux in its radiation field, at say 45 Mc\\/s, is of the order of 60 000 flux units x microseconds,

  16. Catching Cosmic Rays with a DSLR

    ERIC Educational Resources Information Center

    Sibbernsen, Kendra

    2010-01-01

    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…

  17. Cosmic Ray physics with ARGO-YBJ

    NASA Astrophysics Data System (ADS)

    Iacovacci, M.

    2013-06-01

    The ARGO-YBJ experiment has been in stable data taking from November 2007 till February 2013 at the Yang-BaJing Cosmic Ray Laboratory (Tibet, P.R.China, 4300 m a.s.l.). It exploits the full coverage and the high altitude to detect air showers with an energy threshold as low as a few hundred GeV. The detector is made of a single layer of RPCs operated in streamer mode, fully instrumenting a central carpet of about 5800 m. A guard ring extends the partially instrumented area to about 11,000 m. The main results so far achieved on Cosmic Ray physics are reported.

  18. Monopole Annihilation and Highest Energy Cosmic Rays

    E-print Network

    P. Bhattacharjee; G. Sigl

    1994-12-15

    Cosmic rays with energies exceeding $10^{20}\\eV$ have been detected. The origin of these highest energy cosmic rays remains unknown. Established astrophysical acceleration mechanisms encounter severe difficulties in accelerating particles to these energies. Alternative scenarios where these particles are created by the decay of cosmic topological defects have been suggested in literature. In this paper we study the possibility of producing the highest energy cosmic rays through a process that involves formation of metastable magnetic monopole-antimonopole bound states and their subsequent collapse. The annihilation of the heavy monopole-antimonopole pairs constituting the monopolonia can produce energetic nucleons, gamma rays and neutrinos whose expected flux we estimate and discuss in relation to experimental data so far available. The monopoles we consider are the ones that could be produced in the early universe during a phase transition at the grand unification energy scale. We find that observable cosmic ray fluxes can be produced with monopole abundances compatible with present bounds.

  19. Gamma rays from grazing incidence cosmic rays in the earth's atmosphere

    NASA Technical Reports Server (NTRS)

    Ulmer, Andrew

    1994-01-01

    Interactions of grazing incidence, ultra high-energy cosmic rays with the earth's atmosphere may provide a new method of studying energetic cosmic rays with gamma-ray satellites. It is found that these cosmic ray interactions may produce gamma-rays on millisecond timescales which may be detectable by satellites. An extremely low gamma-ray background for transient gamma-ray events and a large area of interaction, the earth's surface, make the scheme plausible. The effective cross section of detection of interactions for cosmic rays above 10(exp 20) eV is found to be more than two orders of magnitude higher than Earth-based detection techniques. This method may eventually offer an efficient way of probing this region of the cosmic-ray energy spectrum where events are scarce. In this paper, a conceptual model is presented for the production of short bursts of gamma-rays based on these grazing incidence encounters with the Earth's atmosphere.

  20. Detection of OH+ in Translucent Interstellar Clouds: New Electronic Transitions and Probing the Primary Cosmic Ray Ionization Rate

    NASA Astrophysics Data System (ADS)

    Zhao, D.; Galazutdinov, G. A.; Linnartz, H.; Kre?owski, J.

    2015-06-01

    We present the detection of rotationally resolved electronic transitions in the OH+ A3?–X3?? (0, 0) and (1, 0) bands toward CD-32 4348, HD 63804, HD 78344, and HD 80077. These four translucent clouds have been studied in a recent Very Large Telescope/Ultraviolet and Visual Echelle Spectrograph observational run. In total, seven absorption features of OH+ are detected, and six of them are identified here for the first time, providing a precise tool to trace OH+ in translucent interstellar clouds. An improved set of line positions and oscillator strengths is compiled to support our data interpretation. A dedicated analysis of the observed features in individual targets yields an accurate determination of OH+ column densities. The results are applied to estimate the primary cosmic ray ionization rate in the investigated translucent clouds, which yields a typical value of ?1.0 × 10?16 s?1. In addition, following this work, two of the new interstellar features recently reported by Bhatt & Cami, at ?3572.65 and 3346.96 Å, can be identified as OH+ absorption lines now. Based on observations collected at the European Organisation for Astronomical Research in the southern hemisphere, Chile, under program 092.C-0019(A).

  1. Cosmic Rays from Cygnus X-3

    Microsoft Academic Search

    P. Kevin MacKeown; Trevor C. Weekes

    1985-01-01

    Today many investigators adhere to the idea that cosmic rays receive all their energy from discrete sources with interstellar space acting only as a diffusive medium. An object that accelerates particles to cosmic-ray velocities will almost inevitably produce gamma rays as well. Hence, gamma rays are therefore an effective probe of the source of cosmic radiation even though they account

  2. X-ray Observations of Cosmic Ray Acceleration

    NASA Technical Reports Server (NTRS)

    Petre, Robert

    2012-01-01

    Since the discovery of cosmic rays, detection of their sources has remained elusive. A major breakthrough has come through the identification of synchrotron X-rays from the shocks of supernova remnants through imaging and spectroscopic observations by the most recent generation of X-ray observatories. This radiation is most likely produced by electrons accelerated to relativistic energy, and thus has offered the first, albeit indirect, observational evidence that diffusive shock acceleration in supernova remnants produces cosmic rays to TeV energies, possibly as high as the "knee" in the cosmic ray spectrum. X-ray observations have provided information about the maximum energy to which these shOCks accelerate electrons, as well as indirect evidence of proton acceleration. Shock morphologies measured in X-rays have indicated that a substantial fraction of the shock energy can be diverted into particle acceleration. This presentation will summarize what we have learned about cosmic ray acceleration from X-ray observations of supernova remnants over the past two decades.

  3. Cosmic Rays and Sunspot Numbers

    NSDL National Science Digital Library

    Susan Higley

    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.

  4. Cosmic Rays and Global Warming

    SciTech Connect

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

    2008-01-24

    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.

  5. The role of antiprotons in cosmic-ray physics

    Microsoft Academic Search

    S. A. Stephens; R. L. Golden

    1988-01-01

    Though success eluded experimentalists from detecting cosmic-ray antiprotons over a long period of time, the study of cosmic-ray antiprotons has now become a fascinating field of research. In this review, we have attempted to elucidate the excitement in this area of research since the discovery of antiprotons in the laboratory. We have described the experiments carried out so far to

  6. Cosmic Rays and Space Situational Awareness in Europe

    Microsoft Academic Search

    F. Jansen; J. Behrens

    In this paper European space weather activities are sketched and the contribution of cosmic ray research and technology to the European space situational awareness programme is described. Especially the cosmic ray muon detection technique is studied - on ground and in future space based -, because it is considered to be very useful for coronal mass ejection forecast in the

  7. People Interview: Cosmic rays uncover universe theories

    NASA Astrophysics Data System (ADS)

    2012-07-01

    INTERVIEW Cosmic rays uncover universe theories David Smith talks to Paula Chadwick about why she is fascinated by cosmic and gamma rays, and how this is the year that their profile is going to be raised

  8. How Cosmic Rays Affect Learning Objectives

    E-print Network

    Christian, Eric

    1 CRaTER: How Cosmic Rays Affect Humans Learning Objectives: · Students will be able to describe.Ontheground,scientistsfoundthatwhenanastronautsawaflash,acosmicrayhadpassedthroughhiseyeball! Background: more recently, the Italian Space Agency created a similar cosmic ray detector

  9. Antennas for the detection of radio emission pulses from cosmic-ray induced air showers at the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Anti?i?, T.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Bäuml, J.; Baus, C.; Beatty, J. J.; 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.; Brancus, I.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Buroker, L.; Burton, R. E.; Caballero-Mora, K. S.; Caccianiga, B.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chirinos Diaz, J.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Collica, L.; 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.; Daniel, B.; 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.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; del Río, M.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Díaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filip?i?, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Gascon Bravo, A.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Gitto, J.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gouffon, P.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jansen, S.; Jarne, C.; Jiraskova, S.; Josebachuili, M.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Katkov, I.; 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.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; LaHurd, D.; Latronico, L.; Lauer, R.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Meyhandan, R.; Mi?anovi?, S.; Micheletti, M. I.; Minaya, I. A.; Miramonti, L.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nožka, L.; Oehlschläger, J.; Olinto, A.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.

    2012-10-01

    The Pierre Auger Observatory is exploring the potential of the radio detection technique to study extensive air showers induced by ultra-high energy cosmic rays. The Auger Engineering Radio Array (AERA) addresses both technological and scientific aspects of the radio technique. A first phase of AERA has been operating since September 2010 with detector stations observing radio signals at frequencies between 30 and 80 MHz. In this paper we present comparative studies to identify and optimize the antenna design for the final configuration of AERA consisting of 160 individual radio detector stations. The transient nature of the air shower signal requires a detailed description of the antenna sensor. As the ultra-wideband reception of pulses is not widely discussed in antenna literature, we review the relevant antenna characteristics and enhance theoretical considerations towards the impulse response of antennas including polarization effects and multiple signal reflections. On the basis of the vector effective length we study the transient response characteristics of three candidate antennas in the time domain. Observing the variation of the continuous galactic background intensity we rank the antennas with respect to the noise level added to the galactic signal.

  10. Research in cosmic and gamma ray astrophysics

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  11. 30TH INTERNATIONAL COSMIC RAY CONFERENCE EAS radio detection at large impact parameter

    E-print Network

    Boyer, Edmond

    numerical approaches which are currently under development. The approximation leading to such a formulation-ray air-shower is a charge and current system whose electromagnetic field carries gen- uine informations with analytical expressions. Such a theoretical tool is most valuable in the present phase where the capabilities

  12. Cosmic rays and hadronic interactions

    SciTech Connect

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

    2013-03-25

    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.

  13. The Cosmic Ray Electron Excess

    NASA Technical Reports Server (NTRS)

    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

    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.

  14. Cosmic-ray sum rules

    SciTech Connect

    Frandsen, Mads T. [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Masina, Isabella [Dip. di Fisica dell'Universita di Ferrara and INFN Sez. di Ferrara, Via Saragat 1, I-44100 Ferrara (Italy); CP3-Origins, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark); Sannino, Francesco [CP3-Origins, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark)

    2011-06-15

    We introduce new sum rules allowing to determine universal properties of the unknown component of the cosmic rays; we show how they can be used to predict the positron fraction at energies not yet explored by current experiments, and to constrain specific models.

  15. A cosmic ray hodoscope system

    E-print Network

    Cantrell, Wallace Gene

    1965-01-01

    A COSMIC EAY HODOSCOPE SYSTEM A Thesis By Wallace Gene Cantrell Submitted to the Graduate College of the Texas A&M University in Partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1965 Major Sub)ect: Physics A... COSMIC RAY HODOSCOPE SYSTEM A Thesis By Wa11ace Gene Cantrell Approved as to style and content by: , V ( Chairman of Committee H, ad of Depar men Zaire Member of Committee ~m i1558 Table of Contents Page Introduction Geometry of the Detector...

  16. High-energy Cosmic Rays

    E-print Network

    Thomas K. Gaisser; Todor Stanev

    2005-10-11

    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.

  17. Earth's magnetic field as a radiator to detect cosmic ray electrons of energy greater than 10 to the 12th eV

    NASA Astrophysics Data System (ADS)

    Balasubrahmanyan, V. K.; Stephens, S. A.

    1983-10-01

    Synchrotron emission by a high-energy electron in the geomagnetic field and its dependence upon different arrival directions over Palestine, Texas, where major balloon-borne experiments are being conducted, is studied. The dependence of detector response on the arrival direction of electron, the different criteria which are adopted to identify an electron event, the area of the detector, and the energy of the electron are discussed. An omnidirectional circular detector is used to examine whether it is possible to determine the energy of an electron without knowing its arrival direction. The collecting power of a detector is estimated as a function of the energy of electrons for different detector areas with different selection criteria, and this information is used to calculate the event rates expected by folding in the energy spectrum of cosmic ray electrons to show the viability of detecting cosmic ray electrons at energies greater than a few TeV.

  18. Earth's magnetic field as a radiator to detect cosmic ray electrons of energy greater than 10 to the 12th eV

    NASA Technical Reports Server (NTRS)

    Balasubrahmanyan, V. K.; Stephens, S. A.

    1983-01-01

    Synchrotron emission by a high-energy electron in the geomagnetic field and its dependence upon different arrival directions over Palestine, Texas, where major balloon-borne experiments are being conducted, is studied. The dependence of detector response on the arrival direction of electron, the different criteria which are adopted to identify an electron event, the area of the detector, and the energy of the electron are discussed. An omnidirectional circular detector is used to examine whether it is possible to determine the energy of an electron without knowing its arrival direction. The collecting power of a detector is estimated as a function of the energy of electrons for different detector areas with different selection criteria, and this information is used to calculate the event rates expected by folding in the energy spectrum of cosmic ray electrons to show the viability of detecting cosmic ray electrons at energies greater than a few TeV.

  19. Plans for Extreme Energy Cosmic Ray Observations from Space

    NASA Technical Reports Server (NTRS)

    Adams, James H., Jr.

    2004-01-01

    Cosmic rays have been detected at energies beyond 10(exp 20) eV, where Universe is predicted to become opaque to protons. The acceleration of cosmic rays to such extreme energies in known astrophysical objects has also proven difficult to understand, leading to many suggestions that new physics may be required to explain their existence. This has prompted the construction of new experiments designed to detect cosmic rays with fluxes below 1 particle/km/century and follow their spectrum to even higher energies. To detect large numbers of these particles, the next generation of these experiments must be performed on space-based platforms that look on very large detection volumes in the Earth's atmosphere. The talk will review the experimental and theoretical investigations of extreme energy cosmic rays and discuss the present and planned experiments to extend measurements beyond 10(exp 21) eV.

  20. Solar panels as cosmic-ray detectors

    E-print Network

    Stella, Carlo; Assis, Pedro; Brogueira, Pedro; Santo, Catarina Espirito; Goncalves, Patricia; Pimenta, Mario; De Angelis, Alessandro

    2014-01-01

    Due to fundamental limitations of accelerators, only cosmic rays can give access to centre-of- mass energies more than one order of magnitude above those reached at the LHC. In fact, extreme energy cosmic rays (1018 eV - 1020 eV) are the only possibility to explore the 100 TeV energy scale in the years to come. This leap by one order of magnitude gives a unique way to open new horizons: new families of particles, new physics scales, in-depth investigations of the Lorentz symmetries. However, the flux of cosmic rays decreases rapidly, being less than one particle per square kilometer per year above 1019 eV: one needs to sample large surfaces. A way to develop large-effective area, low cost, detectors, is to build a solar panel-based device which can be used in parallel for power generation and Cherenkov light detection. Using solar panels for Cherenkov light detection would combine power generation and a non-standard detection device.

  1. Study of multi-muon bundles in cosmic ray showers detected with the DELPHI detector at LEP

    NASA Astrophysics Data System (ADS)

    Delphi Collaboration; Abreu, P.; Adam, W.; Adzic, P.; Albrecht, T.; Alemany-Fernandez, R.; Allmendinger, T.; Allport, P. P.; Amaldi, U.; Amapane, N.; Amato, S.; Anashkin, E.; Andreazza, A.; Andringa, S.; Anjos, N.; Antilogus, P.; Apel, W.-D.; Arnoud, Y.; Ask, S.; Asman, B.; Augustinus, A.; Baillon, P.; Ballestrero, A.; Bambade, P.; Barbier, R.; Bardin, D.; Barker, G. J.; Baroncelli, A.; Battaglia, M.; Baubillier, M.; Becks, K.-H.; Begalli, M.; Behrmann, A.; Ben-Haim, E.; Benekos, N.; Benvenuti, A.; Berat, C.; Berggren, M.; Bertrand, D.; Besancon, M.; Besson, N.; Bloch, D.; Blom, M.; Bluj, M.; Bonesini, M.; Boonekamp, M.; Booth, P. S. L.; Borisov, G.; Botner, O.; Bouquet, B.; Bowcock, T. J. V.; Boyko, I.; Bracko, M.; Brenner, R.; Brodet, E.; Bruckman, P.; Brunet, J. M.; Buschbeck, B.; Buschmann, P.; Calvi, M.; Camporesi, T.; Canale, V.; Carena, F.; Castro, N.; Cavallo, F.; Chapkin, M.; Charpentier, Ph.; Checchia, P.; Chierici, R.; Chliapnikov, P.; Chudoba, J.; Chung, S. U.; Cieslik, K.; Collins, P.; Contri, R.; Cosme, G.; Cossutti, F.; Costa, M. J.; Crennell, D.; Cuevas, J.; D'Hondt, J.; da Silva, T.; da Silva, W.; Della Ricca, G.; de Angelis, A.; de Boer, W.; de Clercq, C.; de Lotto, B.; de Maria, N.; de Min, A.; de Paula, L.; di Ciaccio, L.; di Simone, A.; Doroba, K.; Drees, J.; Eigen, G.; Ekelof, T.; Ellert, M.; Elsing, M.; Espirito Santo, M. C.; Fanourakis, G.; Fassouliotis, D.; Feindt, M.; Fernandez, J.; Ferrer, A.; Ferro, F.; Flagmeyer, U.; Foeth, H.; Fokitis, E.; Fulda-Quenzer, F.; Fuster, J.; Gandelman, M.; Garcia, C.; Gavillet, Ph.; Gazis, E.; Gokieli, R.; Golob, B.; Gomez-Ceballos, G.; Goncalves, P.; Graziani, E.; Grosdidier, G.; Grzelak, K.; Guy, J.; Haag, C.; Hallgren, A.; Hamacher, K.; Hamilton, K.; Haug, S.; Hauler, F.; Hedberg, V.; Hennecke, M.; Herr, H.; Hoffman, J.; Holmgren, S.-O.; Holt, P. J.; Houlden, M. A.; Jackson, J. N.; Jarlskog, G.; Jarry, P.; Jeans, D.; Johansson, E. K.; Jonsson, P.; Joram, C.; Jungermann, L.; Kapusta, F.; Katsanevas, S.; Katsoufis, E.; Kernel, G.; Kersevan, B. P.; Kerzel, U.; King, B. T.; Kjaer, N. J.; Kluit, P.; Kokkinias, P.; Kourkoumelis, C.; Kouznetsov, O.; Krumstein, Z.; Kucharczyk, M.; Lamsa, J.; Leder, G.; Ledroit, F.; Leinonen, L.; Leitner, R.; Lemonne, J.; Lepeltier, V.; Lesiak, T.; Liebig, W.; Liko, D.; Lipniacka, A.; Lopes, J. H.; Lopez, J. M.; Loukas, D.; Lutz, P.; Lyons, L.; MacNaughton, J.; Malek, A.; Maltezos, S.; Mandl, F.; Marco, J.; Marco, R.; Marechal, B.; Margoni, M.; Marin, J.-C.; Mariotti, C.; Markou, A.; Martinez-Rivero, C.; Masik, J.; Mastroyiannopoulos, N.; Matorras, F.; Matteuzzi, C.; Mazzucato, F.; Mazzucato, M.; McNulty, R.; Meroni, C.; Migliore, E.; Mitaroff, W.; Mjoernmark, U.; Moa, T.; Moch, M.; Moenig, K.; Monge, R.; Montenegro, J.; Moraes, D.; Moreno, S.; Morettini, P.; Mueller, U.; Muenich, K.; Mulders, M.; Mundim, L.; Murray, W.; Muryn, B.; Myatt, G.; Myklebust, T.; Nassiakou, M.; Navarria, F.; Nawrocki, K.; Nicolaidou, R.; Nikolenko, M.; Oblakowska-Mucha, A.; Obraztsov, V.; Olshevski, A.; Onofre, A.; Orava, R.; Osterberg, K.; Ouraou, A.; Oyanguren, A.; Paganoni, M.; Paiano, S.; Palacios, J. P.; Palka, H.; Papadopoulou, Th. D.; Pape, L.; Parkes, C.; Parodi, F.; Parzefall, U.; Passeri, A.; Passon, O.; Peralta, L.; Perepelitsa, V.; Perrotta, A.; Petrolini, A.; Piedra, J.; Pieri, L.; Pierre, F.; Pimenta, M.; Piotto, E.; Podobnik, T.; Poireau, V.; Pol, M. E.; Polok, G.; Pozdniakov, V.; Pukhaeva, N.; Pullia, A.; Rames, J.; Read, A.; Rebecchi, P.; Rehn, J.; Reid, D.; Reinhardt, R.; Renton, P.; Richard, F.; Ridky, J.; Rivero, M.; Rodriguez, D.; Romero, A.; Ronchese, P.; Roudeau, P.; Rovelli, T.; Ruhlmann-Kleider, V.; Ryabtchikov, D.; Sadovsky, A.; Salmi, L.; Salt, J.; Sander, C.; Savoy-Navarro, A.; Schwickerath, U.; Sekulin, R.; Shellard, R. C.; Siebel, M.; Sisakian, A.; Smadja, G.; Smirnova, O.; Sokolov, A.; Sopczak, A.; Sosnowski, R.; Spassov, T.; Stanitzki, M.; Stocchi, A.; Strauss, J.; Stugu, B.; Szczekowski, M.; Szeptycka, M.; Szumlak, T.; Tabarelli, T.; Taffard, A. C.; Tegenfeldt, F.; Timmermans, J.; Tkatchev, L.; Tobin, M.; Todorovova, S.; Tome, B.; Tonazzo, A.; Tortosa, P.; Travnicek, P.; Treille, D.; Tristram, G.; Trochimczuk, M.; Troncon, C.; Turluer, M.-L.; Tyapkin, I. A.; Tyapkin, P.; Tzamarias, S.; Uvarov, V.; Valenti, G.; van Dam, P.; van Eldik, J.; van Remortel, N.; van Vulpen, I.; Vegni, G.; Veloso, F.; Venus, W.; Verdier, P.; Verzi, V.; Vilanova, D.; Vitale, L.; Vrba, V.; Wahlen, H.; Washbrook, A. J.; Weiser, C.; Wicke, D.; Wickens, J.; Wilkinson, G.; Winter, M.; Witek, M.; Yushchenko, O.; Zalewska, A.; Zalewski, P.; Zavrtanik, D.; Zhuravlov, V.; Zimin, N. I.; Zintchenko, A.; Zupan, M.

    2007-11-01

    The DELPHI detector at LEP has been used to measure multi-muon bundles originating from cosmic ray interactions with air. The cosmic events were recorded in “parasitic mode” between individual e+e- interactions and the total live time of this data taking is equivalent to 1.6 × 106 s. The DELPHI apparatus is located about 100 m underground and the 84 metres rock overburden imposes a cutoff of about 52 GeV/c on muon momenta. The data from the large volume Hadron Calorimeter allowed the muon multiplicity of 54,201 events to be reconstructed. The resulting muon multiplicity distribution is compared with the prediction of the Monte Carlo simulation based on CORSIKA/QGSJET01. The model fails to describe the abundance of high multiplicity events. The impact of QGSJET internal parameters on the results is also studied.

  2. Secondary Antiprotons in Cosmic Rays

    E-print Network

    I. V. Moskalenko; A. W. Strong; J. F. Ormes; M. S. Potgieter; U. W. Langner

    2001-06-27

    High energy collisions of cosmic ray (CR) nuclei with interstellar gas are believed to be the mechanism producing the majority of CR antiprotons. The distinguishing spectral shape with a maximum at 2 GeV and a sharp decrease towards lower energies makes antiprotons a unique probe of the models of particle propagation in the Galaxy and modulation in the heliosphere. Besides, accurate calculation of the secondary antiproton flux provides a ``background'' for searches for exotic signals from the annihilation of supersymmetric particles and primordial black hole evaporation. Recently new data with large statistics on the antiproton flux have become available which allow for such tests to be performed. We use our 3D Galactic cosmic ray propagation code GALPROP to calculate interstellar propagation in several models. For our best model we make predictions of proton and antiproton fluxes near the Earth for different modulation levels and polarity using a steady-state drift model for heliospheric modulation.

  3. Fractional diffusion of cosmic rays

    E-print Network

    A. A. Lagutin; V. V. Uchaikin

    2001-07-13

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

  4. Cosmic rays: the highest-energy messengers.

    PubMed

    Olinto, Angela V

    2007-01-01

    The origin of the most energetic particles ever observed, cosmic rays, will begin to be revealed in the next few years. Newly constructed ultrahigh-energy cosmic ray observatories together with high-energy gamma-ray and neutrino observatories are well positioned to unveil this mystery before the centenary of their discovery in 2012. Cosmic ray sources are likely to involve the most energetic phenomena ever witnessed in the universe. PMID:17204641

  5. Astrophysics of Galactic charged cosmic rays

    E-print Network

    Castellina, Antonella

    2011-01-01

    A review is given of the main properties of the charged component of galactic cosmic rays, particles detected at Earth with an energy spanning from tens of MeV up to about 10^19 eV. After a short introduction to the topic and an historical overview, the properties of cosmic rays are discussed with respect to different energy ranges. The origin and the propagation of nuclei in the Galaxy are dealt with from a theoretical point of view. The mechanisms leading to the acceleration of nuclei by supernova remnants and to their subsequent diffusion through the inhomogeneities of the galactic magnetic field are discussed and some clue is given on the predictions and observations of fluxes of antimatter, both from astrophysical sources and from dark matter annihilation in the galactic halo. The experimental techniques and instrumentations employed for the detection of cosmic rays at Earth are described. Direct methods are viable up to 10^14 eV, by means of experiments flown on balloons or satellites, while above that ...

  6. Cosmic ray penetration in diffuse clouds

    NASA Astrophysics Data System (ADS)

    Morlino, G.; Gabici, S.

    2015-07-01

    Cosmic rays are a fundamental source of ionization for molecular and diffuse clouds, influencing their chemical, thermal, and dynamical evolution. The amount of cosmic rays inside a cloud also determines the gamma-ray flux produced by hadronic collisions between cosmic rays and cloud material. We study the spectrum of cosmic rays inside and outside of a diffuse cloud by solving the stationary transport equation for cosmic rays including diffusion, advection, and energy losses due to ionization of neutral hydrogen atoms. We found that the cosmic ray spectrum inside a diffuse cloud differs from the one in the interstellar medium (ISM) for energies smaller than Ebr ? 100 MeV, irrespective of the model details. Below Ebr, the spectrum is harder (softer) than that in the ISM if the latter is a power law ?p-s with s larger (smaller) than ˜0.42.

  7. Cosmic ray penetration in diffuse clouds

    E-print Network

    Morlino, G

    2015-01-01

    Cosmic rays are a fundamental source of ionization for molecular and diffuse clouds, influencing their chemical, thermal, and dynamical evolution. The amount of cosmic rays inside a cloud also determines the $\\gamma$-ray flux produced by hadronic collisions between cosmic rays and cloud material. We study the spectrum of cosmic rays inside and outside of a diffuse cloud, by solving the stationary transport equation for cosmic rays including diffusion, advection and energy losses due to ionization of neutral hydrogen atoms. We found that the cosmic ray spectrum inside a diffuse cloud differs from the one in the interstellar medium for energies smaller than $E_{br}\\approx 100$ MeV, irrespective of the model details. Below $E_{br}$, the spectrum is harder (softer) than that in the interstellar medium if the latter is a power law $\\propto p^{-s}$ with $s$ larger (smaller) than $\\sim0.42$.

  8. Gamma Ray Signatures from Ordinary Cosmic Strings

    E-print Network

    Jane H. MacGibbon; Robert H. Brandenberger

    1992-06-19

    We calculate the flux of ultra high energy photons from individual ordinary (i.e. non-superconducting) cosmic strings and compare the results with the sensitivity of current and proposed TeV and EeV telescopes. Our calculations give only upper limits for the gamma ray flux, since the source of the photons, jets from particle production at cusps, may be weakened by back reaction effects. For the usual cosmic distribution of strings, the predicted bursts from strings with the value of mass per unit length associated with galaxy formation or light strings may just be detectable. A diffuse gamma ray background from light strings may also be seen by the Fly's Eye detector at above $7 \\times 10^{10}$ GeV.

  9. Ultrahigh Energy Cosmic Rays from Topological Defects --- Cosmic Strings, Monopoles, Necklaces, and All That

    E-print Network

    Pijushpani Bhattacharjee

    1998-03-03

    The topological defect scenario of origin of the observed highest energy cosmic rays is reviewed. Under a variety of circumstances, topological defects formed in the early Universe can be sources of very massive particles in the Universe today. The decay products of these massive particles may be responsible for the observed highest energy cosmic ray particles above $10^{20}$ eV. Some massive particle production processes involving cosmic strings and magnetic monopoles are discussed. We also discuss the implications of results of certain recent numerical simulations of evolution of cosmic strings. These results (which remain to be confirmed by independent simulations) seem to show that massive particle production may be a generic feature of cosmic strings, which would make cosmic strings an inevitable source of extremely high energy cosmic rays with potentially detectable flux. At the same time, cosmic strings are severely constrained by the observed cosmic ray flux above $10^{20}$ eV, if massive particle radiation is the dominant energy loss mechanism for cosmic strings.

  10. Light Element Evolution and Cosmic Ray Energetics

    E-print Network

    R. Ramaty; S. T. Scully; R. E. Lingenfelter; B. Kozlovsky

    1999-09-01

    Using cosmic-ray energetics as a discriminator, we investigate evolutionary models of LiBeB. We employ a Monte Carlo code which incorporates the delayed mixing into the ISM both of the synthesized Fe, due to its incorporation into high velocity dust grains, and of the cosmic-ray produced LiBeB, due to the transport of the cosmic rays. We normalize the LiBeB production to the integral energy imparted to cosmic rays per supernova. Models in which the cosmic rays are accelerated mainly out of the average ISM significantly under predict the measured Be abundance of the early Galaxy, the increase in [O/Fe] with decreasing [Fe/H] notwithstanding. We suggest that this increase could be due to the delayed mixing of the Fe. But, if the cosmic-ray metals are accelerated out of supernova ejecta enriched superbubbles, the measured Be abundances are consistent with a cosmic-ray acceleration efficiency that is in very good agreement with the current epoch data. We also find that neither the above cosmic-ray origin models nor a model employing low energy cosmic rays originating from the supernovae of only very massive progenitors can account for the $^6$Li data at values of [Fe/H] below $-$2.

  11. A hysteresis effect in cosmic ray modulation

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

    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.

  12. High-energy cosmic ray interactions

    SciTech Connect

    Engel, Ralph [Forschungszentrum Karlsruhe, P.O. Box 3640, 76021 Karlsruhe (Germany); Orellana, Mariana [Instituto Argentino de Radioastronomia (IAR), CCT La Plata (CONICET), C.C.5, 1894 Villa Elisa, Buenos Aires (Argentina); Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque, 1900 La Plata (Argentina); Reynoso, Matias M. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, (7600) Mar del Plata (Argentina); Instituto de Investigaciones Fisicas de Mar del Plata, (UNMdP-CONICET) (Argentina); Vila, Gabriela S. [Instituto Argentino de Radioastronomia (IAR), CCT La Plata (CONICET), C.C.5, 1894 Villa Elisa, Buenos Aires (Argentina)

    2009-04-30

    Research into hadronic interactions and high-energy cosmic rays are closely related. On one hand--due to the indirect observation of cosmic rays through air showers--the understanding of hadronic multiparticle production is needed for deriving the flux and composition of cosmic rays at high energy. On the other hand the highest energy particles from the universe allow us to study the characteristics of hadronic interactions at energies far beyond the reach of terrestrial accelerators. This is the summary of three introductory lectures on our current understanding of hadronic interactions of cosmic rays.

  13. Propagation of cosmic rays in the galaxy

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

    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.

  14. Cosmic ray modulation by interplanetary disturbances

    NASA Astrophysics Data System (ADS)

    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.

    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.

  15. Detection of reflected Cherenkov light from extensive air showers in the SPHERE experiment as a method of studying superhigh energy cosmic rays

    NASA Astrophysics Data System (ADS)

    Antonov, R. A.; Aulova, T. V.; Bonvech, E. A.; Galkin, V. I.; Dzhatdoev, T. A.; Podgrudkov, D. A.; Roganova, T. M.; Chernov, D. V.

    2015-01-01

    Although a large number of experiments were carried out during the last few decades, the uncertainty in the spectrum of all nuclei of primary cosmic rays (PCRs) with superhigh energies is still high, and the results of many experiments on nuclear composition of PCRs are contradictory. An overview of the SPHERE experiment on detecting Vavilov-Cherenkov radiation from extensive air shower (EAS) reflected from a ground snow surface is given. A number of experimental studies implementing this method are presented and their results are analyzed. Some other popular methods of studying PCRs with superhigh energies ( E 0 > 1015 eV) and their main advantages and drawbacks are briefly considered. The detecting equipment of the SPHERE-2 experiment and the technique of its calibration are considered. The optical properties of snow, which are important for experiments on reflected Cherenkov light (CL) from EAS, are discussed and the history of observing reflected EAS CL is described. The algorithm of simulating the detector response and calculating the fiducial acceptance of shower detection is described. The procedure of processing the experimental data with a subsequent reconstruction of the spectrum of all PCR nuclei and analysis of the mass composition is shown. The first results of reconstructing the spectrum and separating groups of cosmic-ray nuclei with high energies in the SPHERE-2 experiment are presented. Main sources of systematic errors are considered. The prospects of developing the technique of observation of reflected EAS CL in future experiments are discussed.

  16. Studies of Cosmic Rays with GeV Gamma Rays

    E-print Network

    Hiroyasu Tajima; Tuneyoshi Kamae; Stefano Finazzi; Johann Cohen-Tanugi; James Chiang

    2007-05-10

    We describe the role of GeV gamma-ray observations with GLAST-LAT (Gamma-ray Large Area Space Telescope - Large Area Telescope) in identifying interaction sites of cosmic-ray proton (or hadrons) with interstellar medium (ISM). We expect to detect gamma rays from neutral pion decays in high-density ISM regions in the Galaxy, Large Magellanic Cloud, and other satellite galaxies. These gamma-ray sources have been detected already with EGRET (Energetic Gamma Ray Experiment Telescope) as extended sources (eg. LMC and Orion clouds) and GLAST-LAT will detect many more with a higher spatial resolution and in a wider spectral range. We have developed a novel image restoration technique based on the Richardson-Lucy algorithm optimized for GLAST-LAT observation of extended sources. Our algorithm calculates PSF (point spread function) for each event. This step is very important for GLAST-LAT and EGRET image analysis since PSF varies more than one order of magnitude from one gamma ray to another depending on its energy as well as its impact point and angle in the instrument. The GLAST-LAT and EGRET image analysis has to cope with Poisson fluctuation due to low number of detected photons for most sources. Our technique incorporates wavelet filtering to minimize effects due to the fluctuation. Preliminary studies on some EGRET sources are presented, which shows potential of this novel image restoration technique for the identification and characterisation of extended gamma-ray sources.

  17. Pionic photons and neutrinos from cosmic ray accelerators

    NASA Astrophysics Data System (ADS)

    Halzen, Francis

    2013-03-01

    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.

  18. Cosmic-ray acceleration in supernova remnants

    NASA Astrophysics Data System (ADS)

    Helder, E. A.

    2010-09-01

    Supernovae are among the most energetic events in the Universe. During the event, they expel their material with enormous speeds into the surroundings. In addition, supernovae are thought to transfer a sizable fraction of their energy into just a few particles: cosmic rays. These cosmic rays acquire so much energy that they escape the supernova material with almost the speed of light. Some of these cosmic rays arrive on Earth, where in an unfortunate case, they can do damage to the electronics onboard satellites. This thesis describes several studies on the observational imprints of cosmic-ray acceleration in supernova remnants. We use optical and X-ray data to study how much energy is lost from the remnants to cosmic rays and how this energy is transferred to the particles.

  19. Supersymmetry and the Cosmic Ray Positron Excess

    SciTech Connect

    Kane, Gordon L.; Wang, Lian-Tao; Wang, Ting T.

    2002-02-15

    We explore several supersymmetric alternatives to explain predictions for the cosmic ray positron excess. Light sneutrino or neutralino LSP's, and a fine-tuned model designed to provide a delta-function input, can give adequate statistical descriptions of the reported HEAT data if non-thermal production of the relic cold dark matter density dominates and/or if"boost factors" (that could originate in uncertainties from propagation or local density fluctuations) to increase the size of the signal are included. All the descriptions can be tested at the Tevatron or LHC, and some in other WIMP detecting experiments.

  20. Research in cosmic and gamma ray astrophysics

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    Research activities in cosmic rays, gamma rays, and astrophysical plasmas are covered. The activities are divided into sections and described, followed by a bibliography. The astrophysical aspects of cosmic rays, gamma rays, and of the radiation and electromagnetic field environment of the Earth and other planets are investigated. These investigations are performed by means of energetic particle and photon detector systems flown on spacecraft and balloons.

  1. The Discovery and Nature of Cosmic Rays

    NSDL National Science Digital Library

    2012-08-03

    In this lesson, students will learn how cosmic rays were discovered and what they are - including their size and speed. Includes background information for the teacher, questions, activities and information about student preconceptions. This is lesson 1 of 4 from "The Cosmic Ray Telescope for the Effects of Radiation (CRaTER)."

  2. Cosmic Rays on the Pacific Ocean

    Microsoft Academic Search

    A. H. Compton; R. N. Turner

    1937-01-01

    Records of cosmic-ray intensity obtained on the R. M. S. Aorangi during 12 voyages between Vancouver, Canada and Sydney, Australia, from March 17, 1936, to January 18, 1937, using a Carnegie model C cosmic-ray meter, are described and discussed. Typical records exhibiting the latitude effect are shown. A summary of the data taken at sea is given in the form

  3. Measuring Cosmic Rays at 1 PeV and Above

    NASA Astrophysics Data System (ADS)

    Rawlins, Katherine

    2012-05-01

    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.

  4. The gamma ray content of ultrahigh energy cosmic radiation

    SciTech Connect

    Kolodziejczak, J.J.

    1990-01-01

    Data from the Utah-Michigan (UM) extensive air shower (EAS) array at Dugway, Utah are examined for evidence of a gamma ray component in the UHE cosmic rays. The UM array consist of a 3 {times} 10{sup 4} sq m surface array with 40 sq m of charged particle detectors, and a 1200 sq m buried array for detecting muons. Data from the large muon array are used to search for a gamma ray signature, since gamma rays are expected to produce far fewer muons in EAS than hadronic cosmic ray primaries. When no evidence for gamma rays is found, limits are set based on expected gamma ray behavior. For a photon energy threshold of 200 TeV, results include: a limit on the omnidirectional gamma ray fraction of cosmic rays at 0.2 pct; a limit on the galactic gamma ray fraction of cosmic rays at 7 {times} 10{sup {minus}5}; no strong evidence for enduring gamma ray point sources at fluxes approx. = 4 {times} 10{sup {minus}14}/sq cm/s; and no strong evidence for bursts on a one day time scale at a flux sensitivity {approx} 2 {times} 10{sup {minus}12}/sq cm/s. These limits and measurements are based on muon poor data. While no strong signal of UHE gamma rays is found, future application to the large Chicago Air Shower Array-Michigan Array (CASA-MIA) is possible.

  5. Tomographic-spectral approach for dark matter detection in the cross-correlation between cosmic shear and diffuse gamma-ray emission

    E-print Network

    Stefano Camera; Mattia Fornasa; Nicolao Fornengo; Marco Regis

    2014-11-17

    We recently proposed to cross-correlate the diffuse gamma-ray emission with the gravitational lensing signal of cosmic shear. This represents a novel and promising strategy to search for annihilating or decaying dark matter (DM) candidates. In the present work, we demonstrate the potential of a tomographic-spectral approach: measuring the cross-correlation in separate bins of redshift and energy significantly improves the sensitivity to a DM signal. Indeed, the power of the proposed technique stems from the capability of simultaneously exploiting the different redshift scaling of astrophysical and DM components, their different energy spectra and their different angular shapes. The sensitivity to a particle DM signal is extremely promising even in the case the gamma-ray emission induced by DM is a subdominant component in the isotropic gamma-ray background. We quantify the prospects of detecting DM by cross-correlating the gamma-ray emission from the Fermi large area telescope (LAT) with the cosmic shear measured by the Dark Energy Survey, using data sets that will be available in the near future. Under the hypothesis of a significant (but realistic) subhalo boost, such a measurement can deliver a 5-sigma detection of DM, if the DM particle has a mass lighter than 300 GeV and thermal annihilation rate. Data from the European Space Agency Euclid satellite (launch planned for 2020) will be even more informative: if used to reconstruct the properties of the DM particle, the cross-correlation of Euclid and Fermi-LAT will allow for a measurement of the DM mass within a factor of 1.5-2, even for moderate subhalo boosts, assuming the DM mass around 100 GeV and a thermal annihilation rate.

  6. Cosmic-Ray Modulation Equations

    NASA Astrophysics Data System (ADS)

    Moraal, H.

    2013-06-01

    The temporal variation of the cosmic-ray intensity in the heliosphere is called cosmic-ray modulation. The main periodicity is the response to the 11-year solar activity cycle. Other variations include a 27-day solar rotation variation, a diurnal variation, and irregular variations such as Forbush decreases. General awareness of the importance of this cosmic-ray modulation has greatly increased in the last two decades, mainly in communities studying cosmogenic nuclides, upper atmospheric physics and climate, helio-climatology, and space weather, where corrections need to be made for these modulation effects. Parameterized descriptions of the modulation are even used in archeology and in planning the flight paths of commercial passenger jets. The qualitative, physical part of the modulation is generally well-understood in these communities. The mathematical formalism that is most often used to quantify it is the so-called Force-Field approach, but the origins of this approach are somewhat obscure and it is not always used correct. This is mainly because the theory was developed over more than 40 years, and all its aspects are not collated in a single document. This paper contains a formal mathematical description intended for these wider communities. It consists of four parts: (1) a description of the relations between four indicators of "energy", namely energy, speed, momentum and rigidity, (2) the various ways of how to count particles, (3) the description of particle motion with transport equations, and (4) the solution of such equations, and what these solutions mean. Part (4) was previously described in Caballero-Lopez and Moraal (J. Geophys. Res, 109: A05105, doi: 10.1029/2003JA010358, 2004). Therefore, the details are not all repeated here. The style of this paper is not to be rigorous. It rather tries to capture the relevant tools to do modulation studies, to show how seemingly unrelated results are, in fact, related to one another, and to point out the historical context of some of the results. The paper adds no new knowledge. The summary contains advice on how to use the theory most effectively.

  7. Models for Galactic cosmic-ray propagation

    E-print Network

    A. W. Strong; I. V. Moskalenko

    2001-01-04

    A new numerical model of particle propagation in the Galaxy has been developed, which allows the study of cosmic-ray and gamma-ray production and propagation in 2D or 3D, including a full reaction network. This is a further development of the code which has been used for studies of cosmic ray reacceleration, Galactic halo size, antiprotons and positrons in cosmic rays, the interpretation of diffuse continuum gamma rays, and dark matter. In this paper we illustrate recent results focussing on B/C, sub-Fe/Fe, ACE radioactive isotope data, source abundances and antiprotons. From the radioactive nuclei we derive a range of 3-7 kpc for the height of the cosmic-ray halo.

  8. The Lateral Trigger Probability function for the ultra-high energy cosmic ray showers detected by the Pierre Auger Observatory

    SciTech Connect

    Abreu, P.; /Lisbon, IST /Lisbon, LIFEP; Aglietta, M.; /INFN, Turin /Turin Observ. /Turin U.; Ahn, E.J.; /Fermilab; Albuquerque, I.F.M.; /Sao Paulo U.; Allard, D.; /APC, Paris; Allekotte, I.; /Centro Atomico Bariloche /Balseiro Inst., San Carlos de Bariloche; Allen, J.; /New York U.; Allison, P.; /Ohio State U.; Alvarez Castillo, J.; /Mexico U.; Alvarez-Muniz, J.; /Santiago de Compostela U.; Ambrosio, M.; /INFN, Naples /Naples U. /Nijmegen U., IMAPP

    2011-01-01

    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{sup 17} and 10{sup 19} eV and zenith angles up to 65{sup o}. 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.

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

    E-print Network

    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

    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.

  10. Study of high energy cosmic ray interactions and primary composition using mountain based detectors

    Microsoft Academic Search

    Y. Fujimoto; V. Kopenkin; A. Ohsawa; M. Tamada; C. E. Navia; C. R. A. Augusto; A. K. Managadze; T. M. Roganova; I. V. Rakobolskaya; L. G. Sveshnikova

    2001-01-01

    We report new experimental results obtained by MSU-Waseda collaboration. Our detector is 60 cm thick lead X-ray emulsion chamber exposed to cosmic rays at Pamirs. We show that this experiment can detect cosmic rays in the wide energy range 1013 - 1017 eV. Using experimental data we discuss the primary cosmic ray composition and the features of hadron interactions in

  11. Cosmic Rays Variations and Human Physiological State

    NASA Astrophysics Data System (ADS)

    Dimitrova, S.

    2009-12-01

    It was obtained in our previous investigations that geomagnetic activity as an indirect indicator of solar activity correlates with some human physiological and psycho-physiological parameters. A lot of studies indicate that other parameters of space weather like cosmic rays Forbush decreases affect myocardial infarction, brain stroke, car accidents, etc. The purpose of that work was to study the effect of cosmic rays variations on human physiological status. It was established that the decrease in cosmic rays intensity was related to an increase in systolic and diastolic blood pressure and reported subjective psycho-physiological complaints in healthy volunteers.

  12. Cosmic ray propagation in the local superbubble

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  13. Cosmic Ray Protons Illuminate Dark Matter Axions

    E-print Network

    H. Tam; Q. Yang

    2011-08-16

    Cosmic ray protons propagating in a spatially-homogeneous but time-dependent field of axions or axion-like particles (ALPs) emit photons in a way that is reminiscent of Cherenkov radiation by charged particles in a preferred background. We compute the emission rate and energy spectrum of the photons, and discuss the possibility of their detection using the Square Kilometre Array which is currently under construction. In the case of a non-detection, constraints can be placed on the parameter space of ALPs whose mass lie between $10^{-7}$eV and $10^{-5}$ eV under the assumption that they are the primary constituent of dark matter.

  14. Diffusion of Cosmic-Rays and Gamma-Ray Sources

    NASA Astrophysics Data System (ADS)

    de Cea del Pozo, E.; Torres, D. F.; Marrero, A. Y. Rodríguez

    It is commonly accepted that supernova remnants (SNR) are one of the most probable scenarios of leptonic and hadronic cosmic-ray (CR) acceleration. Such energetic CR can interact with interstellar gas to produce high-energy gamma rays, which can be detected through ground-based air Cherenkov detectors and space telescopes. Here we present a theoretical model that explains the high energy phenomenology of the neighborhood SNR IC 443, as observed with the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescope and the Energetic Gamma-ray Experiment Telescope (EGRET). We interpret MAGIC J0616 + 225 as delayed TeV emission of CR diffusing from IC 443, what naturally explains the displacement between EGRET and MAGIC sources.

  15. A Simplified Model for the Acceleration of Cosmic Ray Particles

    ERIC Educational Resources Information Center

    Gron, Oyvind

    2010-01-01

    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…

  16. Consistency of cosmic-ray source abudances with explosive nucleosynthesis

    NASA Technical Reports Server (NTRS)

    Kozlovsky, B.; Ramaty, R.

    1973-01-01

    A model was examined in which the cosmic ray abundances of elements from C to Fe are consistent with explosive nucleosynthesis. The observed abundance of cosmic rays near the earth, cosmic ray source abundance, and solar system abundance are discussed along with the ratios of cosmic ray sources to the solar system abundances.

  17. astro-ph/941006720Oct1994 Detection of a Cosmic Ray with Measured Energy Well Beyond the

    E-print Network

    background radiation. In the restframe of such an energetic proton, the cosmic microwave radiation Spectral Cuto Due to Cosmic Microwave Radiation D.J. Bird,1;3 S.C. Corbato,2 H.Y. Dai,3 J.W. Elbert,3 K and produce a pion. In the universal restframe (in which the microwave radiation is at rest), the energetic

  18. Superdiffusion of cosmic rays: Implications for cosmic ray acceleration

    SciTech Connect

    Lazarian, A. [Department of Astronomy, University of Wisconsin, 475 North Charter Street, Madison, WI 53706 (United States); Yan, Huirong [KIAA, Peking University, 5 Yi He Yuan Rd, Beijing, 100871 (China)

    2014-03-20

    Diffusion of cosmic rays (CRs) is the key process for understanding their propagation and acceleration. We employ the description of spatial separation of magnetic field lines in magnetohydrodynamic turbulence in Lazarian and Vishniac to quantify the divergence of the magnetic field on scales less than the injection scale of turbulence and show that this divergence induces superdiffusion of CR in the direction perpendicular to the mean magnetic field. The perpendicular displacement squared increases, not as the distance x along the magnetic field, which is the case for a regular diffusion, but as the x {sup 3} for freely streaming CRs. The dependence changes to x {sup 3/2} for the CRs propagating diffusively along the magnetic field. In the latter case, we show that it is important to distinguish the perpendicular displacement with respect to the mean field and to the local magnetic field. We consider how superdiffusion changes the acceleration of CRs in shocks and show how it decreases efficiency of the CRs acceleration in perpendicular shocks. We also demonstrate that in the case when the small-scale magnetic field is generated in the pre-shock region, an efficient acceleration can take place for the CRs streaming without collisions along the magnetic loops.

  19. Cosmic Ray Nuclei (CRN) detector investigation

    Microsoft Academic Search

    Peter Meyer; Dietrich Muller; Jacques Lheureux; Simon Swordy

    1991-01-01

    The Cosmic Ray Nuclei (CRN) detector was designed to measure elemental composition and energy spectra of cosmic radiation nuclei ranging from lithium to iron. CRN was flown as part of Spacelab 2 in 1985, and consisted of three basic components: a gas Cerenkov counter, a transition radiation detector, and plastic scintillators. The results of the experiment indicate that the relative

  20. EDITORIAL: Focus on High Energy Cosmic Rays FOCUS ON HIGH ENERGY COSMIC RAYS

    NASA Astrophysics Data System (ADS)

    Teshima, Masahiro; Watson, Alan A.

    2009-06-01

    The topic of high-energy cosmic rays has recently attracted significant attention. While the AGASA and HiRes Observatories have closed after many years of successful operation, the Pierre Auger Observatory began taking data in January 2004 and the first results have been reported. Plans for the next generation of instruments are in hand: funding is now being sought for the northern phase of the Auger Observatory and plans for a space detector, JEM-EUSO, to be launched in 2013-14 are well advanced with the long-term target of a dedicated satellite for the 2020s. It therefore seemed an appropriate time to make a collection of outstanding and original research articles from the leading experimental groups and from some of the theorists who seek to interpret the hard-won data and to speculate on the origin of the highest energy cosmic rays. This focus issue in New Journal of Physics on the topic of high energy cosmic rays, contains a comprehensive account of the work of the Yakutsk group (A A Ivanov, S P Knurenko and I Ye Sleptsov) who have used Cerenkov radiation produced by shower particles in the air to provide the basis for energy calibration. This technique contrasts with that of detecting fluorescence radiation from space that is proposed for the JEM-EUSO instrument to be placed on the International Space Station in 2013, described by Y Takahashi. Supplementing this is an article by A Santangelo and A Petrolini describing the scientific goals, requirements and main instrument features of the Super Extreme Universe Space Observatory mission (S-EUSO). The use of fluorescence light to measure energies was the key component of the HiRes instrument and is also used extensively by the Pierre Auger Collaboration so an article, by F Arqueros, F Blanco and J Rosado, summarizing the properties of fluorescence emission, still not fully understood, is timely. M Nagano, one of the architects of the AGASA Observatory, has provided an overview of the experimental situation with regard to the energy spectrum of the highest energy cosmic rays. The remaining contributions are of a more theoretical nature and discuss propagation (T Stanev), the time structure of multi-messenger signals (G H W Sigl), ultra-high energy cosmic ray production near black holes (A Yu Neronov, D V Semikoz and I I Tkachev), production in jets associated with black holes (C D Dermer, S Razzaque, J Finke and A Atoyan) and emission from a specific object, Cen A (M Kachelriess, S S Ostapchenko and R Tomas). Additionally the potential of high energy cosmic rays to give information about features of hadronic interactions, specifically the cross-section for p-air collisions, is discussed in the paper by R Ulrich et al. We thank all our authors most sincerely for their efforts and Tim Smith and his editorial team for their hard work. We believe that this collection of articles will be of great value to workers in the field: further contributions to this focus issue will be published during the course of 2009. Focus on High Energy Cosmic Rays Contents The cosmic ray energy spectrum as measured using the Pierre Auger Observatory Giorgio Matthiae The northern site of the Pierre Auger Observatory Johannes Blümer and the Pierre Auger Collaboration Searching for new physics with ultrahigh energy cosmic rays Floyd W Stecker and Sean T Scully On the measurement of the proton-air cross section using air shower data R Ulrich, J Blümer, R Engel, F Schüssler and M Unger High energy radiation from Centaurus A M Kachelrieß, S Ostapchenko and R Tomàs Ultra-high-energy cosmic rays from black hole jets of radio galaxies C D Dermer, S Razzaque, J D Finke and A Atoyan Ultra-high energy cosmic ray production in the polar cap regions of black hole magnetospheres A Yu Neronov, D V Semikoz and I I Tkachev Time structure and multi-messenger signatures of ultra-high energy cosmic ray sources Günter Sigl Propagation of ultrahigh-energy cosmic rays Todor Stanev Search for the end of the energy spectrum of primary cosmic rays M Nagano Analysis of the fluorescence emission from atmospheric ni

  1. Apollo 17 lunar surface cosmic ray detector

    NASA Technical Reports Server (NTRS)

    Walker, R. M.

    1974-01-01

    The objectives and selected data are presented for the Apollo 17 Lunar Surface Cosmic Ray Experiment (LSCRE) for the purpose of introducing an analysis of three of the separate detectors contained within in LSCRE package. The mica detector for measuring heavy solar wind, and the lexan stack and glass detectors for measuring energetic particles in space are discussed in terms of their deployment, exposure time, calibration, and data yield. Relevant articles on solar particles, interplanetary ions, and cosmic ray nuclei are also included.

  2. SCATTERING OF HIGHER ENERGY COSMIC RAYS

    E-print Network

    Melrose, Don

    s discussed by Wentzel (1969a), Kulsrud and Pearce (1969), Tademaru (1969), S k i l l i n g (1970) and Melrose and Wentzel (1970). As applied t o cosmic rays t h i s theory f a i l s i n t h a t higher energy cosmic rays and Wentzel (1970). Terms of the order vA/c are neglected in (1). The most important of these neglected terms

  3. The 28th International Cosmic Ray Conference 1 X-ray and Gamma-ray Measurements

    E-print Network

    Enomoto, Ryoji

    The 28th International Cosmic Ray Conference 1 X-ray and Gamma-ray Measurements Masaki Mori and gamma-ray measurements, of the 28th International Cosmic Ray Conference. 1. Introduction Thick atmosphere of the earth forces direct observations of X-rays and gamma-rays on satellites in space

  4. Multi-spectra Cosmic Ray Flux Measurement

    NASA Astrophysics Data System (ADS)

    He, Xiaochun; Dayananda, Mathes

    2010-02-01

    The Earth's upper atmosphere is constantly bombarded by rain of charged particles known as primary cosmic rays. These primary cosmic rays will collide with the atmospheric molecules and create extensive secondary particles which shower downward to the surface of the Earth. In recent years, a few studies have been done regarding to the applications of the cosmic ray measurements and the correlations between the Earth's climate conditions and the cosmic ray fluxes [1,2,3]. Most of the particles, which reach to the surface of the Earth, are muons together with a small percentage of electrons, gammas, neutrons, etc. At Georgia State University, multiple cosmic ray particle detectors have been constructed to measure the fluxes and energy distributions of the secondary cosmic ray particles. In this presentation, we will briefly describe these prototype detectors and show the preliminary test results. Reference: [1] K.Borozdin, G.Hogan, C.Morris, W.Priedhorsky, A.Saunders, L.Shultz, M.Teasdale, Nature, Vol.422, 277 (2003). [2] L.V. Egorova, V. Ya Vovk, O.A. Troshichev, Journal of Atmospheric and Terrestrial Physics 62, 955-966 (2000). [3] Henrik Svensmark, Phy. Rev. Lett. 81, 5027 (1998). )

  5. COSMIC-RAY HELIUM HARDENING

    SciTech Connect

    Ohira, Yutaka; Ioka, Kunihito, E-mail: ohira@post.kek.jp [Theory Center, Institute of Particle and Nuclear Studies, KEK (High Energy Accelerator Research Organization), 1-1 Oho, Tsukuba 305-0801 (Japan)

    2011-03-01

    Recent observations by the CREAM and ATIC-2 experiments suggest that (1) the spectrum of cosmic-ray (CR) helium is harder than that of CR protons below the knee energy, 10{sup 15}eV, and (2) all CR spectra become hard at {approx}>10{sup 11}eV nucleon{sup -1}. We propose a new idea, that higher energy CRs are generated in a more helium-rich region, to explain the hardening without introducing different sources for CR helium. The helium-to-proton ratio at {approx}100 TeV exceeds the Big Bang abundance Y = 0.25 by several times, and the different spectrum is not reproduced within the diffusive shock acceleration theory. We argue that CRs are produced in a chemically enriched region, such as a superbubble, and the outward-decreasing abundance naturally leads to the hard spectrum of CR helium if CRs escape from the supernova remnant shock in an energy-dependent way. We provide a simple analytical spectrum that also fits well the hardening due to the decreasing Mach number in the hot superbubble with {approx}10{sup 6} K. Our model predicts hard and concave spectra for heavier CR elements.

  6. Contributions to the 19th International Cosmic Ray Conference

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Various aspects of cosmic radiation, its measurements and their patterns are presented. Measurement techniques and variations in solar cosmic ray patterns and calculations of elemental abundances are reviewed.

  7. Performance of the SciBar cosmic ray telescope (SciCRT) toward the detection of high-energy solar neutrons in solar cycle 24

    NASA Astrophysics Data System (ADS)

    Sasai, Yoshinori; Nagai, Yuya; Itow, Yoshitaka; Matsubara, Yutaka; Sako, Takashi; Lopez, Diego; Itow, Tsukasa; Munakata, Kazuoki; Kato, Chihiro; Kozai, Masayoshi; Miyazaki, Takahiro; Shibata, Shoichi; Oshima, Akitoshi; Kojima, Hiroshi; Tsuchiya, Harufumi; Watanabe, Kyoko; Koi, Tatsumi; Valdés-Galicia, Jose Francisco; González, Luis Xavier; Ortiz, Ernesto; Musalem, Octavio; Hurtado, Alejandro; Garcia, Rocio; Anzorena, Marcos

    2014-12-01

    We plan to observe solar neutrons at Mt. Sierra Negra (4,600 m above sea level) in Mexico using the SciBar detector. This project is named the SciBar Cosmic Ray Telescope (SciCRT). The main aims of the SciCRT project are to observe solar neutrons to study the mechanism of ion acceleration on the surface of the sun and to monitor the anisotropy of galactic cosmic-ray muons. The SciBar detector, a fully active tracker, is composed of 14,848 scintillator bars, whose dimension is 300 cm × 2.5 cm × 1.3 cm. The structure of the detector enables us to obtain the particle trajectory and its total deposited energy. This information is useful for the energy reconstruction of primary neutrons and particle identification. The total volume of the detector is 3.0 m × 3.0 m × 1.7 m. Since this volume is much larger than the solar neutron telescope (SNT) in Mexico, the detection efficiency of the SciCRT for neutrons is highly enhanced. We performed the calibration of the SciCRT at Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) located at 2,150 m above sea level in Mexico in 2012. We installed the SciCRT at Mt. Sierra Negra in April 2013 and calibrated this detector in May and August 2013. We started continuous observation in March 2014. In this paper, we report the detector performance as a solar neutron telescope and the current status of the SciCRT.

  8. Spiral arms as cosmic ray source distributions

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  9. The galactic cosmic ray ionization rate

    PubMed Central

    Dalgarno, A.

    2006-01-01

    The chemistry that occurs in the interstellar medium in response to cosmic ray ionization is summarized, and a review of the ionization rates that have been derived from measurements of molecular abundances is presented. The successful detection of large abundances of H3+ in diffuse clouds and the recognition that dissociative recombination of H3+ is fast has led to an upward revision of the derived ionization rates. In dense clouds the molecular abundances are sensitive to the depletion of carbon monoxide, atomic oxygen, nitrogen, water, and metals and the presence of large molecules and grains. Measurements of the relative abundances of deuterated species provide information about the ion removal mechanisms, but uncertainties remain. The models, both of dense and diffuse clouds, that are used to interpret the observations may be seriously inadequate. Nevertheless, it appears that the ionization rates differ in dense and diffuse clouds and in the intercloud medium. PMID:16894166

  10. 27Fermi Observatory and the Origin of Cosmic Rays Cosmic rays are fast-moving particles

    E-print Network

    Observatory has studied the gamma rays that comes from the remains of two nearby supernovae called IC-443 and W44, and has confirmed that the expanding matter does produce cosmic rays. IC-443 supernova remnant

  11. Nineteenth International Cosmic Ray Conference. HE Sessions, Volume 8

    NASA Technical Reports Server (NTRS)

    Jones, F. C. (compiler)

    1985-01-01

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

  12. TeV Strings and Ultrahigh-Energy Cosmic Rays

    E-print Network

    Illana, J I

    2001-01-01

    The origin and nature of ultrahigh-energy cosmic ray events, above the Greisen-Zatsepin-Kuzmin (GZK) cutoff energy, constitute a long-standing, unsolved mistery. Neutrinos are proposed candidates but their standard interactions with matter are too weak. In the context of a TeV-scale string theory, motivated by possible extra space dimensions, the neutrino-nucleon scattering is examined. Resonant string contributions increase substantially the standard model neutrino-nucleon cross section. Although they seem insufficient to explain the trans-GZK cosmic ray events, their effects might be detected in next experiments.

  13. Gamma-ray astronomy and cosmic ray origin problem

    NASA Astrophysics Data System (ADS)

    Berezhko, E.

    The purpose of this talk is to review some recent work on the model for the origin of the bulk of Galactic cosmic rays (CRs), namely that they are produced by diffusive shock acceleration in shock waves associated with supernova remnants (SNRs). This is currently the modern theory for the origin of Galactic CRs. Selfconsistent nonlinear theory of CR acceleration in SNRs developed during the last decade explains the main characteristics of the observed CR spectrum at least up to the knee energy. Direct information about CR population in young Galactic SNRs obtained from the properties of the nonthermal radiation is analysed. Electron CR component is visible ia a wide range of radiation, which they produce in SNRs, from radio to gamma-ray emission, whereas in the case of nuclear CR component gamma-rays detection is the only possibility to see it. If this nuclear component is strongly enhanced inside SNRs then through inelastic nuclear collisions, leading to pion production and subsequent decay, gamma-rays will be produced at the detectable level. It is argued that the existing data confirm very efficient acceleration of nuclear CRs in SNRs with the efficiency consistent with the requirements for the Galactic CR energy budget and that the theory is not only able to describe the CR dynamics and acceleration in SNRs, but that it constitutes in addition a reliable method to quantitatively determine the effective (strongly amplified) SNR magnetic field strength which is produced in the acceleration process.

  14. Cosmic ray fluctuations parameter as indicator of interplanetary "magnetic cork"

    NASA Astrophysics Data System (ADS)

    Kozlov, V. I.; Kozlov, V. V.

    2013-02-01

    It is established, that the main contribution into dynamics of galactic cosmic ray intensity fluctuations (GCR) in a vicinity of magnetic "cork" from a shock gives a nonrandom, non-Gauss component of GCR intensity. An occurrence of correlated fluctuations is caused by following circumstance: due to laws of conservation the probability that the cosmic ray particles reflected from a magnetic cork (in the expanding magnetic field) will undergo collimations, becomes considerable. The collimation will be manifested in focusing of particles into the anisotropic beams. In this case, observations should show "scintillations" of celestial sphere in cosmic rays i.e. the" HALO" effect. Similar scintillations are the indicator of interplanetary magnetic cork. The algorithm of detection of GCR scintillations is realized in real time using "Cyber-FORSHOCK" robotized system.

  15. Integral Neutron Multiplicity Measurements from Cosmic Ray Interactions in Lead

    SciTech Connect

    Ward, Thomas E. [Techsource Inc., 1418 Luisa St., Santa Fe. New Mexico 87505 (United States); Rimsky-Korsakov, Alexander A.; Kudryashev, Nikolai A. [V. G. Khlopin Radium Institute, 194021, 2-nd Murinsky pr. 28, St. Petersburg (Russian Federation); Beller, Denis E. [University of Nevada, Las Vegas, 4505 Maryland Parkway Box 454027, Las Vegas, NV 89154-4027 (United States)

    2006-07-11

    Sixty element 3He neutron multiplicity detector systems were designed, constructed and tested for use in cosmic ray experiments with a 30-cm cube lead target. A series of measurements were performed for the cosmic ray configuration at ground level (3 meters water equivalent, mwe), in the St. Petersburg metro tunnel (185 mwe), and in the Pyhasalmi mine in Finland (583 and 1185 mwe). Anomalous coincidence events with charged cosmic ray particles at sea level produced events with 100-120 neutrons due possibly to the total disintegration of the Pb nucleus. These events were also detected at 185 mwe, but the particles causing such disintegration are currently unidentified. We present examples of preliminary data from the various measurements and discuss future plans for underground experiments including possible searches for Weakly Interacting Massive Particles (WIMP, dark matter)

  16. Positron fraction in cosmic rays and models of cosmic-ray propagation

    NASA Astrophysics Data System (ADS)

    Cowsik, R.; Burch, B.

    2010-07-01

    The positron fraction observed by PAMELA and other experiments up to ˜100GeV is analyzed in terms of models of cosmic-ray propagation. It is shown that generically we expect the positron fraction to reach ˜0.6 at energies of several TeV, and its energy dependence bears an intimate but subtle connection with that of the boron to carbon ratio in cosmic rays. The observed positron fraction can be fit in a model that assumes a significant fraction of the boron below ˜10GeV is generated through spallation of cosmic-ray nuclei in a cocoonlike region surrounding the sources, and the positrons of energy higher than a few GeV are almost exclusively generated through cosmic-ray interactions in the general interstellar medium. Such a model is consistent with the bounds on cosmic-ray anisotropies and other observations.

  17. Cosmic Ray Interactions in Shielding Materials

    SciTech Connect

    Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Ankney, Austin S.; Orrell, John L.; Berguson, Timothy J.; Troy, Meredith D.

    2011-09-08

    This document provides a detailed study of materials used to shield against the hadronic particles from cosmic ray showers at Earth’s surface. This work was motivated by the need for a shield that minimizes activation of the enriched germanium during transport for the MAJORANA collaboration. The materials suitable for cosmic-ray shield design are materials such as lead and iron that will stop the primary protons, and materials like polyethylene, borated polyethylene, concrete and water that will stop the induced neutrons. The interaction of the different cosmic-ray components at ground level (protons, neutrons, muons) with their wide energy range (from kilo-electron volts to giga-electron volts) is a complex calculation. Monte Carlo calculations have proven to be a suitable tool for the simulation of nucleon transport, including hadron interactions and radioactive isotope production. The industry standard Monte Carlo simulation tool, Geant4, was used for this study. The result of this study is the assertion that activation at Earth’s surface is a result of the neutronic and protonic components of the cosmic-ray shower. The best material to shield against these cosmic-ray components is iron, which has the best combination of primary shielding and minimal secondary neutron production.

  18. Ultra heavy cosmic ray experiment (A0178)

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    The Ultra Heavy Cosmic Ray Experiment (UHCRE) is based on a modular array of 192 side viewing solid state nuclear track detector stacks. These stacks were mounted in sets of four in 48 pressure vessels using 16 peripheral LDEF trays. The geometry factor for high energy cosmic ray nuclei, allowing for Earth shadowing, was 30 sq m sr, giving a total exposure factor of 170 sq m sr y at an orbital inclination of 28.4 degs. Scanning results indicate that about 3000 cosmic ray nuclei in the charge region with Z greater than 65 were collected. This sample is more than ten times the current world data in the field (taken to be the data set from the HEAO-3 mission plus that from the Ariel-6 mission) and is sufficient to provide the world's first statistically significant sample of actinide cosmic rays. Results are presented including a sample of ultra heavy cosmic ray nuclei, analysis of pre-flight and post-flight calibration events and details of track response in the context of detector temperature history. The integrated effect of all temperature and age related latent track variations cause a maximum charge shift of + or - 0.8e for uranium and + or - 0.6e for the platinum-lead group. Astrophysical implications of the UHCRE charge spectrum are discussed.

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

    NASA Technical Reports Server (NTRS)

    Moiseev, Alexander

    2011-01-01

    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,

  20. Cosmic Ray Nuclei (CRN) detector investigation

    NASA Technical Reports Server (NTRS)

    Meyer, Peter; Muller, Dietrich; Lheureux, Jacques; Swordy, Simon

    1991-01-01

    The Cosmic Ray Nuclei (CRN) detector was designed to measure elemental composition and energy spectra of cosmic radiation nuclei ranging from lithium to iron. CRN was flown as part of Spacelab 2 in 1985, and consisted of three basic components: a gas Cerenkov counter, a transition radiation detector, and plastic scintillators. The results of the experiment indicate that the relative abundance of elements in this range, traveling at near relativistic velocities, is similar to those reported at lower energy.

  1. Search for correlations of GRB and cosmic rays

    NASA Astrophysics Data System (ADS)

    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

    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.

  2. Low-energy cosmic rays in the Orion region

    Microsoft Academic Search

    Martin Pohl

    1998-01-01

    The recently observed nuclear ?-ray line emission from the Orion complex implies a high flux of low-energy cosmic rays (LECR) with unusual abundance. This cosmic ray component would dominate the energy density, pressure, and ionising power of cosmic rays, and thus would have a strong impact on the general structure of the interstellar medium. We propose an independent test for

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  4. Did Cosmic Rays Reionize the Intergalactic Medium?

    E-print Network

    Biman B. Nath; Peter L. Biermann

    1993-06-02

    We investigate the role of cosmic rays from young galaxies in heating and ionizing the intergalactic medium (IGM) at high redshift. Using the IRAS observations at $60 \\mu m$, we estimate the cosmic ray luminosity density at the present epoch. We consider various forms of luminosity evolution in redshift and calculate (a) the thresholds corresponding to the upper limits of Gunn-Peterson optical depth, (b) the Compton $y$ parameter for an IGM heated by cosmic rays and compare with the upper limits from COBE measurements and (c) an estimated limit from the integral of metal enrichment. We show that certain models, with rather strong evolution and early formation of galaxies, allow reionization of the IGM, consistent with all known constraints.

  5. Cosmic ray ionization of the interstellar medium

    E-print Network

    Biman B. Nath; Peter L. Biermann

    1993-11-18

    We consider a cosmic ray spectrum that is a power law in momentum down to a cutoff and derive a lower cutoff corresponding to $E_{kin} \\sim (30-60)$ MeV from the observed ionization rates in nearby diffuse clouds. While the real spectra of cosmic rays may not be so simple, we argue that one expects a substantial change in the spectra at such energies and that, at first approximation, a power law spectra with a lower cutoff is appropriate. Such a description of the cosmic rays in the interstellar medium is not only theoretically more attractive than the spectra used in the literature, but is also supported by recent observations.

  6. The LDEF ultra heavy cosmic ray experiment

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    The Long Duration Exposure Facility (LDEF) Ultra Heavy Cosmic Ray Experiment (UHCRE) used 16 side viewing LDEF trays giving a total geometry factor for high energy cosmic rays of 30 sq m sr. The total exposure factor was 170 sq m sr y. The experiment is based on a modular array of 192 solid state nuclear track detector stacks, mounted in sets of 4 pressure vessels (3 experiment tray). The extended duration of the LDEF mission has resulted in a greatly enhanced potential scientific yield from the UHCRE. Initial scanning results indicate that at least 2000 cosmic ray nuclei with Z greater than 65 were collected, including the world's first statistically significant sample of actinides. Postflight work to date and the current status of the experiment are reviewed. Provisional results from analysis of preflight and postflight calibrations are presented.

  7. The LDEF ultra heavy cosmic ray experiment

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  8. Cosmic ray interactions with the Venusian atmosphere

    NASA Astrophysics Data System (ADS)

    Plainaki, Christina; Paschalis, Pavlos; Grassi, Davide; Mavromichalaki, Helen; Andriopoulou, Maria

    2015-04-01

    The interactions between galactic cosmic ray particles and the atmosphere of Venus result in extensive nuclear and electromagnetic cascades that can affect cloud formation and atmospheric physics in deep atmospheric layers. In this work, we perform a calculation of the atmosphere ionization and ion production rates caused by cosmic rays, as a function of depth in the Venusian atmosphere. In order to perform this estimation, we use a Monte Carlo modeling technique based on the Geant4 software, previously applied for the Earth case; our predictions are afterwards compared to other estimations derived from previous studies. The current method is furthermore proposed as a paradigm for studying cosmic rays-atmosphere interactions in all terrestrial planets possessing atmospheres.

  9. 28th International Cosmic Ray Conference 333 The Lateral Distribution Function of Shower Signals in the

    E-print Network

    28th International Cosmic Ray Conference 333 The Lateral Distribution Function of Shower Signals the primary energy can be estimated from the signal S(1000) at a distance of about 1000 m from the shower axis energy cosmic rays (CRs) are detected via the extensive air showers (EAS) they produce in the Earth

  10. 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

  11. Cosmic-ray acceleration in supernova shocks

    E-print Network

    Vincent Tatischeff

    2008-07-25

    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.

  12. Supernova remnants as cosmic ray accelerators. SNR IC 443

    E-print Network

    B. Hnatyk; O. Petruk

    1999-02-10

    We examine the hypothesis that some supernova remnants (SNRs) may be responsible for some unidentified gamma-ray sources detected by EGRET instrument aboard the Compton Gamma Ray Observatory. If this is the case, gamma-rays are produced via pion production and decay from direct inelastic collisions of accelerated by SNR shock wave ultrarelativistic protons with target protons of the interstellar medium. We develop a 3-D hydrodynamical model of SNR IC 443 as a possible cosmic gamma-ray source 2EG J0618+2234. The derived parameters of IC 443: the explosion energy E_o=2.7*10^{50} erg, the initial hydrogen number density n(0)=0.21 cm^{-3}, the mean radius R=9.6 pc and the age t=4500 yr result in too low gamma-ray flux, mainly because of the low explosion energy. Therefore, we investigate in detail the hydrodynamics of IC 443 interaction with a nearby massive molecular cloud and show that the reverse shock wave considerably increases the cosmic ray density in the interaction region. Meantime, the Rayleigh-Taylor instability of contact discontinuity between the SNR and the cloud provides an effective mixing of the containing cosmic ray plasma and the cloud material. We show that the resulting gamma-ray flux is consistent with the observational data.

  13. The Interstellar Transport of Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Lave, Kelly A.

    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 spectra of galactic cosmic rays with energies from ˜50--550 MeV/nucleon and nuclear charge 5?Z?28 are reported here. These results cover observations during two solar minimum periods of the solar cycle, the most recent of which exhibited very low levels of solar activity and the highest galactic cosmic-ray intensities of the space era. Observations of secondary cosmic-ray species, those produced primarily by spallation interactions of accelerated material with the interstellar medium, and their primary progenitors are used to test the models of the transport of cosmic rays in the Galaxy. Two principal models were tested: the simple leaky-box model and the nested leaky-box model. In the simple leaky-box model, cosmic rays accelerated at their sources are transported uniformly through the interstellar medium and escape in an energy-dependent fashion from the Galaxy. In the nested leaky-box model, cosmic rays are accelerated at their sources and briefly stored in surrounding cocoon regions before they escape into the Galaxy; escape from the cocoon regions is energy dependent while escape from the Galaxy is independent of energy. Our observed B/C and (Sc+ Ti+V)/Fe ratios are compared with the results from these two models, and we find that the simple leaky-box model fits the data very well only when escape from the Galaxy has an unphysical energy dependence below ˜1 GeV/nucleon. Though the nested leaky-box model is considered to be more physically reasonable, we could not simultaneously fit the B/C and (Sc+Ti+ V)/Fe ratios at all energies. A model that includes a small amount of reacceleration, a process that boosts low-energy cosmic rays up to higher energies, is found to agree well with results from the simple leaky-box model.

  14. Threshold meson production and cosmic ray transport

    E-print Network

    John W. Norbury; Lawrence W. Townsend; Ryan B. Norman

    2006-12-11

    An interesting accident of nature is that the peak of the cosmic ray spectrum, for both protons and heavier nuclei, occurs near the pion production threshold. The Boltzmann transport equation contains a term which is the cosmic ray flux multiplied by the cross section. Therefore when considering pion and kaon production from proton-proton reactions, small cross sections at low energy can be as important as larger cross sections at higher energy. This is also true for subthreshold kaon production in nuclear collisions, but not for subthreshold pion production.

  15. Cosmic ray modulation inside stellar wind cavities

    NASA Astrophysics Data System (ADS)

    Van Der Schyff, August; Scherer, Klaus; Ferreira, Stefan; Toit Strauss, Du

    In this study we attempt to model the cosmic ray flux in a stellar wind cavity of a O or B type star using a transport model based on stochastic differential equations. The required parameters, for example the coefficients of the diffusion tensor, are determined from an underlying magneto-hydrodynamical model. We discuss the transport in different astrospheric models with varying parameters for the transport coefficients. We will argue that large stellar wind cavities can act as sinks for the galactic cosmic ray flux.

  16. Propagation of Cosmic Rays and Diffuse Galactic Gamma Rays

    E-print Network

    I. V. Moskalenko

    2004-10-08

    This paper presents an introduction to the astrophysics of cosmic rays and diffuse gamma rays and discusses some of the puzzles that have emerged recently due to more precise data and improved propagation models: the excesses in Galactic diffuse gamma-ray emission, secondary antiprotons and positrons, and the flatter than expected gradient of cosmic rays in the Galaxy. These also involve the dark matter, a challenge to modern physics, through its indirect searches in cosmic rays. Though the final solutions are yet to be found, I discuss some ideas and results obtained mostly with the numerical propagation model GALPROP. A fleet of spacecraft and balloon experiments targeting these specific issues is set to lift off in a few years, imparting a feeling of optimism that a new era of exciting discoveries is just around the corner. A complete and comprehensive discussion of all the recent results is not attempted here due to the space limitations.

  17. The Heliosphere and Galactic Cosmic Rays - Duration: 39 seconds.

    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...

  18. The Isotopic Composition of Cosmic-Ray Iron and Nickel

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, M.; Binns, W.; Christian, E.; Cummings, A.; George, J.; Hink, P.; Klarmann, J.; Leske, R.; Lijowski, M.; Mewaldt, R.; Stone, E.; Rosenvinge, T. von

    2000-01-01

    Observations from the Cosmic Ray Isotope Spectrometer (CRIS) on ACE have been used to derive contraints on the locations, physical conditions, and time scales for cosmic-ray acceleration and transport.

  19. Rare components in cosmic rays with AMS-02

    NASA Astrophysics Data System (ADS)

    Sabellek, A.; AMS Collaboration

    2008-07-01

    The Alpha Magnetic Spectrometer 02 (AMS-02), like the AMS-01 experiment flown in 1998 on board the Space Shuttle, offers a unique opportunity for exploration of cosmic rays. AMS-02 will be installed to the International Space Station (ISS) providing precise data on cosmic radiation spectra in a wide energy range for at least three years. Although the major part of cosmic ray particles is of astrophysical origin, a small component may originate from interaction of dark matter particles. Redundant detection in several sub-detectors with accurate particle identification allows precision measurements and identification of up to now concealed or undetected deviation from Standard Model prediction. After an introduction to detector design, an overview of physics goals of AMS-02 is given.

  20. Pulsars, supernovae, and ultrahigh energy cosmic rays

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    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.

  1. Cosmic Rays for Heliospheric Space Weather Storm Prediction

    NASA Astrophysics Data System (ADS)

    Jansen, Frank; Behrens, Jörg

    2011-06-01

    The classical imaging of CME's by solar UV light is successfully applied on many satellites like for instance on SOHO, STEREO A and B or SDO. CME detection via UV light from ground based telescopes can't be carried out, because of the absorption of UV light in the Earth atmosphere. However CME detection is done on ground by means of cosmic ray muon telescopes in the Global Muon Detection Network (GMDN). Therefore the astrophysics and solar physics for GMDN are summarized in chapter 1. GMDN data and results are described in chapter 2. A space situational awareness (SSA) satellite, which has also the purpose of CME imaging by means of a telescope for cosmic rays are sketched in chapter 3.

  2. Angular correlation of cosmic neutrinos with ultrahigh-energy cosmic rays and implications for their sources

    E-print Network

    Reetanjali Moharana; Soebur Razzaque

    2015-01-21

    Cosmic neutrino events detected by the IceCube Neutrino Observatory with energy $\\gtrsim 30$ TeV have poor angular resolutions to reveal their origin. Ultrahigh-energy cosmic rays (UHECRs), with better angular resolutions at $>60$ EeV energies, can be used to check if the same astrophysical sources are responsible for producing both neutrinos and UHECRs. We test this hypothesis, with statistical methods which emphasize invariant quantities, by using data from the Pierre Auger Observatory, Telescope Array and past cosmic-ray experiments. We find that the arrival directions of the cosmic neutrinos are correlated with $\\ge 100$ EeV UHECR arrival directions at confidence level $\\approx 93\\%$. The strength of the correlation decreases with decreasing UHECR energy and no correlation exists at energy $\\sim 60$ EeV. A search in astrophysical databases within $3^\\circ$ of the arrival directions of UHECRs with energy $\\ge 100$ EeV, that are correlated with the IceCube cosmic neutrinos, resulted in 18 sources from the Swift-BAT X-ray catalog with redshift $z\\le 0.06$. We also found 3 objects in the K\\"uhr catalog of radio sources using the same criteria. The sources are dominantly Seyfert galaxies with Cygnus A being the most prominent member. We calculate the required neutrino and UHECR fluxes to produce the observed correlated events, and estimate the corresponding neutrino luminosity (25 TeV-2.2 PeV) and cosmic-ray luminosity (500 TeV-180 EeV), assuming the sources are the ones we found in the Swift-BAT and K\\"uhr catalogs. We compare these luminosities with the X-ray luminosity of the corresponding sources and discuss possibilities of accelerating protons to $\\gtrsim 100$ EeV and produce neutrinos in these sources.

  3. Cosmic strings and ultra-high energy cosmic rays

    NASA Technical Reports Server (NTRS)

    Bhattacharjee, Pijushpani

    1989-01-01

    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.

  4. Microphysics of Cosmic Ray Driven Plasma Instabilities

    NASA Astrophysics Data System (ADS)

    Bykov, A. M.; Brandenburg, A.; Malkov, M. A.; Osipov, S. M.

    2013-10-01

    Energetic nonthermal particles (cosmic rays, CRs) are accelerated in supernova remnants, relativistic jets and other astrophysical objects. The CR energy density is typically comparable with that of the thermal components and magnetic fields. In this review we discuss mechanisms of magnetic field amplification due to instabilities induced by CRs. We derive CR kinetic and magnetohydrodynamic equations that govern cosmic plasma systems comprising the thermal background plasma, comic rays and fluctuating magnetic fields to study CR-driven instabilities. Both resonant and non-resonant instabilities are reviewed, including the Bell short-wavelength instability, and the firehose instability. Special attention is paid to the longwavelength instabilities driven by the CR current and pressure gradient. The helicity production by the CR current-driven instabilities is discussed in connection with the dynamo mechanisms of cosmic magnetic field amplification.

  5. Microphysics of Cosmic Ray Driven Plasma Instabilities

    NASA Astrophysics Data System (ADS)

    Bykov, A. M.; Brandenburg, A.; Malkov, M. A.; Osipov, S. M.

    Energetic nonthermal particles (cosmic rays, CRs) are accelerated in supernova remnants, relativistic jets and other astrophysical objects. The CR energy density is typically comparable with that of the thermal components and magnetic fields. In this review we discuss mechanisms of magnetic field amplification due to instabilities induced by CRs. We derive CR kinetic and magnetohydrodynamic equations that govern cosmic plasma systems comprising the thermal background plasma, comic rays and fluctuating magnetic fields to study CR-driven instabilities. Both resonant and non-resonant instabilities are reviewed, including the Bell short-wavelength instability, and the firehose instability. Special attention is paid to the longwavelength instabilities driven by the CR current and pressure gradient. The helicity production by the CR current-driven instabilities is discussed in connection with the dynamo mechanisms of cosmic magnetic field amplification.

  6. Are Clusters as Indicators of the Cosmic Ray Anisotropy ?

    E-print Network

    A. A. Mikhailov; N. N. Efremov

    2004-11-01

    The clusters (doublets) in ultrahigh energy cosmic rays are considered based on Yakutsk and AGASA extensive air shower array data. The problem of cluster origin is discussed. It is found that arrival directions of the clusters can point to a cosmic ray anisotropy. As a result of analysis of clusters, the conclusion on composition and origin of ultrahigh energy cosmic rays has been made.

  7. Gamma-ray astronomy and the origin of cosmic rays

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1978-01-01

    New surveys of galactic gamma ray emission together with millimeter wave radio surveys indicated that cosmic rays were produced as the result of supernova explosions in our galaxy with the most intense production occurring in a Great Galactic Ring about 35,000 light years in diameter where supernova remnants and pulsars were concentrated.

  8. Numerical likelihood analysis of cosmic ray anisotropies

    SciTech Connect

    Carlos Hojvat et al.

    2003-07-02

    A numerical likelihood approach to the determination of cosmic ray anisotropies is presented which offers many advantages over other approaches. It allows a wide range of statistically meaningful hypotheses to be compared even when full sky coverage is unavailable, can be readily extended in order to include measurement errors, and makes maximum unbiased use of all available information.

  9. Believability of signals from cosmic ray sources

    SciTech Connect

    Goodman, M.

    1990-11-01

    This paper discusses some of the criteria by which an observer judges whether to believe a signal or limit that has been reported for a cosmic ray source. The importance of specifying the test before looking at the data is emphasized. 5 refs.

  10. Terrestrial Effects of High Energy Cosmic Rays

    E-print Network

    Atri, Dimitra

    2011-04-26

    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...

  11. The energy spectrum of cosmic ray positrons

    Microsoft Academic Search

    M. Giler; J. Wdowczyk; A. W. Wolfendale

    1977-01-01

    A calculation has been made of the predicted energy spectrum of positrons generated by the positive pions and kaons produced in turn in the interactions of cosmic ray nuclei with the interstellar medium (ISM). A critical appraisal of the results and a comparison with the predictions of other workers are given. Experimental data on the measured energy spectrum have been

  12. A Cosmic-Ray Radio Sonde

    Microsoft Academic Search

    H. V. Neher; W. H. Pickering

    1942-01-01

    The cosmic-ray radio sonde described in this paper was used for observations in the stratosphere near the magnetic equator. The instrument can be used for single counters or coincidences up to fourfold. It includes the necessary amplifiers and scaling circuits to operate a relay which keys the radio-transmitter. High voltage for the counters is provided by a buzzer and transformer

  13. Searching for Dark Matter with Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Seo, Eun-Suk

    2015-04-01

    One of the most exciting possibilities in cosmic ray research is the potential to discover new phenomena. A number of elementary particles were discovered in cosmic rays before modern-day accelerators became available to study their detailed properties. Since the discovery of cosmic ray antiprotons in 1979 using a balloon-borne magnet spectrometer, a series of magnet spectrometers have been flown to search for the signature of dark matter annihilation in antiprotons and positrons. Being the same as particles except for their opposite charge sign, antiparticles are readily distinguished as they bend in opposite directions in the magnetic field. As long-duration balloon flights over Antarctica became available, not only antiproton to proton ratios but also measurements of antiproton energy spectra became possible. More recently, space missions are also providing precision measurements of electron and position energy spectra. With other measurements to constrain cosmic ray propagation models, these new measurements play key roles in constraining dark-matter models for understanding the nature of dark matter. Recent results, their implications, and outlook for the field will be presented.

  14. Cosmic Ray Acceleration by Magnetic Traps

    E-print Network

    V. N. Zirakashvili

    2001-06-05

    Cosmic ray acceleration in turbulent interstellar medium is considered. Turbulence is treated as ensemble of moving magnetic traps. We derive equations for particle momentum distribution function that describes acceleration of particles in this case. Rate of acceleration calculated is estimated for our Galaxy and compared with ones given by other acceleration mechanisms.

  15. Cosmic-ray ionisation in collapsing clouds

    NASA Astrophysics Data System (ADS)

    Padovani, M.; Hennebelle, P.; Galli, D.

    2013-12-01

    Context. Cosmic rays play an important role in dense molecular cores, affecting their thermal and dynamical evolution and initiating the chemistry. Several studies have shown that the formation of protostellar discs in collapsing clouds is severely hampered by the braking torque exerted by the entrained magnetic field on the infalling gas, as long as the field remains frozen to the gas. Aims: In this paper we examine the possibility that the concentration and twisting of the field lines in the inner region of collapse can produce a significant reduction of the ionisation fraction. Methods: To check whether the cosmic-ray ionisation rate can fall below the critical value required to maintain good coupling, we first study the propagation of cosmic rays in a model of a static magnetised cloud varying the relative strength of the toroidal/poloidal components and the mass-to-flux ratio. We then follow the path of cosmic rays using realistic magnetic field configurations generated by numerical simulations of a rotating collapsing core with different initial conditions. Results: We find that an increment of the toroidal component of the magnetic field, or, in general, a more twisted configuration of the field lines, results in a decrease in the cosmic-ray flux. This is mainly due to the magnetic mirroring effect that is stronger where larger variations in the field direction are present. In particular, we find a decrease of the cosmic-ray ionisation rate below 10-18 s-1 in the central 300-400 AU, where density is higher than about 109 cm-3. This very low value of the ionisation rate is attained in the cases of intermediate and low magnetisation (mass-to-flux ratio ? = 5 and 17, respectively) and for toroidal fields larger than about 40% of the total field. Conclusions: Magnetic field effects can significantly reduce the ionisation fraction in collapsing clouds. We provide a handy fitting formula to compute approximately the attenuation of the cosmic-ray ionisation rate in a molecular cloud as a function of the density and the magnetic configuration.

  16. High altitude cosmic ray research on Tibet highland

    NASA Astrophysics Data System (ADS)

    Tan, Youheng

    2003-12-01

    With the development of ?-ray astronomy, a cosmic ray observatory was founded in the Yangbajing valley of Tibet highland (4300 m.a.s.l.) 10 years ago. Its EAS array of China-Japan AS? Collaboration detected successfully the steady emission of multi-TeV ? rays from the Crab Nebula, the strong outbursts from AGN Mrk 501 in 1997 and from Mrk 421 in 2000, which is the first detection in the EAS experiments. The deviation and movement of Sun shadow by cosmic rays induced by solar and interplanetary magnetic field, has been only observed and will be adopted to monitor the variations of solar activity. Taking the advantages of high altitude and the combination of experiments of EAS array and emulsion chambers + burst detectors, the primary energy spectrum and composition of ultra-high energy cosmic ray have been studied. For exploring the 100 GeV gap region between the space and ground-based experiments, the project of China-Italy ARGO Collaboration is under constructing. Finally, to challenge the 5 GeV low threshold and the highly variable extragalactic sources, a high altitude huge IACT project 5@YorG in the future is discussed.

  17. In Search of Cosmic Rays: A Student Physics Project Aimed at Finding the Origin of Cosmic Rays.

    ERIC Educational Resources Information Center

    Antonelli, Jamie; Mahoney, Sean; Streich, Derek; Liebl, Michael

    2001-01-01

    Describes an ongoing project, the Cosmic Ray Observatory Project (CROP), being conducted by the University of Nebraska in partnership with several high schools. Each school group has installed cosmic ray detectors, and initial activities have included calibrating equipment, gathering preliminary data, and learning about cosmic ray showers. Aims to…

  18. Supernova Remnants as the Sources of Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Vink, J.

    2013-01-01

    The origin of cosmic rays holds still many mysteries hundred years after they were first discovered. Supernova remnants have for long been the most likely sources of Galactic cosmic rays. I discuss here some recent evidence that suggests that supernova remnants can indeed efficiently accelerate cosmic rays. For this conference devoted to the Astronomical Institute Utrecht I put the emphasis on work that was done in my group, but placed in a broader context: efficient cosmic-ray acceleration and the implications for cosmic-ray escape, synchrotron radiation and the evidence for magnetic-field amplification, potential X-ray synchrotron emission from cosmic-ray precursors, and I conclude with the implications of cosmic-ray escape for a Type Ia remnant like Tycho and a core-collapse remnant like Cas A.

  19. Elemental technetium and promethium as cosmic-ray clocks

    NASA Technical Reports Server (NTRS)

    Drach, J.; Salamon, M. H.

    1987-01-01

    The possibility of using elemental Tc (Z = 43) and Pm (Z = 61) as clocks to measure the mean cosmic-ray confinement time in the Galaxy, tau(epsilon) is considered. For this purpose it is necessary to estimate the unknown beta(+) decay half-lives of several Tc and Pm isotopes; these estimates are obtained using beta-decay systematics. In the case of Tc it is possible to estimate the half-lives sufficiently well and show that this element can indeed be used as a cosmic-ray clock; in the case of Pm the half-lives are too uncertain to permit any conclusion. In order to make meaningful measurement of tau(epsilon) using elemental Tc, a comsic-ray detector must have a charge resolution less than about 0.25e in the region around Tc, and enough collecting power to detect a few hundred Tc nuclei.

  20. Cosmic ray propagation with CRPropa 3

    NASA Astrophysics Data System (ADS)

    Alves Batista, R.; Erdmann, M.; Evoli, C.; Kampert, K.-H.; Kuempel, D.; Mueller, G.; Sigl, G.; Van Vliet, A.; Walz, D.; Winchen, T.

    2015-05-01

    Solving the question of the origin of ultra-high energy cosmic rays (UHECRs) requires the development of detailed simulation tools in order to interpret the experimental data and draw conclusions on the UHECR universe. CRPropa is a public Monte Carlo code for the galactic and extragalactic propagation of cosmic ray nuclei above ? 1017 eV, as well as their photon and neutrino secondaries. In this contribution the new algorithms and features of CRPropa 3, the next major release, are presented. CRPropa 3 introduces time-dependent scenarios to include cosmic evolution in the presence of cosmic ray deflections in magnetic fields. The usage of high resolution magnetic fields is facilitated by shared memory parallelism, modulated fields and fields with heterogeneous resolution. Galactic propagation is enabled through the implementation of galactic magnetic field models, as well as an efficient forward propagation technique through transformation matrices. To make use of the large Python ecosystem in astrophysics CRPropa 3 can be steered and extended in Python.

  1. Fluoresence Detection of Cosmic Ray Air Showers Between 10 16 . 5 eV and 1019 eV with the Telescope Array Low Energy Extension (TALE)

    NASA Astrophysics Data System (ADS)

    Zundel, Zachary; Smith, Jeremy; Thomas, Stan; Abuzayyad, Tareq; Ivanov, Dmitri; Matthews, John; Jui, Charlie

    2014-03-01

    The Telescope Array Experiment has been observing cosmic ray air showers at energies above 1018 eV since 2008. TA operates three Fluorescence Detector (FD) sites, with telescopes that observe 3-31 deg in elevation. The FD sites are located at the periphery of a surface array of 507 scintillation counters covering 700 km2 , with 1.2 km spacing. The TA Collaboration has completed building a low-energy extension at its Middle drum FD site. Ten new telescopes currently observe between 33 and 51 degrees in elevation. A graded ground array of between 400 and 600m will be placed in front of the TALE FD. With these upgrades, the physics threshold of TA will be lowered to 10 16 . 5 eV. The TA Low Energy Extension (TALE) will explore the energy regime corresponding to that of the LHC in center-of-mass frame. This is also the range where the transition from galactic to extra- galactic cosmic ray flux is suspected to occur. We will give a brief overview of the physics, and report on the progress of TALE toward measuring the cosmic ray spectrum between 10 16 . 5 eV and 1019 eV.

  2. On Cosmic Rays, IP Structures and Geospace Consequences During WHI

    Microsoft Academic Search

    A. Dal Lago; F. L. Guarnieri; M. R. da Silva; W. D. Gonzalez; C. R. Braga; N. J. Schuch; K. Munakata; C. Kato; J. W. Bieber; T. Kuwabara; M. Tokumaru; M. L. Duldig; J. E. Humble

    2010-01-01

    This work presents some observations during the period of the Whole Heliosphere Interval (WHI) of the effects of interplanetary (IP) structures on the near-Earth space using three sets of observations: magnetic field and plasma from the Advanced Composition Explorer (ACE) satellite, ground-based cosmic ray data from the Global Muon Detection Network (GMDN) and geomagnetic indices (Disturbance storm-time, Dst, and auroral

  3. Nonthermal X-Rays from the Galactic Ridge: a Tracer of Low Energy Cosmic Rays ?

    E-print Network

    V. Tatischeff; R. Ramaty; A. Valinia

    1999-03-22

    A distinct low energy cosmic-ray component has been proposed to explain the essentially constant Be/Fe ratio at low metallicities. Atomic collisions of such low energy ions produce characteristic nonthermal X-ray emission. In this paper, we study the possible contribution of such X-rays to the Galactic ridge emission. We show that they would account for X-rays in this energy range are essentially produced below the thresholds of the Be-producing cross sections, their detection does not necessarily imply a low energy cosmic-ray origin for the spallogenic light elements. A significant contribution of nonthermal X-rays could alleviate the problem of the origin of the hard component observed with ASCA in the Scutum arm region.

  4. Pointlike gamma ray sources as signatures of distant accelerators of ultrahigh energy cosmic rays.

    PubMed

    Gabici, Stefano; Aharonian, Felix A

    2005-12-16

    We discuss the possibility of observing distant accelerators of ultrahigh energy cosmic rays in synchrotron gamma rays. Protons propagating away from their acceleration sites produce extremely energetic electrons during photopion interactions with cosmic microwave background photons. If the accelerator is embedded in a magnetized region, these electrons will emit high energy synchrotron radiation. The resulting synchrotron source is expected to be pointlike, steady, and detectable in the GeV-TeV energy range if the magnetic field is at the nanoGauss level. PMID:16384444

  5. Ultrahigh Energy Cosmic Rays: New Physics or Old Physics?

    E-print Network

    F. W. Stecker

    2004-07-15

    We consider the advantages of and the problems associated with hypotheses to explain the origin of ulthrahigh energy cosmic rays (UHECR: E > 10 EeV) and the "trans GZK" cosmic rays (TGZK: E > 100 EeV), both through "old physics" (acceleration in cosmic sources) and "new physics" (new particles, topological defects, fat neutrino cross sections, Lorentz invariance violation).

  6. Precision studies of cosmic rays with PAMELA

    NASA Astrophysics Data System (ADS)

    Pearce, Mark

    The PAMELA satellite-borne apparatus was launched into an elliptical low earth orbit with an inclination of 70 degrees on June 15th 2006. The combination of a permanent magnet silicon strip spectrometer, and a silicon-tungsten imaging calorimeter allows precision studies of the charged cosmic radiation to be conducted over a wide energy range ( 100 MeV - 100's GeV) with high statistics. The primary scientific goal is the measurement of the antiproton and positron energy spectrum in order to search for exotic sources, such as dark matter particle annihilations. PAMELA is also searching for primordial antinuclei (anti-helium), and testing cosmic-ray propagation models through precise measurements of the antiparticle energy spectrum and precision studies of light nuclei and their isotopes. Concomitant goals include a study of solar physics and solar modulation during the 24th solar minimum by investigating low energy particles in the cosmic radiation; and a reconstruction of the cosmic ray electron energy spectrum up to several TeV thereby allowing a possible contribution from local sources to be studied. The status of the PAMELA experiment will be reviewed, and initial scientific results discussed.

  7. Cosmic movement detection using image processing

    NASA Astrophysics Data System (ADS)

    Dhage, Sudhir N.; Mishra, Akassh A.; Patil, Rajesh

    2011-10-01

    Cosmic Movement Detection is concerned with the difficult task of taking the images of sky through high powered telescope or satellite transmitted images and performing image processing in order to discover new galaxies, stars and other cosmic objects or to describe already known galaxies, stars and other cosmic objects. Description meant to describe the type of cosmic object under consideration, whether it's already been recognized previously or not, whether it's moving close to Earth or moving away from Earth. It has several applications astrophysics, astronomy and astroscience. Automating this process to a computer requires the use of various image processing techniques. The method which the present paper describes is based on Doppler Effect of light i.e. red and blue shifting property. Several factors like poor illumination, noise disturbance, viewpoint-dependence, Climate factors, Transmission and Imaging conditions can affect the algorithm working. This paper reports an algorithm for Cosmic Movement Detection using image processing and Doppler Effect of light. The present paper suggests Cosmic Movement can be detected checking the color of the galaxy and it can help in determining whether it's moving towards Earth or its moving away.

  8. Supernova Remnant Kes 17: An Efficient Cosmic Ray Accelerator inside a Molecular Cloud

    NASA Astrophysics Data System (ADS)

    Gelfand, Joseph D.; Castro, Daniel; Slane, Patrick O.; Temim, Tea; Hughes, John P.; Rakowski, Cara

    2013-11-01

    The supernova remnant Kes 17 (SNR G304.6+0.1) is one of a few but growing number of remnants detected across the electromagnetic spectrum. In this paper, we analyze recent radio, X-ray, and ?-ray observations of this object, determining that efficient cosmic ray acceleration is required to explain its broadband non-thermal spectrum. These observations also suggest that Kes 17 is expanding inside a molecular cloud, though our determination of its age depends on whether thermal conduction or clump evaporation is primarily responsible for its center-filled thermal X-ray morphology. Evidence for efficient cosmic ray acceleration in Kes 17 supports recent theoretical work concluding that the strong magnetic field, turbulence, and clumpy nature of molecular clouds enhance cosmic ray production in supernova remnants. While additional observations are needed to confirm this interpretation, further study of Kes 17 is important for understanding how cosmic rays are accelerated in supernova remnants.

  9. Cosmic rays & Neutrinos Historical development

    E-print Network

    Gaisser, Thomas K.

    | Perm in hairdressing Deutsch The Neutrino Wolfgang Pauli's name is inseparable from his pioneering. The starting point for Pauli was the continuous energy spectrum of beta rays, which could not be interpreted conservation, which Pauli could not accept because the principle of the conservation of energy had proved

  10. Quantum Black Holes from Cosmic Rays

    E-print Network

    Xavier Calmet; Lauretiu Ioan Caramete; Octavian Micu

    2012-11-19

    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.

  11. Cosmic rays, solar activity and the climate

    NASA Astrophysics Data System (ADS)

    Sloan, T.; Wolfendale, A. W.

    2013-12-01

    Although it is generally believed that the increase in the mean global surface temperature since industrialization is caused by the increase in green house gases in the atmosphere, some people cite solar activity, either directly or through its effect on cosmic rays, as an underestimated contributor to such global warming. In this letter a simplified version of the standard picture of the role of greenhouse gases in causing the global warming since industrialization is described. The conditions necessary for this picture to be wholly or partially wrong are then introduced. Evidence is presented from which the contributions of either cosmic rays or solar activity to this warming is deduced. The contribution is shown to be less than 10% of the warming seen in the twentieth century.

  12. Cosmic Rays, Solar Activity and the Climate

    NASA Astrophysics Data System (ADS)

    Sloan, T.

    2013-02-01

    Although it is generally believed that the increase in the mean global surface temperature since industrialisation is caused by the increase in green house gases in the atmosphere, some people cite solar activity, either directly or through its effect on cosmic rays, as an underestimated contributor to such global warming. In this paper a simplified version of the standard picture of the role of greenhouse gases in causing the global warming since industrialisation is described. The conditions necessary for this picture to be wholly or partially wrong are then introduced. Evidence is presented from which the contributions of either cosmic rays or solar activity to this warming is deduced. The contribution is shown to be less than 10% of the warming seen in the twentieth century.

  13. Cosmic Ray Electron Science with GLAST

    NASA Technical Reports Server (NTRS)

    Ormes, J. F.; Moiseev, Alexander

    2007-01-01

    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.

  14. Galactic cosmic ray modulation from 1965 1970

    Microsoft Academic Search

    I. H. Urch; L. J. Gleeson

    1972-01-01

    Numerical solutions of the cosmic-ray equation of transport within the solar cavity and including the effects of diffusion, convection, and energy losses due to adiabatic deceleration, have been used to reproduce the modulation of galactic electrons, protons and helium nuclei observed during the period 1965 1970. Kinetic energies between 10 and 104 MeV\\/nucleon are considered. Computed and observed spectra (where

  15. Cosmic Ray Induced Bit-Flipping Experiment

    NASA Astrophysics Data System (ADS)

    Pu, Ge; Callaghan, Ed; Parsons, Matthew; Cribflex Team

    2015-04-01

    CRIBFLEX is a novel approach to mid-altitude observational particle physics intended to correlate the phenomena of semiconductor bit-flipping with cosmic ray activity. Here a weather balloon carries a Geiger counter and DRAM memory to various altitudes; the data collected will contribute to the development of memory device protection. We present current progress toward initial flight and data acquisition. This work is supported by the Society of Physics Students with funding from a Chapter Research Award.

  16. Cosmic ray gradients in the outer heliosphere

    NASA Technical Reports Server (NTRS)

    Fillius, W.; Wake, B.; Ip, W.-H.; Axford, I.

    1983-01-01

    Launched in 1972 and 1973 respectively, the Pioneer 10 and 11 spacecraft are now probing the outer heliosphere on their final escape from the sun. The data in this paper extend for almost an entire solar cycle from launch to early 1983, when Pioneer 10 was at a heliocentric distance of 29 AU and Pioneer 11, 13 AU. The UCSD instruments on board were used to study the gradient, and to look at the time and spatial variations of the cosmic ray intensities.

  17. Scientific Set of Instruments "Solar Cosmic Rays"

    NASA Astrophysics Data System (ADS)

    Kuznetsov, S. N.; Bogomolov, A. V.; Galkin, V. I.; Denisov, Yu. I.; Podorolsky, A. N.; Ryumin, S. P.; Kudela, K.; Rojko, J.

    A set of scientific instruments SCR (Solar Cosmic Rays) was developed by the scientists of SINP MSU and IEP SAS in order to study relations between the radiation conditions in the near-Earth space and solar activity. This set of instruments was installed on board the satellites CORONAS-I and CORONAS-F launched to the orbit on March 2, 1994, and July 30, 2001, respectively. Detailed description of the instruments is presented.

  18. Statistical properties of the time histories of cosmic gamma-ray bursts detected by the BATSE experiment of the Compton gamma-ray observatory

    NASA Technical Reports Server (NTRS)

    Sagdeev, Roald

    1995-01-01

    The main scientific objectives of the project were: (1) Calculation of average time history for different subsets of BATSE gamma-ray bursts; (2) Comparison of averaged parameters and averaged time history for different Burst And Transient Source Experiments (BASTE) Gamma Ray Bursts (GRB's) sets; (3) Comparison of results obtained with BATSE data with those obtained with APEX experiment at PHOBOS mission; and (4) Use the results of (1)-(3) to compare current models of gamma-ray bursts sources.

  19. Reference Radiation for Cosmic Rays in RBE Research 

    E-print Network

    Feng, Shaoyong

    2011-10-21

    When astronauts travel in space, they are exposed to high energy cosmic radiations. The cosmic ray spectrum contains very high energy particles, generally up to several GeV per nucleon. Currently NASA is funding research on the effects...

  20. Reference Radiation for Cosmic Rays in RBE Research

    E-print Network

    Feng, Shaoyong

    2011-10-21

    When astronauts travel in space, they are exposed to high energy cosmic radiations. The cosmic ray spectrum contains very high energy particles, generally up to several GeV per nucleon. Currently NASA is funding research on the effects...

  1. Cosmic Ray and Tev Gamma Ray Generation by Quasar Remnants

    NASA Technical Reports Server (NTRS)

    Boldt, Elihu; Loewenstein, Michael; White, Nicholas E. (Technical Monitor)

    2000-01-01

    Results from new broadband (radio to X-ray) high-resolution imaging studies of the dormant quasar remnant cores of nearby giant elliptical galaxies are now shown to permit the harboring of compact dynamos capable of generating the highest energy cosmic ray particles and associated curvature radiation of TeV photons. Confirmation would imply a global inflow of interstellar gas all the way to the accretion powered supermassive black hole at the center of the host galaxy.

  2. Cosmic X-ray background and solitars.

    NASA Astrophysics Data System (ADS)

    Chiu, H.-Y.

    In this paper the authors has examined the observational consequences of a class of new astronomical objects proposed by Friedberg, Lee and Pang, called solitars which are degenerate vacuum states embedded with particles. A study is made to include finite temperature effect and pair creation. Quark is believed to be the only species that can exist in the interior of solitars. Massive quark solitars are primarily X-ray emitters and may account for the large unexplained thermal component of the cosmic X-ray background.

  3. Primary Cosmic Rays Composition: Simulations and Detector Design

    SciTech Connect

    Supanitsky, D.; Etchegoyen, A.; Medina, C. [Laboratorio Tandar, CNEA Av. Del Libertador 8250, Buenos Aires (Argentina); Medina-Tanco, G. [Instituto Astronomico e Geofisico, Univ. Sao Paulo Rua do Matao 1226, Sao Pablo (Brazil); Gomez Berisso, M. [Instituto Balseiro, Centro Atomico Bariloche/CNEA San Carlos de Bariloche (Argentina)

    2007-02-12

    The Pierre Auger Observatory is a hybrid detector system for the detection of very high energy cosmic rays. A most difficult and important problem in these studies is the determination of the primary cosmic ray composition for which muon content in air showers appears to be one of the best parameters to discriminate between different composition types.Although the Pierre Auger surface detectors, which consist of water Cherenkov tanks, are sensitive to muon content they are not able to measure the number of muons directly. In this work we study using simulations the information that can be gained by adding muon detectors to the Auger surface detectors. We consider muon counters with two alternative areas.

  4. Constraining the Cosmic-ray Acceleration and Gamma-ray Emission Processes in IC 443

    NASA Astrophysics Data System (ADS)

    Ritchey, Adam

    2014-10-01

    Supernova remnants are widely believed to be the sources responsible for the acceleration of Galactic cosmic rays. Over the last few years, observations made with the Fermi Gamma-ray Space Telescope have confirmed that cosmic-ray nuclei are indeed accelerated in some supernova remnants, including IC 443, which is a prototype for supernova remnants interacting with molecular clouds. Still, while cosmic-ray acceleration has been confirmed for IC 443, through the detection of the characteristic pion-decay signature, the acceleration processes are not fully understood, in part because the basic model parameters are not always well constrained. Here, we propose FUV observations of two stars probing diffuse molecular gas in IC 443. One star probes the interior region of the supernova remnant, while the other is located just outside the visible edge of IC 443. This arrangement will allow us to evaluate the physical conditions in pre-shock and post-shock gas through a comprehensive analysis of interstellar absorption lines. A major component of the analysis will involve the derivation of gas densities and kinetic temperatures from the relative populations of collisionally-excited fine-structure levels in C I and O I. A determination of the post-shock temperature will yield the shock velocity, which will constrain not only the age of IC 443, but also the cosmic-ray acceleration efficiency. The observed B/O ratio will also help to constrain the cosmic-ray content in the gas. These results will be of primary importance in accessing the role of supernova remnants as sources of Galactic cosmic rays.

  5. Detection Prospects of the Cosmic Neutrino Background

    E-print Network

    Yu-Feng Li

    2015-04-15

    The existence of the cosmic neutrino background (CnuB) is a fundamental prediction of the standard Big Bang cosmology. Although current cosmological probes provide indirect observational evidence, the direct detection of the CnuB in a laboratory experiment is a great challenge to the present experimental techniques. We discuss the future prospects for the direct detection of the CnuB, with the emphasis on the method of captures on beta-decaying nuclei and the PTOLEMY project. Other possibilities using the electron-capture (EC) decaying nuclei, the annihilation of extremely high-energy cosmic neutrinos (EHEC\

  6. Detection Prospects of the Cosmic Neutrino Background

    E-print Network

    Li, Yu-Feng

    2015-01-01

    The existence of the cosmic neutrino background (CnuB) is a fundamental prediction of the standard Big Bang cosmology. Although current cosmological probes provide indirect observational evidence, the direct detection of the CnuB in a laboratory experiment is a great challenge to the present experimental techniques. We discuss the future prospects for the direct detection of the CnuB, with the emphasis on the method of captures on beta-decaying nuclei and the PTOLEMY project. Other possibilities using the electron-capture (EC) decaying nuclei, the annihilation of extremely high-energy cosmic neutrinos (EHEC\

  7. On the escape of particles from cosmic ray modified shocks

    E-print Network

    D. Caprioli; P. Blasi; E. Amato

    2009-02-02

    Stationary solutions to the problem of particle acceleration at shock waves in the non-linear regime, when the dynamical reaction of the accelerated particles on the shock cannot be neglected, are known to show a prominent energy flux escaping from the shock towards upstream infinity. On physical grounds, the escape of particles from the upstream region of a shock has to be expected in all those situations in which the maximum momentum of accelerated particles, $p_{max}$, decreases with time, as is the case for the Sedov-Taylor phase of expansion of a shell Supernova Remnant, when both the shock velocity and the cosmic ray induced magnetization decrease. In this situation, at each time $t$, particles with momenta larger than $p_{max}(t)$ leave the system from upstream, carrying away a large fraction of the energy if the shock is strongly modified by the presence of cosmic rays. This phenomenon is of crucial importance for explaining the cosmic ray spectrum detected at Earth. In this paper we discuss how this escape flux appears in the different approaches to non-linear diffusive shock acceleration, and especially in the quasi-stationary semi-analytical kinetic ones. We apply our calculations to the Sedov-Taylor phase of a typical supernova remnant, including in a self-consistent way particle acceleration, magnetic field amplification and the dynamical reaction on the shock structure of both particles and fields. Within this framework we calculate the temporal evolution of the maximum energy reached by the accelerated particles and of the escape flux towards upstream infinity. The latter quantity is directly related to the cosmic ray spectrum detected at Earth.

  8. Are cosmic rays effective for ionization of the solar nebula?

    NASA Technical Reports Server (NTRS)

    Dolginov, A. Z.; Stepinski, T. F.

    1993-01-01

    In this paper, we argue that the effectiveness of cosmic rays to ionize the bulk of the nebular gas may be further impaired by the influence of the magnetic field on the propagation of cosmic rays. When cosmic rays enter the nebular disk they ionize the gas and make the dynamo generation of magnetic fields possible. However, once magnetic fields are embedded in the nebular gas, the upcoming cosmic rays can no longer penetrate directly into the nebular disk because they start to interact with the magnetic field and lose their energy before propagating significantly toward the midplane. That, in turn, undercuts the ionization source within the bulk of the gas stopping the dynamo action. Nebular dynamo models ignored this back reaction of magnetic fields on cosmic rays. We calculate this back reaction effect, but for the sake of mathematical simplicity, we ignore the effect of magnetic field weakening due to diminishing ionization by cosmic rays.

  9. Slow Diffusion of Cosmic-Rays around a Supernova Remnant

    E-print Network

    Fujita, Yutaka; Takahara, Fumio

    2010-01-01

    We study the escape of cosmic-ray protons accelerated at a supernova remnant (SNR). We are interested in their propagation in interstellar medium (ISM) after they leave the shock neighborhood where they are accelerated, but when they are still near the SNR with their energy density higher than that in the average ISM. Using Monte-Carlo simulations, we found that the cosmic-rays with energies of scale of the SNR itself if the ISM is highly ionized. Thus, even if the cosmic-rays can leave the shock, scattering by the waves prevents them from moving further away from the SNR. The cosmic-rays form a slowly expanding cosmic-ray bubble, and they spend a long time around the SNR. This means that the cosmic-rays cannot actually escape from the SNR until a fairly late stage of the SNR evolution. This is consistent with some results of Fermi and H.E.S.S. observations.

  10. Cosmic rays, interplanetary magnetic field and Coronal mass ejections

    NASA Astrophysics Data System (ADS)

    Mishra, Rajesh Kumar; Agarwal Mishra, Rekha

    Coronal Mass Ejections are vast structures of plasma and magnetic fields that are expelled from the sun into the heliosphere. This material is detected by remote sensing and in-situ spacecraft observations. The present study deals with the influence of four types of CMEs namely Asymmetric 'Full' Halo CMEs, Partial Halo CMEs, Asymmetric and Complex 'Full' Halo CMEs and 'Full' Halo CMEs on cosmic ray neutron monitor intensity. The data of ground based neutron monitor of Moscow and CME events observed with instruments onboard and Wind spacecraft have been used in the present analysis. The method of superposed epoch (Chree) analysis has been used to the arrival times of these CMEs. It is noteworthy that the frequency of occurrence of Asymmetric 'Full' Halo CMEs is significantly high, whereas frequency of occurrence of Asymmetric and Complex 'Full' Halo CMEs is low compared to other CMEs. Significant enhancement in cosmic ray intensity is observed after 4 days of the onset of asymmetric full halo and 6 days after the onset of full halo CMEs. The fluctuations in cosmic ray intensity are more prior to the onset of both types of the CMEs. However, during Partial Halo CMEs the cosmic ray intensity peaks, 8-9 days prior to the onset of CMEs and depressed 3 days prior to the onset of CMEs, whereas in case of asymmetric and complex full CMEs, the intensity depressed 2 days prior to the onset of CMEs and enhanced 2 days after the onset of CMEs. The deviations in cosmic ray intensity are more pronounced in case for asymmetric and complex full halo CMEs compared to other CMEs. The cosmic ray intensity shows nearly good anti-correlation with IMF strength (B) during asymmetric full halo CMEs and partial halo CMEs, whereas it shows poor correlation with B during other CMEs. The IMF, B significantly decreased five days prior to the onset of asymmetric and full halo CMEs and four days after the onset of partial halo CMEs, whereas IMF strength (B) significantly enhanced 5-6 days prior and after the onset of asymmetric and complex full halo CMEs. IMF strength (B) significantly depressed 2 days prior and 4 days after the onset of full halo CMEs. However, IMF, B significantly enhanced from its minimum to maximum values in 2 days interval prior to the onset of CMEs and in 3 days interval after the onset of CMEs.

  11. The isotopic composition of cosmic-ray calcium

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, M. E.; George, J. S.; Binns, W. R.; Christian, E. R.; Cummings, A. C.; Davis, A. J.; Israel, M. H.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.; Rosenvinge, T. T. von

    2001-01-01

    We find that the relative abundance of cosmic ray calcium isotopes in the cosmic-ray source are very similar to those found in solar-system material, in spite of the fact that different types of stars are thought to be responsible for producing these two isotopes. This observation is consistent with the view that cosmic rays are derived from a mixed sample of interstellar matter.

  12. Detectors for high energy cosmic rays on Spacelab

    Microsoft Academic Search

    J. Lheureux; P. Meyer; D. Muller; S. Swordy

    1985-01-01

    Two instruments designed to determine the spectra of the individual cosmic-ray components at very high energies are described. One of these (CRNE) uses a combination of gas Cerenkov counters and transition radiation detectors for the cosmic-ray nuclei lithium to nickel; the other (TRIC) is optimized for the light cosmic rays (electrons, protons, helium) and uses a transition-radiation\\/ionization-calorimeter combination. The CRNE

  13. Exotic Neutrino Interactions in Cosmic Rays

    E-print Network

    Markus Ahlers

    2006-11-29

    The spectrum of extra-galactic cosmic rays (CRs) is expected to follow the Greisen-Zatsepin-Kuzmin (GZK) cutoff at about 5x10^10 GeV which results from energy losses of charged nuclei in the cosmic microwave background. So far the confrontation of this feature with CR data is inconclusive. In the absence of close-by sources a power-law continuation of the spectrum might signal the contribution of new physics. We have investigated the statistical significance of a model where exotic interactions of cosmogenic neutrinos are the origin of super-GZK events. A strong neutrino-nucleon interaction is favored by CR data, even if we account for a systematic shift in energy calibration.

  14. Muon acceleration in cosmic-ray sources

    SciTech Connect

    Klein, Spencer R.; Mikkelsen, Rune E. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Becker Tjus, Julia [Fakultät für Physik and Astronomie, Theoretische Physik I, Ruhr-Universität Bochum, D-44780 Bochum (Germany)

    2013-12-20

    Many models of ultra-high energy cosmic-ray production involve acceleration in linear accelerators located in gamma-ray bursts, magnetars, or other sources. These transient sources have short lifetimes, which necessitate very high accelerating gradients, up to 10{sup 13} keV cm{sup –1}. At gradients above 1.6 keV cm{sup –1}, muons produced by hadronic interactions undergo significant acceleration before they decay. This muon acceleration hardens the neutrino energy spectrum and greatly increases the high-energy neutrino flux. Using the IceCube high-energy diffuse neutrino flux limits, we set two-dimensional limits on the source opacity and matter density, as a function of accelerating gradient. These limits put strong constraints on different models of particle acceleration, particularly those based on plasma wake-field acceleration, and limit models for sources like gamma-ray bursts and magnetars.

  15. Muon Acceleration in Cosmic-ray Sources

    E-print Network

    Klein, Spencer R; Tjus, Julia K Becker

    2012-01-01

    Many models of ultra-high energy cosmic-ray production involve acceleration in linear accelerators located in Gamma-Ray Bursts magnetars, or other sources. These source models require very high accelerating gradients, $10^{13}$ keV/cm, with the minimum gradient set by the length of the source. At gradients above 1.6 keV/cm, muons produced by hadronic interactions undergo significant acceleration before they decay. This acceleration hardens the neutrino energy spectrum and greatly increases the high-energy neutrino flux. We rule out many models of linear acceleration, setting strong constraints on plasma wakefield accelerators and on models for sources like Gamma Ray Bursts and magnetars.

  16. Muon Acceleration in Cosmic-ray Sources

    E-print Network

    Spencer R. Klein; Rune Mikkelsen; Julia K. Becker Tjus

    2012-08-09

    Many models of ultra-high energy cosmic-ray production involve acceleration in linear accelerators located in Gamma-Ray Bursts magnetars, or other sources. These source models require very high accelerating gradients, $10^{13}$ keV/cm, with the minimum gradient set by the length of the source. At gradients above 1.6 keV/cm, muons produced by hadronic interactions undergo significant acceleration before they decay. This acceleration hardens the neutrino energy spectrum and greatly increases the high-energy neutrino flux. We rule out many models of linear acceleration, setting strong constraints on plasma wakefield accelerators and on models for sources like Gamma Ray Bursts and magnetars.

  17. Muon Acceleration in Cosmic-Ray Sources

    NASA Astrophysics Data System (ADS)

    Klein, Spencer R.; Mikkelsen, Rune E.; Becker Tjus, Julia

    2013-12-01

    Many models of ultra-high energy cosmic-ray production involve acceleration in linear accelerators located in gamma-ray bursts, magnetars, or other sources. These transient sources have short lifetimes, which necessitate very high accelerating gradients, up to 1013 keV cm-1. At gradients above 1.6 keV cm-1, muons produced by hadronic interactions undergo significant acceleration before they decay. This muon acceleration hardens the neutrino energy spectrum and greatly increases the high-energy neutrino flux. Using the IceCube high-energy diffuse neutrino flux limits, we set two-dimensional limits on the source opacity and matter density, as a function of accelerating gradient. These limits put strong constraints on different models of particle acceleration, particularly those based on plasma wake-field acceleration, and limit models for sources like gamma-ray bursts and magnetars.

  18. Gamma-rays, cosmic rays, and galactic structure

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1976-01-01

    The relation of SAS-2 observations of galactic gamma-rays to the large scale distribution of cosmic rays and interstellar gas in the galaxy is reviewed. Starting with a discussion of production rates, the case for pion decay being the predominant production mechanism in the galactic disk above 100 MeV is reestablished, and it is also pointed out that Compton gamma-rays can be a significant source near l = 0. The concepts of four distinct galactic regions are defined, viz. the nebulodisk, ectodisk, radiodisk and exodisk. Bremsstrahlung and pion decay gamma-rays are associated with the first two (primarily the first) regions, and Compton gamma-rays and synchrotron radiation are associated with the latter two regions. On a large scale, the cosmic rays, interstellar gas (primarily H2 clouds in the inner galaxy) and gamma-ray emissivity all peak between 5 and 6 kpc from the galactic center. This correlation is related to correlation with other population I phenomena and is discussed in terms of the density wave concept of galactic structure.

  19. Isotopic composition of cosmic-ray boron and nitrogen

    NASA Technical Reports Server (NTRS)

    Krombel, K. E.; Wiedenbeck, M. E.

    1988-01-01

    New measurements of the cosmic-ray boron and nitrogen isotopes at earth and of the elemental abundances of boron, carbon, nitrogen, and oxygen are presented. A region of mutually allowed values for the cosmic-ray nitrogen source ratios is determined, and the cosmic-ray escape mean free path is determined as a function of energy using a leaky box model for cosmic-ray propagation in the Galaxy. Relative to O-16, a N-15 source abundance consistent with solar system composition and a N-14 source abundance which is a factor of about three underabundant relative to the solar value are found.

  20. Lunar surface cosmic ray experiment S-152, Apollo 16

    NASA Technical Reports Server (NTRS)

    Fleischer, R. L.; Hart, H. R., Jr.; Carter, M.; Comostock, G. M.; Renshaw, A.; Woods, R. T.

    1973-01-01

    This investigation was directed at determining the energy spectra and abundances of low energy heavy cosmic rays (0.03 E or = 150 MeV/nucleon). The cosmic rays were detected using plastic and glass particle track detectors. Particles emitted during the 17 April 1972 solar flare dominated the spectra for energies below about 70 MeV/nucleon. Two conclusions emerge from the low energy data: (1) The differential energy spectra for solar particles vary rapidly for energies as low as 0.05 MeV/nucleon for iron-group nuclei. (2) The abundance ratio of heavy elements changes with energy at low energies; heavy elements are enhanced relative to higher elements increasingly as the energy decreases. Galactic particle fluxes recorded within the spacecraft are in agreement with those predicted taking into account solar modulation and spacecraft shielding. The composition of the nuclei at energies above 70 MeV/nucleon imply that these particles originate outside the solar system and hence are galactic cosmic rays.

  1. Image reconstruction and material Z discrimination via cosmic ray muon radiography

    Microsoft Academic Search

    L. J. Schultz; K. N. Borozdin; J. J. Gomez; G. E. Hogan; J. A. McGill; C. L. Morris; W. C. Priedhorsky; A. Saunders; M. E. Teasdale

    2004-01-01

    Highly penetrating cosmic ray muons shower the Earth at the rate of 10,000m?2min?1 at sea level. In our previous work (Nature 422 (2003) 277; Rev. Sci. Instr. 74(10) (2003) 4294; Cosmic Ray Muon Radiography for Contraband Detection, in: Proceedings of AccApp’03, San Diego, CA, June 2003), we presented a novel muon radiography technique which exploits the multiple Coulomb scattering of

  2. Cosmic ray investigations during the marco polo and eneide missions with the sileye-3\\/alteino experiment

    Microsoft Academic Search

    M. Casolino

    2007-01-01

    The Sileye-3\\/Alteino experiment is devoted to the measurement of the radiation environment and the cosmic ray nuclear abundance\\u000a inside the International Space Station. Other goals include the investigation of the Light Flash phenomenon and the measurement\\u000a of the shielding effectiveness of different materials. The detectors used are a silicon strip detector capable to detect cosmic\\u000a rays up to Iron in

  3. High Energy Cosmic Rays from Local GRBs

    E-print Network

    Atoyan, A

    2005-01-01

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

  4. Effect of energy deposited by cosmic-ray particles on interferometric gravitational wave detectors

    E-print Network

    Kazuhiro Yamamoto; Hideaki Hayakawa; Atsushi Okada; Takashi Uchiyama; Shinji Miyoki; Masatake Ohashi; Kazuaki Kuroda; Nobuyuki Kanda; Daisuke Tatsumi; Yoshiki Tsunesada

    2008-08-03

    We investigated the noise of interferometric gravitational wave detectors due to heat energy deposited by cosmic-ray particles. We derived a general formula that describes the response of a mirror against a cosmic-ray passage. We found that there are differences in the comic-ray responses (the dependence of temperature and cosmic-ray track position) in cases of interferometric and resonant gravitational wave detectors. The power spectral density of vibrations caused by low-energy secondary muons is 100-times smaller than the goal sensitivity of future second-generation interferometer projects, such as LCGT and Advanced LIGO. The arrival frequency of high-energy cosmic-ray muons that generate enough large showers inside mirrors of LCGT and Advanced LIGO is one per a millennium. We also discuss the probability of exotic-particle detection with interferometers.

  5. Calculations for cosmic axion detection

    NASA Technical Reports Server (NTRS)

    Krauss, L.; Moody, J.; Wilczek, F.; Morris, D. E.

    1985-01-01

    Calculations are presented, using properly nomalized couplings and masses for Dine-Fischler-Srednicki axions, of power rates and signal temperatures for axion-photon conversion in microwave cavities. The importance of the galactic-halo axion line shape is emphasized. Spin-coupled detection as an alternative to magnetic-field-coupled detection is mentioned.

  6. Underground cosmic-ray experiment EMMA

    NASA Astrophysics Data System (ADS)

    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

    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.

  7. Cosmic Ray Induced Bit-Flipping Experiment

    NASA Astrophysics Data System (ADS)

    Callaghan, Edward; Parsons, Matthew

    2015-04-01

    CRIBFLEX is a novel approach to mid-altitude observational particle physics intended to correlate the phenomena of semiconductor bit-flipping with cosmic ray activity. Here a weather balloon carries a Geiger counter and DRAM memory to various altitudes; the data collected will contribute to the development of memory device protection. We present current progress toward initial flight and data acquisition. This work is supported by the Society of Physics Students with funding from a Chapter Research Award. Supported by a Society of Physics Students Chapter Research Award.

  8. Galactic origin of cosmic rays I

    SciTech Connect

    Colgate, S.A.

    1981-01-01

    The theoretical basis for the supernova envelope shock origin of cosmic rays is reviewed. The theoretical explanation of the SN Type I light curve requires the ejection of a relativistic mass fraction. The criterion of the adiabatic decelleration by Alfven wave trapping neither applies in theory, when ..beta.. > 1, or practice, the Starfish high altitude nuclear explosion experiment. Arguments of delayed acceleration due to K-capture are not applicable to SN ejecta because a period of prompt recombination exists before subsequent stripping in propagation.

  9. Probing cosmic-ray acceleration and propagation with H3+ observations

    NASA Astrophysics Data System (ADS)

    Indriolo, Nick; Fields, Brian D.; McCall, Benjamin J.

    2015-01-01

    As cosmic rays traverse the interstellar medium (ISM) they interact with the ambient gas in various ways. These include ionization of atoms and molecules, spallation of nuclei, excitation of nuclear states, and production of pions among others. All of these interactions produce potential observables which may be used to trace the flux of cosmic rays. One such observable is the molecular ion H3+-produced via the ionization of an H2 molecule and its subsequent collision with another H2-which can be identified by absorption lines in the 3.5-4 ?m spectral region. We have detected H3+ in several Galactic diffuse cloud sight lines and used the derived column densities to infer ?2, the cosmic-ray ionization rate of H2. Ionization rates determined in this way vary from about 7×10-17 s-1 to about 8×10-16 s-1, and suggest the possibility of discrete sources producing high local fluxes of low-energy cosmic rays. Theoretical calculations of the ionization rate from postulated cosmic-ray spectra also support this possibility. Our recent observations of H3+ near the supernova remnant IC 443 (a likely site of cosmic-ray acceleration) point to even higher ionization rates, on the order of 10-15 s-1. Together, all of these results can further our understanding of the cosmic-ray spectrum both near the acceleration source and in the general Galactic ISM.

  10. Cosmic-ray physics with the milagro gamma-ray observatory

    SciTech Connect

    Sinnis, Gus [Los Alamos National Laboratory

    2008-01-01

    The Milagro gamma-ray observatory is a water Cherenkov detector with an energy response between 100 GeV and 100 TeV. While the major scientific goals of Milagro were to detect and study cosmic sources of TeV gamma rays, Milagro has made measurements important to furthering our understanding of the cosmic radiation that pervades our Galaxy. Milagro has made the first measurement of the Galactic diffuse emission in the TeV energy band. In the Cygnus Region we measure a flux {approx}2.7 times that predicted by GALPROP. Milagro has also made measurements of the anisotropy of the arrival directions of the local cosmic radiation. On large scales the measurements made by Milagro agree with those previously reported by the Tibet AS{gamma} array. However, we have also discovered a time dependence to this anisotropy, perhaps due to solar modulation. On smaller scales, {approx}10 degrees, we have detected two regions of excess. These excesses have a spectrum that is inconsistent with the local cosmic-ray spectrum.

  11. Detection of Gamma Rays from a Starburst Galaxy

    Microsoft Academic Search

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

    2009-01-01

    Starburst galaxies exhibit in their central regions a highly increased rate of supernovae, the remnants of which are thought to accelerate energetic cosmic rays up to energies of ~1015 electron volts. We report the detection of gamma rays---tracers of such cosmic rays---from the starburst galaxy NGC 253 using the High Energy Stereoscopic System (H.E.S.S.) array of imaging atmospheric Cherenkov telescopes.

  12. Gamma-Ray Spectra due to Cosmic-Ray Interactions with Dense Gas Clouds 1

    E-print Network

    Mori, Masaki

    Gamma-Ray Spectra due to Cosmic-Ray Interactions with Dense Gas Clouds 1 Michiko Ohishi, Masaki Telescope National Facility, CSIRO, Australia Abstract. Gamma-ray spectra from cosmic-ray proton, and the resulting gamma-ray spectra are computed as a function of cloud column-density. These calculations are used

  13. Detection of gamma rays from a starburst galaxy.

    PubMed

    Acero, F; Aharonian, F; Akhperjanian, A G; Anton, G; Barres de Almeida, U; Bazer-Bachi, A R; Becherini, Y; Behera, B; Bernlöhr, 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; Chounet, L-M; Clapson, A C; Coignet, G; Dalton, M; Daniel, M K; Davids, I D; Degrange, B; Deil, C; Dickinson, H J; Djannati-Ataï, A; Domainko, W; Drury, L O'C; Dubois, F; Dubus, G; Dyks, J; Dyrda, M; Egberts, K; Emmanoulopoulos, D; Espigat, P; Farnier, C; Fegan, S; Feinstein, F; Fiasson, A; Förster, A; Fontaine, G; Füssling, M; Gabici, S; Gallant, Y A; Gérard, L; Gerbig, D; Giebels, B; Glicenstein, J F; Glück, B; Goret, P; Göring, D; Hauser, D; Hauser, M; Heinz, S; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hoffmann, A; Hofmann, W; Hofverberg, P; Hoppe, S; Horns, D; Jacholkowska, A; de Jager, O C; Jahn, C; Jung, I; Katarzy?ski, K; Katz, U; Kaufmann, S; Kerschhaggl, M; Khangulyan, D; Khélifi, B; Keogh, D; Klochkov, D; Klu?niak, W; Kneiske, T; Komin, Nu; Kosack, K; Kossakowski, R; Lamanna, G; Lenain, J-P; Lohse, T; Marandon, V; Martineau-Huynh, O; 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; Nicholas, B; Niemiec, J; Nolan, S J; Ohm, S; Olive, J-F; de Oña Wilhelmi, E; 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; Rieger, F; Ripken, J; Rob, L; Rosier-Lees, S; Rowell, G; Rudak, B; Rulten, C B; Ruppel, J; Sahakian, V; Santangelo, A; Schlickeiser, R; Schöck, F M; Schwanke, U; Schwarzburg, S; Schwemmer, S; Shalchi, A; Sikora, M; Skilton, J L; Sol, H; Stawarz, ?; Steenkamp, R; Stegmann, C; Stinzing, F; Superina, G; Szostek, A; Tam, P H; Tavernet, J-P; Terrier, R; Tibolla, O; Tluczykont, M; van Eldik, C; Vasileiadis, G; Venter, C; Venter, L; Vialle, J P; Vincent, P; Vivier, M; Völk, H J; Volpe, F; Wagner, S J; Ward, M; Zdziarski, A A; Zech, A

    2009-11-20

    Starburst galaxies exhibit in their central regions a highly increased rate of supernovae, the remnants of which are thought to accelerate energetic cosmic rays up to energies of approximately 10(15) electron volts. We report the detection of gamma rays--tracers of such cosmic rays--from the starburst galaxy NGC 253 using the High Energy Stereoscopic System (H.E.S.S.) array of imaging atmospheric Cherenkov telescopes. The gamma-ray flux above 220 billion electron volts is F = (5.5 +/- 1.0(stat) +/- 2.8(sys)) x 10(-13) cm(-2) s(-1), implying a cosmic-ray density about three orders of magnitude larger than that in the center of the Milky Way. The fraction of cosmic-ray energy channeled into gamma rays in this starburst environment is five times as large as that in our Galaxy. PMID:19779150

  14. Nineteenth International Cosmic Ray Conference. HE Sessions, Volume 7

    NASA Technical Reports Server (NTRS)

    Jones, F. C. (compiler)

    1985-01-01

    Papers submitted for presentation at the 19th International Cosmic ray Conference are compiled. This volume contains papers which address various aspects of extensive air showers (EAS) produced by energetic particles and gamma rays.

  15. Significance of Ultra High Energy Cosmic Rays

    E-print Network

    Sidhu, Jasdeep

    2011-01-01

    The study of ultra high energy cosmic rays is a very important scientific problem. It is likely to have a huge impact in our understanding of the universe. Very high energy particles have been observed to hit the Earth whose origin is likely to be outside our Galaxy. Infact, particles with energies exceeding 10^ (20) electron volts which only hit the earth once in a century have been observed recently. The source of these high energy particles remains a deep and fascinating mystery yet to be resolved. Recently, a huge detector 30 times the size of the city of Paris is built by Pierre Auger Observatory to study these high energy particles. These detectors use the properties of Cherenkov radiation to identify the particles. Firstly, the paper will briefly explain the scientific motivation behind studying ultra high energy cosmic rays. Secondly, this paper will try to explain the reasons behind using water Cherenkov detectors. Thirdly, the paper within its limited scope, will try to give an overview of the exact...

  16. REal-time COsmic Ray Database (RECORD)

    NASA Astrophysics Data System (ADS)

    Usoskin, I.; Kozlov, Valery; Ksenofontov, Leonid, Kudela, Karel; Starodubtsev, Sergei; Turpanov, Alexey; Yanke, Victor

    2003-07-01

    In this paper we present a first distributed REal-time COsmic Ray Database (RECORD). The aim of the project is to develop a unified database with data from different neutron monitors collected together, in unified format and to provide a user with several commonly used data access methods. The database contains not only original cosmic ray data but also auxiliary data necessary for scientific data analysis. Currently the database includes Lomn.Stit, Moscow, Oulu; Tixie Bay, Yakutsk stations. The main database server is located in IKFIA SB RAS (Yakutsk) but there will be several mirrors of the database. The database and all its mirrors are up dated on the nearly real-time (1 hour) basis. The data access software includes WWW-interface, Perl scripts and C library, which may be linked to a user program. Most of frequently used functions are implemented to make it operable to users without SQL language knowledge. A draft of the data representation standard is suggested, based on common practice of neutron monitor community. The database engine is freely distributed open-sourced PostgreSQL server coupled with a set of replication to ols developed at Bio engineering division of the IRCCS E.Medea, Italy.

  17. The Origin of Galactic Cosmic Rays

    E-print Network

    Blasi, Pasquale

    2013-01-01

    One century ago Viktor Hess carried out several balloon flights that led him to conclude that the penetrating radiation responsible for the discharge of electroscopes was of extraterrestrial origin. One century from the discovery of this phenomenon seems to be a good time to stop and think about what we have understood about Cosmic Rays. The aim of this review is to illustrate the ideas that have been and are being explored in order to account for the observable quantities related to cosmic rays and to summarize the numerous new pieces of observation that are becoming available. In fact, despite the possible impression that development in this field is somewhat slow, the rate of new discoveries in the last decade or so has been impressive, and mainly driven by beautiful pieces of observation. At the same time scientists in this field have been able to propose new, fascinating ways to investigate particle acceleration inside the sources, making use of multifrequency observations that range from the radio, to t...

  18. Cosmic ray acceleration at modified shocks

    E-print Network

    A. Meli; P. L. Biermann; S. Dimitrakoudis

    2007-08-10

    The non-linear back reaction of accelerated cosmic rays at the shock fronts, leads to the formation of a smooth precursor with a length scale corresponding to the diffusive scale of the energetic particles. Past works claimed that shocklets could be created in the precursor region of a specific shock width, which might energize few thermal particles to sufficient acceleration and furthermore this precursor region may act as confining large angle scatterer for very high energy cosmic rays. On the other hand, it has been shown that the smoothing of the shock front could lower the acceleration efficiency. These controversies motivated us to investigate numerically by Monte Carlo simulations the particle acceleration efficiency in oblique modified shocks. The results show flatter spectra compared to the spectra of the pressumed sharp discontinuity shock fronts. The findings are in accordance with theoretical predictions, since the scattering inside the precursor confines high energy particles to further scattering, resulting in higher energies making the whole acceleration process more efficient.

  19. GZK Photons as Ultra High Energy Cosmic Rays

    E-print Network

    Graciela B. Gelmini; Oleg E. Kalashev; Dmitry V. Semikoz

    2007-11-01

    We calculate the flux of "GZK-photons", namely the flux of Ultra High Energy Cosmic Rays (UHECR) consisting of photons produced by extragalactic nucleons through the resonant photoproduction of pions, the so called GZK effect. We We calculate the flux of "GZK-photons", namely the flux of Ultra High Energy Cosmic Rays (UHECR) consisting of photons produced by extragalactic nucleons through the resonant photoproduction of pions, the so called GZK effect. We show that, for primary nucleons, the GZK photon fraction of the total UHECR flux is between $10^{-4}$ and $10^{-2}$ above $10^{19}$ eV and up to the order of 0.1 above $10^{20}$ eV. The GZK photon flux depends on the assumed UHECR spectrum, slope of the nucleon flux at the source, distribution of sources and intervening backgrounds. Detection of this photon flux would open the way for UHECR gamma-ray astronomy. Detection of a larger photon flux would imply the emission of photons at the source or new physics. We compare the photon fractions expected for GZK photons and the minimal predicted by Top-Down models. We find that the photon fraction above $10^{19}$ eV is a crucial test for Top-Down models.

  20. A new transition radiation detector for cosmic ray nuclei

    NASA Technical Reports Server (NTRS)

    Lheureux, J.; Meyer, P.; Muller, D.; Swordy, S.

    1981-01-01

    Test measurements on materials for transition radiation detectors at a low Lorentz factor are reported. The materials will be based on board Spacelab-2 for determining the composition and energy spectra of nuclear cosmic rays in the 1 TeV/nucleon range. The transition radiation detectors consist of a sandwich of radiator-photon detector combinations. The radiators emit X-rays and are composed of polyolefin fibers used with Xe filled multiwired proportional chamber (MWPC) detectors capable of detecting particle Lorentz factors of several hundred. The sizing of the detectors is outlined, noting the requirement of a thickness which provides a maximum ratio of transition radiation to total signal in the chambers. The fiber radiator-MWPC responses were tested at Fermilab and in an electron cyclotron. An increase in transition radiation detection was found as a square power law of Z, and the use of six radiator-MWPC on board the Spacelab-2 is outlined.

  1. Non-thermal radiation from molecular clouds illuminated by cosmic rays from nearby supernova remnants

    E-print Network

    Stefano Gabici; Sabrina Casanova; Felix A. Aharonian

    2008-09-30

    Molecular clouds are expected to emit non-thermal radiation due to cosmic ray interactions in the dense magnetized gas. Such emission is amplified if a cloud is located close to an accelerator of cosmic rays and if cosmic rays can leave the accelerator and diffusively reach the cloud. We consider the situation in which a molecular cloud is located in the proximity of a supernova remnant which is accelerating cosmic rays and gradually releasing them into the interstellar medium. We calculate the multiwavelength spectrum from radio to gamma rays which emerges from the cloud as the result of cosmic ray interactions. The total energy output is dominated by the gamma ray emission, which can exceed the emission from other bands by an order of magnitude or more. This suggests that some of the unidentified TeV sources detected so far, with no obvious or very weak counterpart in other wavelengths, might be associated with clouds illuminated by cosmic rays coming from a nearby source.

  2. Ninteenth International Cosmic Ray Conference. SH Sessions, Volume 4

    NASA Technical Reports Server (NTRS)

    Jones, F. C. (compiler)

    1985-01-01

    Papers submitted for presentation at the 19th International Cosmic Ray Conference are compiled. This volume covers solar and heliospheric phenomena, specifically, particle acceleration; cosmic ray compsotion, spectra, and anisotropy; propagation of solar and interplanetary energetic particles; solar-cycle modulation; and propagation of galactic particles in the heliosphere.

  3. Ninteenth International Cosmic Ray Conference. OG Sessions, Volume 2

    NASA Technical Reports Server (NTRS)

    Jones, F. C. (compiler)

    1985-01-01

    Contributed papers addressing cosmic ray origin and galactic phenomena are compiled. Topic areas include the composition, spectra, and anisotropy of cosmic ray nuclei with energies and 1 TeV, isotopes, antiprotons and related subjects, and electrons, positrons, and measurements of synchrotron radiation.

  4. On the ultra-high energy cosmic ray horizon

    E-print Network

    D. Harari; S. Mollerach; E. Roulet

    2006-11-06

    We compute the ultra-high energy cosmic ray horizon, i.e. the distance up to which cosmic ray sources may significantly contribute to the fluxes above a certain threshold on the observed energies. We obtain results both for proton and heavy nuclei sources.

  5. Early developments: Particle physics aspects of cosmic rays

    NASA Astrophysics Data System (ADS)

    Grupen, Claus

    2014-01-01

    Cosmic rays is the birthplace of elementary particle physics. The 1936 Nobel prize was shared between Victor Hess and Carl Anderson. Anderson discovered the positron in a cloud chamber. The positron was predicted by Dirac several years earlier. In subsequent cloud chamber investigations Anderson and Neddermeyer saw the muon, which for some time was considered to be a candidate for the Yukawa particle responsible for nuclear binding. Measurements with nuclear emulsions by Lattes, Powell, Occhialini and Muirhead clarified the situation by the discovery of the charged pions in cosmic rays. The cloud chamber continued to be a powerful instrument in cosmic ray studies. Rochester and Butler found V's, which turned out to be shortlived neutral kaons decaying into a pair of charged pions. Also ?'s, ?'s, and ?'s were found in cosmic rays. But after that accelerators and storage rings took over. The unexpected renaissance of cosmic rays started with the search for solar neutrinos and the observation of the supernova 1987A. Cosmic ray neutrino results were best explained by the assumption of neutrino oscillations opening a view beyond the standard model of elementary particles. After 100 years of cosmic ray research we are again at the beginning of a new era, and cosmic rays may contribute to solve the many open questions, like dark matter and dark energy, by providing energies well beyond those of accelerators.

  6. THE COSMIC-RAY INTENSITY NEAR THE ARCHEAN EARTH

    SciTech Connect

    Cohen, O.; Drake, J. J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Kota, J. [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721-0092 (United States)

    2012-11-20

    We employ three-dimensional state-of-the-art magnetohydrodynamic models of the early solar wind and heliosphere and a two-dimensional model for cosmic-ray transport to investigate the cosmic-ray spectrum and flux near the Archean Earth. We assess how sensitive the cosmic-ray spectrum is to changes in the sunspot placement and magnetic field strength, the large-scale dipole magnetic field strength, the wind ram pressure, and the Sun's rotation period. Overall, our results confirm earlier work that suggested the Archean Earth would have experienced a greatly reduced cosmic-ray flux than is the case today. The cosmic-ray reduction for the early Sun is mainly due to the shorter solar rotation period and tighter winding of the Parker spiral, and to the different surface distribution of the more active solar magnetic field. These effects lead to a global reduction of the cosmic-ray flux at 1 AU by up to two orders of magnitude or more. Variations in the sunspot magnetic field have more effect on the flux than variations in the dipole field component. The wind ram pressure affects the cosmic-ray flux through its influence on the size of the heliosphere via the pressure balance with the ambient interstellar medium. Variations in the interstellar medium pressure experienced by the solar system in orbit through the Galaxy could lead to order of magnitude changes in the cosmic-ray flux at Earth on timescales of a few million years.

  7. Detection prospects of the cosmic neutrino background

    NASA Astrophysics Data System (ADS)

    Li, Yu-Feng

    2015-04-01

    The existence of the cosmic neutrino background (C?B) is a fundamental prediction of the standard Big Bang cosmology. Although current cosmological probes provide indirect observational evidence, the direct detection of the C?B in a laboratory experiment is a great challenge to the present experimental techniques. We discuss the future prospects for the direct detection of the C?B, with the emphasis on the method of captures on beta-decaying nuclei and the PTOLEMY project. Other possibilities using the electron-capture (EC) decaying nuclei, the annihilation of extremely high-energy cosmic neutrinos (EHEC?s) at the Z-resonance, and the atomic de-excitation method are also discussed in this review (talk given at the International Conference on Massive Neutrinos, Singapore, 9-13 February 2015).

  8. CRIME - cosmic ray interactions in molecular environments

    E-print Network

    Krause, Julian; Gabici, Stefano

    2015-01-01

    Molecular clouds act as targets for cosmic rays (CR), revealing their presence through either gamma-ray emission due to proton-proton interactions, and/or through the ionization level in the cloud, produced by the CR flux. The ionization rate is a unique tool, to some extent complementary to the gamma-ray emission, in that it allows to constrain the CR spectrum especially for energies below the pion production rate ($\\approx 280$ MeV). Here we study the effect of ionization on $H_2$ clouds due to both CR protons and electrons, using the fully relativistic ionization cross sections, which is important to correctly account for the contribution due to relativistic CRs. The contribution to ionization due to secondary electrons is also included self-consistently. The whole calculation has been implemented into a numerical code which is publicly accessible through a web-interface. The code also include the calculation of gamma-ray emission once the CR spectrum

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    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.

  10. Constraints on Cosmic-Ray Origin Theories from TeV Gamma-Ray Observations

    E-print Network

    R. W. Lessard; P. J. Boyle; S. M. Bradbury; J. H. Buckley; A. C. Burdett; J. Bussons Gordo; D. A. Carter-Lewis; M. Catanese; M. F. Cawley; D. J. Fegan; J. P. Finley; J. A. Gaidos; A. M. Hillas; F. Krennrich; R. C. Lamb; C. Masterson; J. E. McEnery; G. Mohanty; J. Quinn; A. J. Rodgers; H. J. Rose; F. W. Samuelson; G. H. Sembroski; R. Srinivasan; T. C. Weekes; J. Zweerink

    1997-06-13

    If supernova remnants (SNRs) are the sites of cosmic-ray acceleration, the associated nuclear interactions should result in observable fluxes of TeV gamma-rays from the nearest SNRs. Measurements of the gamma-ray flux from six nearby, radio-bright, SNRs have been made with the Whipple Observatory gamma-ray telescope. No significant emission has been detected and upper limits on the $>$300 GeV flux are reported. Three of these SNRs (IC443, gamma-Cygni and W44) are spatially coincident with low latitude unidentified sources detected with EGRET. These upper limits weaken the case for the simplest models of shock acceleration and energy dependent propagation.

  11. Constraints on Cosmic-Ray Origin Theories from TeV $\\gamma$-Ray Observations

    E-print Network

    Lessard, R W; Bradbury, S M; Buckley, J H; Burdett, A C; Gordo, J B; Carter-Lewis, D A; Catanese, M; Cawley, M F; Fegan, D J; Finley, J P; Gaidos, J A; Hillas, A M; Krennrich, F; Lamb, R C; Masterson, C; McEnery, J E; Mohanty, G B; Quinn, J; Rodgers, A J; Rose, H J; Samuelson, F W; Sembroski, G H; Srinivasan, R; Weekes, T C; Zweerink, J A

    1997-01-01

    If supernova remnants (SNRs) are the sites of cosmic-ray acceleration, the associated nuclear interactions should result in observable fluxes of TeV gamma-rays from the nearest SNRs. Measurements of the gamma-ray flux from six nearby, radio-bright, SNRs have been made with the Whipple Observatory gamma-ray telescope. No significant emission has been detected and upper limits on the $>$300 GeV flux are reported. Three of these SNRs (IC443, gamma-Cygni and W44) are spatially coincident with low latitude unidentified sources detected with EGRET. These upper limits weaken the case for the simplest models of shock acceleration and energy dependent propagation.

  12. Strong magnetic fields and cosmic rays in very young galaxies

    E-print Network

    H. Lesch; M. Hanasz

    2003-02-08

    We present a scenario for efficient magnetization of very young galaxies about 0.5 Gigayears after the Big-Bang by a cosmic ray-driven dynamo. These objects experience a phase of strong star formation during this first $10^9$ years. We transfer the knowledge of the connection between star formation and the production rate of cosmic rays by supernova remnants to such high redshift objects. Since the supernova rate is a direct measure for the production rate of cosmic rays we conclude that very young galaxies must be strong sources of cosmic rays. The key argument of our model is the finding that magnetic fields and cosmic rays are dynamically coupled, i.e. a strong cosmic ray source contains strong magnetic fields since the relativistic particles drive an efficient dynamo in a galaxy via their buoyancy. We construct a phenomenological model of a dynamo driven by buoyancy of cosmic rays and show that if azimuthal shearing is strong enough the dynamo amplification timescale is close to the buoyancy timescale of the order of several $10^7 \\div 10^8$ yr. We predict that young galaxies are strongly magnetized and may contribute significantly to the gamma-ray-background.

  13. Cosmic ray drift, shock wave acceleration and the anomalous component of cosmic rays

    NASA Technical Reports Server (NTRS)

    Pesses, M. E.; Jokipii, J. R.; Eichler, D.

    1981-01-01

    A model of the anomalous component of the quiet-time cosmic ray flux is presented in which ex-interstellar neutral particles are accelerated continuously in the polar regions of the solar-wind termination shock, and then drift into the equatorial regions of the inner heliosphere. The observed solar-cycle variations, radial gradient, and apparent latitude gradient of the anomalous component are a natural consequence of this model.

  14. Low-energy cosmic ray protons from nuclear interactions of cosmic rays with the interstellar medium.

    NASA Technical Reports Server (NTRS)

    Wang, H. T.

    1973-01-01

    The intensity of low-energy (less than 100 MeV) protons from nuclear interactions of higher-energy (above 100 MeV) cosmic rays with the interstellar medium is calculated. The resultant intensity in the 10- to 100-MeV range is larger by a factor of 3-5 than the observed proton intensity near earth. The calculated intensity from nuclear interactions constitutes a lower limit on the actual proton intensity in interstellar space.

  15. Estimates of cellular mutagenesis from cosmic rays

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Wilson, John W.

    1994-01-01

    A parametric track structure model is used to estimate the cross section as a function of particle velocity and charge for mutations at the hypoxanthine guanine phosphoribosyl transferase (HGPRT) locus in human fibroblast cell cultures. Experiments that report the fraction of mutations per surviving cell for human lung and skin fibroblast cells indicate small differences in the mutation cross section for these two cell lines when differences in inactivation rates between these cell lines are considered. Using models of cosmic ray transport, the mutation rate at the HGPRT locus is estimated for cell cultures in space flight and rates of about 2 to 10 x 10(exp -6) per year are found for typical spacecraft shielding. A discussion of how model assumptions may alter the predictions is also presented.

  16. Relativistic cosmic rays and corotating interaction regions

    SciTech Connect

    Duggal, S.P.; Tsurutani, B.T.; Pomerantz, M.A.; Tsao, C.H.; Smith, E.J.

    1981-09-01

    Analyses of relativistic galactic cosmic ray intensity variations have been conducted to determine the nature of the modulations that are related to the presence of corotating interaction regions (CIR) in interplanetary space. The corotating interaction regions have been identified from the plasma and field observations recorded by Pioneer 10 and 11 spacecrafts during the period 1972--1974. This investigation has established that the nucleonic intensity recorded at the polar stations Thule and McMurdo decreases as the streams associated with the CIR overtake the earth. However, this modulation occurs only for those CIR-associated streams in which a neutral sheet is imbedded. In contrast, geomagnetic storms are related to CIR streams with or without neutral sheets. Taken together, these results suggest that the ostensible effect of CIR'S on the intensity of high-energy particles is primarily a consequence of drifts related to neutral sheets, although diffusion effects cannot be ruled out at this stage.

  17. Cosmic Ray Spectrum in Supernova Remnant Shocks

    NASA Astrophysics Data System (ADS)

    Kang, H.

    2011-10-01

    We performed kinetic simulations of diffusive shock acceleration in Type Ia supernova remnants (SNRs) expanding into a uniform interstellar medium (ISM). The preshock gas temperature is the primary parameter that governs the cosmic ray (CR) acceleration, while magnetic field strength and CR injection rate are secondary parameters. SNRs in the hot ISM, with an injection fraction smaller than 10-4, are inefficient accelerators with less than 10 % energy getting converted to CRs. The shock structure is almost test-particle like and the ensuing CR spectrum can be steeper than E-2. Although the particles can be accelerated to the knee energy of 1015.5ZeV with amplified magnetic fields in the precursor, Alfvénic drift of scattering centers softens the source spectrum as steep as E-2.1 and reduces the CR acceleration efficiency.

  18. Cosmic-Ray Exposure Ages of Meteorites

    NASA Astrophysics Data System (ADS)

    Herzog, G. F.; Caffee, M. W.

    The concept of a cosmic-ray exposure (CRE) age for a meteorite is based on a simple but useful picture of meteorite evolution, the one-stage irradiation model. CRE ages have implications for several interrelated questions. From how many different parent bodies do meteorites come? How well do meteorites represent the population of their source region? How many distinct collisions on each parent body have created the known meteorites of each type? How often do parent bodies collide? How big and how energetic were the collisions that produced meteoroids? What factors control the CRE age of a meteorite and how do meteoroid orbits evolve through time? This chapter touches on these questions as it examines the data. In recent years, CRE ages also have become important for interpreting small variations in the abundances of stable isotopes.

  19. Review of the theoretical and experimental status of dark matter identification with cosmic-ray antideuterons

    E-print Network

    Aramaki, T; Bufalino, S; Dal, L; von Doetinchem, P; Donato, F; Fornengo, N; Fuke, H; Grefe, M; Hailey, C; Hamilton, B; Ibarra, A; Mitchell, J; Mognet, I; Ong, R A; Pereira, R; Perez, K; Putze, A; Raklev, A; Salati, P; Sasaki, M; Tarle, G; Urbano, A; Vittino, A; Wild, S; Xue, W; Yoshimura, K

    2015-01-01

    Recent years have seen increased theoretical and experimental effort towards the first-ever detection of cosmic-ray antideuterons, in particular as an indirect signature of dark matter annihilation or decay. In contrast to indirect dark matter searches using positrons, antiprotons, or gamma-rays, which suffer from relatively high and uncertain astrophysical backgrounds, searches with antideuterons benefit from very suppressed conventional backgrounds, offering a potential breakthrough in unexplored phase space for dark matter. This article is based on the first dedicated cosmic-ray antideuteron workshop, which was held at UCLA in June 2014. It reviews broad classes of dark matter candidates that result in detectable cosmic-ray antideuteron fluxes, as well as the status and prospects of current experimental searches. The coalescence model of antideuteron production and the influence of antideuteron measurements at particle colliders are discussed. This is followed by a review of the modeling of antideuteron pr...

  20. Searching for New Physics with Ultrahigh Energy Cosmic Rays

    E-print Network

    Floyd W. Stecker; Sean T. Scully

    2009-08-12

    Ultrahigh energy cosmic rays that produce giant extensive showers of charged particles and photons when they interact in the Earth's atmosphere provide a unique tool to search for new physics. Of particular interest is the possibility of detecting a very small violation of Lorentz invariance such as may be related to the structure of space-time near the Planck scale of $\\sim 10^{-35}$m. We discuss here the possible signature of Lorentz invariance violation on the spectrum of ultrahigh energy cosmic rays as compared with present observations of giant air showers. We also discuss the possibilities of using more sensitive detection techniques to improve searches for Lorentz invariance violation in the future. Using the latest data from the Pierre Auger Observatory, we derive a best fit to the LIV parameter of $3.0^{+1.5}_{-3.0} \\times 10^{-23}$, corresponding to an upper limit of $4.5 \\times 10^{-23}$ at a proton Lorentz factor of $\\sim 2 \\times 10^{11}$. This result has fundamental implications for quantum gravity models.

  1. Extragalactic cosmic rays and their signatures

    NASA Astrophysics Data System (ADS)

    Berezinsky, V.

    2014-01-01

    The signatures of UHE proton propagation through CMB radiation are pair-production dip and GZK cutoff. The visible manifestations of these two spectral features are ankle, which is intrinsic part of the dip, beginning of GZK cutoff in the differential spectrum and E in integral spectrum. Observed practically in all experiments since 1963, the ankle is usually interpreted as a feature caused by transition from galactic to extragalactic cosmic rays. Using the mass composition measured by HiRes, Telescope Array and Auger detectors at energy (1-3) EeV, calculated anisotropy of galactic cosmic rays at these energies, and the elongation curves we strongly argue against the interpretation of the ankle given above. The transition must occur at lower energy, most probably at the second knee as the dip model predicts. The other prediction of the dip model, the shape of the dip, is well confirmed by HiRes, Telescope Array (TA), AGASA and Yakutsk detectors, and, after recalibration of energies, by Auger detector. Predicted beginning of GZK cutoff and E agree well with HiRes and TA data. However, directly measured mass composition remains a puzzle. While HiRes and TA detectors observe the proton-dominated mass composition, as required by the dip model, the data of Auger detector strongly evidence for nuclei mass composition becoming progressively heavier at energy higher than 4 EeV and reaching Iron at energy about 35 EeV. The Auger-based scenario is consistent with another interpretation of the ankle at energy Ea?4 EeV as transition from extragalactic protons to extragalactic nuclei. The heavy-nuclei dominance at higher energies may be provided by low-energy of acceleration for protons Epmax?4 EeV and rigidity-dependent EAmax=ZEpmax for nuclei. The highest energy suppression may be explained as nuclei-photodisintegration cutoff.

  2. A connection between star formation activity and cosmic rays in the starburst galaxy M82

    NASA Astrophysics Data System (ADS)

    VERITAS Collaboration; Acciari, V. A.; Aliu, E.; Arlen, T.; Aune, T.; Bautista, M.; Beilicke, M.; Benbow, W.; Boltuch, D.; Bradbury, S. M.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cannon, A.; Celik, O.; Cesarini, A.; Chow, Y. C.; Ciupik, L.; Cogan, P.; Colin, P.; Cui, W.; Dickherber, R.; Duke, C.; Fegan, S. J.; Finley, J. P.; Finnegan, G.; Fortin, P.; Fortson, L.; Furniss, A.; Galante, N.; Gall, D.; Gibbs, K.; Gillanders, G. H.; Godambe, S.; Grube, J.; Guenette, R.; Gyuk, G.; Hanna, D.; Holder, J.; Horan, D.; Hui, C. M.; Humensky, T. B.; Imran, A.; Kaaret, P.; Karlsson, N.; Kertzman, M.; Kieda, D.; Kildea, J.; Konopelko, A.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; Lebohec, S.; Maier, G.; McArthur, S.; McCann, A.; McCutcheon, M.; Millis, J.; Moriarty, P.; Mukherjee, R.; Nagai, T.; Ong, R. A.; Otte, A. N.; Pandel, D.; Perkins, J. S.; Pizlo, F.; Pohl, M.; Quinn, J.; Ragan, K.; Reyes, L. C.; Reynolds, P. T.; Roache, E.; Rose, H. J.; Schroedter, M.; Sembroski, G. H.; Smith, A. W.; Steele, D.; Swordy, S. P.; Theiling, M.; Thibadeau, S.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Wagner, R. G.; Wakely, S. P.; Ward, J. E.; Weekes, T. C.; Weinstein, A.; Weisgarber, T.; Williams, D. A.; Wissel, S.; Wood, M.; Zitzer, B.

    2009-12-01

    Although Galactic cosmic rays (protons and nuclei) are widely believed to be mainly accelerated by the winds and supernovae of massive stars, definitive evidence of this origin remains elusive nearly a century after their discovery. The active regions of starburst galaxies have exceptionally high rates of star formation, and their large size-more than 50 times the diameter of similar Galactic regions-uniquely enables reliable calorimetric measurements of their potentially high cosmic-ray density. The cosmic rays produced in the formation, life and death of massive stars in these regions are expected to produce diffuse ?-ray emission through interactions with interstellar gas and radiation. M82, the prototype small starburst galaxy, is predicted to be the brightest starburst galaxy in terms of ?-ray emission. Here we report the detection of >700-GeV ?-rays from M82. From these data we determine a cosmic-ray density of 250eVcm-3 in the starburst core, which is about 500 times the average Galactic density. This links cosmic-ray acceleration to star formation activity, and suggests that supernovae and massive-star winds are the dominant accelerators.

  3. Cosmic ray decreases and shock structure: A multispacecraft study

    NASA Technical Reports Server (NTRS)

    Cane, H. V.; Richardson, I. G.; Von Rosenvinge, T. T.; Wibberenz, G.

    1994-01-01

    We examine greater than 60-MeV/amu ion data from three spacecraft (IMP 8 and Helios 1 and 2) at the time of a number of short term (less than 20-day duration) cosmic ray decreases (greater than 1 GeV) detected by ground-based neutron monitors in the years 1976 to 1979. The multispacecraft data allow us to investigate the structure of the modulation region and in particular the relative importance, as a function of location, of the shock and shock driver (ejecta) in causing the reduction in particle densities. Although the shocks contributing to cosmic ray decrease often have particle enhancements associated with them in the greater than 60-meV/amu data, this is not the case for three of the events discussed in this paper where a shock-associated decrease is also evident. Whereas the shock can cause an increase or decrease at low (i.e., less than neutron monitor) energies, the reduction of particle densities in the driver, if it is intercepted, is usually evident at all energies. Thus the overall shape of a decrease at greater than 60 MeV/amu depends primarily on whether the ejecta is intercepted. We find that the particle density inside ejecta increases with increasing radical distance from the Sun. In many of the events in this study, entry and exit of ejecta are accompanied by abrupt changes in the decrease and recovery rates which indicate that the effect of the ejecta is local. In contrast, the effect of the shock lasts many days after the shock has passed by and is evident at large angular distances from the longitude of the solar source, i.e., the effect of the shock is nonlocal. Within 1 AU there seems to be no radial dependence of the shock effect. One cosmic ray decrease seen at Earth, which had an unusual profile, can be understood if the median plane of the ejecta was inclined to the ecliptic.

  4. Change in cosmic-ray spectrum through the production of electron-positron pairs (analytical approach)

    SciTech Connect

    Vlasov, V. P., E-mail: vlasov@nfi.kiae.ru; Trubnikov, B. A., E-mail: batrub@nfi.kiae.r [Russian Research Center Kurchatov Institute (Russian Federation)

    2009-12-15

    We consider the change in primordial cosmic-ray spectrum through the production of electron-positron pairs in collisions with cosmic microwave background radiation photons. We suggest using these results to estimate the distances to cosmic-ray sources.

  5. Plasma Effects on Extragalactic Ultra-high-energy Cosmic Ray Hadron Beams in Cosmic Voids

    NASA Astrophysics Data System (ADS)

    Krakau, S.; Schlickeiser, R.

    2014-07-01

    The linear instability of an ultrarelativistic hadron beam (? b ? 106) in the unmagnetized intergalactic medium (IGM) is investigated with respect to the excitation of collective electrostatic and aperiodic electromagnetic fluctuations. This analysis is important for the propagation of extragalactic ultrarelativistic cosmic rays (E > 1015 eV) from their distant sources to Earth. We calculate minimum instability growth times that are orders of magnitude shorter than the cosmic ray propagation time in the IGM. Due to nonlinear effects, especially the modulation instability, the cosmic ray beam stabilizes and can propagate with nearly no energy loss through the IGM.

  6. Detection of x ray sources in PROS

    NASA Technical Reports Server (NTRS)

    Deponte, J.; Primini, F. A.

    1992-01-01

    The problem of detecting discrete sources in x-ray images has much in common with the problem of automatic source detection at other wavelengths. In all cases, one searches for positive brightness enhancements exceeding a certain threshold, which appear consistent with what one expects for a point source, in the presence of a (possibly) spatially variable background. Multidimensional point spread functions (e.g., dependent on detector position and photon energy) are also common. At the same time, the problem in x-ray astronomy has some unique aspects. For example, for typical x-ray exposures in current or recent observatories, the number of available pixels far exceeds the number of actual x-ray events, so Poisson, rather than Gaussian statistics apply. Further, extended cosmic x-ray sources are common, and one often desires to detect point sources in the vicinity or even within bright, diffuse x-ray emission. Finally, support structures in x-ray detectors often cast sharp shadows in x-ray images making it necessary to detect sources in a region of rapidly varying exposure. We have developed a source detection package within the IRAF/PROS environment which attempts to deal with some of the problems of x-ray source detection. We have patterned our package after the successful Einstein Observatory x-ray source detection programs. However, we have attempted to improve the flexibility and accessibility of the functions and to provide a graphical front-end for the user. Our philosophy has been to use standard IRAF tasks whenever possible for image manipulation and to separate general functions from mission-specific ones. We will report on the current status of the package and discuss future developments, including simulation tasks, to allow the user to assess detection efficiency and source significance, tasks to determine source intensity, and alternative detection algorithms.

  7. Origin and Propagation of Ultra-High Energy Cosmic Rays

    E-print Network

    Gustavo A. Medina Tanco; Elisabete M. de Gouveia Dal Pino; Jorge E. Horvatth

    1999-01-06

    The existence of cosmic ray particles up to the ultra-high energy limit (> 10^20 eV) is now beyond any doubt. The detection of cosmic particles with such energies imposes a challenge for the comprehension of their sources and nature. On one side, particles with such high energies are difficult to be produced by any astrophysical source. On the other side, the interactions of these particles with photons of the cosmic microwave background cause substantial losses of energy which constraint the maximum distances that the particles are able to travel from the sources to the detectors. Aiming to help to elucidate the problem of UHECR source identification, we have performed 3-D simulations of particle trajectories propagated through the stochastic intergalactic and an extended Galactic halo magnetic fields. Going further, we have also performed simulations of proton and Fe nuclei through the spiral Galactic magnetic field (GMF) and built full-sky maps of their arrival direction distribution in both the detector (after deflection in the GMF) and just outside the Galaxy. In this work we summarize the main results of these investigations.

  8. Acceleration and Interaction of Ultra High Energy Cosmic Rays

    E-print Network

    R. J. Protheroe

    1998-12-03

    In this chapter I give an overview of shock acceleration, including a discussion of the maximum energies possible and the shape of the spectrum near cut-off, interactions of high energy cosmic rays with, and propagation through, the background radiation, and the resulting electron-photon cascade. Possible sources of the highest energy cosmic rays are discussed including active galaxies, gamma ray bursts and topological defects. I argue that while the origin of the highest energy cosmic rays is still uncertain, it is not necessary to invoke exotic models such as emission by topological defects to explain the existing data. It seems likely that shock acceleration at Fanaroff-Riley Class II radio galaxies can account for the existing data. However, new cosmic ray data, as well as better estimates of the extragalactic radiation fields and magnetic fields will be necessary before we will be certain of the origin of the highest energy particles occurring in nature.

  9. Evidence for primary interstellar cosmic-ray electrons

    NASA Technical Reports Server (NTRS)

    Cummings, A. C.; Stone, E. C.; Vogt, R. E.

    1974-01-01

    We have performed a comparative study of the absolute solar modulation of cosmic-ray positrons and electrons. We find that the interstellar electron spectrum, which is described by a power-law slope at higher energies, must flatten below about 100 MeV, that a significant fraction of interstellar cosmic-ray electrons must originate in primary sources, and that the rigidity dependence of the interplanetary cosmic-ray diffusion coefficient, R raised to the power of alpha, changes from alpha greater than zero at higher rigidities to alpha -1 below about 60 MV.

  10. Solar Variability, Cosmic Rays and Climate: What's up? The topic of possible relations between solar and cosmic

    E-print Network

    Usoskin, Ilya G.

    Preface Solar Variability, Cosmic Rays and Climate: What's up? The topic of possible relations between solar and cosmic ray variability on one hand, and Earth's climate on the other hand, is quite in Space Research topical issue on Solar Variability, Cosmic Rays and Climate presents a collection

  11. Cosmic ray Implications for Human Health

    Microsoft Academic Search

    M. A. Shea; D. F. Smart

    2000-01-01

    There appears to be concern among some people about the possible effects of cosmic radiation on everyday life. The amount of cosmic radiation that reaches the Earth and its environment is a function of solar cycle, altitude and latitude. The possible effect of naturally occurring cosmic radiation on airplane crews and space flight personal is a subject of current study.

  12. Optimal filters for detecting cosmic bubble collisions

    NASA Astrophysics Data System (ADS)

    McEwen, J. D.; Feeney, S. M.; Johnson, M. C.; Peiris, H. V.

    2012-05-01

    A number of well-motivated extensions of the ?CDM concordance cosmological model postulate the existence of a population of sources embedded in the cosmic microwave background. One such example is the signature of cosmic bubble collisions which arise in models of eternal inflation. The most unambiguous way to test these scenarios is to evaluate the full posterior probability distribution of the global parameters defining the theory; however, a direct evaluation is computationally impractical on large datasets, such as those obtained by the Wilkinson Microwave Anisotropy Probe (WMAP) and Planck. A method to approximate the full posterior has been developed recently, which requires as an input a set of candidate sources which are most likely to give the largest contribution to the likelihood. In this article, we present an improved algorithm for detecting candidate sources using optimal filters, and apply it to detect candidate bubble collision signatures in WMAP 7-year observations. We show both theoretically and through simulations that this algorithm provides an enhancement in sensitivity over previous methods by a factor of approximately two. Moreover, no other filter-based approach can provide a superior enhancement of these signatures. Applying our algorithm to WMAP 7-year observations, we detect eight new candidate bubble collision signatures for follow-up analysis.

  13. The Origin of Cosmic Rays: What can GLAST Say?

    NASA Technical Reports Server (NTRS)

    Ormes, Jonathan F.; Digel, Seith; Moskalenko, Igor V.; Moiseev, Alexander; Williamson, Roger

    2000-01-01

    Gamma rays in the band from 30 MeV to 300 GeV, used in combination with direct measurements and with data from radio and X-ray bands, provide a powerful tool for studying the origin of Galactic cosmic rays. Gamma-ray Large Area Space Telescope (GLAST) with its fine 10-20 arcmin angular resolution will be able to map the sites of acceleration of cosmic rays and their interactions with interstellar matter, It will provide information that is necessary to study the acceleration of energetic particles in supernova shocks, their transport in the interstellar medium and penetration into molecular clouds.

  14. Cosmic Ray Nuclei (CRN) detector investigation. Final Report

    Microsoft Academic Search

    P. Meyer; D. Muller; J. Lheureux; S. Swordy

    1991-01-01

    The Cosmic Ray Nuclei (CRN) detector was designed to measure elemental composition and energy spectra of cosmic radiation nuclei ranging from lithium to iron. CRN was flown as part of Spacelab 2 in 1985, and consisted of three basic components: a gas Cerenkov counter, a transition radiation detector, and plastic scintillators. The results of the experiment indicate that the relative

  15. EFFECT OF COSMIC MICROWAVE BACKGROUND ON X-RAY

    E-print Network

    Wolfe, Patrick J.

    EFFECT OF COSMIC MICROWAVE BACKGROUND ON X-RAY RADIATION OF HIGH REDSHIFT JETS Kathryn McKeough1;Introduction & Background ¨ Inverse Compton (IC) Scattering ¨ Cosmic Microwave Background (CMB) ­ relativistic, USA 3. Harvard University, 1 Oxford St, Cambridge MA 02318, USA #12;Introduction & Background

  16. RADAR SENSING OF ULTRA-HIGH ENERGY COSMIC RAY SHOWERS

    E-print Network

    overview of a currently planned radar experiment at the Telescope Array. There is much activity in cosmic-VHF with a large obstruction between receiver and transmitter (such as a mountain or earth curvature), which][6][7] Figure 1.2: Diagram of EAS shower and ionization column[8] Cosmic rays of this energy are extremely rare

  17. Gamma Line Radiation Emission from Stellar Winds in Orion Complex: A test for cosmic ray origin theory

    E-print Network

    Biman B. Nath; Peter L. Biermann

    1994-07-01

    We consider $\\gamma$-ray emission from heavy nuclei that are accelerated in the shocks of stellar winds and are excited in interactions with the ambient matter in the Orion complex. We show that the recent detection of $\\gamma$-ray lines in the Orion complex by COMPTEL telescope can be explained by such a scenario, assuming cosmic abundances. The scenario is consistent with recent models of cosmic ray acceleration in stellar winds of massive stars.

  18. Exploring Cosmic X-ray Source Polarization

    NASA Technical Reports Server (NTRS)

    Swank, Jean Hebb; Jahodal, K.; Kallman, T. R.; Kaaret, P.

    2008-01-01

    Cosmic X-ray sources are expected to be polarized, either because of their asymmetry and the role of scattering in their emission or the role of magnetic fields. Polarization at other wavelengths has been useful. X-ray polarization will provide a new handle on black hole parameters, in particular the spin, on accretion flows and outflows, on neutron star spin orientations and emission mechanisms, on the quantum mechanical effects of super-strong magnetic fields of magnetars, and on the structure of supernovae shocks. The proposed Gravity and Extreme Magnetism SMEX (GEMS) will use high efficiency polarimeters behind thin foil mirrors. The statistical sensitivity and control of systematics will allow measurement of polarization fractions as small as 1% from many galactic and extragalactic sources. Targets which should be polarized at the level that GEMS can easily measure include stellar black holes, Seyfert galaxies and quasars, blazars, rotation-powered and accretion-powered pulsars, magnetars, shell supernova remnants and pulsar wind nebulae. The polarimeters are Time Projection Chambers that allow reconstruction of images of photoelectron tracks for 2-10 keV Xrays. They can be deep without sacrificing modulation. These polarimeters do not image the sky, but the telescope point spread function and detector collimation allow structure to be resolved at the 10 arcmin level. Rotation of the spacecraft is not needed for the signal measurement in the Time Projection Chambers, but provides for measurement and correction of systematic errors. It also allows a small Bragg reflection soft X-ray experiment to be included that can be used for isolated neutron stars and blazars.

  19. The History of Cosmic Ray Studies after Hess

    NASA Astrophysics Data System (ADS)

    Grupen, Claus

    2013-06-01

    The discovery of cosmic rays by Victor Hess was confirmed with balloon flights at higher altitudes by Kolhörster. Soon the interest turned into questions about the nature of cosmic rays: gamma rays or particles? Subsequent investigations have established cosmic rays as the birthplace of elementary particle physics. The 1936 Nobel prize was shared between Victor Hess and Carl Anderson. Anderson discovered the positron in a cloud chamber. The positron was predicted by Dirac several years earlier. Many new results came now from studies with cloud chambers and nuclear emulsions. Anderson and Neddermeyer saw the muon, which for some time was considered to be a candidate for the Yukawa particle responsible for nuclear binding. Lattes, Powell, Occhialini and Muirhead clarified the situation by the discovery of the charged pions in cosmic rays. Rochester and Butler found V's, which turned out to be short-lived neutral kaons decaying into a pair of charged pions. ?'s, ?'s and ?'s were found in cosmic rays using nuclear emulsions. After that period, accelerators and storage rings took over. The unexpected renaissance of cosmic rays started with the search for solar neutrinos and the observation of the supernova 1987A and other accelerators in the sky. With the observation of neutrino oscillations one began to look beyond the standard model of elementary particles. After 100 years of cosmic ray research we are again at the beginning of a new era, and cosmic rays may contribute to solve the many open questions, like dark matter and dark energy, by providing energies well beyond those of earth-bound accelerators.

  20. A high-resolution study of ultra-heavy cosmic-ray nuclei (A0178)

    NASA Technical Reports Server (NTRS)

    Osullivan, D.; Thompson, A.; Oceallaigh, C.; Domingo, V.; Wenzel, K. P.

    1984-01-01

    The main objective of the experiment is a detailed study of the charge spectra of ultraheavy cosmic-ray nuclei from zinc (Z = 30) to uranium (Z = 92) and beyond using solid-state track detectors. Special emphasis will be placed on the relative abundances in the region Z or - 65, which is thought to be dominated by r-process nucleosynthesis. Subsidiary objectives include the study of the cosmic-ray transiron spectrum a search for the postulated long-lived superheavy (SH) nuclei (Z or = 110), such as (110) SH294, in the contemporary cosmic radiation. The motivation behind the search for super-heavy nuclei is based on predicted half-lives that are short compared to the age of the Earth but long compared to the age of cosmic rays. The detection of such nuclei would have far-reaching consequences for nuclear structure theory. The sample of ultraheavy nuclei obtained in this experiment will provide unique opportunities for many tests concerning element nucleosynthesis, cosmic-ray acceleration, and cosmic-ray propagation.

  1. The Cosmic Ray Yield Of Supernova Remnants IC 443 And Puppis A

    NASA Astrophysics Data System (ADS)

    Hewitt, John W.

    2011-01-01

    Supernovae have long been thought responsible for accelerating Galactic cosmic rays. Recent observations with the Fermi Gamma-ray Space Telescope clearly identify GeV energy emission towards several supernova remnants. Combining data from radio to gamma-rays, we assemble the broadband spectral energy distribution of IC 443 and Puppis A, supernova remnants which are interacting with molecular clouds and have spatially extended gamma-ray emission. We account for strong infrared emission from shock heated dust which contributes significantly to inverse Compton gamma-ray emission. Spectral breaks are detected at both radio and gamma-ray wavelengths, placing constraints on the underlying relativistic particle distribution responsible for nonthermal emission. We discuss the implications of our results for the yield of cosmic rays accelerated during the evolution of supernova remnants.

  2. Refractory nuclides in the cosmic-ray source

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, M. E.; Binns, W. R.; Cummings, A. C.; Davis, A. J.; Nolfo, G. de; George, J. S.; Israel, M. H.; Labrador, A. W.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.; Rosenvinge, T. T. von

    2003-01-01

    New observations of the abundances and energy spectra of the isotopes of Mg, Al, and Si from ACE/CRIS are used to extend our previous results on the composition of refractory nuclides in cosmic-ray source material.

  3. A cosmochemical view of cosmic rays and solar particles

    NASA Technical Reports Server (NTRS)

    Price, P. B.

    1973-01-01

    The composition of cosmic rays and solar particles is reviewed with emphasis on the question of whether they are representative samples of Galactic and solar matter. The composition of solar particles changes with energy and from flare to flare. A strong excess of heavy elements at energies below a few MeV/nuc decreases with energy, and at energies above 15 MeV/nuc the composition of solar particles resembles that of galactic cosmic rays somewhat better than that of the solar atmosphere. The elements Ne through Pb have remarkably similar abundances in cosmic ray sources and in the matter of the solar system. The lighter elements are depleted in cosmic rays, whereas U and Th may be enriched or not, depending on whether the meteoritic or solar abundance of Th is used.

  4. Galactic cosmic rays and N2 dissociation on Titan

    NASA Technical Reports Server (NTRS)

    Capone, L. A.; Dubach, J.; Prasad, S. S.; Whitten, R. C.

    1983-01-01

    The electromagnetic and particle cascade resulting from the absorption of galactic cosmic rays in the atmosphere of Titan is shown to be an important mechanism for driving the photochemistry at pressures of 1 to 50 mbar in the atmosphere. In particular, the cosmic ray cascade dissociates N2, a process necessary for the synthesis of nitrogen organics such as HCN. The important interactions of the cosmic ray cascade with the atmosphere are discussed. The N2 excitation and dissociation rates and the ionization rates of the principal atmospheric consituents are computed for a Titan model atmosphere that is consistent with Voyager 1 observations. It is suggested that HCN may be formed efficiently in the lower atmosphere through the photodissociation of methylamine. It is also argued that models of nitrogen and hydrocarbon photochemistry in the lower atmosphere of Titan should include the absorption of galactic cosmic rays as an important energy source.

  5. ASPIRE - Cloud Chambers as an Introduction to Cosmic Ray Observation

    NASA Astrophysics Data System (ADS)

    Callahan, Julie; Matthews, John; Jui, Charles

    2012-03-01

    ASPIRE is the K12 - Education & Public Outreach program for the Telescope Array ultra-high energy cosmic ray research project in Utah. The Telescope Array experiment studies ultra-high energy cosmic rays with an array of ˜500 surface scintillator detectors and three fluorescence telescope stations observing over 300 square miles in the West Desert of Utah. Telescope Array is a collaboration of international institutions from the United States, Japan, Korea, Russia and Belgium. Cloud chambers are an inexpensive and easy demonstration to visually observe evidence of charged particles and cosmic ray activity both for informal events as well as for K12 classroom activities. Join us in building a cloud chamber and observe cosmic rays with these table-top demonstrations. A brief overview of the Telescope Array project in Millard County, Utah will also be presented.

  6. The contribution by Domenico Pacini to the Cosmic Ray Physics

    E-print Network

    Nicola Giglietto

    2011-01-02

    Between 1900 and 1913 several people were investigating about the unknown radiation, later identified as Cosmic Rays. Several experimentalist tried to identify the origin of this radiation and in particular Victor Franz Hess, Theodor Wulf and Domenico Pacini. Among them Domenico Pacini had a crucial role to address the answer to the origin of this radiation in the right way, and V.F.~Hess performed the complete set of measurements that definitively excluded an origin connected to the soil radioactive elements. However the most interesting and may be surprising point it that these pioneers defined 1 century ago the three experimental lines to study the Cosmic Rays: from space, on ground and underground and using only electroscopes. Domenico Pacini in particular may be considered the pioneer of the underground measurements on Cosmic Rays and Hess with his set of systematic measurements with balloon flights, originated the air-space studies on Cosmic Rays.

  7. The contribution by Domenico Pacini to the Cosmic Ray Physics

    E-print Network

    Giglietto, Nicola

    2011-01-01

    Between 1900 and 1913 several people were investigating about the unknown radiation, later identified as Cosmic Rays. Several experimentalist tried to identify the origin of this radiation and in particular Victor Franz Hess, Theodor Wulf and Domenico Pacini. Among them Domenico Pacini had a crucial role to address the answer to the origin of this radiation in the right way, and V.F.~Hess performed the complete set of measurements that definitively excluded an origin connected to the soil radioactive elements. However the most interesting and may be surprising point it that these pioneers defined 1 century ago the three experimental lines to study the Cosmic Rays: from space, on ground and underground and using only electroscopes. Domenico Pacini in particular may be considered the pioneer of the underground measurements on Cosmic Rays and Hess with his set of systematic measurements with balloon flights, originated the air-space studies on Cosmic Rays.

  8. Experimental Ultra--High-Energy Cosmic Ray Physics

    E-print Network

    Stefan Westerhoff

    2005-12-07

    One of the most striking astrophysical phenomena today is the existence of cosmic ray particles with energies in excess of 10^20 eV. While their presence has been confirmed by a number of experiments, it is not clear where and how these particles are accelerated to these energies and how they travel astronomical distances without substantial energy loss. We are entering an exciting new era in cosmic ray physics, with instruments now producing data of unprecedented quality and quantity to tackle the many open questions. This paper reviews the current experimental status of cosmic ray physics and summarizes recent results on the energy spectrum and arrival directions of ultra-high-energy cosmic rays.

  9. Ultra High Energy Cosmic Rays: Observations and Theoretical Aspects

    E-print Network

    Daniel De Marco

    2006-09-05

    We present a brief introduction to the physics of Ultra High Energy Cosmic Rays (UHECRs), concentrating on the experimental results obtained so far and on what, from these results, can be inferred about the sources of UHECRs.

  10. Heliosphere Changes Affect Cosmic Ray Penetration - Duration: 18 seconds.

    NASA Video Gallery

    The changes in the size of our solar systemâ??s boundaries also cause changes to the galactic cosmic rays that enter the solar system. Although these boundaries do a good job of deflecting the majo...

  11. The Determination of the Muon Magnetic Moment from Cosmic Rays

    ERIC Educational Resources Information Center

    Amsler, C.

    1974-01-01

    Describes an experiment suited for use in an advanced laboratory course in particle physics. The magnetic moment of cosmic ray muons which have some polarization is determined with an error of about five percent. (Author/GS)

  12. Cosmic ray synthesis of organic molecules in Titan's atmosphere

    NASA Technical Reports Server (NTRS)

    Capone, L. A.; Dubach, J.; Whitten, R. C.; Prasad, S. S.; Santhanam, K.

    1980-01-01

    The possible synthesis of organic molecules by the absorption of galactic cosmic rays in an N2-CH4-H2 Titan model atmosphere has been studied. The cosmic-ray-induced ionization results in peak electron densities of 2000/cu cm, with NH(+), C3H9(+), and C4H9(+) being among the important positive ions. Details of the ion and neutral chemistry relevant to the production of organic molecules are discussed. The potential importance of N(2D) reactions with CH4 and H2 is also demonstrated. Although the integrated production rate of organic matter due to the absorption of the cosmic ray cascade is much less than that by solar ultraviolet radiation, the production of nitrogen-bearing organic molecules by cosmic rays may be greater.

  13. Active galactic nuclei, neutrinos, and interacting cosmic rays in NGC 253 and NGC 1068

    SciTech Connect

    Yoast-Hull, Tova M.; Zweibel, Ellen G. [Department of Physics, University of Wisconsin-Madison, WI 53706 (United States); Gallagher III, J. S. [Department of Astronomy, University of Wisconsin-Madison, WI 53706 (United States); Everett, John E., E-mail: yoasthull@wisc.edu [Center for Interdisciplinary Exploration and Research in Astrophysics, Northwestern University, IL 60208 (United States)

    2014-01-10

    The galaxies M82, NGC 253, NGC 1068, and NGC 4945 have been detected in ?-rays by Fermi. Previously, we developed and tested a model for cosmic-ray interactions in the starburst galaxy M82. Now, we aim to explore the differences between starburst and active galactic nucleus (AGN) environments by applying our self-consistent model to the starburst galaxy NGC 253 and the Seyfert galaxy NGC 1068. Assuming a constant cosmic-ray acceleration efficiency by supernova remnants with Milky Way parameters, we calculate the cosmic-ray proton and primary and secondary electron/positron populations, predict the radio and ?-ray spectra, and compare with published measurements. We find that our models easily fit the observed ?-ray spectrum for NGC 253 while constraining the cosmic-ray source spectral index and acceleration efficiency. However, we encountered difficultly modeling the observed radio data and constraining the speed of the galactic wind and the magnetic field strength, unless the gas mass is less than currently preferred values. Additionally, our starburst model consistently underestimates the observed ?-ray flux and overestimates the radio flux for NGC 1068; these issues would be resolved if the AGN is the primary source of ?-rays. We discuss the implications of these results and make predictions for the neutrino fluxes for both galaxies.

  14. The high energy cosmic ray detector for Spacelab II

    Microsoft Academic Search

    J. E. Lamport; J. Lheureux; P. Meyer; D. Muller

    1980-01-01

    A large cosmic ray detector to be flown on Spacelab II is presently under construction at the University of Chicago. The instrument, with a geometric factor of 5 sq m-ster, is designed to measure the elemental composition and the energy spectra of individual cosmic ray nuclei (Li to Fe) from 50 GeV\\/nucleon to several TeV\\/nucleon. Plastic scintillators are used for

  15. Cosmic Ray Ruggedness of Power Semiconductor Devices for Hybrid Vehicles

    NASA Astrophysics Data System (ADS)

    Nishida, Shuichi; Shoji, Tomoyuki; Ohnishi, Toyokazu; Fujikawa, Touma; Nose, Noboru; Ishiko, Masayasu; Hamada, Kimimori

    Power semiconductors that are used under high voltage conditions in hybrid vehicles (HVs) are required to have a high destruction tolerance against cosmic rays as well as to meet conventional quality standards. In this paper, the failure mechanism for single event burnouts (SEB) induced by cosmic rays in insulated gate bipolar transistors (IGBTs) was investigated. Device destruction tolerance can be greatly improved by adopting an optimized device design that greatly suppresses parasitic thyristor action.

  16. Ultra-High Energy Cosmic Rays and Symmetries of Spacetime

    E-print Network

    O. Bertolami

    2001-05-15

    High energy cosmic rays allow probing phenomena that are inacessible to accelerators. Observation of cosmic rays, presumebly protons, with energies beyond $4 \\times 10^{19} eV$, the so-called Greisen-Zatsepin-Kuzmin (GZK) cut-off, give origin to two puzzles: How do particles accelerate to such energies ? Are their sources within $50 - 100 Mpc$ from Earth, or Lorentz invariance is actually a broken symmetry ?

  17. Ultra-heavy cosmic rays: Theoretical implications of recent observations

    NASA Technical Reports Server (NTRS)

    Blake, J. B.; Hainebach, K. L.; Schramm, D. N.; Anglin, J. D.

    1977-01-01

    Extreme ultraheavy cosmic ray observations (Z greater or equal 70) are compared with r-process models. A detailed cosmic ray propagation calculation is used to transform the calculated source distributions to those observed at the earth. The r-process production abundances are calculated using different mass formulae and beta-rate formulae; an empirical estimate based on the observed solar system abundances is used also. There is the continued strong indication of an r-process dominance in the extreme ultra-heavy cosmic rays. However it is shown that the observed high actinide/Pt ratio in the cosmic rays cannot be fit with the same r-process calculation which also fits the solar system material. This result suggests that the cosmic rays probably undergo some preferential acceleration in addition to the apparent general enrichment in heavy (r-process) material. As estimate also is made of the expected relative abundance of superheavy elements in the cosmic rays if the anomalous heavy xenon in carbonaceous chondrites is due to a fissioning superheavy element.

  18. Ultraheavy cosmic rays - Theoretical implications of recent observations

    NASA Technical Reports Server (NTRS)

    Blake, J. B.; Hainebach, K. L.; Schramm, D. N.; Anglin, J. D.

    1978-01-01

    The recent extreme ultraheavy cosmic-ray observations (Z greater than or equal to 70) are compared with r-process models. A detailed cosmic ray propagation calculation is used to transform the calculated source distributions to those observed at the earth. The r-process production abundances are calculated using different mass formulae and beta-rate formulae; an empirical estimate based on the observed solar-system abundances is also used. There is the continued strong indication of an r-process dominance in the extreme ultraheavy cosmic rays. It is shown that the observed high actinide/Pt ratio in the cosmic rays cannot be fitted with the same r-process calculation which also fits the solar-system material. This result suggests that the cosmic rays probably undergo some preferential acceleration in addition to the apparent general enrichment in heavy (r-process) material. An estimate is also made of the expected relative abundance of superheavy elements in the cosmic rays if the anomalous heavy xenon in carbonaceous chondrites is due to a fissioning superheavy element.

  19. The Cosmic Ray Intensity Near the Archean Earth

    E-print Network

    Cohen, O; Kota, J

    2012-01-01

    We employ three-dimensional state of the art magnetohydrodynamic models of the early solar wind and heliosphere and a two-dimensional model for cosmic ray transport to investigate the cosmic ray spectrum and flux near the Archean Earth. We assess how sensitive the cosmic ray spectrum is to changes in the sunspot placement and magnetic field strength, the large scale dipole magnetic field strength, the wind ram pressure, and the Sun's rotation period. Overall, our results confirm earlier work that suggested the Archean Earth would have experienced a greatly reduced cosmic ray flux than is the case today. The cosmic ray reduction for the early Sun is mainly due to the shorter solar rotation period and tighter winding of the Parker spiral, and to the different surface distribution of the more active solar magnetic field. These effects lead to a global reduction of the cosmic ray flux at 1AU by up to two orders of magnitude or more. Variations in the sunspot magnetic field have more effect on the flux than variat...

  20. Galactic Cosmic Ray Density Variations in Magnetic Clouds

    NASA Astrophysics Data System (ADS)

    Belov, A.; Abunin, A.; Abunina, M.; Eroshenko, E.; Oleneva, V.; Yanke, V.; Papaioannou, A.; Mavromichalaki, H.

    2015-05-01

    We investigate the characteristics of Galactic cosmic rays in events associated with magnetic clouds that reach Earth. A mathematical model, capable of describing the distribution of the cosmic-ray density in a magnetic cloud is considered. We show that in most cases the behavior of the cosmic-ray density within magnetic clouds at 1 AU can be described accurately by a parabolic function of the distance to the center of the magnetic cloud measured in gyroradii. As expected, the majority of magnetic clouds modulate cosmic rays, resulting in a reduction of their density. However, there is a group of events (about one fifth of the total sample) in which the density of cosmic rays in a magnetic cloud increases. Furthermore, the extremum (a minimum or a maximum) of the cosmic-ray density is found closer to the cloud center and not at its edges. We consider a number of the factors contributing to the model and estimate the effect of each factor.

  1. Cosmic-ray Positrons from Millisecond Pulsars

    NASA Astrophysics Data System (ADS)

    Venter, C.; Kopp, A.; Harding, A. K.; Gonthier, P. L.; Büsching, I.

    2015-07-01

    Observations by the Fermi Large Area Telescope of ?-ray millisecond pulsar (MSP) light curves imply copious pair production in their magnetospheres, and not exclusively in those of younger pulsars. Such pair cascades may be a primary source of Galactic electrons and positrons, contributing to the observed enhancement in positron flux above ?10 GeV. Fermi has also uncovered many new MSPs, impacting Galactic stellar population models. We investigate the contribution of Galactic MSPs to the flux of terrestrial cosmic-ray electrons and positrons. Our population synthesis code predicts the source properties of present-day MSPs. We simulate their pair spectra invoking an offset-dipole magnetic field. We also consider positrons and electrons that have been further accelerated to energies of several TeV by strong intrabinary shocks in black widow (BW) and redback (RB) systems. Since MSPs are not surrounded by pulsar wind nebulae or supernova shells, we assume that the pairs freely escape and undergo losses only in the intergalactic medium. We compute the transported pair spectra at Earth, following their diffusion and energy loss through the Galaxy. The predicted particle flux increases for non-zero offsets of the magnetic polar caps. Pair cascades from the magnetospheres of MSPs are only modest contributors around a few tens of GeV to the lepton fluxes measured by the Alpha Magnetic Spectrometer, PAMELA, and Fermi, after which this component cuts off. The contribution by BWs and RBs may, however, reach levels of a few tens of percent at tens of TeV, depending on model parameters.

  2. Cosmic Ray Anomalies from the MSSM?

    SciTech Connect

    Cotta, R.C.; /SLAC; Conley, J.A.; /Bonn U.; Gainer, J.S.; /Argonne /Northwestern U.; Hewett, J.L.; Rizzo, T.G.; /SLAC

    2011-08-11

    The recent positron excess in cosmic rays (CR) observed by the PAMELA satellite may be a signal for dark matter (DM) annihilation. When these measurements are combined with those from FERMI on the total (e{sup +} + e{sup -}) ux and from PAMELA itself on the {anti p}p ratio, these and other results are difficult to reconcile with traditional models of DM, including the conventional minimal Supergravity (mSUGRA) version of Supersymmetry even if boosts as large as 10{sup 3-4} are allowed. In this paper, we combine the results of a previously obtained scan over a more general 19-parameter subspace of the Minimal Supersymmetric Standard Model (MSSM) with a corresponding scan over astrophysical parameters that describe the propagation of CR. We then ascertain whether or not a good fit to this CR data can be obtained with relatively small boost factors while simultaneously satisfying the additional constraints arising from gamma ray data. We find that a specific subclass of MSSM models where the Lightest Supersymmetric Particle (LSP) is mostly pure bino and annihilates almost exclusively into {tau} pairs comes very close to satisfying these requirements. The lightest in this set of models is found to be relatively close in mass to the LSP and is in some cases the nLSP. These models lead to a significant improvement in the overall fit to the data by {approx}1 unit of {chi}{sup 2}/dof in comparison to the best fit without Supersymmetry while employing boosts in the range {approx}100-200. The implications of these models for future experiments are discussed.

  3. Solution to the cosmic ray anisotropy problem.

    PubMed

    Mertsch, Philipp; Funk, Stefan

    2015-01-16

    In the standard diffusive picture for transport of cosmic rays (CRs), a gradient in the CR density induces a typically small, dipolar anisotropy in their arrival directions. This is being widely advertised as a tool for finding nearby sources. However, the predicted dipole amplitude at TeV and PeV energies exceeds the measured one by almost 2 orders of magnitude. Here, we critically examine the validity of this prediction, which is based on averaging over an ensemble of turbulent magnetic fields. We focus on (1) the deviations of the dipole in a particular random realization from the ensemble average, and (2) the possibility of a misalignment between the regular magnetic field and the CR gradient. We find that if the field direction and the gradient direction are close to ?90°, the dipole amplitude is considerably suppressed and can be reconciled with observations, which sheds light on a long-standing problem. Furthermore, we show that the dipole direction in general does not coincide with the gradient direction, thus hampering the search for nearby sources. PMID:25635539

  4. Cosmic Ray Spectrum in Supernova Remnant Shocks

    NASA Astrophysics Data System (ADS)

    Kang, Hyesung

    According to kinetic simulations of diffusive shock acceleration (DSA) in Type Ia supernova remnants (SNRs) expanding into a uniform interstellar medium (ISM), the preshock gas tem-perature is the primary parameter that governs the cosmic ray (CR) acceleration efficiency and energy spectrum, while the CR injection rate is a secondary parameter. For SNRs in the warm ISM, if the injection fraction is larger than 10-4 , the DSA is efficient enough to convert more than 20 % of the SN explosion energy into CRs and the accelerated CR spectrum exhibits a concave curvature flattening to E -1.6 . Such a flat source spectrum near the knee energy, how-ever, may not be reconciled with the CR spectrum observed at Earth. On the other hand, SNRs in the hot ISM, with an injection fraction smaller than 10-4 , are inefficient accelerators with less than 10 energy getting converted to CRs. Also the shock structure is almost test-particle like and the ensuing CR spectrum can be steeper than E -2 . With amplified magnetic field strength of order of 30microG, Alfven waves generated by the streaming instability may drift upstream fast enough to make the modified test-particle power-law as steep as E -2.3 , which is more consistent with the observed CR spectrum.

  5. Calibration of the Galactic Cosmic Ray Flux

    NASA Technical Reports Server (NTRS)

    Mathew, K. J.; Marti, K.

    2004-01-01

    We report first Xe data on the cross-calibration of I-129-Xe-129(sub n) ages with conventional CRE ages, a method which is expected to provide information on the long-term constancy of the galactic cosmic ray (GCR) flux. We studied isotopic signatures of Xe released in stepwise heating, decomposition and melting of troilites in the Cape York iron meteorite to identify isotopic shifts in Xe-129 and Xe-131 due to neutron capture in Te-128 and Te-130. We also resolve components due to extinct 129I, spallation and fission Xe. There has recently been much speculation on the constancy of GCR over long time scales, as may be inferred from iron meteorites. If GCRs originate from supernova events, this provides the basis for postulating increased fluxes at locations with higher than average densities of supernovae, specifically in OB-associations. The solar system at present appears to be inside a local bubble between spiral arms and may experience an increased GCR flux.

  6. Cosmic ray Implications for Human Health

    Microsoft Academic Search

    M. A. Shea; D. F. Smart

    2000-01-01

    There appears to be concern among some people about the possible effects of cosmic radiation on everyday life. The amount\\u000a of cosmic radiation that reaches the Earth and its environment is a function of solar cycle, altitude and latitude. The possible\\u000a effect of naturally occurring cosmic radiation on airplane crews and space flight personal is a subject of current study.

  7. Galactic Cosmic Rays from Supernova Remnants (I) - a Cosmic Ray Composition controlled by Volatility and Mass-to-Charge Ratio

    Microsoft Academic Search

    Donald C. Ellison

    1997-01-01

    This is the first of a series of papers analysing the Galactic Cosmic Ray\\u000acomposition and origin. We show that the Galactic Cosmic Ray source (GCRS)\\u000acomposition is best described in terms of (i) a general enhancement of the\\u000arefractory elements relative to the volatile ones, and (ii) among the volatile\\u000aelements, an enhancement of the heavier elements relative to

  8. Extreme-Energy Cosmic Rays: Puzzles, Models, and Maybe Neutrinos

    E-print Network

    Thomas J. Weiler

    2001-03-02

    The observation of twenty cosmic-ray air-showers at and above 10^{20} eV poses fascinating problems for particle astrophysics: how the primary particles are accelerated to these energies, how the primaries get here through the 2.7K microwave background filling the Universe, and how the highest-energy events exhibit clustering on few-degree angular scales on the sky when charged particles are expected be bent by cosmic magnetic fields. An overview of the puzzles is presented, followed by a brief discussion of many of the models proposed to solve these puzzles. Emphasis is placed on (i) the signatures by which cosmic ray experiments in the near future will discriminate among the many proposed models, and (ii) the role neutrino primaries may play in resolving the observational issues. It is an exciting prospect that highest-energy cosmic rays may have already presented us with new physics not accessible in terrestrial accelerator searches.

  9. Cosmic-Ray Positron Energy Spectrum Measured by PAMELA

    NASA Astrophysics Data System (ADS)

    Adriani, O.; Barbarino, G. C.; Bazilevskaya, G. A.; Bellotti, R.; Bianco, A.; Boezio, M.; Bogomolov, E. A.; Bongi, M.; Bonvicini, V.; Bottai, S.; Bruno, A.; Cafagna, F.; Campana, D.; Carbone, R.; Carlson, P.; Casolino, M.; Castellini, G.; De Donato, C.; De Santis, C.; De Simone, N.; Di Felice, V.; Formato, V.; Galper, A. M.; Karelin, A. V.; Koldashov, S. V.; Koldobskiy, S. A.; Krutkov, S. Y.; Kvashnin, A. N.; Leonov, A.; Malakhov, V.; Marcelli, L.; Martucci, M.; Mayorov, A. G.; Menn, W.; Mergé, M.; Mikhailov, V. V.; Mocchiutti, E.; Monaco, A.; Mori, N.; Munini, R.; Osteria, G.; Palma, F.; Papini, P.; Pearce, M.; Picozza, P.; Pizzolotto, C.; Ricci, M.; Ricciarini, S. B.; Rossetto, L.; Sarkar, R.; Scotti, V.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stochaj, S. J.; Stockton, J. C.; Stozhkov, Y. I.; Vacchi, A.; Vannuccini, E.; Vasilyev, G. I.; Voronov, S. A.; Yurkin, Y. T.; Zampa, G.; Zampa, N.; Zverev, V. G.

    2013-08-01

    Precision measurements of the positron component in the cosmic radiation provide important information about the propagation of cosmic rays and the nature of particle sources in our Galaxy. The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray positron flux and fraction that extends previously published measurements up to 300 GeV in kinetic energy. The combined measurements of the cosmic-ray positron energy spectrum and fraction provide a unique tool to constrain interpretation models. During the recent solar minimum activity period from July 2006 to December 2009, approximately 24 500 positrons were observed. The results cannot be easily reconciled with purely secondary production, and additional sources of either astrophysical or exotic origin may be required.

  10. The cosmic-ray positron energy spectrum measured by PAMELA

    E-print Network

    Adriani, O; Bazilevskaya, G A; Bellotti, R; Bianco, A; Boezio, M; Bogomolov, E A; Bongi, M; Bonvicini, V; Bottai, S; Bruno, A; Cafagna, F; Campana, D; Carbone, R; Carlson, P; Casolino, M; Castellini, G; De Donato, C; De Santis, C; De Simone, N; Di Felice, V; Formato, V; Galper, A M; Karelin, A V; Koldashov, S V; Koldobskiy, S A; Krutkov, S Y; Kvashnin, A N; Leonov, A; Malakhov, V; Marcelli, L; Martucci, M; Mayorov, A G; Menn, W; Merge', M; Mikhailov, V V; Mocchiutti, E; Monaco, A; Mori, N; Munini, R; Osteria, G; Palma, F; Papini, P; Pearce, M; Picozza, P; Pizzolotto, C; Ricci, M; Ricciarini, S B; Rossetto, L; Sarkar, R; Scotti, V; Simon, M; Sparvoli, R; Spillantini, P; Stochaj, S J; Stockton, J C; Stozhkov, Y I; Vacchi, A; Vannuccini, E; Vasilyev, G I; Voronov, S A; Yurkin, Y T; Zampa, G; Zampa, N; Zverev, V G

    2013-01-01

    Precision measurements of the positron component in the cosmic radiation provide important information about the propagation of cosmic rays and the nature of particle sources in our Galaxy. The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray positron flux and fraction that extends previously published measurements up to 300 GeV in kinetic energy. The combined measurements of the cosmic-ray positron energy spectrum and fraction provide a unique tool to constrain interpretation models. During the recent solar minimum activity period from July 2006 to December 2009 approximately 24500 positrons were observed. The results cannot be easily reconciled with purely secondary production and additional sources of either astrophysical or exotic origin may be required.

  11. The relationship between the galactic matter distribution, cosmic ray dynamics, and gamma ray production

    NASA Technical Reports Server (NTRS)

    Kniffen, D. A.; Fichtel, C. E.; Thompson, D. J.

    1976-01-01

    Theoretical considerations and analysis of the results of gamma ray astronomy suggest that the galactic cosmic rays are dynamically coupled to the interstellar matter through the magnetic fields, and hence the cosmic ray density should be enhanced where the matter density is greatest on the scale of galactic arms. This concept has been explored in a galactic model using recent 21 cm radio observations of the neutral hydrogen and 2.6 mm observations of carbon monoxide, which is considered to be a tracer of molecular hydrogen. The model assumes: (1) cosmic rays are galactic and not universal; (2) on the scale of galactic arms, the cosmic ray column (surface) density is proportional to the total interstellar gas column density; (3) the cosmic ray scale height is significantly larger than the scale height of the matter; and (4) ours is a spiral galaxy characterized by an arm to interarm density ratio of about 3:1.

  12. 30TH INTERNATIONAL COSMIC RAY CONFERENCE Observation of VHE gamma rays from HESS J1804-216 with CANGAROO-III

    E-print Network

    Enomoto, Ryoji

    30TH INTERNATIONAL COSMIC RAY CONFERENCE Observation of VHE gamma rays from HESS J1804 higashi@cr.scphys.kyoto-u.ac.jp Abstract: The H.E.S.S. collaboration has reported the detection of the gamma-ray emission from eight new sources located in the Galactic Plane. HESS J1804-216 is one

  13. Investigation of cosmic ray variations at the Samarkand neutron supermonitor facility

    NASA Astrophysics Data System (ADS)

    Dorman, L. I.; Makhmudov, B. M.; Alimov, T. A.; Libin, I. Ia.; Sirodzhev, N. S.; Turniiazov, R. K.; Iusupov, A. A.; Iudakhin, K. F.; Ianke, V. G.; Klepach, E. G.

    1991-10-01

    An analysis of cosmic ray fluctuations in September 1989 was conducted on the basis of data of the Samarkand comprehensive cosmic radiation facility. A comparison of calculated cosmic ray spectra for the Samarkand facility and the IZMIRAN cosmic ray station in Moscow is presented. Good agreement between these data and sources in the literature is shown.

  14. A monte-carlo analysis of the cosmic-ray charge abundance spectrum from the ultra-heavy cosmic-ray experiment

    NASA Astrophysics Data System (ADS)

    Donnelly, J.; Thompson, A.; O'Sullivan, D.; Drury, L. O'c.; Wenzel, K.-P.

    A Monte-Carlo simulation has been developed to analyse the data from the Ultra-Heavy Cosmic Ray Experiment (UHCRE). Current best estimates of confidence intervals on key elemental abundance ratios (such as Th/U) in the ultra-heavy galactic cosmic rays will be presented and considered in the context of current theories of cosmic-ray origin.

  15. Propagation of Cosmic Rays: Nuclear Physics in Cosmic-ray Studies

    NASA Technical Reports Server (NTRS)

    Moskalenko, Igor V.; Strong, Andrew W.; Mashnik, Stepan G.

    2004-01-01

    The nuclei fraction in cosmic rays (CR) far exceeds the fraction of other CR species, such as antiprotons, electrons, and positrons. Thus the majority of information obtained from CR studies is based on interpretation of isotopic abundances using CR propagation models where the nuclear data and isotopic production cross sections in p- and alpha-induced reactions are the key elements. This paper presents an introduction to the astrophysics of CR and diffuse gamma-rays and dimsses some of the puzzles that have emerged recently due to more precise data and improved propagation models. Merging with cosmology and particle physics, astrophysics of CR has become a very dynamic field with a large potential of breakthrough and discoveries in the near fume. Exploiting the data collected by the CR experiments to the fullest requires accurate nuclear cross sections.

  16. Propagation of cosmic rays: nuclear physics in cosmic-ray studies

    E-print Network

    I. V. Moskalenko; A. W. Strong; S. G. Mashnik

    2004-11-15

    The nuclei fraction in cosmic rays (CR) far exceeds the fraction of other CR species, such as antiprotons, electrons, and positrons. Thus the majority of information obtained from CR studies is based on interpretation of isotopic abundances using CR propagation models where the nuclear data and isotopic production cross sections in p- and alpha-induced reactions are the key elements. This paper presents an introduction to the astrophysics of CR and diffuse gamma rays and discusses some of the puzzles that have emerged recently due to more precise data and improved propagation models. Merging with cosmology and particle physics, astrophysics of CR has become a very dynamic field with a large potential of breakthrough and discoveries in the near future. Exploiting the data collected by the CR experiments to the fullest requires accurate nuclear cross sections.

  17. Propagation of Cosmic Rays: Nuclear Physics in Cosmic-Ray Studies

    SciTech Connect

    Moskalenko, Igor V. [NASA/Goddard Space Flight Center, Code 661, Greenbelt, MD 20771 (United States); Joint Center for Astrophysics/University of Maryland, Baltimore County, Baltimore, MD 21250 (United States); Strong, Andrew W. [Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1603, D-85740 Garching (Germany); Mashnik, Stepan G. [Los Alamos National Laboratory, Los Alamos, NM 87544 (United States)

    2005-05-24

    The nuclei fraction in cosmic rays (CR) far exceeds the fraction of other CR species, such as antiprotons, electrons, and positrons. Thus the majority of information obtained from CR studies is based on interpretation of isotopic abundances using CR propagation models where the nuclear data and isotopic production cross sections in p- and {alpha}-induced reactions are the key elements. This paper presents an introduction to the astrophysics of CR and diffuse {gamma}-rays and discusses some of the puzzles that have emerged recently due to more precise data and improved propagation models. Merging with cosmology and particle physics, astrophysics of CR has become a very dynamic field with a large potential of breakthrough and discoveries in the near future. Exploiting the data collected by the CR experiments to the fullest requires accurate nuclear cross sections.

  18. Searching for Extra Dimensions in High Energy Cosmic Rays

    E-print Network

    Alessandro Cafarella; Claudio Coriano'; T. N. Tomaras

    2004-10-27

    We present a study of the decay of an intermediate mini black hole at the first impact of a cosmic ray particle with the atmosphere, in the context of D-brane world scenarios with TeV scale gravity and large extra dimensions. We model the decay of the black hole using the semiclassical approximation and include the corrections coming from energy loss into the bulk. Extensive simulations show that mini black hole events are characterized by essentially different multiplicities and wider lateral distributions of the air showers as a function of the energy of the incoming primary, as compared to standard events. Implications for their detection and some open issues on their possible discovery are also briefly addressed.

  19. Commissioning of the ATLAS Muon Spectrometer with Cosmic Rays

    E-print Network

    The ATLAS Collaboration

    2010-08-02

    The ATLAS detector at the Large Hadron Collider has collected several hundred million cosmic ray events during 2008 and 2009. These data were used to commission the Muon Spectrometer and to study the performance of the trigger and tracking chambers, their alignment, the detector control system, the data acquisition and the analysis programs. We present the performance in the relevant parameters that determine the quality of the muon measurement. We discuss the single element efficiency, resolution and noise rates, the calibration method of the detector response and of the alignment system, the track reconstruction efficiency and the momentum measurement. The results show that the detector is close to the design performance and that the Muon Spectrometer is ready to detect muons produced in high energy proton-proton collisions.

  20. On Cosmic Rays, IP Structures and Geospace Consequences During WHI

    NASA Astrophysics Data System (ADS)

    Lago, A. Dal; Guarnieri, F. L.; da Silva, M. R.; Gonzalez, W. D.; Braga, C. R.; Schuch, N. J.; Munakata, K.; Kato, C.; Bieber, J. W.; Kuwabara, T.; Tokumaru, M.; Duldig, M. L.; Humble, J. E.

    2010-11-01

    This work presents some observations during the period of the Whole Heliosphere Interval (WHI) of the effects of interplanetary (IP) structures on the near-Earth space using three sets of observations: magnetic field and plasma from the Advanced Composition Explorer (ACE) satellite, ground-based cosmic ray data from the Global Muon Detection Network (GMDN) and geomagnetic indices (Disturbance storm-time, Dst, and auroral electrojet index, AE). Since WHI was near minimum solar activity, high speed streams and corotating interaction regions (CIRs) were the dominant structures observed in the interplanetary space surrounding Earth. Very pronounced geomagnetic effects are shown to be correlated to CIRs, especially because they can cause the so-called High-Intensity Long-Duration Continuous AE Activity (HILDCAAs) - Tsurutani and Gonzalez (1987). At least a few high speed streams can be identified during the period of WHI. The focus here is to characterize these IP structures and their geospace consequences.

  1. Commissioning of the ATLAS Muon Spectrometer with Cosmic Rays

    E-print Network

    Aad, Georges; Abdallah, Jalal; Abdelalim, Ahmed Ali; Abdesselam, Abdelouahab; Abdinov, Ovsat; Abi, Babak; Abolins, Maris; Abramowicz, Halina; Abreu, Henso; Acharya, Bobby Samir; Adams, David; Addy, Tetteh; Adelman, Jahred; Adorisio, Cristina; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahmed, Hossain; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov , Andrei; Aktas, Adil; Alam, Mohammad; Alam, Muhammad Aftab; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Aliyev, Magsud; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alviggi, Mariagrazia; Amako, Katsuya; Amelung, Christoph; Amorim, Antonio; Amorós, Gabriel; Amram, Nir; Anastopoulos, Christos; Andeen, Timothy; Anders, Christoph Falk; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angerami, Aaron; Anghinolfi, Francis; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonelli, Stefano; Antos, Jaroslav; Antunovic, Bijana; Anulli, Fabio; Aoun, Sahar; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Archambault, John-Paul; Arfaoui, Samir; Arguin, Jean-Francois; Argyropoulos, Theodoros; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnault, Christian; Artamonov, Andrei; Arutinov, David; Asai, Makoto; Asai, Shoji; Silva, José; Asfandiyarov, Ruslan; Ask, Stefan; Åsman, Barbro; Asner, David; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Astvatsatourov, Anatoli; Atoian, Grigor; Auerbach, Benjamin; Augsten, Kamil; Aurousseau, Mathieu; Austin, Nicholas; Avolio, Giuseppe; Avramidou, Rachel Maria; Axen, David; Ay, Cano; Azuelos, Georges; Azuma, Yuya; Baak, Max; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Badescu, Elisabeta; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Mark; Baker, Oliver Keith; Baker, Sarah; Baltasar Dos Santos Pedrosa, Fernando; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Baranov, Sergey; Baranov, Sergei; Barashkou, Andrei; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Barrillon, Pierre; Bartoldus, Rainer; Bartsch, Detlef; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Bazalova, Magdalena; Beare, Brian; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Becerici, Neslihan; Bechtle, Philip; Beck, Graham; Beck, Hans Peter; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Ayda; Beddall, Andrew; Bednyakov, Vadim; Bee, Christopher; Begel, Michael; Behar Harpaz, Silvia; Behera, Prafulla; Beimforde, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellina, Francesco; Bellomo, Massimiliano; Belloni, Alberto; Belotskiy, Konstantin; Beltramello, Olga; Ben Ami, Sagi; Benary, Odette; Benchekroun, Driss; Bendel, Markus; Benedict, Brian Hugues; Benekos, Nektarios; Benhammou, Yan; Benincasa, Gianpaolo; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertin, Antonio; Besana, Maria Ilaria; Besson, Nathalie; Bethke, Siegfried; Bianchi, Riccardo-Maria; Bianco, Michele; Biebel, Otmar; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biscarat, Catherine; Bitenc, Urban; Black, Kevin; Blair, Robert; Blanchard, Jean-Baptiste; Blanchot, Georges; Blocker, Craig; Blondel, Alain; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bocci, Andrea; Boehler, Michael; Boek, Jennifer; Boelaert, Nele; Böser, Sebastian; Bogaerts, Joannes Andreas; Bogouch, Andrei; Bohm, Christian; Bohm, Jan; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Bondarenko, Valery; Bondioli, Mario; Boonekamp, Maarten; Bordoni, Stefania; Borer, Claudia; Borisov, Anatoly; Borissov, Guennadi; Borjanovic, Iris; Borroni, Sara; Bos, Kors

    2010-01-01

    The ATLAS detector at the Large Hadron Collider has collected several hundred million cosmic ray events during 2008 and 2009. These data were used to commission the Muon Spectrometer and to study the performance of the trigger and tracking chambers, their alignment, the detector control system, the data acquisition and the analysis programs. We present the performance in the relevant parameters that determine the quality of the muon measurement. We discuss the single element efficiency, resolution and noise rates, the calibration method of the detector response and of the alignment system, the track reconstruction efficiency and the momentum measurement. The results show that the detector is close to the design performance and that the Muon Spectrometer is ready to detect muons produced in high energy proton-proton collisions.

  2. Observation of Polarised Microwave Emission from Cosmic Ray Air Showers

    E-print Network

    Smida, R; Engel, R; Arteaga-Velazquez, J C; Bekk, K; Bertaina, M; Bluemer, J; Bozdog, H; Brancus, I M; Chiavassa, A; Cossavella, F; Di Pierro, F; Doll, P; Fuchs, B; Fuhrmann, D; Grupen, C; Haungs, A; Heck, D; Hoerandel, J R; Huber, D; Huege, T; Kampert, K -H; Kang, D; Klages, H; Kleifges, M; Kroemer, O; Link, K; Luczak, P; Ludwig, M; Mathes, H J; Mayer, H J; Mathys, S; Melissas, M; Morello, C; Neunteufel, P; Oehlschlaeger, J; Palmieri, N; Pekala, J; Pierog, T; Rautenberg, J; Rebel, H; Riegel, M; Roth, M; Salamida, F; Schieler, H; Schoo, S; Schroeder, F G; Sima, O; Stasielak, J; Toma, G; Trinchero, G C; Unger, M; Weber, M; Weindl, A; Wilczynski, H; Will, M; Wochele, J; Zabierowski, J

    2013-01-01

    We report on the first direct measurement of the basic features of microwave radio emission from extensive air showers. Using a trigger provided by the KASCADE-Grande air shower array, the signals of the microwave antennas of the CROME (Cosmic-Ray Observation via Microwave Emission) experiment have been read out and searched for signatures of radio emission by high-energy air showers. Microwave signals have been detected for more than 30 showers with energies above $3\\times10^{16}$\\,eV. The observations presented in this Letter are consistent with a mainly forward-beamed, coherent and polarised emission process in the GHz frequency range. An isotropic, unpolarised radiation is disfavoured as the dominant emission model. The measurements show that microwave radiation offers a new means of studying air showers at very high energy.

  3. Design and performance in orbit of the bristol cosmic ray detector on the ariel VI satellite

    Microsoft Academic Search

    P. H. Fowler; A. M. Gay; M. R. W. Masheder; R. T. Moses; R. N. F. Walker; A. Worley

    1989-01-01

    The Ariel VI satellite carried, as a major part of its payload, an instrument designed by the Bristol University group to detect heavy primary cosmic rays. Owing to the extreme rarity of the heaviest of these particles, an unusual spherically symmetric design was chosen, thus maximising the aperture factor for a given size. This design, which included gas scintillator, plastic

  4. A Search for Microwave Emission From Ultra-High Energy Cosmic Rays

    E-print Network

    Alvarez-Muñiz, J; Bogdan, M; Bohá?ová, M; Bonifazi, C; Carvalho, W R; Neto, J R T de Mello; Luis, P Facal San; Genat, J F; Hollon, N; Mills, E; Monasor, M; Privitera, P; Reyes, L C; d'Orfeuil, B Rouille; Santos, E M; Wayne, S; Williams, C; Zas, E; Zhou, J

    2012-01-01

    We present a search for microwave emission from air showers induced by ultra-high energy cosmic rays with the MIcrowave Detection of Air Showers (MIDAS) experiment. No events were found, ruling out a wide range of power flux and coherence of the putative emission, including those suggested by recent laboratory measurements.

  5. The MIDAS experiment: A prototype for the microwave emission of UltraHigh Energy Cosmic Rays

    Microsoft Academic Search

    M. Monasor; I. Alekotte; J. Alvarez-Muñiz; X. Bertou; M. Bodgan; M. Bohacova; C. Bonifazi; W. Carvalho; J. F. Genat; P. Facal San Luis; E. Mills; S. Wayne; L. C. Reyes; E. M. Santos; P. Privitera; C. Williams; E. Zas

    2011-01-01

    Recent measurements suggest that extensive air showers initiated by ultra-high energy cosmic rays (UHECR) emit signals in the microwave band of the electromagnetic spectrum caused by the collisions of the free-electrons with the atmospheric neutral molecules in the plasma produced by the passage of the shower. Such emission is isotropic and could allow the detection of air showers with 100%

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

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    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.

  7. Light Transmission From Extended Air Showers Produced By Cosmic-Rays and Gamma-Rays

    Microsoft Academic Search

    S. F. Taylor; T. Abu-Zayyad; K. Belov; Z. Cao; G. Chen; C. C. H. Jui; D. B. Kieda; J. N. Matthews; M. Salamon; P. V. Sokolsky; J. D. Smith; P. Sommers; R. W. Springer; B. T. Stokes; S. B. Thomas; L. R. Wiencke; J. A. J. Matthews; R. W. Clay; B. R. Dawson; K. Simpson; J. Bells; J. Boyer; B. Knapp; B. H. Song; X. Z. Zhang

    1999-01-01

    Cosmic-ray and gamma-ray experiments that use the atmosphere as a calorimeter, such as the High Resolution Fly's Eye (HiRes) and the Telescope Array (TA), require understanding the transmission of the light from the air shower of particles produced by the cosmic-ray or gamma-ray striking the atmosphere. To better understand the scattering and transmission of light to the detectors, HiRes measures

  8. Gamma-Ray Emission from Galaxy Clusters : DARK MATTER AND COSMIC-RAYS

    NASA Astrophysics Data System (ADS)

    Pinzke, Anders

    The quest for the first detection of a galaxy cluster in the high energy gamma-ray regime is ongoing, and even though clusters are observed in several other wave-bands, there is still no firm detection in gamma-rays. To complement the observational efforts we estimate the gamma-ray contributions from both annihilating dark matter and cosmic-ray (CR) proton as well as CR electron induced emission. Using high-resolution simulations of galaxy clusters, we find a universal concave shaped CR proton spectrum independent of the simulated galaxy cluster. Specifically, the gamma-ray spectra from decaying neutral pions, which are produced by CR protons, dominate the cluster emission. Furthermore, based on our derived flux and luminosity functions, we identify the galaxy clusters with the brightest galaxy clusters in gamma-rays. While this emission is challenging to detect using the Fermi satellite, major observations with Cherenkov telescopes in the near future may put important constraints on the CR physics in clusters. To extend these predictions, we use a dark matter model that fits the recent electron and positron data from Fermi, PAMELA, and H.E.S.S. with remarkable precision, and make predictions about the expected gamma-ray flux from nearby clusters. In order to remain consistent with the EGRET upper limit on the gamma-ray emission from Virgo, we constrain the minimum mass of substructures for cold dark matter halos. In addition, we find comparable levels of gamma-ray emission from CR interactions and dark matter annihilations without Sommerfeld enhancement.

  9. Cosmic Ray Spectrum in Supernova Remnant Shocks

    NASA Astrophysics Data System (ADS)

    Kang, Hyesung

    2010-04-01

    We perform kinetic simulations of diffusive shock acceleration (DSA) in Type Ia supernova remnants (SNRs) expanding into a uniform interstellar medium (ISM). Bohm-like diffusion due to self-excited Alfvén waves is assumed,and simple models for Alfvénic drift and dissipation are adopted. Phenomenological models for thermal leakage injection are considered as well. We find that the preshock gas temperature is the primary parameter that governs the cosmic ray (CR) acceleration efficiency and energy spectrum,while the CR injection rate is a secondary parameter. For SNRs in the warm ISM of T_0 ? 10^5K, if the injection fraction is ? ? 10^{-4},the DSA is efficient enough to convert more than 20 % of the SN explosion energy into CRs and the accelerated CR spectrum exhibits a concave curvature flattening to E^{-1.6}, which is characteristic of CR modified shocks. Such a flat source spectrum near the knee energy, however, may not be reconciled with the CR spectrum observed at Earth.On the other hand, SNRs in the hot ISM of T_0? 10^6K with a small injection fraction, ? < 10^{-4}, are inefficient accelerators with less than 10 % of the explosion energy getting converted to CRs. Also the shock structure is almost test-particle like and the ensuing CR spectrum can be steeper than E^{-2}. With amplified magnetic field strength of order of 30?G, Alfvén waves generated by the streaming instability may drift upstream fast enough to make the modified test-particle power-law as steep as E^{-2.3}, which is more consistent with the observed CR spectrum.

  10. Assessment of galactic cosmic ray models

    NASA Astrophysics Data System (ADS)

    Mrigakshi, Alankrita Isha; Matthiä, Daniel; Berger, Thomas; Reitz, Günther; Wimmer-Schweingruber, Robert F.

    2012-08-01

    Among several factors involved in the development of a manned space mission concept, the astronauts' health is a major concern that needs to be considered carefully. Galactic cosmic rays (GCRs), which mainly consist of high-energetic nuclei ranging from hydrogen to iron and beyond, pose a major radiation health risk in long-term space missions. It is therefore required to assess the radiation exposure of astronauts in order to estimate their radiation risks. This can be done either by performing direct measurements or by making computer based simulations from which the dose can be derived. A necessary prerequisite for an accurate estimation of the exposure using simulations is a reliable description of the GCR spectra. The aim of this work is to compare GCR models and to test their applicability for the exposure assessment of astronauts. To achieve this, commonly used models capable of describing both light and heavy GCR particle spectra were evaluated by investigating the model spectra for various particles over several decades. The updated Badhwar-O'Neill model published in the year 2010, CREME2009 which uses the International Standard model for GCR, CREME96 and the Burger-Usoskin model were examined. Hydrogen, helium, oxygen and iron nuclei spectra calculated by the different models are compared with measurements from various high-altitude balloon and space-borne experiments. During certain epochs in the last decade, there are large discrepancies between the GCR energy spectra described by the models and the measurements. All the models exhibit weaknesses in describing the increased GCR flux that was observed in 2009-2010.

  11. Exploring cosmic rays at the highest-energy frontier with the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Dobrigkeit, Carola

    2015-05-01

    The Pierre Auger Observatory studies the most energetic cosmic rays arriving at Earth, those with energies from 1017 eV up to 1020 eV and beyond. In continuous operation since 2004, the Observatory employs two complementary detection techniques for measuring air showers induced by those extremely energetic particles. For the past few years new detectors and techniques are being added in order to augment the sensitivity of the measurements. Data accumulated in ten years have led to major advances in our knowledge of the origin and nature of cosmic rays. We present a summary of the latest results for the spectrum of cosmic rays, their arrival directions and composition, as well as the challenges for the future operation of the Observatory.

  12. Monte Carlo Study of Cosmic-Ray Propagation in the Galaxy and Diffuse Gamma-Ray Production

    E-print Network

    C. -Y. Huang; M. Pohl

    2007-06-04

    This work presents preliminary results for the time-dependent cosmic-ray propagation in the Galaxy by a fully 3-dimensional Monte Carlo simulation. The distribution of cosmic-rays (both protons and helium nuclei) in the Galaxy is studied on various spatial scales for both constant and variable cosmic-ray sources. The continuous diffuse gamma-ray emission produced by cosmic-rays during the propagation is evaluated.

  13. Supernova Remnants as Cosmic X-Ray Sources. Tycho SNR

    Microsoft Academic Search

    B. Hnatyk; O. Petruk

    1998-01-01

    Basic steps in history of X-ray astronomy and models of the one of the brightest cosmic X-ray sources, supernova remnants (SNRs), are described. The model of evolution of the SNR Tycho which takes into account the nonuniform ambient medium is presented for the first time. Characteristics of the SNR are found: energy of supenova explosion E = 1050 erg, ambient

  14. Study of TeV Cosmic Rays with HAWC

    NASA Astrophysics Data System (ADS)

    Fiorino, Daniel; Buelo, Collin; The HAWC Collaboration

    2015-04-01

    The High-Altitude Water Cherenkov (HAWC) Observatory is an extensive air-shower detector located at an altitude of 4100 meters in Mexico. HAWC is sensitive to cosmic rays and gamma rays at TeV energies. The cosmic-ray arrival-direction distribution at these energies shows significant anisotropy on large and small angular scales, including several regions of part-per-mille excess flux. We present studies of the anisotropy and the excess regions based on data observed with HAWC since June 2013 during the construction phase.

  15. The anomaly in the cosmic-ray positron spectrum

    E-print Network

    C. H. Chung; H. Gast; J. Olzem; S. Schael

    2007-10-12

    A recent analysis of cosmic-ray data from a space borne experiment by the AMS collaboration supports the observation of an excess in the cosmic-ray positron spectrum by previous balloon experiments. The combination of the various experimental data establishes a deviation from the expected background with a significance of more than four standard deviations. The observed change in the spectral index cannot be explained without introducing a new source of positrons. When interpreted within the MSSM a consistent description of the antiproton spectrum, the diffuse gamma-ray flux and the positron fraction is obtained which is compatible with all other experimental data, including recent WMAP data.

  16. Cosmic-Ray Anisotropy with the HAWC Observatory

    NASA Astrophysics Data System (ADS)

    Fiorino, Daniel

    2014-03-01

    The High-Altitude Water Cherenkov (HAWC) Observatory is a TeV gamma-ray and cosmic-ray detector operating at an altitude of 4100 meters in Mexico. HAWC is an extensive air-shower array. Upon completion in 2014, it will comprise 300 optically-isolated water-Cherenkov detectors. While the observatory is only partially deployed, with ~ 100 Cherenkov detectors in data acquisition since summer 2013, statistics are sufficient to perform studies of cosmic-ray anisotropy. We discuss the status and performance of the detector, including the pointing accuracy and angular resolution as inferred from the observation of the moon shadow and simulations, and present new results on small-scale cosmic-ray anisotropy from our ever-growing detector and dataset. We acknowledge the support of US NSF; US DOE Office of High-Energy Physics; The Laboratory Directed Research and Development (LDRD) program of Los Alamos National Lab; The Wisconsin Alumni Research Foundation.

  17. Cosmic-ray Propagation and Interactions in the Galaxy

    SciTech Connect

    Strong, Andrew W.; /Garching, Max Planck Inst., MPE; Moskalenko, Igor V.; /Stanford U., HEPL /KIPAC, Menlo Park; Ptuskin, Vladimir S.; /Troitsk, IZMIRAN

    2007-01-22

    We survey the theory and experimental tests for the propagation of cosmic rays in the Galaxy up to energies of 10{sup 15} eV. A guide to the previous reviews and essential literature is given, followed by an exposition of basic principles. The basic ideas of cosmic-ray propagation are described, and the physical origin of its processes are explained. The various techniques for computing the observational consequences of the theory are described and contrasted. These include analytical and numerical techniques. We present the comparison of models with data including direct and indirect--especially gamma-ray--observations, and indicate what we can learn about cosmic-ray propagation. Some particular important topics including electrons and antiparticles are chosen for discussion.

  18. Cosmic ray modulation and noise level on the extended multidirectional muons detector telescope installed in south of Brazil: preliminary analysis

    Microsoft Academic Search

    C. R. Braga; J. F. Savian; M. R. da Silva; S. M. da Silva; C. W. da Silva; A. Dal Lago; T. Kuwabara; K. Munakata; J. W. Bieber; N. J. Schuch

    2006-01-01

    Because of the large detector mass required to detect high-energy cosmic rays ground-based instruments remain the state-of-the-art method for studying these particles At energies up to 100 GeV primary galactic cosmic rays experience significant variation in response to solar wind disturbances such as interplanetary coronal mass ejections ICMEs In this way ground-based detectors can provide unique information on conditions in

  19. Fermi LAT observations of cosmic-ray electrons from 7 GeV to 1 TeV

    Microsoft Academic Search

    M. Ackermann; M. Ajello; W. B. Atwood; L. Baldini; J. Ballet; G. Barbiellini; D. Bastieri; B. M. Baughman; K. Bechtol; F. Bellardi; R. Bellazzini; F. Belli; B. Berenji; R. D. Blandford; E. D. Bloom; J. R. Bogart; E. Bonamente; A. W. Borgland; T. J. Brandt; J. Bregeon; A. Brez; M. Brigida; P. Bruel; R. Buehler; T. H. Burnett; G. Busetto; S. Buson; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; P. Carlson; S. Carrigan; J. M. Casandjian; M. Ceccanti; C. Cecchi; Ö. Çelik; E. Charles; A. Chekhtman; C. C. Cheung; J. Chiang; A. N. Cillis; S. Ciprini; R. Claus; J. Cohen-Tanugi; J. Conrad; R. Corbet; M. Deklotz; C. D. Dermer; A. de Angelis; F. de Palma; S. W. Digel; G. di Bernardo; E. Do Couto E Silva; P. S. Drell; A. Drlica-Wagner; R. Dubois; D. Fabiani; C. Favuzzi; S. J. Fegan; P. Fortin; Y. Fukazawa; S. Funk; P. Fusco; D. Gaggero; F. Gargano; D. Gasparrini; N. Gehrels; S. Germani; N. Giglietto; P. Giommi; F. Giordano; M. Giroletti; T. Glanzman; G. Godfrey; D. Grasso; I. A. Grenier; M.-H. Grondin; J. E. Grove; S. Guiriec; M. Gustafsson; D. Hadasch; A. K. Harding; M. Hayashida; E. Hays; D. Horan; R. E. Hughes; G. Jóhannesson; A. S. Johnson; R. P. Johnson; W. N. Johnson; T. Kamae; H. Katagiri; J. Kataoka; M. Kerr; J. Knödlseder; M. Kuss; J. Lande; L. Latronico; M. Lemoine-Goumard; M. Llena Garde; F. Longo; F. Loparco; B. Lott; M. N. Lovellette; P. Lubrano; A. Makeev; M. N. Mazziotta; J. E. McEnery; J. Mehault; P. F. Michelson; M. Minuti; W. Mitthumsiri; T. Mizuno; A. A. Moiseev; C. Monte; M. E. Monzani; E. Moretti; A. Morselli; I. V. Moskalenko; S. Murgia; T. Nakamori; M. Naumann-Godo; P. L. Nolan; J. P. Norris; E. Nuss; T. Ohsugi; A. Okumura; N. Omodei; E. Orlando; J. F. Ormes; M. Ozaki; D. Paneque; J. H. Panetta; D. Parent; V. Pelassa; M. Pepe; M. Pesce-Rollins; V. Petrosian; M. Pinchera; F. Piron; T. A. Porter; S. Profumo; S. Rainò; R. Rando; E. Rapposelli; M. Razzano; A. Reimer; O. Reimer; T. Reposeur; J. Ripken; S. Ritz; L. S. Rochester; R. W. Romani; M. Roth; H. F.-W. Sadrozinski; N. Saggini; D. Sanchez; A. Sander; C. Sgrò; E. J. Siskind; P. D. Smith; G. Spandre; P. Spinelli; L. Stawarz; T. E. Stephens; M. S. Strickman; A. W. Strong; D. J. Suson; H. Tajima; H. Takahashi; T. Takahashi; T. Tanaka; J. B. Thayer; J. G. Thayer; D. J. Thompson; L. Tibaldo; O. Tibolla; D. F. Torres; G. Tosti; A. Tramacere; M. Turri; Y. Uchiyama; T. L. Usher; J. Vandenbroucke; V. Vasileiou; N. Vilchez; V. Vitale; A. P. Waite; E. Wallace; P. Wang; B. L. Winer; K. S. Wood; Z. Yang; T. Ylinen; M. Ziegler

    2010-01-01

    We present the results of our analysis of cosmic-ray electrons using about 8×106 electron candidates detected in the first 12 months on-orbit by the Fermi Large Area Telescope. This work extends our previously published cosmic-ray electron spectrum down to 7 GeV, giving a spectral range of approximately 2.5 decades up to 1 TeV. We describe in detail the analysis and

  20. Cosmic Ray "Knee": A Herald of New Physics?

    E-print Network

    D. Kazanas; A. Nicolaidis

    2001-09-26

    We propose that the knee in the cosmic ray spectrum at energies E ~ 10^{15.5} eV is due to "new physics", namely to a channel in the high energy (~ TeV in the CM) proton interactions hitherto unaccounted for in estimating the energies of the air shower cosmic rays. The new interaction transfers part of the primary particle's energy to modes which do not trigger the experimental arragement (neutrinos, lightest supersymmetric particle, gravitons) thus underestimating its true energy. We show that this underestimate leads naturally to the observed break (the "knee") in the inferred cosmic ray spectrum. The suggestion we advance fits nicely to current theoretical extensions of the Standard Model (supersymmetry, technicolor, low scale gravity) where new physics at the TeV scale manifests with the distinct signature of missing energy. We present a simple model where the new physics proceeds via gluon fusion and assuming a single power law for the galactic (E ~ 10^{18.5} eV) cosmic ray spectrum, we produce a good fit to the data in the 10^{14}-10^{18.5} eV range. Our proposal should be testable in laboratory experiments (LHC) in the near future and, should it be proven correct, it would signal besides the presence of new physics in high energy interactions, a drastically different interpretation of the sources and acceleration of cosmic rays.

  1. Cosmic Rays and Stochastic Magnetic Reconnection in the Heliotail

    E-print Network

    Desiati, P

    2012-01-01

    Galactic cosmic rays are believed to be generated by diffusive shock acceleration processes in Supernova Remnants, and the arrival direction is likely determined by the distribution of their sources throughout the Galaxy, in particular by the nearest and youngest ones. Transport to Earth through the interstellar medium is expected to affect the cosmic ray properties as well. However, the observed anisotropy of TeV cosmic rays and its energy dependence cannot be explained with diffusion models of particle propagation in the Galaxy. Within a distance of a few parsec, diffusion regime is not valid and particles with energy below about 100 TeV must be influenced by the heliosphere and its elongated tail. The observation of a highly significant localized excess region of cosmic rays from the apparent direction of the downstream interstellar flow at 1-10 TeV energies might provide the first experimental evidence that the heliotail can affect the transport of energetic particles. In particular, TeV cosmic rays propa...

  2. Estimates of galactic cosmic ray shielding requirements during solar minimum

    NASA Technical Reports Server (NTRS)

    Townsend, Lawrence W.; Nealy, John E.; Wilson, John W.; Simonsen, Lisa C.

    1990-01-01

    Estimates of radiation risk from galactic cosmic rays are presented for manned interplanetary missions. The calculations use the Naval Research Laboratory cosmic ray spectrum model as input into the Langley Research Center galactic cosmic ray transport code. This transport code, which transports both heavy ions and nucleons, can be used with any number of layers of target material, consisting of up to five different arbitrary constituents per layer. Calculated galactic cosmic ray fluxes, dose and dose equivalents behind various thicknesses of aluminum, water and liquid hydrogen shielding are presented for the solar minimum period. Estimates of risk to the skin and the blood-forming organs (BFO) are made using 0-cm and 5-cm depth dose/dose equivalent values, respectively, for water. These results indicate that at least 3.5 g/sq cm (3.5 cm) of water, or 6.5 g/sq cm (2.4 cm) of aluminum, or 1.0 g/sq cm (14 cm) of liquid hydrogen shielding is required to reduce the annual exposure below the currently recommended BFO limit of 0.5 Sv. Because of large uncertainties in fragmentation parameters and the input cosmic ray spectrum, these exposure estimates may be uncertain by as much as a factor of 2 or more. The effects of these potential exposure uncertainties or shield thickness requirements are analyzed.

  3. A ready-to-use galactic cosmic ray model

    NASA Astrophysics Data System (ADS)

    Matthiä, Daniel; Berger, Thomas; Mrigakshi, Alankrita I.; Reitz, Günther

    2013-02-01

    Galactic cosmic ray nuclei close to Earth are of great importance in different fields of research. By studying their intensity in near-Earth interplanetary space and modeling their modulation in the heliosphere it is possible to gain knowledge both about the structure of the heliosphere and the transport processes within. Additionally, secondary phenomena like cloud formation, ionization processes in the atmosphere, cosmogenic nuclide production and radiation exposure in space and at aviation altitudes are related to the intensity of the galactic cosmic rays and their modulation in the heliosphere. In order to improve the knowledge about these processes and underlying mechanisms it is often beneficial to perform numerical simulations. A necessary prerequisite for such simulations is a model describing the galactic cosmic ray intensities for all particle types and energies of importance. Several of these models exist in the literature. However, many of these do not provide essential characteristics like the description of heavier nuclei or it is difficult to associate them to recent or actual solar modulation conditions. In this work a model is presented which describes the galactic cosmic ray spectra of nuclei based on a single parameter. The values of this parameter for different solar modulation conditions are derived from measurements of the Advanced Composition Explorer (ACE) spacecraft and Oulu neutron monitor count rates. Comparing the galactic cosmic ray spectra predicted by the model to a comprehensive set of experimental data from literature shows very good agreement.

  4. Modified non-linear Burgers' equations and cosmic ray shocks

    NASA Technical Reports Server (NTRS)

    Zank, G. P.; Webb, G. M.; Mckenzie, J. F.

    1988-01-01

    A reductive perturbation scheme is used to derive a generalized non-linear Burgers' equation, which includes the effects of dispersion, in the long wavelength regime for the two-fluid hydrodynamical model used to describe cosmic ray acceleration by the first-order Fermi process in astrophysical shocks. The generalized Burger's equation is derived for both relativistic and non-relativistic cosmic ray shocks, and describes the time evolution of weak shocks in the theory of diffusive shock acceleration. The inclusion of dispersive effects modifies the phase velocity of the shock obtained from the lower order non-linear Burger's equation through the introduction of higher order terms from the long wavelength dispersion equation. The travelling wave solution of the generalized Burgers' equation for a single shock shows that larger cosmic ray pressures result in broader shock transitions. The results for relativistic shocks show a steepening of the shock as the shock speed approaches the relativistic cosmic ray sound speed. The dependence of the shock speed on the cosmic ray pressure is also discussed.

  5. Cosmic rays flux and geomagnetic field variations at midlatitudes

    NASA Astrophysics Data System (ADS)

    Morozova, Anna; Ribeiro, Paulo; Tragaldabas Collaboration Team

    2014-05-01

    It is well known that the cosmic rays flux is modulated by the solar wind and the Earth's magnetic field. The Earth's magnetic field deflects charged particles in accordance with their momentum and the local field strength and direction. The geomagnetic cutoffs depend both on the internal and the external components of the geomagnetic field, therefore reflecting the geodynamo and the solar activity variations. A new generation, high performance, cosmic ray detector Tragaldabas was recently installed at the University of Santiago de Compostela (Spain). The detector has been acquiring test data since September 2013 with a rate of about 80 events/s over a solid angle of ~5 srad. around the vertical direction. To take full advantage of this new facility for the study of cosmic rays arriving to the Earth, an international collaboration has been organized, of about 20 researchers from 10 laboratories of 5 European countries. The Magnetic Observatory of Coimbra (Portugal) has been measuring the geomagnetic field components for almost 150 years since the first measurements in 1866. It is presently equipped with up-to-date instruments. Here we present a preliminary analysis of the global cosmic ray fluxes acquired by the new Tragaldabas detector in relation to the geomagnetic field variations measured by the Coimbra observatory. We also compare the data from the new cosmic rays detector with results obtained by the Castilla-La Mancha Neutron Monitor (CaLMa, Gadalajara, Spain) that is in operation since October 2011.

  6. Detecting Cosmic Gravitational-wave Background from Super-heavy Cosmic Strings with LISA

    E-print Network

    Alf Tang; Timothy J. Sumner

    2012-02-16

    Although cosmic string scenario for galaxy formation is disfavored by CMB data, it is of great interest in the generation of cosmic gravitational-wave background. This research aims to develop an algorithm to extract cosmic gravitational-wave background produced by cosmic strings from the LISA data stream, and apply the algorithm to the simulated data stream containing the background produced by cosmic strings with various strength to study the detection threshold for this source. For 1-yr observation, It is found that the detection threshold of G{\\mu} is 3.12 \\times 10^-16 in the standard scenario. In the case that p and {\\epsilon} are adjustable, the detectable region in parameter space is defined by (G{\\mu})^2/3 {\\epsilon}^-1/3 / p> 4.6 \\times 10-11.

  7. On the origin of cosmic rays. [gamma rays and supernova remnants

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1975-01-01

    Using Recent surveys of molecular clouds and gamma rays in the galaxy, it is possible to determine the distribution of 1 to 10 GeV cosmic-ray nucleons in the galaxy. This distribution appears to be identical to the supernova remnant distribution to within experimental error and provides strong support for the hypothesis that supernovae produce most of the observed cosmic rays. This distribution resembles that of OB associations of average age approximately 30 million years suggesting that cosmic rays are produced by population objects about 30 million years after their birth.

  8. Ultra High Energy Comic Rays in the Cosmic Microwave Background

    E-print Network

    W-Y. Pauchy Hwang; Bo-Qiang Ma

    2011-07-22

    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.

  9. Ultra High Energy Comic Rays in the Cosmic Microwave Background

    E-print Network

    Hwang, W-Y Pauchy

    2011-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

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

  11. Gamma Ray Bursts, Cosmic Ray Origin, and the Unidentified EGRET Sources

    E-print Network

    Charles D. Dermer

    2000-10-27

    Statistical arguments show that the volume- and time-averaged kinetic power of GRBs and fireball transients (FTs) into an L* galaxy like the Milky Way is at the level of 10^40 ergs/s. This number, though with wide uncertainties related to the internal or external shock efficiency, is sufficient to power hadronic cosmic rays observed locally. The release of energy by the high-mass progenitor stars of GRBs and FTs is sufficient to power the ultrahigh energy cosmic rays, as already shown by Waxman and Vietri in 1995. It is sufficient to power the cosmic rays above the knee of the cosmic-ray spectrum. Indeed, all hadronic cosmic rays could originate from the high-mass (>~ 100 M_o) stars that collapse to black holes, in the process forming GRBs and FTs. This source class represents a new solution to the problem of cosmic-ray origin. The ~10^4 - 10^7 black holes made by these stars could make their presence known by radiating as they accrete from the ISM, by microlensing background radiations, and by forming luminous binary systems. Some unidentified EGRET sources could be isolated black holes that accrete from the ISM. Better imaging and sensitivity with GLAST and TeV observatories will test this model for the unidentified gamma-ray sources, and this theory for cosmic-ray origin.

  12. Cosmic Ray Electrons and Protons, and Their Antiparticles

    NASA Astrophysics Data System (ADS)

    Boezio, Mirko

    2014-10-01

    Cosmic rays are a sample of solar, galactic, and extragalactic matter. Their origin, acceleration mechanisms, and subsequent propagation toward Earth have intrigued scientists since their discovery. These issues can be studied via analysis of the energy spectra and composition of cosmic rays. Protons are the most abundant component of the cosmic radiation, and many experiments have been dedicated to the accurate measurement of their spectra. Complementary information is provided by electrons, which comprise about 1 % of the cosmic radiation. Because of their low mass, electrons experience severe energy losses through synchrotron emission in the galactic magnetic field and inverse Compton scattering of radiation fields. Electrons therefore provide information on the local galactic environment that is not accessible from the study of the cosmic ray nuclei. Antiparticles, namely antiprotons and positrons, are produced in the interaction between cosmic ray nuclei and the interstellar matter. They are therefore intimately linked to the propagation mechanisms of the parent nuclei. Novel sources of primary cosmic ray antiparticles of either astrophysical (e.g., positrons from pulsars) or exotic origin (e.g., annihilation of dark matter particles) may exist. The nature of dark matter is one of the most prominent open questions in science today. An observation of positrons from pulsars would open a new observation window on these sources. Several experiments equipped with state-of-the art detector systems have recently presented results on the energy spectra of electrons, protons, and their antiparticles with a significant improvement in statistics and better control of systematics. The status of the field will be reviewed, with a focus on these recent scientific results.

  13. Footprint Characteristics of Cosmic-Ray Neutron Sensors for Soil Moisture Monitoring

    NASA Astrophysics Data System (ADS)

    Schrön, Martin; Köhli, Markus; Zreda, Marek; Dietrich, Peter; Zacharias, Steffen

    2015-04-01

    Cosmic-ray neutron sensing is a unique and an increasingly accepted method to monitor the effective soil water content at the field scale. The technology is famous for its low maintenance, non-invasiveness, continuous measurement, and most importantly, for its large footprint. Being more representative than point data and finer resolved than remote-sensing products, cosmic-ray neutron derived soil moisture products provide unrivaled advantage for mesoscale hydrologic and land surface models. The method takes advantage of neutrons induced by cosmic radiation which are extraordinarily sensitive to hydrogen and behave like a hot gas. Information about nearby water sources are quickly mixed in a domain of tens of hectares in air. Since experimental determination of the actual spatial extent is hardly possible, scientists have applied numerical models to address the footprint characteristics. We have revisited previous neutron transport simulations and present a modified conceptual design and refined physical assumptions. Our revised study reveals new insights into probing distance and water sensitivity of detected neutrons under various environmental conditions. These results sharpen the range of interpretation concerning the spatial extent of integral soil moisture products derived from cosmic-ray neutron counts. Our findings will have important impact on calibration strategies, on scales for data assimilation and on the interpolation of soil moisture data derived from mobile cosmic-ray neutron surveys.

  14. Numerical simulations of planetary gamma-ray spectra induced by galactic cosmic rays

    SciTech Connect

    Masarik, J.; Reedy, R.C.

    1994-07-01

    The fluxes of cosmic-ray-produced gamma rays escaping from Mars were calculated using the LAHET Code System and basic nuclear data for {gamma}-ray production. Both surface water content and atmospheric thickness strongly affect the fluxes of {gamma}-ray lines escaping from Mars.

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

    PubMed

    2012-04-19

    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

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

    NASA Astrophysics Data System (ADS)

    Abbasi, R.; Abdou, Y.; 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.; Bazo Alba, J. L.; 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.; Bertrand, D.; Besson, 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.; Cruz Silva, A. H.; 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.; Haj Ismail, A.; 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.; Pérez de Los Heros, C.; 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.; IceCube Collaboration

    2012-04-01

    Very energetic astrophysical events are required to accelerate cosmic rays to above 1018electronvolts. 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 1018electronvolts or that the efficiency of neutrino production is much lower than has been predicted.

  17. The acceleration rate of cosmic rays at cosmic ray modified shocks

    NASA Astrophysics Data System (ADS)

    Saito, Tatsuhiko; Hoshino, Masahiro; Amano, Takanobu

    It is a still controversial matter whether the production efficiency of cosmic rays (CRs) is relatively efficient or inefficient (e.g. Helder et al. 2009; Hughes et al. 2000; Fukui 2013). In upstream region of SNR shocks (the interstellar medium), the energy density of CRs is comparable to a substantial fraction of that of the thermal plasma (e.g. Ferriere 2001). In such a situation, CRs can possibly exert a back-reaction to the shocks and modify the global shock structure. These shocks are called cosmic ray modified shocks (CRMSs). In CRMSs, as a result of the nonlinear feedback, there are almost always up to three steady-state solutions for given upstream parameters, which are characterized by CR production efficiencies (efficient, intermediate and inefficient branch). We evaluate qualitatively the efficiency of the CR production in SNR shocks by considering the stability of CRMS, under the effects of i) magnetic fields and ii) injection, which play significant roles in efficiency of acceleration. By adopting two-fluid model (Drury & Voelk, 1981), we investigate the stability of CRMSs by means of time-dependent numerical simulations. As a result, we show explicitly the bi-stable feature of these multiple solutions, i.e., the efficient and inefficient branches are stable and the intermediate branch is unstable, and the intermediate branch transit to the inefficient one. This feature is independent of the effects of i) shock angles and ii) injection. Furthermore, we investigate the evolution from a hydrodynamic shock to CRMS in a self-consistent manner. From the results, we suggest qualitatively that the CR production efficiency at SNR shocks may be the least efficient.

  18. The Detection of Ionizing Radiation by Plasma Panel Sensors: Cosmic Muons, Ion Beams and Cancer Therapy

    E-print Network

    Friedman, Peter S; Chapman, J W; Ferretti, Claudio; Levin, Daniel S; Weaverdyck, Curtis; Zhou, Bing; Benhammou, Yan; Etzion, Erez; Guttman, Nir; Moshe, M Ben; Silver, Yiftah; Beene, James R; Varner, Robert L

    2012-01-01

    The plasma panel sensor is an ionizing photon and particle radiation detector derived from PDP technology with high gain and nanosecond response. Experimental results in detecting cosmic ray muons and beta particles from radioactive sources are described along with applications including high energy and nuclear physics, homeland security and cancer therapeutics

  19. Detection of Ionizing Radiation by Plasma-Panel Sensors: Cosmic Muons, Ion Beams, and Cancer Therapy

    SciTech Connect

    Friedman, Dr. Peter S. [Integrated Sensors, LLC; Ferretti, Claudio [University of Michigan; Ball, Robert [University of Michigan; Beene, James R [ORNL; Ben Moshe, M. [Tel Aviv University; Benhammou, Yan [Tel Aviv University; Chapman, J. Wehrley [University of Michigan; Levin, Daniel S. [University of Michigan; Silver, Yiftah [Tel Aviv University; Weaverdyck, Curtis [University of Michigan; Zhou, Bing [University of Michigan; Etzion, E [Tel Aviv University; Moshe, M. [Tel Aviv University; Bentefour, E [Ion Beam Applications

    2012-01-01

    The plasma panel sensor is an ionizing photon and particle radiation detector derived from PDP technology with high gain and nanosecond response. Experimental results in detecting cosmic ray muons and beta particles from radioactive sources are described along with applications including high energy and nuclear physics, homeland security and cancer therapeutics.

  20. Method to extract the primary cosmic ray spectrum from very high energy gamma-ray data and its application to SNR RX J1713.7-3946

    E-print Network

    F. L. Villante; F. Vissani

    2008-01-04

    Supernova remnants are likely to be the accelerators of the galactic cosmic rays. Assuming the correctness of this hypothesis, we develop a method to extract the parent cosmic ray spectrum from the VHE gamma ray flux emitted by supernova remnants (and other gamma transparent sources). Namely, we calculate semi-analytically the (inverse) operator which relates an arbitrary gamma ray flux to the parent cosmic ray spectrum, without relying on any theoretical assumption about the shape of the cosmic ray and/or photon spectrum. We illustrate the use of this technique by applying it to the young SNR RX J1713.7-3946 which has been observed by H.E.S.S. experiment during the last three years. Specific implementations of the method permit to use as an input either the parameterized VHE gamma ray flux or directly the raw data. The possibility to detect features in the cosmic rays spectrum and the error in the determination of the parent cosmic ray spectrum are also discussed.

  1. On the effect of cosmic rays in bolometric cosmic microwave background measurements from the stratosphere

    NASA Astrophysics Data System (ADS)

    Masi, S.; Battistelli, E.; de Bernardis, P.; Lamagna, L.; Nati, F.; Nati, L.; Natoli, P.; Polenta, G.; Schillaci, A.

    2010-09-01

    Context. Precision measurements of the anisotropy of the cosmic microwave background (CMB) are able to detect low-level non-Gaussian features caused by either topological defects or the inflation process. These measurements are becoming feasable with the development of large arrays of ultra-sensitive bolometric detectors and their use in balloon-borne or satellite missions. However, the space environment includes a population of cosmic rays (CRs), which produce spurious spikes in bolometric signals. Aims: We analyze the effect of CRs on the measurement of CMB anisotropy maps and the estimate of cosmological non-Gaussianity and angular power spectra of the CMB. Methods: Using accurate simulations of noise and CR events in bolometric detectors, and de-spiking techniques, we produce simulated measured maps and analyze the Gaussianity and power spectrum of the maps for different levels and rates of CR events. Results: We find that a de-spiking technique based on outlier removal in the detector signals contributing to the same sky pixel is effective in removing CR events larger than the noise. However, low level events hidden in the noise produce a positive shift of the average power signal measured by a bolometer, and increase its variance. If the number of hits per pixel is large enough, the data distribution for each sky pixel is approximately Gaussian, but the skewness and the kurtosis of the temperatures of the pixels indicate the presence of some low-level non-Gaussianity. The standard noise estimation pipeline produces a positive bias in the power spectrum at high multipoles. Conclusions: In the case of a typical balloon-borne survey, the CR-induced non-Gaussianity will be marginally detectable in the membrane bolometer channels, but be negligible in the spider-web bolometer channels. In experiments with detector sensitivity better than 100 ?K/?{Hz}, in an environment less favorable than the earth stratosphere, the CR-induced non-Gaussianity is likely to significantly affect the results.

  2. Quantifying mesoscale soil moisture with the cosmic-ray rover

    NASA Astrophysics Data System (ADS)

    Chrisman, Bobby B.

    Existing techniques measure soil moisture either at a point or over a large area many kilometers across. To bridge these two scales, we used the mobile cosmic-ray probe, or cosmic-ray rover, an instrument similar to the recently developed COSMOS probe, but bigger and mobile. This study explores the challenges and opportunities for making maps of soil moisture over large areas using the cosmic-ray rover. In 2012, soil moisture was mapped 22 times in a 25 km x 40 km survey area of the Tucson Basin at 1 km 2 resolution, i.e., at a scale comparable to that of a pixel for the Soil Moisture and Ocean Salinity (SMOS) satellite mission. The soil moisture distribution is influenced mainly by climatic variations, notably by the North American monsoon, which resulted in a systematic change in the regional variance as a function of the mean soil moisture.

  3. Cosmic Ray Acceleration by Spiral Shocks in the Galactic Wind

    E-print Network

    H. J. Voelk; V. N. Zirakashvili

    2004-01-19

    Cosmic ray acceleration by shocks related with Slipping Interaction Regions (SIRs) in the Galactic Wind is considered. SIRs are similar to Solar Wind Corotating Interaction Regions. The spiral structure of our Galaxy results in a strong nonuniformity of the Galactic Wind flow and in SIR formation at distances of 50 to 100 kpc. SIRs are not corotating with the gas and magnetic field because the angular velocity of the spiral pattern differs from that of the Galactic rotation. It is shown that the collective reacceleration of the cosmic ray particles with charge $Ze$ in the resulting shock ensemble can explain the observable cosmic ray spectrum beyond the "knee" up to energies of the order of $10^{17}Z$ eV. For the reaccelerated particles the Galactic Wind termination shock acts as a reflecting boundary.

  4. Origin and propagation of the highest energy cosmic rays

    E-print Network

    R. J. Protheroe

    1996-12-22

    In this lecture I give an overview of shock acceleration, interactions of high energy cosmic rays with, and propagation through, the background radiation, and the resulting electron-photon cascade. I argue that while the origin of the highest energy cosmic rays is still uncertain, it is not necessary to invoke exotic models such as emission by topological defects to explain the existing data. It seems likely that shock acceleration at Fanaroff-Riley Class II radio galaxies can account for the existing data. However, new cosmic ray data, as well as better estimates of the extragalactic radiation fields and magnetic fields will be necessary before we will be certain of the origin of the highest energy particles occurring in nature.

  5. Pinpointing cosmic ray propagation with the AMS-02 experiment

    SciTech Connect

    Pato, Miguel [Dipartimento di Fisica, Università degli Studi di Padova, via Marzolo 8, I-35131, Padova (Italy); Hooper, Dan [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Simet, Melanie, E-mail: pato@iap.fr, E-mail: dhooper@fnal.gov, E-mail: msimet@uchicago.edu [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)

    2010-06-01

    The Alpha Magnetic Spectrometer (AMS-02), which is scheduled to be deployed onboard the International Space Station later this year, will be capable of measuring the composition and spectra of GeV-TeV cosmic rays with unprecedented precision. In this paper, we study how the projected measurements from AMS-02 of stable secondary-to-primary and unstable ratios (such as boron-to-carbon and beryllium-10-to-beryllium-9) can constrain the models used to describe the propagation of cosmic rays throughout the Milky Way. We find that within the context of fairly simple propagation models, all of the model parameters can be determined with high precision from the projected AMS-02 data. Such measurements are less constraining in more complex scenarios, however, which allow for departures from a power-law form for the diffusion coefficient, for example, or for inhomogeneity or stochasticity in the distribution and chemical abundances of cosmic ray sources.

  6. On Measuring Cosmic Ray Energy Spectra with the Rapidity Distributions

    NASA Technical Reports Server (NTRS)

    Bashindzhagyan, G.; Adams, J.; Chilingarian, A.; Drury, L.; Egorov, N.; Golubkov, S.; Korotkova, N.; Panasyuk, M.; Podorozhnyi, D.; Procqureur, J.

    2000-01-01

    An important goal of cosmic ray research is to measure the elemental energy spectra of galactic cosmic rays up to 10(exp 16) eV. This goal cannot be achieved with an ionization calorimeter because the required instrument is too massive for space flight. An alternate method will be presented. This method is based on measuring the primary particle energy by determining the angular distribution of secondaries produced in a target layer. The proposed technique can be used over a wide range of energies (10 (exp 11) -10 (exp 16) eV) and gives an energy resolution of 60% or better. Based on this technique, a conceptual design for a new instrument (KLEM) will be presented. Due to its light weight, this instrument can have a large aperture enabling the direct measurement of cosmic rays to 1016 eV.

  7. Opportunities in cosmic-ray physics and astrophysics

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Board on Physics and Astronomy of the National Research Council established the Committee on Cosmic-Ray Physics to prepare a review of the field that addresses both experimental and theoretical aspects of the origin of cosmic radiation from outside the heliosphere. The following recommendations are made: NASA should provide the opportunity to measure cosmic-ray electrons, positrons, ultraheavy nuclei, isotopes, and antiparticles in space; NASA, the National Science Foundation (NSF), and the Department of Energy (DOE) should facilitate direct and indirect measurement of the elemental composition to as high an energy as possible, for which the support of long-duration ballooning and hybrid ground arrays will be needed; NSF and DOE should support the new Fly's Eye and provide for U.S. participation in the big projects on the horizon, which include giant arrays, ground-based gamma-ray astronomy, and neutrino telescopes; and NASA, NSF, and DOE should support a strong program of relevant theoretical investigations.

  8. Photon losses in cosmic ray acceleration in active galactic nuclei

    SciTech Connect

    Colgate, S.A.

    1984-01-01

    The usual assumption of the acceleration of ultrahigh energy cosmic rays, greater than or equal to 10/sup 18/ eV in quasars, Seyfert galaxies, and other active galactic nuclei is challenged on the basis of the photon interactions with the accelerated nucleons. This is similar to the effect of the black body radiation on particles > 10/sup 20/ eV for times of the age of the universe except that the photon spectrum is harder and the energy density greater by approx. = 10/sup 13/. Hence, a single traversal, radial or circumferential, of radiation whose energy density is no greater than the emitted flux will damp an ultrahigh energy cosmic ray 10/sup 20/ eV by greater than 10/sup 4/ times its energy. Hence, it is unlikely that any reasonable configuration of acceleration can avoid disastrous photon energy loss. A different site for ultrahigh energy cosmic ray acceleration must be found.

  9. COSMIC RAY HEATING OF THE WARM IONIZED MEDIUM

    SciTech Connect

    Wiener, Joshua; Peng Oh, S. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States)] [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Zweibel, Ellen G. [Departments of Astronomy and Physics, and Center for Magnetic Self-Organization, University of Wisconsin-Madison, Madison, WI 53706 (United States)] [Departments of Astronomy and Physics, and Center for Magnetic Self-Organization, University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2013-04-10

    Observations of line ratios in the Milky Way's warm ionized medium suggest that photoionization is not the only heating mechanism present. For the additional heating to explain the discrepancy, it would have to have a weaker dependence on the gas density than the cooling rate, {Lambda}n{sub e}{sup 2}. Reynolds et al. suggested turbulent dissipation or magnetic field reconnection as possible heating sources. We investigate here the viability of MHD-wave mediated cosmic ray heating as a supplemental heating source. This heating rate depends on the gas density only through its linear dependence on the Alfven speed, which goes as n{sub e}{sup -1/2}. We show that, scaled to appropriate values of cosmic ray energy density, cosmic ray heating can be significant. Furthermore, this heating is stable to perturbations. These results should also apply to warm ionized gas in other galaxies.

  10. IONS (ANURADHA): Ionization states of low energy cosmic rays

    NASA Technical Reports Server (NTRS)

    Biswas, S.; Chakraborti, R.; Cowsik, R.; Durgaprasad, N.; Kajarekar, P. J.; Singh, R. K.; Vahia, M. N.; Yadav, J. S.; Dutt, N.; Goswami, J. N.

    1987-01-01

    IONS (ANURADHA), the experimental payload designed specifically to determine the ionization states, flux, composition, energy spectra and arrival directions of low energy (10 to 100 MeV/amu) anomalous cosmic ray ions of helium to iron in near-Earth space, had a highly successful flight and operation Spacelab-3 mission. The experiment combines the accuracy of a highly sensitive CR-39 nuclear track detector with active components included in the payload to achieve the experimental objectives. Post-flight analysis of detector calibration pieces placed within the payload indicated no measurable changes in detector response due to its exposure in spacelab environment. Nuclear tracks produced by alpha-particles, oxygen group and Fe ions in low energy anomalous cosmic rays were identified. It is calculated that the main detector has recorded high quality events of about 10,000 alpha-particles and similar number of oxygen group and heavier ions of low energy cosmic rays.

  11. Cosmic-ray produced neon in Antarctic rocks

    NASA Astrophysics Data System (ADS)

    Graf, Th.; Kohl, C. P.; Marti, K.; Nishiizumi, K.

    1991-02-01

    Three Antarctic rocks and quartz separates thereof for their records of cosmic-ray produced Ne-21. All three samples reveal an excess of Ne-21 and in two of them a cosmic-ray origin is documented by the spallation ratios Ne-22/Ne-21. He-3 is shown to be incompletely retained in quartz (less than 10 percent). Previous studies have shown the suitability of quartz as a monitor for cosmic-ray produced radionuclides Be-10 and Al-26, and therefore as a tracer for geological processes. Al-26/Be-10 ratios allow the calculation of minimum exposure ages and maximum erosion rates, and measured ratios Ne-21/Be-10 and Ne-21/Al-26 add significant information to exposure histories, especially in the case of a complex exposure. This information is necessary for an evaluation of erosion rates and to define geological processes, such as uplift and variations ih the Antarctic ice cover.

  12. Cosmic rays muon flux measurements at Belgrade shallow underground laboratory

    NASA Astrophysics Data System (ADS)

    Veselinovi?, N.; Dragi?, A.; Maleti?, D.; Jokovi?, D.; Savi?, M.; Banjanac, R.; Udovi?i?, V.; Ani?in, I.

    2015-02-01

    The Belgrade underground laboratory is a shallow underground one, at 25 meters of water equivalent. It is dedicated to low-background spectroscopy and cosmic rays measurement. Its uniqueness is that it is composed of two parts, one above ground, the other bellow with identical sets of detectors and analyzing electronics thus creating opportunity to monitor simultaneously muon flux and ambient radiation. We investigate the possibility of utilizing measurements at the shallow depth for the study of muons, processes to which these muons are sensitive and processes induced by cosmic rays muons. For this purpose a series of simulations of muon generation and propagation is done, based on the CORSIKA air shower simulation package and GEANT4. Results show good agreement with other laboratories and cosmic rays stations.

  13. Gamma-ray bursts: Potential sources of ultra high energy cosmic-rays

    E-print Network

    E. Waxman

    2004-12-21

    The arguments suggesting an association between the sources of cosmological gamma-ray bursts (GRBs) and the sources of ultra-high energy cosmic rays (UHECRs) are presented. Recent GRB and UHECR observations are shown to strengthen these arguments. Predictions of the GRB model for UHECR production, that may be tested with large area high energy cosmic-ray detectors which are either operating or under construction, are outlined.

  14. Cosmic rays, lithium abundance and excess entropy in galaxy clusters

    E-print Network

    Biman B. Nath; Piero Madau; Joseph Silk

    2005-11-21

    We consider the production of $^6$Li in spallation reactions by cosmic rays in order to explain the observed abundance in halo metal-poor stars. We show that heating of ambient gas by cosmic rays is an inevitable consequence of this process, and estimate the energy input required to reproduce the observed abundance of $^6$Li/H$\\sim 10^{-11}$ to be of order a few hundred eV per particle. We draw attention to the possibility that this could explain the excess entropy in gas in galaxy groups and clusters. The evolution of $^6$Li and the accompanying heating of gas is calculated for structures collapsing at the present epoch with injection of cosmic rays at high redshift. We determine the energy required to explain the abundance of $^6$Li at $z \\sim 2$ corresponding to the formation epoch of halo metal-poor stars, and also an increased entropy level of $\\sim 300$ keV cm$^2$ necessary to explain X-ray observations of clusters. The energy budget for this process is consistent with the expected energy output of radio-loud AGNs, and the diffusion length scale of cosmic-ray protons responsible for heating is comparable to the size of regions with excess entropy. We also discuss the constraints imposed by the extragalactic gamma-ray background.

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

    Microsoft Academic Search

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

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

  16. Deexcitation nuclear gamma-ray line emission from low-energy cosmic rays in the inner Galaxy

    E-print Network

    Benhabiles-Mezhoud, H; Tatischeff, V; Strong, A W

    2012-01-01

    Recent observations of high ionization rates of molecular hydrogen in diffuse interstellar clouds point to a distinct low-energy cosmic-ray component. Supposing that this component is made of nuclei, two models for the origin of such particles are explored and low-energy cosmic-ray spectra are calculated which, added to the standard cosmic ray spectra, produce the observed ionization rates. The clearest evidence of the presence of such low-energy nuclei between a few MeV per nucleon and several hundred MeV per nucleon in the interstellar medium would be a detection of nuclear \\gamma-ray line emission in the range E_ 0.1 - 10 MeV, which is strongly produced in their collisions with the interstellar gas and dust. Using a recent \\gamma-ray cross section compilation for nuclear collisions, \\gamma-ray line emission spectra are calculated alongside with the high-energy \\gamma-ray emission due to {\\pi} 0 decay, the latter providing normalization of the absolute fluxes by comparison with Fermi-LAT observations of the...

  17. On the Observation of the Cosmic Ray Anisotropy below 10$^{15}$ eV

    E-print Network

    G. Di Sciascio; R. Iuppa

    2014-07-08

    The measurement of the anisotropy in the arrival direction of cosmic rays is complementary to the study of their energy spectrum and chemical composition to understand their origin and propagation. It is also a tool to probe the structure of the magnetic fields through which cosmic rays travel. As cosmic rays are mostly charged nuclei, their trajectories are deflected by the action of galactic magnetic field they propagate through before reaching the Earth atmosphere, so that their detection carries directional information only up to distances as large as their gyro-radius. If cosmic rays below $10^{15}{\\rm\\,eV}$ are considered and the local galactic magnetic field ($\\sim3{\\rm\\,\\mu G}$) is accounted for, gyro-radii are so short that isotropy is expected. At most, a weak di-polar distribution may exist, reflecting the contribution of the closest CR sources. However, a number of experiments observed an energy-dependent \\emph{"large scale"} anisotropy in the sidereal time frame with an amplitude of about 10$^{-4}$ - 10$^{-3}$, revealing the existence of two distinct broad regions: an excess distributed around 40$^{\\circ}$ to 90$^{\\circ}$ in Right Ascension (commonly referred to as "tail.in" excess) and a deficit (the "loss cone") around 150$^{\\circ}$ to 240$^{\\circ}$ in Right Ascension. In recent years the Milagro and ARGO-YBJ collaborations reported the of a "medium" scale anisotropy inside the tail-in region. The observation of such small features has been recently claimed by the IceCube experiment also in the Southern hemisphere. So far, no theory of cosmic rays in the Galaxy exists which is able to explain the origin of these different anisotropies leaving the standard model of cosmic rays and that of the galactic magnetic field unchanged at the same time.

  18. Investigating the Cosmic-Ray Ionization Rate in the Galactic ISM with H_3^+ Observations

    NASA Astrophysics Data System (ADS)

    Indriolo, Nick; Geballe, Thomas R.; Oka, Takeshi; McCall, Benjamin J.

    2011-06-01

    Observations of H_3^+ in the Galactic diffuse interstellar medium (ISM) have led to various surprising results, including the conclusion that the cosmic-ray ionization rate (?_2) is variable by over 1 order of magnitude between different diffuse cloud sight lines, with values as high as 8×10-16 S-1, and 3? upper limits as low as 0.7×10-16 S-1. This variation is interesting, as it contradicts the typical assumption that the cosmic-ray spectrum is relatively uniform throughout the Galaxy. Instead, the flux of low-energy cosmic rays responsible for ionizing H_2 must be decreased in some regions due to particle propagations effects, and increased in other regions by local acceleration sites. Whether or not acceleration in and propagation from supernova remnants (thought to be the primary accelerators of Galactic cosmic rays) alone can account for such variability remains unknown. At present, the survey of H_3^+ in diffuse clouds consists of observations toward 52 sight lines, with detections in 20 of those. In an attempt to understand variations in the inferred ionization rates, I have studied the environments through which all of these sight lines pass. I have also observed H_3^+ in 6 sight lines that probe gas in close proximity to the supernova remnant IC 443. Ionization rates inferred in 2 of these sight lines are about 20×10-16 S-1, indicating a high flux of low-energy particles, but the other 4 sight lines do not show absorption from H_3^+, so the high ionization rate and particle flux seems very localized. Combining these results near a supernova remnant to those in the general ISM further enhances the variability seen in the cosmic-ray ionization rate, and requires that the concept of a uniform cosmic-ray spectrum be reviewed.

  19. Investigating the Cosmic-Ray Ionization Rate in the Galactic ISM With H3+ Observations

    NASA Astrophysics Data System (ADS)

    Indriolo, Nick

    2011-01-01

    Observations of H3+ in the Galactic diffuse interstellar medium (ISM) have led to various surprising results, including the conclusion that the cosmic-ray ionization rate (?2) is variable by over 1 order of magnitude between different diffuse cloud sight lines, with values as high as 8×10-16 s-1, and 3? upper limits as low as 0.7×10-16 s-1. This variation is interesting, as it contradicts the typical assumption that the cosmic-ray spectrum is relatively uniform throughout the Galaxy. Instead, the flux of low-energy cosmic rays responsible for ionizing H2 must be decreased in some regions due to particle propagation effects, and increased in other regions by local acceleration sites. Whether or not acceleration in and propagation from supernova remnants (thought to be the primary accelerators of Galactic cosmic rays) alone can account for such variability remains unknown. I have conducted a survey of H3+ in diffuse clouds, which at present consists of observations toward 52 sight lines, with detections in 20 of those. In an attempt to understand variations in the inferred ionization rates, I have studied the environments through which all of these sight lines pass. I have also observed H3+ in 6 sight lines that probe gas in close proximity to the supernova remnant IC 443. Ionization rates inferred in 2 of these sight lines are about 20×10-16 s-1, indicating a high flux of low-energy particles, but the other 4 sight lines do not show absorption from H3+, so the high ionization rate and particle flux seems very localized. Combining these results near a supernova remnant with those in the general ISM further enhances the variability seen in the cosmic-ray ionization rate, and requires that the concept of a uniform cosmic-ray spectrum be reviewed.

  20. Cosmic-ray shock acceleration in oblique MHD shocks

    NASA Technical Reports Server (NTRS)

    Webb, G. M.; Drury, L. OC.; Volk, H. J.

    1986-01-01

    A one-dimensional, steady-state hydrodynamical model of cosmic-ray acceleration at oblique MHD shocks is presented. Upstream of the shock the incoming thermal plasma is subject to the adverse pressure gradient of the accelerated particles, the J x B force, as well as the thermal gas pressure gradient. The efficiency of the acceleration of cosmic-rays at the shock as a function of the upstream magnetic field obliquity and upstream plasma beta is investigated. Astrophysical applications of the results are briefly discussed.

  1. Causes of forbush decreases and other cosmic ray variations

    NASA Technical Reports Server (NTRS)

    Barouch, E.; Burlaga, L. F.

    1974-01-01

    The relationship between neutron monitor variations and the intensity variations of the interplanetary magnetic field is studied, using Deep River data and IMP-series satellite data. In over 80% of the cases studied, identifiable depressions of the cosmic ray intensity are associated with magnetic field enhancements of several hours duration and intensity above 10 gamma. Conversely, each magnetic field enhancement has an identifiable effect (though not necessarily a marked depression) on the cosmic ray intensity. Long lasting Forbush decreases are found to be the consequence of the successive action of several such features. An explanation is presented and discussed.

  2. EMMA - A New Underground Cosmic-Ray Experiment

    E-print Network

    T. Enqvist; V. Föhr; J. Joutsenvaara; T. Jämsén; P. Keränen; P. Kuusiniemi; H. Laitala; M. Lehtola; A. Mattila; J. Narkilahti; J. Peltoniemi; H. Remes; M. Reponen; T. Räihä; J. Sarkamo; C. Shen; I. Usoskin; M. Vaittinen; Z. Zhang; L. Ding; Q. Zhu; M. Roos; I. Dzaparova; S. Karpov; A. Kurenya; V. Petkov; A. Yanin; H. Fynbo

    2005-12-15

    A new type of cosmic-ray experiment is under construction in the Pyh\\"asalmi mine in the underground laboratory of the University of Oulu, Finland. It aims to study the composition of cosmic rays at and above the knee region. The experiment, called EMMA, will cover approximately 150 square-metres of detector area. The array is capable of measuring the multiplicity and the lateral distribution of underground muons, and the arrival direction of the air shower. The full-size detector is expected to run by the end of 2007.

  3. Cosmic ray produced nitrogen in extra terrestrial matter

    Microsoft Academic Search

    K. J. Mathew; S. V. S. Murty

    1993-01-01

    Production rates of15N by both solar cosmic rays (SCR) and galactic cosmic rays (GCR) have been calculated for moon, as well as meteorites of various\\u000a sizes. Our production rates of15N which considered both the reaction channels16O(p, pn)15O and16O(p, 2p)15N separately are about 30% higher than those by Reedy (1981) who considered only the channel16O(p, pn)15O and used an empirical scaling

  4. The estimation of galactic cosmic ray penetration and dose rates

    NASA Technical Reports Server (NTRS)

    Burrell, M. O.; Wright, J. J.

    1972-01-01

    This study is concerned with approximation methods that can be readily applied to estimate the absorbed dose rate from cosmic rays in rads - tissue or rems inside simple geometries of aluminum. The present work is limited to finding the dose rate at the center of spherical shells or behind plane slabs. The dose rate is calculated at tissue-point detectors or for thin layers of tissue. This study considers cosmic-rays dose rates for both free-space and earth-orbiting missions.

  5. IMF sector boundary and cosmic ray intensity variations

    NASA Astrophysics Data System (ADS)

    Fujimoto, K.; Murakami, K.; Nagashima, K.; Kojima, H.

    It is shown, by an analysis of cosmic ray intensity variations around IMF sector boundaries using the Chree epoch method, that cosmic ray density is high near the sector boundary irrespective of the sense of IMF polarity change. The decrease of neutron intensities after the boundary passage appears to be due to Forbush decreases which occur often after boundary passages. The increment per change of the solar wind velocity is found to be consistent with the 0.5 percent per 100 km/sec change rate of decrease derived by Iucci et al. (1979) and Munakata et al. (1979).

  6. Field testing for cosmic ray soft errors in semiconductor memories

    SciTech Connect

    O`Gorman, T.J.; Ross, J.M.; Taber, A.H.; Ziegler, J.F.; Muhlfeld, H.P.; Montrose, C.J.; Curtis, H.W.; Walsh, J.L.

    1996-01-01

    This paper presents a review of experiments performed by IBM to investigate the causes of soft errors in semiconductor memory chips under field test conditions. The effects of alpha-particles and cosmic rays are separated by comparing multiple measurements of the soft-error rate (SER) of samples of memory chips deep underground and at various altitudes above the earth. The results of case studies on four different memory chips show that cosmic rays are an important source of the ionizing radiation that causes soft errors. The results of field testing are used to confirm the accuracy of the modeling and the accelerated testing of chips.

  7. Cosmic-Ray Positron Identification with the PAMELA experiment

    E-print Network

    Adriani, O; Bazilevskaya, G A; Bellotti, R; Bianco, A; Boezio, M; Bogomolov, E A; Bongi, M; Bonvicini, V; Bottai, S; Bruno, A; Cafagna, F; Campana, D; Carbone, R; Carlson, P; Casolino, M; Castellini, G; De Santis, C; De Pascale, M P; De Donato, C; De Simone, N; Di Felice, V; Formato, V; Galper, A M; Karelin, A V; Koldashov, S V; Koldobskiy, S; Krut'kov, S Yu; Kvashnin, A N; Leonov, A; Malakhov, V; Marcelli, L; Martucci, M; Mayorov, A G; Menn, W; Merge`, M; Mikhailov, V V; Mocchiutti, E; Monaco, A; Mori, N; Munini, R; Osteria, G; Palma, F; Papini, P; Pearce, M; Picozza, P; Pizzolotto, C; Ricci, M; Ricciarini, S B; Rossetto, L; Sarkar, R; Simon, M; Scotti, V; Sparvoli, R; Spillantini, P; Stochaj, S J; Stockton, J C; Stozhkov, Y I; Vacchi, A; Vannuccini, E; Vasilyev, G; Voronov, S A; Yurkin, Y T; Zampa, G; Zampa, N; Zverev, V G

    2013-01-01

    The PAMELA satellite borne experiment is designed to study cosmic rays with great accuracy in a wide energy range. One of PAMELA's main goal is the study of the antimatter component of cosmic rays. The experiment, housed on board the Russian satellite Resurs-DK1, was launched on June 15th 2006 and it is still taking data. In this work we present the measurement of galactic positron energy spectrum in the energy range between 500 MeV and few hundred GeV.

  8. Energy spectrum of ultra high energy cosmic rays

    E-print Network

    Ioana C. Maris; for the Pierre Auger Collaboration

    2008-08-12

    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.

  9. Response of the D0 calorimeter to cosmic ray muons

    SciTech Connect

    Kotcher, J.

    1992-10-01

    The D0 Detector at the Fermi National Accelerator Laboratory is a large multi-purpose detector facility designed for the study of proton-antiproton collision products at the center-of-mass energy of 2 TeV. It consists of an inner tracking volume, hermetic uranium/liquid argon sampling calorimetry, and an outer 4{pi} muon detector. In preparation for our first collider run, the collaboration organized a Cosmic Ray Commissioning Run, which took place from February - May of 1991. This thesis is a detailed study of the response of the central calorimeter to cosmic ray muons as extracted from data collected during this run.

  10. Measuring 10-1000 GeV Cosmic Ray Electrons with GLAST/LAT

    E-print Network

    Alexander A. Moiseev; Jonathan F. Ormes; Igor V. Moskalenko

    2007-06-06

    We present here the capabilities of the GLAST Large Area Telescope to detect cosmic ray high-energy (HE) electrons in the energy range from 10 GeV to 1 TeV. We also discuss the science topics that can be investigated with HE electron data and quantify the results with LAT instrument simulations. The science topics include CR propagation, calibration of the IC gamma-ray model, testing hypotheses regarding the origin of HE energy cosmic-ray electrons, searching for any signature of Kaluza Klein Dark Matter annihilation, and measuring the HE electron anisotropy. We expect to detect ~ 107 electrons above 20 GeV per year of LAT operation.

  11. On cosmic ray acceleration in supernova remnants and the FERMI/PAMELA data

    E-print Network

    Markus Ahlers; Philipp Mertsch; Subir Sarkar

    2009-12-08

    We discuss recent observations of high energy cosmic ray positrons and electrons in the context of hadronic interactions in supernova remnants, the suspected accelerators of galactic cosmic rays. Diffusive shock acceleration can harden the energy spectrum of secondary positrons relative to that of the primary protons (and electrons) and thus explain the rise in the positron fraction observed by PAMELA above 10 GeV. We normalize the hadronic interaction rate by holding pion decay to be responsible for the gamma-rays detected by HESS from some SNRs. By simulating the spatial and temporal distribution of SNRs in the Galaxy according to their known statistics, we are able to then fit the electron (plus positron) energy spectrum measured by Fermi. It appears that IceCube has good prospects for detecting the hadronic neutrino fluxes expected from nearby SNRs.

  12. On cosmic ray acceleration in supernova remnants and the FERMI/PAMELA data

    E-print Network

    Ahlers, Markus; Sarkar, Subir

    2009-01-01

    We discuss recent observations of high energy cosmic ray positrons and electrons in the context of hadronic interactions in supernova remnants, the suspected accelerators of galactic cosmic rays. Diffusive shock acceleration can harden the energy spectrum of secondary positrons relative to that of the primary protons (and electrons) and thus explain the rise in the positron fraction observed by PAMELA above 10 GeV. We normalize the hadronic interaction rate by holding pion decay to be responsible for the gamma-rays detected by HESS from some SNRs. By simulating the spatial and temporal distribution of SNRs in the Galaxy according to their known statistics, we are able to then fit the electron (plus positron) energy spectrum measured by Fermi. It appears that IceCube has good prospects for detecting the hadronic neutrino fluxes expected from nearby SNRs.

  13. Cosmic ray acceleration in supernova remnants and the FERMI/PAMELA data

    SciTech Connect

    Ahlers, Markus; Mertsch, Philipp; Sarkar, Subir [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP (United Kingdom)

    2009-12-15

    We discuss recent observations of high energy cosmic ray positrons and electrons in the context of hadronic interactions in supernova remnants (SNRs), the suspected accelerators of galactic cosmic rays. Diffusive shock acceleration can harden the energy spectrum of secondary positrons relative to that of the primary protons and electrons and thus explain the rise in the positron fraction observed by PAMELA above 10 GeV. We normalize the hadronic interaction rate by holding pion decay to be responsible for the gamma rays detected by HESS from some SNRs. By simulating the spatial and temporal distribution of SNRs in the Galaxy according to their known statistics, we are able to then fit the electron (plus positron) energy spectrum measured by Fermi. It appears that IceCube has good prospects for detecting the hadronic neutrino fluxes expected from nearby SNRs.

  14. Cosmic ray acceleration in supernova remnants and the FERMI/PAMELA data

    NASA Astrophysics Data System (ADS)

    Ahlers, Markus; Mertsch, Philipp; Sarkar, Subir

    2009-12-01

    We discuss recent observations of high energy cosmic ray positrons and electrons in the context of hadronic interactions in supernova remnants (SNRs), the suspected accelerators of galactic cosmic rays. Diffusive shock acceleration can harden the energy spectrum of secondary positrons relative to that of the primary protons and electrons and thus explain the rise in the positron fraction observed by PAMELA above 10 GeV. We normalize the hadronic interaction rate by holding pion decay to be responsible for the gamma rays detected by HESS from some SNRs. By simulating the spatial and temporal distribution of SNRs in the Galaxy according to their known statistics, we are able to then fit the electron (plus positron) energy spectrum measured by Fermi. It appears that IceCube has good prospects for detecting the hadronic neutrino fluxes expected from nearby SNRs.

  15. Ultra-High Energy Cosmic Rays, Spiral galaxies and Magnetars

    E-print Network

    G. Ghisellini; G. Ghirlanda; F. Tavecchio; F. Fraternali; G. Pareschi

    2008-08-17

    We measure the correlation between the arrival directions of the highest energy cosmic rays detected by the Pierre Auger Observatory with the position of the galaxies in the HI Parkes All Sky Survey (HIPASS) catalogue, weighted for their HI flux and Auger exposure. The use of this absorption-free catalogue, complete also along the galactic plane, allows us to use all the Auger events. The correlation is significant, being 86.2% for the entire sample of HI galaxies, and becoming 99% when considering the richest galaxies in HI content, or 98% with those lying between 40-55. We interpret this result as the evidence that spiral galaxies are the hosts of the producers of UHECR and we briefly discuss classical (i.e energetic and distant) long Gamma Ray Burst (GRBs), short GRBs, as well as newly born or late flaring magnetars as possible sources of the Auger events. With the caveat that these events are still very few, and that the theoretical uncertainties are conspicuous, we found that newly born magnetars are the best candidates. If so, they could also be associated with sub-energetic, spectrally soft, nearby, long GRBs. We finally discuss why there is a clustering of Auger events in the direction on the radio-galaxy Cen A and an absence of events in the direction of the radio-galaxy M87.

  16. On the record of galactic cosmic ray flux and traffic break-ups in iron meteorites

    NASA Technical Reports Server (NTRS)

    Regnier, S.; Lavielle, B.; Marti, K.; Simonoff, G. N.

    1984-01-01

    Iron meteorites contain the record of the galactic cosmic ray intensity over a 100 to 1000 Myr time scale. A method was developed to calculate the cosmic ray exposure ages of iron meteorites. Discrepanices between exposure ages are discussed.

  17. Gamma rays and cosmic rays at Venus: The Pioneer Venus gamma ray detector and considerations for future measurements

    NASA Astrophysics Data System (ADS)

    Lorenz, Ralph D.; Lawrence, David J.

    2015-05-01

    We draw attention to, and present a summary archive of the data from, the Pioneer Venus Orbiter Gamma-ray Burst Detector (OGBD), an instrument not originally conceived with Venus science in mind. We consider the possibility of gamma-ray flashes generated by lightning and model the propagation of gamma rays in the Venusian atmosphere, finding that if gamma rays originate at the upper range of reported cloud top altitudes (75 km altitude), they may be attenuated by factors of only a few, whereas from 60 km altitude they are attenuated by over two orders of magnitude. The present archive is too heavily averaged to reliably detect such a source (and we appeal to investigators who may have retained a higher-resolution archive), but the data do provide a useful and unique record of the cosmic ray flux at Venus 1978-1993. We consider other applications of future orbital gamma ray data, such as atmospheric occultations and the detection of volcanic materials injected high in the atmosphere.

  18. Can Gamma Ray Bursts Produce the Observed Cosmic Rays Above $10^{20}$ eV?

    E-print Network

    F. W. Stecker

    2000-04-03

    It has been suggested that cosmological gamma-ray bursts (GRBs) can produce the observed flux and spectrum of cosmic rays at the highest energies. However, recent observations indicate that the redshift distribution of GRBs most likely follows that of the star formation rate in the universe, a rate which was much higher at redshifts 1.5-2 than it is today. Thus, most GRBs are at high redshifts. As a consequence, any cosmic rays emitted by these GRBs at energies above 2-3 X 10^{19} eV would be strongly attenuated by interactions with the 3K background radiation. If one assumes rough equality between the energy released in 10^{-2} to 1 MeV photons and that released in 10^{20} eV cosmic rays, then less than 10 per cent of the cosmic rays observed above 10^{20} eV can be accounted for by GRBs.

  19. Measurements of Cosmic Ray Antiprotons with

    E-print Network

    Haviland, David

    -borne apparatus designed to study charged particles, and especially antiparticles, in the cosmic radiation, a tail catcher scintillator and a neutron detector. The combination of detectors allows antiprotons of antiproton measurements and provides significantly higher statistics. During about 800 days of data

  20. Edge detection, cosmic strings and the south pole telescope

    NASA Astrophysics Data System (ADS)

    Stewart, Andrew; Brandenberger, Robert

    2009-02-01

    We develop a method of constraining the cosmic string tension G? which uses the Canny edge detection algorithm as a means of searching CMB temperature maps for the signature of the Kaiser-Stebbins effect. We test the potential of this method using high resolution, simulated CMB temperature maps. By modeling the future output from the South Pole Telescope project (including anticipated instrumental noise), we find that cosmic strings with G? > 5.5 × 10-8 could be detected.

  1. Cosmic ray background effects on the neutron intercepting silicon chip (NISC)

    NASA Astrophysics Data System (ADS)

    Çelik, Cihangir; Ünlü, Kenan; Narayanan, Vijaykrishnan; Irwin, Mary J.

    2011-10-01

    Cosmic rays are mainly composed of galactic and solar particles. Galactic particles have enormous energies and interact in the atmosphere causing cascades of secondary particles, which can travel through the atmosphere and reach sea level. The origin of the cosmic terrestrial neutrons is galactic particles and these neutrons contribute almost 97% of the cosmic rays at sea level. Solar particles originate from the sun and have less energy compared to galactic particles. Almost all the solar particles are absorbed in the atmosphere before reaching sea level. The solar particle flux depends on the 11-year solar cycle and varies by multiple orders of magnitude between these cycles. In this study, cosmic ray induced soft errors in the neutron intercepting silicon chip (NISC) are investigated via the NISC Soft Error Analysis Tool (NISCSAT), which uses Geant4 as the transport and tracking engine. The NISC is a new unconventional neutron monitoring/detection system, designed to enhance the soft error occurrences in the semiconductor memories by introducing 10B-enriched regions in the memory node structure. The main driving force comes from the reaction products of 10B (n,?) 7Li reaction because both ? and 7Li particles can induce soft errors in the memory. Since the 10B (n,?) 7Li reaction strictly depends on the incoming neutron energy and has a high cross-section at the thermal neutron energies, effects of the background cosmic thermal neutrons on the NISC are investigated in this study.

  2. Cosmic ray neutron monitor intensity in relation to Coronal Mass Ejections and Interplanetary Magnetic Field

    NASA Astrophysics Data System (ADS)

    Mishra, Rajesh Kumar; Agarwal Mishra, Rekha

    2012-07-01

    It is well known that Coronal Mass Ejections are vast structures of plasma and magnetic fields that are expelled from the sun into the heliosphere, which is detected by remote sensing and in-situ spacecraft observations. Recent work indicates that the open magnetic flux from coronal holes may be a more important driver of cosmic-ray modulation than coronal mass ejections (CMEs), which originate from closed-field regions on the Sun. Influence of four types of CMEs namely Asymmetric 'Full' Halo CMEs, Partial Halo CMEs, Asymmetric and Complex 'Full' Halo CMEs and 'Full' Halo CMEs on cosmic ray neutron monitor intensity have been investigated in this study. The data of two different ground based neutron monitors and CME events observed with instruments onboard and Wind spacecraft have been used in the present analysis. The method of superposed epoch (Chree) analysis has been used to the arrival times of these CMEs. The occurrence frequency of three different types of CMEs used in the present analysis shows complex behavior. However, significant increase in cosmic ray intensity is observed few days after the onset of asymmetric full halo and few days after the onset of full halo CMEs. The fluctuations in cosmic ray intensity are more prior to the onset of both types of the CMEs. However, during Partial Halo CMEs the cosmic ray intensity peaks, 8- 9 days prior to the onset of CMEs and depressed 3 days prior to the onset of CMEs, whereas in case of asymmetric and complex full CMEs, the intensity depressed 2 days prior to the onset of CMEs and enhanced 2 days after the onset of CMEs. The deviations in cosmic ray intensity are more pronounced in case for asymmetric and complex full halo CMEs compared to other CMEs. The cosmic ray intensity shows nearly good anti-correlation with interplanetary magnetic field strength (B) during asymmetric full halo CMEs and partial halo CMEs, whereas it shows poor correlation with B during other CMEs. The interplanetary magnetic field strength B shows significant characteristics before and after the onset of these three types of CMEs. Keywords: cosmic ray, coronal mass ejections, interplanetary magnetic field.

  3. Contribution of a nearby Pulsar to Cosmic Rays observed at Earth

    E-print Network

    A. Bhadra

    2006-02-14

    Contribution of nearby pulsars to the cosmic rays observed at Earth has been studied. It is found that the experimental bound on amplitude of cosmic ray anisotropy may produce significant constraint on the efficiency of converting pulsar rotational energy to emitted particles kinetic energy. Cosmic ray fluxes from two well known nearby gamma ray pulsars, namely the Vela and Geminga pulsars, are estimated. The analysis suggests that observed bound on cosmic ray anisotropy restricts the contributions of the Vela and the Geminga pulsars to at most 1 % of the observed cosmic rays below the knee.

  4. Cosmic ray composition investigations using ICE/ISEE-3

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, Mark E.

    1992-01-01

    The analysis of data from the high energy cosmic experiment on ISEE-3 and associated modeling and interpretation activities are discussed. The ISEE-3 payload included two instruments capable of measuring the composition of heavy cosmic rays. The designs of these two instruments incorporated innovations which made it possible, for the first time, to measure isotopic as well as the chemical composition for a wide range of elements. As the result of the demonstrations by these two instruments of the capability to resolve individual cosmic ray isotopes, a new generation of detectors was developed using very similar designs, but having improved reliability and increased sensitive area. The composition measurements which were obtained from the ISEE-3 experiment are summarized.

  5. Single particle effects, Biostack, and risk evaluation - Studies on the radiation risk from Galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Curtis, Stanley B.

    1993-01-01

    The possible health risks posed by Galactic cosmic rays, especially the possible heightened cancer risk, are examined. The results of the Biostack studies of the biological effects of high-energy cosmic rays are discussed. The biological mechanisms involved in possible harm due to cosmic rays are considered.

  6. Three dimensional structure of correlations between intensity variation of cosmic rays and solar wind velocity

    Microsoft Academic Search

    H. Kojima; T. Fujii; Y. Hayashi; S. Kawakami; M. Minamino; H. Miyauchi; T. Nonaka; S. Ogio; H. Tanaka; E. Usui; Y. Yamashita; A. Oshima; H. M. Antia; S. R. Dugad; U. D. Goswami; S. K. Gupta; P. K. Mohanty; P. K. Nayak; P. Subramanian; S. C. Tonwar; S. Shibata; I. Morishita

    A three dimensional structure of a solar wind effect on the intensity variation of cosmic rays has been investigated by using the regression analysis method in this paper. The solar wind effect discussed here is represented by the regression coefficients between the intensity variation of cosmic rays and the solar wind velocity. The data of cosmic ray intensity used in

  7. On scaling cosmogenic nuclide production rates for altitude and latitude using cosmic-ray measurements

    Microsoft Academic Search

    Darin Desilets; Marek Zreda

    2001-01-01

    The wide use of cosmogenic nuclides for dating terrestrial landforms has prompted a renewed interest in characterizing the spatial distribution of terrestrial cosmic rays. Cosmic-ray measurements from neutron monitors, nuclear emulsions and cloud chambers have played an important role in developing new models for scaling cosmic-ray neutron intensities and, indirectly, cosmogenic production rates. Unfortunately, current scaling models overlook or misinterpret

  8. In situ formation of cosmogenic 14 C by cosmic ray nucleons in polar ice

    E-print Network

    In situ formation of cosmogenic 14 C by cosmic ray nucleons in polar ice Aleksandr Nesterenok 2011 Available online 8 October 2011 Keywords: Cosmic rays Polar ice Radiocarbon In situ production a b s t r a c t We study interactions of cosmic ray particles with the Earth's atmosphere and polar ice

  9. Interactions of High Energy Cosmic Rays with Extragalactic Infrared Radiation Background

    E-print Network

    E. V. Bugaev; P. A. Klimai

    2005-09-14

    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.

  10. Cosmic-ray Muon Radiography of a Volcano Seismo Seminor at Caltech, Nov 5, 2004

    E-print Network

    Heaton, Thomas H.

    Cosmic-ray Muon Radiography of a Volcano Seismo Seminor at Caltech, Nov 5, 2004 Hiroyuki Tanaka method with cosmic-ray muons to create a direct snapshot of the density profile in a volcano will be discussed as a complementary technique. We call this technique cosmic-ray muon radiography. The principal

  11. The JADE project: an angular cosmic ray detector

    NASA Astrophysics Data System (ADS)

    Le Maire, Victor; Jago, Alban; Mertens, Alexandre; de Crombrugghe, Guerric; Reydams, Marc; van Vynckt, Delphine; Denies, Jonathan; de Lobkowicz, Ysaline

    JADE (JUMP Angular Detection Experiment) is part of the JUMP Martian mission simulation conducted by students in the Mars Desert Research Station (MDRS) a habitat installed by the Mars Society (MS) in the Utah desert. The campaign was supported by ILEWG International Lunar Exploration Working Group, ESTEC, NASA Ames, and partners. It consists in a cosmic ray detector that can measure the angle of incidence of the particles. To develop such instru-ments, one usually uses two pixel silicium detectors that allow computing the particle trajectory. However such equipments are very expensive and require a complex electronic interface. This implies also that a significant amount of data has to be collected when a particle goes through the detector which can rapidly become a difficult constraint for limited bandwidth system as used in space instruments. JADE will be a modification an alternative solution proposed in [1], and it will take advantage of the geometry of the instrument in order to measure the incidence angle, with the innovative use of scintillators (a crystal emitting light when crossed by a charged particle) which are cheaper and stronger than silicium sensors. The detector consists in four scintillators disposed one above the other with a well determined relative angle (30). When a particle goes through a scintillator, light is emitted, collected through optical fibers and transformed into an electrical signal by a photomultiplier. This signal is proportional to the energy deposited in the scintillator by the particle which in turn is proportional to the distance travelled by the particle into the scintillator. Based on the distance travelled in each scintillator, it is then possible to compute the incidence angle. During the simulation several aspects of the use of this detector by astronauts will be tested. Its installation by astronauts wearing EVA suits will be studied with care. Furthermore, we will try to find an efficient way to fix the detector to the ground using a backpack drilling system. We will also use the angular measurement to monitor the cosmic ray activity by measuring the angular distribution of muons produced in the atmosphere, according to the time of the day and the weather conditions. We shall report on the science and technical results, and implications for Earth-Mars compar-ative studies. Reference: [1] CONNELL J.J. LOPATE C. MCKIBBEN R.B., Angle detecting inclined sensors (ADIS) system: Measuring particle angles of incidence without position sensing detectors, 2001, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 457 (1-2), pp. 220-229.

  12. Cosmic-rays induced Titan tholins and their astrobiological significances

    NASA Astrophysics Data System (ADS)

    Kobayashi, Kensei; Taniuchi, Toshinori; Hosogai, Tomohiro; Kaneko, Takeo; Takano, Yoshinori; Khare, Bishun; McKay, Chris

    Titan is the largest satellite of Saturn. It is quite unique satellite since it has a dense atmosphere composed of nitrogen and methane, and has been sometimes considered as a model of primitive Earth. In Titan atmosphere, a wide variety of organic compounds and mists made of complex organics. Such solid complex organics are often referred to as tholins. A number of laboratory experiments simulating reactions in Titan atmosphere have been conducted. In most of them, ultraviolet light and discharges (simulating actions of electrons in Saturn magnetosphere) were used, which were simulation of the reactions in upper dilute atmosphere of Titan. We examined possible formation of organic compounds in the lower dense atmosphere of Titan, where cosmic rays are major energies. A Mixture of 35 Torr of methane and 665 Torr of nitrogen was irradiated with high-energy protons (3 MeV) from a van de Graaff accelerator (TIT, Japan) or from a Tandem accelerator (TIARA, QUBS, JAEA, Japan). In some experiments, 13 C-labelled methane was used. We also performed plasma discharges in a mixture of methane (10 %) and nitrogen (90 %) to simulate the reactions in the upper atmosphere of Titan. Solid products by proton irradiation and those by plasma discharges are hereafter referred to as PI-tholins and PD-tholins, respectively. The resulting PI-tholins were observed with SEM and AFM. They were characterized by pyrolysis-GC/MS, gel permeation chromatography, FT-IR, etc. Amino acids in PI-and PD-tholins were analyzed by HPLC, GC/MS and MALDI-TOF-MS after acid hydrolysis. 18 O-Labelled water was used in some cases during hydrolysis. Filamentary and/or globular-like structures were observed by SEM and AFM. By pyrolysis-GC/MS of PI-tholins, ammonia and hydrogen cyanide were detected, which was the same as the results obtained in Titan atmosphere during the Huygens mission. A wide variety of amino acids were detected after hydrolysis of both tholins. It was proved that oxygen atoms in the amino acids in PI-tholins were incorporated from water during hydrolysis by the experiments with 18 O-Labelled water. Estimating from the G-values of amino acids and the flux of each energy in Titan atmosphere, it is strongly suggested that amino acid precursors in the form of tholins can be produced mainly in the lower Titan atmosphere by cosmic rays. The tholins containing amino acid precursors could be concentrated on some part of Titan surface by the flow of liquid methane. Amino acid precursors on the surface of Titan is promising targets in future Titan missions.

  13. Precision studies of cosmic rays with PAMELA

    Microsoft Academic Search

    Mark Pearce

    2008-01-01

    The PAMELA satellite-borne apparatus was launched into an elliptical low earth orbit with an inclination of 70 degrees on June 15th 2006. The combination of a permanent magnet silicon strip spectrometer, and a silicon-tungsten imaging calorimeter allows precision studies of the charged cosmic radiation to be conducted over a wide energy range ( 100 MeV - 100's GeV) with high

  14. Cosmic Ray Spectra in Nambu-Goldstone Dark Matter Models

    SciTech Connect

    Ibe, Masahiro; /SLAC; Murayama, Hitoshi; /UC, Berkeley /LBL, Berkeley /Tokyo U., IPMU; Shirai, Satoshi; /Tokyo U. /Tokyo U., IPMU; Yanagida, Tsutomu T.; /Tokyo U., IPMU /Tokyo U.; ,

    2010-06-11

    We discuss the cosmic ray spectra in annihilating/decaying Nambu-Goldstone dark matter models. The recent observed positron/electron excesses at PAMELA and Fermi experiments are well fitted by the dark matter with a mass of 3TeV for the annihilating model, while with a mass of 6TeV for the decaying model. We also show that the Nambu-Goldstone dark matter models predict a distinctive gamma-ray spectrum in a certain parameter space.

  15. Probing the cosmic web: intercluster filament detection using gravitational lensing

    Microsoft Academic Search

    James M. G. Mead; Lindsay J. King; Ian G. McCarthy

    2010-01-01

    The problem of detecting dark matter filaments in the cosmic web is considered. Weak lensing is an ideal probe of dark matter, and therefore forms the basis of particularly promising detection methods. We consider and develop a number of weak lensing techniques that could be used to detect filaments in individual or stacked cluster fields, and apply them to synthetic

  16. An Inexpensive Cosmic Ray Detector for the Classroom

    ERIC Educational Resources Information Center

    Goldader, Jeffrey D.; Choi, Seulah

    2010-01-01

    Finding ways to demonstrate--in a high school classroom--that subatomic particles from space produce other particles capable of reaching the Earth's surface is not a trivial task. In this paper, we describe a Geiger-Muller tube-based cosmic ray coincidence detector we produced at a total cost of less than $200, using two tubes purchased used…

  17. Solar Cycle in the Heliosphere and Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Bazilevskaya, Galina A.; Cliver, Edward W.; Kovaltsov, Gennady A.; Ling, Alan G.; Shea, M. A.; Smart, D. F.; Usoskin, Ilya G.

    2014-12-01

    Manifestations of the 11-year solar cycle and longer time-scale variability in the heliosphere and cosmic rays are considered. We briefly review the cyclic variability of such heliospheric parameters as solar wind speed and density and heliospheric magnetic field, open magnetic flux and latitude variations of the heliospheric current sheet. It is discussed whether the local in-situ observation near Earth can represent the global 3D heliospheric pattern. Variability of cosmic rays near Earth provides an indirect useful tool to study the heliosphere. We discuss details of the heliospheric modulation of galactic cosmic rays, as recorded at and near Earth, and their relation to the heliospheric conditions in the outer heliosphere. On the other hand, solar energetic particles can serve as probes for explosive phenomena on the Sun and conditions in the corona and inner heliosphere. The occurrence of major solar proton events depicts an overall tendency to follow the solar cycle but individual events may appear at different phases of the solar cycle, as defined by various factors. The solar cycle in the heliosphere and cosmic rays depicts a complex pattern which includes different processes and cannot be described by a simple correlation with sunspot number.

  18. Ring imaging detector for cosmic-ray observations

    Microsoft Academic Search

    Don Ellithorpe; Edward Diehl; Dietrich Mueller; Simon Swordy

    1996-01-01

    The measurement of particle velocities in cosmic ray experiments has largely been made by counters which determine the total amount of Cherenkov light emitted by a radiator material. Here we discuss a far more accurate technique which measures the angle of emission of individual Cherenkov photons by imaging the emission cone onto a ring. This approach has the advantage of

  19. Transport of cosmic ray nuclei in various materials

    NASA Technical Reports Server (NTRS)

    Silberberg, R.; Tsao, C. H.; Letaw, J. R.

    1988-01-01

    Cosmic-ray heavy ions have become a concern in space radiation effects analyses. Heavy ions rapidly deposit energy and create dense ionization trails as they traverse materials. Collection of the free charge disrupts the operation of microelectronic circuits. This effect, called the single-event upset, can cause a loss of digital data. Passage of high linear energy transfer particles through the eyes has been observed by Apollo astronauts. These heavy ions have great radiobiological effectiveness and are the primary risk factor for leukemia induction on a manned Mars mission. Models of the transport of heavy cosmic-ray nuclei through materials depend heavily on our understanding of the cosmic-ray environment, nuclear spallation cross sections, and computer transport codes. Our group has initiated and pursued the development of a full capability for modeling these transport processes. A recent review of this ongoing effort is presented in Ref. 5. In this paper, we discuss transport methods and present new results comparing the attenuation of cosmic rays in various materials.

  20. Cosmic-ray neutron simulations and measurements in Taiwan.

    PubMed

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

    2014-10-01

    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

  1. Investigation of resonance integrals occurring in cosmic ray diffusion theory

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

    Critical assessment of two versions of a procedure for calculating the pitch angle diffusion coefficient for cosmic rays in a static random magnetic field using the 'resonance integral' method of Hasselmann and Wiberenz (1968) and Jokipii (1972). One of these versions is shown to represent the physics of the situation more accurately than the other.

  2. Are cosmic rays effective for ionization of protoplanetary disks?

    NASA Technical Reports Server (NTRS)

    Dolginov, Arkady Z.; Stepinski, Tomasz F.

    1994-01-01

    The principal uncertainty in studying the magnetic properties of protoplanetary disks concerns the ionization levels of the disk's gas. The low gas temperature precludes thermal ionization, leaving cosmic rays as the dominant source of ionization. It has been shown that the resulting electrical conductivity is just high enough for a MHD dynamo to produce contemporaneously a magnetic field in most of the extended parts of a turbulent protoplanetary disk. Here we argue that the effectiveness of cosmic rays to ionize the bulk of the gas is impaired by the influence of the generated magnetic field on the propagation of cosmic rays within a disk. Cosmic rays scatter on magnetic inhomogeneities, and, as a result, their penetration depth decreases to only a fraction of the disk half-thickness, resulting in a severe depletion of free charge from the midplane regions of a disk. That, in turn, undercuts the dynamo mechanism, so extended parts of the disk are free from a dynamically significant magnetic field. We also point out that any additional, even small, in situ source of ionization, such as radioactive Al-26, may again make a dynamo a viable regeneration process capable of producing a dynamically important magnetic field.

  3. EMMA a new underground cosmic-ray experiment T. Enqvista

    E-print Network

    Usoskin, Ilya G.

    and Nuclear Safety Authority ­ STUK, Helsinki, Finland d Centre for Underground Physics at Pyh¨asalmi (CUPP.11.018 #12;Figure 1. Schematic layout of the EMMA array in the underground site at 85 metres. The arrayEMMA ­ a new underground cosmic-ray experiment T. Enqvista , J. Joutsenvaaraa , T. J¨ams´enb , P

  4. The Acceleration and Transport of Cosmic Rays with Heliospheric Examples

    Microsoft Academic Search

    J. R. Jokipii

    2004-01-01

    Cosmic rays are ubiquitous in space, and are apparently present wherever the matter density is small enough that they are not removed by collisions with ambient particles. The essential similarity of their energy spectra in many different regions places significant general constraints on the mechanisms for their acceleration and confinement. Diffusive shock acceleration is at present the most successful acceleration

  5. Field testing for cosmic ray soft errors in semiconductor memories

    Microsoft Academic Search

    Timothy J. O'gorman; John M. Ross; Allen H. Taber; James F. Ziegler; Hans P. Muhlfeld; Charles J. Montrose; Huntington W. Curtis; James L. Walsh

    1996-01-01

    This paper presents a review of experiments performed by IBM to investigate the causes of soft errors in semiconductor memory chips under field test conditions. The effects of alpha-particles and cosmic rays are separated by comparing multiple measurements of the soft-error rate (SER) of samples of memory chips deep underground and at various altitudes above the earth. The results of

  6. Protostellar Cosmic Rays and Extinct Radioactivities in Meteorites

    Microsoft Academic Search

    Typhoon Lee; Frank H. Shu; Hsien Shang; Alfred E. Glassgold; K. E. Rehm

    1998-01-01

    Calcium-aluminumârich inclusions (CAIs) and chondrules of chondritic meteorites may originate with the melting of dustballs launched by a magnetically driven bipolar outflow from the inner edge of the primitive solar nebula. Bombardment by protostellar cosmic rays may make the rock precursors of CAIs and chondrules radioactive, producing radionuclides found in meteorites that are difficult to obtain with other mechanisms. Reasonable

  7. Ultra High-Energy Cosmic Rays from Quasar Remnants

    Microsoft Academic Search

    Timothy Hamilton; Elihu Boldt; Michael Loewenstein

    2004-01-01

    The sources of Ultra High-Energy Cosmic Rays (UHECR) are still mysterious, but those at the highest energies may be accelerated in a compact dynamo, such as a quasar remnant. Such a dynamo is composed of a supermassive black hole with a substantial, accretion-supported magnetic field, an especially dark radiation environment, and near maximal spin. This kind of compact dynamo at

  8. Solar-Cosmic-Ray-Produced Nuclides in Extraterrestrial Matter

    NASA Technical Reports Server (NTRS)

    Reedy, Robert C.

    1999-01-01

    There are two main types of cosmic rays that have sufficient energy to induce nuclear reactions -- the galactic cosmic rays (GCR) and solar cosmic rays (also called solar energetic particles). Both types of particles can have production rates and production ratios in the small objects often found in cold and hot deserts that are different from those seen for most meteorites, which typically have radii of approx. 10-100 centimeters. GCR production rates are often lower than those for most meteorites. GCR production ratios, such as Ne-22/Ne-21, are also often different in small objects. Smaller meteoroids also are more likely to have nuclides made by solar-cosmic-ray (SCR) particles than typically-sized meteorites. The very small meteorite Salem had large amounts of SCR-produced radionuclides. Meteorites recovered in Antarctica are more likely to contain SCR-produced nuclides than other meteorites. Martian and lunar meteorites are also likely to have SCR-produced nuclides. Production rates and profiles for SCR-produced nuclides in meteoroids have been calculated previously. However, the cross sections for the nuclear reactions making many SCR-produced nuclides, such as Be-10 were not well measured then. New rates and profiles are calculated here using good cross sections for the reactions making these nuclides.

  9. Solar-Cosmic-Ray-Produced Nuclides in Extraterrestrial Matter

    NASA Technical Reports Server (NTRS)

    Reedy, Robert C.

    2000-01-01

    There are two main types of cosmic rays that have sufficient energy to induce nuclear reactions -- the galactic cosmic rays (GCR) and solar cosmic rays (also called solar energetic particles). Both types of particles can have production rates and production ratios in the small objects often found in cold and hot deserts that are different from those seen for most meteorites, which typically have radii of approx.10-100 centimeters. GCR production rates are often lower than those for most meteorites. GCR production ratios, such as Ne-22/Ne-21, are also often different in small objects. Smaller meteoroids also are more likely to have nuclides made by solar-cosmic-ray (SCR) particles than typically-sized meteorites. The very small meteorite Salem had large amounts of SCR-produced radionuclides. Meteorites recovered in Antarctica are more likely to contain SCR-produced nuclides than other meteorites. Martian and lunar meteorites are also likely to have SCR-produced nuclides. Production rates and profiles for SCR-produced nuclides in meteoroids have been calculated previously. However, the cross sections for the nuclear reactions making many SCR-produced nuclides, such as Be-10, were not well measured then. New rates and profiles are calculated here using good cross sections for the reactions making these nuclides.

  10. Commissioning of the ATLAS Semiconductor Tracker with cosmic rays

    Microsoft Academic Search

    2007-01-01

    This paper presents the results of the tests with cosmic rays of the ATLAS Semiconductor Tracker (SCT) as well as operational experience of running the fully integrated silicon detector during the commissioning of the completed SCT. Prior to inserting into ATLAS, the barrel part of the SCT has been integrated with the Transition Radiation Tracker (TRT) barrel and tested with

  11. Design of a transition radiation detector for cosmic rays

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    Transition radiation detectors consisting of sandwiches of plastic foam radiators and multiwire proportional chambers can be used to identify cosmic ray particles with energies gamma ? E/mc-squared is greater than 10 to the 3rd and to measure their energy in the region gamma is roughly equal to 10 to the 3rd

  12. Early results from the ultra heavy cosmic ray experiment

    SciTech Connect

    Osullivan, D.; Thompson, A.; Bosch, J.; Keegan, R.; Wenzel, K.P.; Jansen, F.; Domingo, C. [European Space Agency. European Space Research and Technology Center, ESTEC, Noordwijk (Netherlands); [Autonoma de Barcelona Univ., Barcelona (Spain)

    1995-02-01

    Data extraction and analysis of the LDEF Ultra Heavy Cosmic Ray Experiment is continuing. Almost twice the pre LDEF world sample has been investigated and some details of the charge spectrum in the region from Z approximately 70 up to and including the actinides are presented. The early results indicate r process enhancement over solar system source abundances.

  13. Response Of A MOSFET To A Cosmic Ray

    NASA Technical Reports Server (NTRS)

    Benumof, Reuben; Zoutendyk, John A.

    1988-01-01

    Theoretical paper discusses response of enhancement-mode metal oxide/semiconductor field-effect transistor to cosmic-ray ion that passes perpendicularly through gate-oxide layers. Even if ion causes no permanent damage, temporary increase of electrical conductivity along track of ion large enough and long enough to cause change in logic state in logic circuit containing MOSFET.

  14. Cosmic ray particles behavior during last solar minimum

    NASA Astrophysics Data System (ADS)

    Rockenbach, Marlos; Dal Lago, Alisson; Munakata, Kazuoki; Kato, Chihiro; Kuwabara, Takao; Bieber, John; Schuch, Nelson; Duldig, Marc; Humble, John; Jassar, Hala Al; Sharma, Madan; Sabbah, Ismail

    2013-04-01

    The work presents the Heliosphere characterization during the minimum solar activity. It is possible to identify phenomena caused by the Corrotating Interaction Regions - CIRs, during this solar activity phase. CIRs can be visualized in satellite data for each 27 days, approximately, and it is frequently accompanied by the Earth crossing through the Heliospheric Current Sheath - HCS. These crossing occur in a period of time lower than a day, and it is possible to study the behavior of cosmic rays particles in two different regions with opposite magnetic field polarities. The last solar minimum was special because their long duration and it was the first that the Global Muon Detector Network - GMDN operated in its full capacity. This cosmic ray detectors network is composed by muon scintillators installed in Nagoya - Japan, Hobart - Australia, São Martinho da Serra - Brazil and Kuwait City - Kuwait. Analyzing the GMDN data together with data from SOHO and/or ACE satellites it is possible to study the behavior of the cosmic ray particles and presents a Heliosphere characterization during the minimum solar activity, giving a better understanding of the cosmic ray particles modulation.

  15. Positrons and Low Energy Cosmic Rays from Supernovae

    Microsoft Academic Search

    Stirling A. Colgate

    1970-01-01

    Burgeret al. (1970) calculated the positron flux from the decay of56Co-->56Fe from cosmic rays injected from supernovae. The plasma properties of the ejected matter are determined in the present calculation in order to include the ionization loss of the positrons as the matter expands. It is found that using the matter velocity distribution of previous supernova model calculations that roughly

  16. Positrons and low energy cosmic rays from supernovae

    Microsoft Academic Search

    Stirling A. Colgate

    1970-01-01

    Burgeret al. (1970) calculated the positron flux from the decay of56Co?56Fe from cosmic rays injected from supernovae. The plasma properties of the ejected matter are determined in the present calculation in order to include the ionization loss of the positrons as the matter expands. It is found that using the matter velocity distribution of previous supernova model calculations that roughly

  17. The radiation monitor cosmic X-ray experiment OSO-1

    NASA Technical Reports Server (NTRS)

    Randall, R. F.

    1973-01-01

    A comprehensive technical description is presented of the Radiation Monitor which is part of the GSFC cosmic X-ray experiment to be flown on the OSO-1 satellite. The theory of operation, fabrication and assembly, and cone angle determination are reported.

  18. Search for ultra high energy cosmic ray anisotropy with Auger

    Microsoft Academic Search

    Pedram Boghrat

    2008-01-01

    Although the existence of ultra high energy cosmic rays (UHECR) with energies on the order of 10 20 eV, has been shown by past experiments, the source of these particles is not yet understood. Theoretical models motivate the consideration of nearby active galactic nuclei (AGN) as a source candidate. However, AGN have not been declared as the source unambiguously and

  19. Nuclear cross sections, cosmic ray propagation and source composition

    Microsoft Academic Search

    R. Silberberg; C. H. Tsao; J. R. Letaw

    1986-01-01

    Because cosmic rays with atomic number greater than 6 undergo nuclear composition transformations as a result of nuclear collisions in the interstellar gas, isotopic and elemental source composition have to be inferred in near-earth observation with a degree of uncertainty that is proportional to the uncertainty as to cross sections. The present consideration of these uncertainties proceeds with a comparison

  20. Probing the structure of space-time with cosmic rays

    Microsoft Academic Search

    Roberto Aloisio; Pasquale Blasi; Piera L. Ghia; Aurelio F. Grillo

    2000-01-01

    The study of the interactions of cosmic rays (CR's) with universal diffuse background radiation can provide very stringent tests of the validity of special relativity. The interactions we consider are the ones characterized by well defined energy thresholds whose energy position can be predicted on the basis of special relativity. We argue that the experimental confirmation of the existence of

  1. Early results from the ultra heavy cosmic ray experiment

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    Data extraction and analysis of the LDEF Ultra Heavy Cosmic Ray Experiment is continuing. Almost twice the pre LDEF world sample has been investigated and some details of the charge spectrum in the region from Z approximately 70 up to and including the actinides are presented. The early results indicate r process enhancement over solar system source abundances.

  2. Cosmic ray transport - Modulation and the anomalous component

    SciTech Connect

    Evenson, P.; Tuska, E.B. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

    1991-01-01

    Cosmic ray transport research is reviewed for the 1987-1990 time period, focusing on diffusive transport. Problems discussed include the diffusion model, anomalous components, radial gradient and north south anisotropy, short term modulation, long-term solar modulation, and charge sign dependent modulation. 249 refs.

  3. Jodrell Bank and the pursuit of cosmic rays

    NASA Astrophysics Data System (ADS)

    Gunn, A. G.

    Radio astronomy is a subject full of serendipity and coincidence. This paper recounts the strange sequence of incidental events and oversights that led to the establishment of Jodrell Bank as one of radio astronomy's founding institutions. Particular emphasis is given to the purpose for which it was originally intended; the study of high-energy cosmic rays.

  4. Assessing access of galactic cosmic rays at Moon's orbit

    Microsoft Academic Search

    Chia-Lin Huang; Harlan E. Spence; Brian T. Kress

    2009-01-01

    Characterizing the lunar radiation environment is essential for preparing future robotic and human explorations on lunar bases. Galactic cosmic rays (GCR) represent one source of ionizing radiation at the Moon that poses a biological risk. Because GCR are charged particles, their paths are affected by the magnetic fields along their trajectories. Unlike the Earth, the Moon has no strong, shielding

  5. Cosmic-ray Detector with Interdigitated-Finger Pixels for two-dimensional Position Information from a Singel Wafer Side

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    This paper describes a type of cosmic ray detector for isotopic and energy detection of energetic nuclei which derives both dimensions of position information from one side of the detector. This simplifies the required readout electronics, since only one precision amplifier connected to the other side is required for an accurate detection of the energy loss.

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

    E-print Network

    Abhijit L. Chavda; L. K. Chavda

    2008-06-03

    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.

  7. On the Observation of the Cosmic Ray Anisotropy below 10$^{15}$ eV

    E-print Network

    Di Sciascio, G

    2014-01-01

    The measurement of the anisotropy in the arrival direction of cosmic rays is complementary to the study of their energy spectrum and chemical composition to understand their origin and propagation. It is also a tool to probe the structure of the magnetic fields through which cosmic rays travel. As cosmic rays are mostly charged nuclei, their trajectories are deflected by the action of galactic magnetic field they propagate through before reaching the Earth atmosphere, so that their detection carries directional information only up to distances as large as their gyro-radius. If cosmic rays below $10^{15}{\\rm\\,eV}$ are considered and the local galactic magnetic field ($\\sim3{\\rm\\,\\mu G}$) is accounted for, gyro-radii are so short that isotropy is expected. At most, a weak di-polar distribution may exist, reflecting the contribution of the closest CR sources. However, a number of experiments observed an energy-dependent \\emph{"large scale"} anisotropy in the sidereal time frame with an amplitude of about 10$^{-4...

  8. Could Cosmic Rays Affect Instabilities in the Transition Layer of Nonrelativistic Collisionless Shocks?

    NASA Astrophysics Data System (ADS)

    Stroman, Thomas; Pohl, Martin; Niemiec, Jacek; Bret, Antoine

    2012-02-01

    There is an observational correlation between astrophysical shocks and nonthermal particle distributions extending to high energies. As a first step toward investigating the possible feedback of these particles on the shock at the microscopic level, we perform particle-in-cell (PIC) simulations of a simplified environment consisting of uniform, interpenetrating plasmas, both with and without an additional population of cosmic rays. We vary the relative density of the counterstreaming plasmas, the strength of a homogeneous parallel magnetic field, and the energy density in cosmic rays. We compare the early development of the unstable spectrum for selected configurations without cosmic rays to the growth rates predicted from linear theory, for assurance that the system is well represented by the PIC technique. Within the parameter space explored, we do not detect an unambiguous signature of any cosmic-ray-induced effects on the microscopic instabilities that govern the formation of a shock. We demonstrate that an overly coarse distribution of energetic particles can artificially alter the statistical noise that produces the perturbative seeds of instabilities, and that such effects can be mitigated by increasing the density of computational particles.

  9. Quantifying mesoscale soil moisture with the cosmic-ray rover

    NASA Astrophysics Data System (ADS)

    Chrisman, B.; Zreda, M.

    2013-06-01

    Soil moisture governs the surface fluxes of mass and energy and is a major influence on floods and drought. Existing techniques measure soil moisture either at a point or over a large area many kilometers across. To bridge these two scales we used the cosmic-ray rover, an instrument similar to the recently developed COSMOS probe, but bigger and mobile. This paper explores the challenges and opportunities for mapping soil moisture over large areas using the cosmic-ray rover. In 2012, soil moisture was mapped 22 times in a 25 km × 40 km survey area of the Tucson Basin at 1 km2 resolution, i.e., a survey area extent comparable to that of a pixel for the Soil Moisture and Ocean Salinity (SMOS) satellite mission. The soil moisture distribution is dominated by climatic variations, notably by the North American monsoon, that results in a systematic increase in the standard deviation, observed up to 0.022 m3 m-3, as a function of the mean, between 0.06 and 0.14 m3 m-3. Two techniques are explored to use the cosmic-ray rover data for hydrologic applications: (1) interpolation of the 22 surveys into a daily soil moisture product by defining an approach to utilize and quantify the observed temporal stability producing an average correlation coefficient of 0.82 for the soil moisture distributions that were surveyed and (2) estimation of soil moisture profiles by combining surface moisture from satellite microwave sensors with deeper measurements from the cosmic-ray rover. The interpolated soil moisture and soil moisture profile estimates allow for basin-wide mass balance calculation of evapotranspiration, totaling 241 mm for the year 2012. Generating soil moisture maps with cosmic-ray rover at this intermediate scale may help in the calibration and validation of satellite campaigns and may also aid in various large scale hydrologic studies.

  10. A large detector for cosmic ray abundance and energy measurements

    NASA Astrophysics Data System (ADS)

    Alsop, C.

    A large aperture, balloon borne cosmic ray detector was designed to measure the energy spectra of individual cosmic ray species with Z greater than 8 in the energy range 0.3GeV/N to 400GeV/N. The energy dependence of the abundance spectrum extending up to such high energies will provide valuable data for determining the nature of the origin and propagation of cosmic rays in the Galaxy. The properties of cosmic ray nuclei and the interpretation of the energy dependence of the abundance spectrum are discussed. The design and response of the BUGS IV cosmic ray detector are described. The measurement techniques used are gas scintillation, gas proportional scintillation and Cerenkov radiation from both gases and solids. The light collection properties of the detector and several experimental investigations of the light collection efficiency of the drift chamber region are described. The expected signals from the gas scintillation and gas Cerenkov emissions are predicted and the choice of a suitable scintillating gas mixture for minimizing the uncertainty in the charge and energy measurements is considered. The theoretical aspects of electron drift and diffusion in gases and several experimental investigations on the electron drift in the BUGS IV drift chamber are given. Also some preliminary results from a uniform field drift chamber are included which demonstrate the sensitivity of the electron drift velocity in inert gas mixtures to water vapor contamination. The expected overall performance of BUGS IV and the results of an experimental simulation of the parachute landing of the detector are given.

  11. On the Origin of Ultra High Energy Cosmic Rays

    SciTech Connect

    Fowler, T; Colgate, S; Li, H

    2009-07-01

    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.

  12. Record Intensities of Galactic Cosmic Rays in 2009

    NASA Astrophysics Data System (ADS)

    Mewaldt, R. A.; Davis, Andrew; Lave, Kelly; Leske, Richard; Wiedenbeck, Mark; Binns, Walter; Cummings, A. C.; Israel, Martin; Stone, E. C.; von Rosenvinge, Tycho

    Data from the Advanced Composition Explorer (ACE) show that in late 2009 the galactic cosmic ray (GCR) intensity at 200 MeV/nuc (near the peak in the spectrum at 1 AU) reached the highest intensities of the space era. During mid-2007 GCR intensities had apparently leveled off at intensities comparable to those measured in the 1976-77 and 1997-1998 solar minima, and the onset of new solar activity was expected in 2008. Instead, solar-minimum conditions continued, and the GCR intensity began to increase again in early 2008. By the end of 2009 the 200 MeV/nuc intensities of the major species from C to Fe were all about 20 percent above those in the 1997-1998 solar minimum. Comparisons with earlier spacecraft data show conclusively that the GCR intensities late 2009 were the highest of the space era. However, viewed in the context of the long-term Be-10 record, the space era has experienced a below-average cosmic-ray intensity. The record-setting intensity levels are likely due to a combination of factors that include the weakened interplanetary magnetic field strength, the reduced solar wind speed and dynamic pressure, and the extended solar minimum conditions. In addition, during alternate solar minima, including the present one, the drift pattern of cosmic rays in the heliosphere is sensitive to the tilt of the interplanetary magnetic current sheet, which gradually declined during 2008-2009, eventually reaching 10 degrees. This paper will compare the 2009 cosmic ray intensities with those from the past 50 years and with the long-term archival record, and discuss the role of the various solar-wind parameters in modulating the near-Earth cosmic ray intensity.

  13. Level crossing analysis of cosmic microwave background radiation: a method for detecting cosmic strings

    SciTech Connect

    Movahed, M. Sadegh [Department of Physics, Shahid Beheshti University, G.C., Evin, Tehran 19839 (Iran, Islamic Republic of); Khosravi, Shahram, E-mail: m.s.movahed@ipm.ir, E-mail: khosravi@ipm.ir [Department of Physics, Faculty of Science, Tarbiat Moallem University, Tehran (Iran, Islamic Republic of)

    2011-03-01

    In this paper we study the footprint of cosmic string as the topological defects in the very early universe on the cosmic microwave background radiation. We develop the method of level crossing analysis in the context of the well-known Kaiser-Stebbins phenomenon for exploring the signature of cosmic strings. We simulate a Gaussian map by using the best fit parameter given by WMAP-7 and then superimpose cosmic strings effects on it as an incoherent and active fluctuations. In order to investigate the capability of our method to detect the cosmic strings for the various values of tension, G?, a simulated pure Gaussian map is compared with that of including cosmic strings. Based on the level crossing analysis, the superimposed cosmic string with G??>4 × 10{sup ?9} in the simulated map without instrumental noise and the resolution R = 1' could be detected. In the presence of anticipated instrumental noise the lower bound increases just up to G??>5.8 × 10{sup ?9}.

  14. Level crossing analysis of cosmic microwave background radiation: a method for detecting cosmic strings

    NASA Astrophysics Data System (ADS)

    Sadegh Movahed, M.; Khosravi, Shahram

    2011-03-01

    In this paper we study the footprint of cosmic string as the topological defects in the very early universe on the cosmic microwave background radiation. We develop the method of level crossing analysis in the context of the well-known Kaiser-Stebbins phenomenon for exploring the signature of cosmic strings. We simulate a Gaussian map by using the best fit parameter given by WMAP-7 and then superimpose cosmic strings effects on it as an incoherent and active fluctuations. In order to investigate the capability of our method to detect the cosmic strings for the various values of tension, G?, a simulated pure Gaussian map is compared with that of including cosmic strings. Based on the level crossing analysis, the superimposed cosmic string with G?gtrsim4 × 10-9 in the simulated map without instrumental noise and the resolution R = 1' could be detected. In the presence of anticipated instrumental noise the lower bound increases just up to G?gtrsim5.8 × 10-9.

  15. Monte Carlo Simulations of Cosmic Rays Hadronic Interactions

    SciTech Connect

    Aguayo Navarrete, Estanislao; Orrell, John L.; Kouzes, Richard T.

    2011-04-01

    This document describes the construction and results of the MaCoR software tool, developed to model the hadronic interactions of cosmic rays with different geometries of materials. The ubiquity of cosmic radiation in the environment results in the activation of stable isotopes, referred to as cosmogenic activities. The objective is to use this application in conjunction with a model of the MAJORANA DEMONSTRATOR components, from extraction to deployment, to evaluate cosmogenic activation of such components before and after deployment. The cosmic ray showers include several types of particles with a wide range of energy (MeV to GeV). It is infeasible to compute an exact result with a deterministic algorithm for this problem; Monte Carlo simulations are a more suitable approach to model cosmic ray hadronic interactions. In order to validate the results generated by the application, a test comparing experimental muon flux measurements and those predicted by the application is presented. The experimental and simulated results have a deviation of 3%.

  16. On the Origin of the Highest Energy Cosmic Rays

    E-print Network

    F. W. Stecker

    1997-10-30

    We present the results of a new estimation of the photodisintegration and propagation of ultrahigh energy cosmic ray (UHCR) nuclei in intergalactic space. The critical interactions for photodisintegration and energy loss of UHCR nuclei occur with photons of the infrared background radiation (IBR). We have reexamined this problem making use of a new determination of the IBR based on empirical data, primarily from IRAS galaxies, and also collateral information from TeV gamma-ray observations of two nearby BL Lac objects. Our results indicate that a 200 EeV Fe nucleus can propagate apx. 100 Mpc through the IBR. We argue that it is possible that the highest energy cosmic rays observed may be heavy nuclei.

  17. Examining the Origin of Cosmic Rays: A New Conceptual Approach

    E-print Network

    C. L. Herzenberg

    2001-08-25

    A new conceptual approach for examining the origin of cosmic rays is developed by considering the characteristics of particle trajectory distributions in four-dimensional Euclidean space-time. Transformation of an isotropic distribution into a velocity distribution in ordinary three-dimensional space results in a spatially isotropic flux of highly relativistic particles. This particle flux exhibits a power-law energy spectrum that decreases with increasing energy approximately inversely as the square of the energy and peaks at much lower energies. This model also provides additional results resembling the observed characteristics of cosmic radiation.

  18. CMS Data Processing Workflows during an Extended Cosmic Ray Run

    SciTech Connect

    Not Available

    2009-11-01

    The CMS Collaboration conducted a month-long data taking exercise, the Cosmic Run At Four Tesla, during October-November 2008, with the goal of commissioning the experiment for extended operation. With all installed detector systems participating, CMS recorded 270 million cosmic ray events with the solenoid at a magnetic field strength of 3.8 T. This paper describes the data flow from the detector through the various online and offline computing systems, as well as the workflows used for recording the data, for aligning and calibrating the detector, and for analysis of the data.

  19. Simulations of Disk Galaxies with Cosmic Ray Driven Galactic Winds

    NASA Astrophysics Data System (ADS)

    Booth, C. M.; Agertz, Oscar; Kravtsov, Andrey V.; Gnedin, Nickolay Y.

    2013-11-01

    We present results from high-resolution hydrodynamic simulations of isolated Small Magellanic Cloud (SMC)- and Milky-Way-sized galaxies that include a model for feedback from galactic cosmic rays (CRs). We find that CRs are naturally able to drive winds with mass loading factors of up to ~10 in dwarf systems. The scaling of the mass loading factor with circular velocity between the two simulated systems is consistent with \\eta \\propto v_circ^{1-2} required to reproduce the faint end of the galaxy luminosity function. In addition, simulations with CR feedback reproduce both the normalization and the slope of the observed trend of wind velocity with galaxy circular velocity. We find that winds in simulations with CR feedback exhibit qualitatively different properties compared to supernova-driven winds, where most of acceleration happens violently in situ near star forming sites. The CR-driven winds are accelerated gently by the large-scale pressure gradient established by CRs diffusing from the star-forming galaxy disk out into the halo. The CR-driven winds also exhibit much cooler temperatures and, in the SMC-sized system, warm (T ~ 104 K) gas dominates the outflow. The prevalence of warm gas in such outflows may provide a clue as to the origin of ubiquitous warm gas in the gaseous halos of galaxies detected via absorption lines in quasar spectra.

  20. SIMULATIONS OF DISK GALAXIES WITH COSMIC RAY DRIVEN GALACTIC WINDS

    SciTech Connect

    Booth, C. M.; Agertz, Oscar; Kravtsov, Andrey V.; Gnedin, Nickolay Y., E-mail: cmbooth@oddjob.uchicago.edu [Department of Astronomy and Astrophysics, The University of Chicago, Chicago, IL 60637 (United States)

    2013-11-01

    We present results from high-resolution hydrodynamic simulations of isolated Small Magellanic Cloud (SMC)- and Milky-Way-sized galaxies that include a model for feedback from galactic cosmic rays (CRs). We find that CRs are naturally able to drive winds with mass loading factors of up to ?10 in dwarf systems. The scaling of the mass loading factor with circular velocity between the two simulated systems is consistent with ??v{sub circ}{sup 1-2} required to reproduce the faint end of the galaxy luminosity function. In addition, simulations with CR feedback reproduce both the normalization and the slope of the observed trend of wind velocity with galaxy circular velocity. We find that winds in simulations with CR feedback exhibit qualitatively different properties compared to supernova-driven winds, where most of acceleration happens violently in situ near star forming sites. The CR-driven winds are accelerated gently by the large-scale pressure gradient established by CRs diffusing from the star-forming galaxy disk out into the halo. The CR-driven winds also exhibit much cooler temperatures and, in the SMC-sized system, warm (T ? 10{sup 4} K) gas dominates the outflow. The prevalence of warm gas in such outflows may provide a clue as to the origin of ubiquitous warm gas in the gaseous halos of galaxies detected via absorption lines in quasar spectra.

  1. QUASI-BIENNIAL MODULATION OF GALACTIC COSMIC RAYS

    SciTech Connect

    Laurenza, M.; Storini, M. [INAF/IFSI-Roma, Via Fosso del Cavaliere 100, 00133 Roma (Italy); Vecchio, A.; Carbone, V., E-mail: monica.laurenza@ifsi-roma.inaf.it [Dipartimento di Fisica, Universita della Calabria, 87036 Rende (Italy)

    2012-04-20

    The time variability of the cosmic-ray (CR) intensity at three different rigidities has been analyzed through the empirical mode decomposition technique for the period 1964-2004. Apart from the {approx}11 yr cycle, quasi-biennial oscillations (QBOs) have been detected as a prominent scale of variability in CR data, as well as in the heliomagnetic field magnitude at 1 AU and in the sunspot area. The superposition of the {approx}11 yr and QBO contributions reproduces the general features of the CR modulation, such as most of the step-like decreases and the Gnevyshev Gap phenomenon. A significant correlation has also been found between QBOs of the heliospheric magnetic field and the CR intensity during even solar activity cycles, suggesting that the former are responsible for step-like decreases in CR modulation, probably dominated by the particle diffusion/convection in such periods. In contrast, during odd-numbered cycles, no significant correlation is found. This could be explained with an enhanced drift effect also during the solar maximum or a greater influence of merged interaction regions at great heliocentric distances during odd cycles. Moreover, the QBOs of CR data are delayed with respect to sunspot activity, the lag being shorter for A > 0 periods of even cycles ({approx}1-4 months) than for A < 0 periods of odd cycles ({approx}7-9 months); we suggest that solar QBOs also affect the recovery of the CR intensity after the solar activity maximum.

  2. Transitional solar dynamics, cosmic rays and global warming

    E-print Network

    A. Bershadskii

    2009-04-12

    Solar activity is studied using a cluster analysis of the time-fluctuations of the sunspot number. It is shown that in an Historic period the high activity components of the solar cycles exhibit strong clustering, whereas in a Modern period (last seven solar cycles: 1933-2007) they exhibit a white-noise (non-)clustering behavior. Using this observation it is shown that in the Historic period, emergence of the sunspots in the solar photosphere was strongly dominated by turbulent photospheric convection. In the Modern period, this domination was broken by a new more active dynamics of the inner layers of the convection zone. Then, it is shown that the dramatic change of the sun dynamics at the transitional period (between the Historic and Modern periods, solar cycle 1933-1944yy) had a clear detectable impact on Earth climate. A scenario of a chain of transitions in the solar convective zone is suggested in order to explain the observations, and a forecast for the global warming is suggested on the basis of this scenario. A relation between the recent transitions and solar long-period chaotic dynamics has been found. Contribution of the galactic turbulence (due to galactic cosmic rays) has been discussed. These results are also considered in a content of chaotic climate dynamics at millennial timescales.

  3. Observation of the shadowing of cosmic rays by the Moon using a deep underground detector

    Microsoft Academic Search

    M. Ambrosio; R. Antolini; C. Aramo; G. Auriemma; A. Baldini; G. C. Barbarino; B. C. Barish; G. Battistoni; R. Bellotti; C. Bemporad; P. Bernardini; H. Bilokon; V. Bisi; C. Bloise; C. Bower; S. Bussino; F. Cafagna; M. Calicchio; D. Campana; M. Carboni; M. Castellano; S. Cecchini; F. Cei; V. Chiarella; B. C. Choudhary; S. Coutu; L. De Benedictis; G. De Cataldo; H. Dekhissi; C. De Marzo; I. De Mitri; J. Derkaoui; M. De Vincenzi; A. Di Credico; O. Erriquez; C. Favuzzi; C. Forti; P. Fusco; G. Giacomelli; G. Giannini; N. Giglietto; M. Giorgini; M. Grassi; L. Gray; A. Grillo; F. Guarino; P. Guarnaccia; C. Gustavino; A. Habig; K. Hanson; R. Heinz; Y. Huang; E. Iarocci; E. Katsavounidis; E. Kearns; H. Kim; S. Kyriazopoulou; E. Lamanna; D. S. Levin; P. Lipari; N. P. Longley; M. J. Longo; F. Maaroufi; G. Mancarella; S. Manzoor; A. Margiotta Neri; A. Marini; D. Martello; A. Marzari-Chiesa; M. N. Mazziotta; C. Mazzotta; D. G. Michael; S. Mikheyev; L. Miller; P. Monacelli; T. Montaruli; M. Monteno; S. Mufson; J. Musser; D. Nicolo; C. Orth; G. Osteria; M. Ouchrif; O. Palamara; V. Patera; L. Patrizii; R. Pazzi; C. W. Peck; S. Petrera; P. Pistilli; V. Popa; V. Pugliese; J. Reynoldson; F. Ronga; U. Rubizzo; C. Satriano; L. Satta; E. Scapparone; K. Scholberg; A. Sciubba; P. Serra-Lugaresi; M. Severi; M. Sioli; M. Severi; P. Spinelli; M. Spinetti; M. Spurio; R. Steinberg; J. L. Stone; L. R. Sulak; A. Surdo; G. Tarle; D. Ugolotti; M. Vakili; C. W. Walter; R. Webb

    1999-01-01

    Using data collected by the MACRO experiment during the years 1989-1996, we show evidence for the shadow of the Moon in the underground cosmic ray flux with a significance of 3.6sigma. This detection of the shadowing effect is the first by an underground detector. A maximum-likelihood analysis is used to determine that the angular resolution of the apparatus is 0.9°+\\/-0.3°.

  4. The MIDAS experiment: A prototype for the microwave emission of UltraHigh Energy Cosmic Rays

    Microsoft Academic Search

    M. Monasor; I. Alekotte; J. Alvarez-Muniz; X. Bertou; M. Bodgan; M. Bohacova; C. Bonifazi; W. Carvalho; J. F. Genat; P. Facal San Luis; E. Mills; B. Rouille d'Orfeuil; S. Wayne; L. C. Reyes; E. M. Santos; P. Privitera; C. Williams; E. Zas

    2010-01-01

    Recent measurements suggest that extensive air showers initiated by\\u000aultra-high energy cosmic rays (UHECR) emit signals in the microwave band of the\\u000aelectromagnetic spectrum caused by the collisions of the free-electrons with\\u000athe atmospheric neutral molecules in the plasma produced by the passage of the\\u000ashower. Such emission is isotropic and could allow the detection of air showers\\u000awith 100%

  5. Nuclear Physics in Space: What We Can Learn From Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Moskalenko, Igor V.

    2004-01-01

    Studies and discoveries in cosmic-ray physics and generally in Astrophysics provide a fertile ground for research in many areas of Particle Physics and Cosmology, such as the search for dark matter, antimatter, new particles, and exotic physics, studies of the nucleosynthesis, origin of Galactic and extragalactic gamma-ray diffuse emission, formation of the large scale structure of the universe etc. In several years new missions are planned for cosmic-ray experiments, which will tremendously increase the quality and accuracy of cosmic-ray data. On the other hand, direct measurements of cosmic rays are possible in only one location on the outskirts of the Milky Way galaxy and present only a snapshot of very dynamic processes. It has been recently realized that direct information about the fluxes and spectra of cosmic rays in distant locations is provided by the Galactic diffuse gamma-rays, therefore, complementing the local cosmic-ray studies. A wealth of information is also contained in the isotopic abundances of cosmic rays, therefore, accurate evaluation of the isotopic production cross sections is of primary importance for Astrophysics of cosmic rays, studies of the galactic chemical evolution, and Cosmology. In this talk, I will show new results obtained with GALPROP, the most advanced numerical model for cosmic-ray propagation, which includes in a self-consistent way all cosmic-ray species (stable and long-lived radioactive isotopes from H to Ni, antiprotons, positrons and electrons, gamma rays and synchrotron radiation), and all relevant processes and reactions.

  6. The time structure of Cherenkov images generated by TeV ?-rays and by cosmic rays

    NASA Astrophysics Data System (ADS)

    Heß, M.; Bernlöhr, K.; Daum, A.; Hemberger, M.; Hermann, G.; Hofmann, W.; Lampeitl, H.; Aharonian, F. A.; Akhperjanian, A. G.; Barrio, J. A.; Beteta, J. J. G.; Contreras, J. L.; Cortina, J.; Deckers, T.; Fernandez, J.; Fonseca, V.; Gonzalez, J. C.; Heinzelmann, G.; Heusler, A.; Hohl, H.; Holl, I.; Horns, D.; Kankanyan, R.; Kestel, M.; Kirstein, O.; Köhler, C.; Konopelko, A.; Kornmayer, H.; Kranich, D.; Krawczynski, H.; Lindner, A.; Lorenz, E.; Magnussen, N.; Meyer, H.; Mirzoyan, R.; Moralejo, A.; Padilla, L.; Panter, M.; Petry, D.; Plaga, R.; Prahl, J.; Prosch, C.; Pühlhofer, G.; Rauterberg, G.; Rhode, W.; Röhring, A.; Samorski, M.; Sanchez, J. A.; Schmele, D.; Schröder, F.; Stamm, W.; Völk, H. J.; Wiebel-Sooth, B.; Wiedner, C. A.; Willmer, M.; HEGRA Collaboration

    1999-07-01

    The time profiles of Cherenkov images of cosmic-ray showers and of ?-rays showers are investigated, using data gathered with the HEGRA system of imaging atmospheric Cherenkov telescopes during the 1997 outbursts of Mrk 501. Photon arrival times are shown to vary across the shower images. The dominant feature is a time gradient along the major axis of the images. The gradient varies with the distance between the telescope and the shower core, and is maximal for large distances. The time profiles of cosmic-ray showers and of ?-ray showers differ in a characteristic fashion. The main features of the time profiles can be understood in terms of simple geometrical models. Use of the timing information towards improved shower reconstruction and cosmic-ray supperssion is discussed.

  7. Searches for Large-scale Anisotropy in the Arrival Directions of Cosmic Rays Detected above Energy of 1019 eV at the Pierre Auger Observatory and the Telescope Array

    NASA Astrophysics Data System (ADS)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, M.; Bleve, C.; Blümer, H.; Bohá?ová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filip?i?, A.; Fox, B. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Fuji, T.; Gaior, R.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; González, N.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Islo, K.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Maccarone, M. C.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mari?, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J. A. J.; Matthews, J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mi?anovi?, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; P?kala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Peters, C.; Petrera, S.; Petrolini, A.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.

    2014-10-01

    Spherical harmonic moments are well-suited for capturing anisotropy at any scale in the flux of cosmic rays. An unambiguous measurement of the full set of spherical harmonic coefficients requires full-sky coverage. This can be achieved by combining data from observatories located in both the northern and southern hemispheres. To this end, a joint analysis using data recorded at the Telescope Array and the Pierre Auger Observatory above 1019 eV is presented in this work. The resulting multipolar expansion of the flux of cosmic rays allows us to perform a series of anisotropy searches, and in particular to report on the angular power spectrum of cosmic rays above 1019 eV. No significant deviation from isotropic expectations is found throughout the analyses performed. Upper limits on the amplitudes of the dipole and quadrupole moments are derived as a function of the direction in the sky, varying between 7% and 13% for the dipole and between 7% and 10% for a symmetric quadrupole.

  8. Spectra of cosmic X-ray sources

    NASA Technical Reports Server (NTRS)

    Holt, S. S.; Mccray, R.

    1982-01-01

    X-ray measurements provide the most direct probes of astrophysical environments with temperatures exceeding one million K. Progress in experimental research utilizing dispersive techniques (e.g., Bragg and grating spectroscopy) is considerably slower than that in areas utilizing photometric techniques, because of the relative inefficiency of the former for the weak X-ray signals from celestial sources. As a result, the term "spectroscopy" as applied to X-ray astronomy has traditionally satisfied a much less restrictive definition (in terms of resolving power) than it has in other wavebands. Until quite recently, resolving powers of order unity were perfectly respectable, and still provide (in most cases) the most useful spectroscopic data. In the broadest sense, X-ray photometric measurements are spectroscopic, insofar as they represent samples of the overall electromagnetic continua of celestial objects.

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  10. LORD Space Experiment for Investigation of Ultrahigh Energy Cosmic-ray Particles

    NASA Astrophysics Data System (ADS)

    Ryabov, V. A.; Gusev, G. A.; Chechin, V. A.

    2013-02-01

    The problem of detecting cosmic rays and neutrinos of energies above the GZK cutoff is reviewed. Nowadays, it becomes clear that registration of nature's most energetic particles requires approaches based on new principles. First of all, we imply the detection of the coherent Cherenkov radio emission in cascades of ultrahigh-energy particles in radio-transparent natural dense media, i.e., ice shields of Antarctica, mineral salt, and lunar regolith. The Luna-Glob space mission planned for launching in the near future involves the Lunar Orbital Radio Detector (LORD) whose aperture for cosmic rays and neutrinos of energies E >= 1020 eV exceeds all existing ground-based arrays. The feasibility of LORD to detect radio signals from showers initiated by ultrahigh-energy particles interacting with the lunar regolith is examined. The design of the LORD space instrument and its scientific potentialities for registration of low-intense cosmic-ray particle fluxes above the GZK cut-off up to 1025 eV is discussed.

  11. A rocket borne instrument for the study of soft X-ray emission from cosmic X-ray sources

    NASA Technical Reports Server (NTRS)

    Agrawal, P. C.; Moore, W. E.; Garmire, G. P.

    1974-01-01

    Details about a rocket-borne instrument designed for studying the various characteristics of soft X-ray emission from cosmic X-ray sources in the energy range of 0.2 to 3 keV are presented. The X-ray detector consists of a bank of four multilayer, wall-less proportional counters, each with an area of 400 sq cm. The detectors are covered by windows of 1.4-micron polypropylene and are maintained at a constant pressure in flight using a gas control system. Two of the detectors are equipped with 0.4- by 10-deg collimators for mapping the spatial distribution of soft X-rays from extended X-ray sources. A pair of balanced filters consisting of oxygen and CF4 are used for detecting oxygen emission lines.

  12. Supernova Remnants and Cosmic Ray Acceleration in Nearby Galaxies

    NASA Astrophysics Data System (ADS)

    Pannuti, T. G.

    Supernova remnants (SNRs) have attracted a considerable amount of interest in modern astrophysics from both observational and theoretical perspectives. SNRs play an integral role in numerous processes associated with the evolution of galaxies, including the injection of significant amounts of kinetic energy and heavy-element enriched material into the interstellar medium (ISM). In addition, SNRs have emerged as the leading candidates for the acceleration of cosmic rays within the disks of galaxies through the proposed diffusive shock acceleration (DSA) mechanism. Observations of SNRs have been conducted at three particular wavelengths, based on distinct processes of energy emission associated with these objects. Thermal bremsstrahlung emission from gas shock-heated to temperatures of 10^6 - 10^7 K, recombination radiation from ionized atomic species such as [S II] and non-thermal synchrotron emission from relativistic electrons gyrating in the SNR's magnetic field produce X-ray, optical and radio emission, respectively. Studies of SNRs within our own Galaxy have been hampered by considerable distance uncertainties and massive extinction along Galactic lines of sight, particularly at the X-ray and optical wavelengths. In contrast, the study of SNRs located in nearby galaxies -- particularly galaxies located at high Galactic latitudes with face-on or nearly face-on orientations -- offers the opportunity to examine equidistant samples of SNRs that are nearly free of obscuration. We present a multi-wavelength (X-ray, optical and radio) study of the resident SNR populations of the Sculptor Group galaxies NGC 300 and NGC 7793 and the northern grand-design spiral NGC 6946. These three galaxies are nearby (2.1 Megaparsecs, 3.34 Megaparsecs and 5.1 Megaparsecs distant, respectively), located at high Galactic latitudes and clearly exhibit extensive massive star formation throughout their disks. We have observed these galaxies at the wavelengths of 6 and 20 cm with the Very Large Array (VLA), and complemented this data with our own H-alpha images and archived X-ray observations made with the Positional Sensitive Proportional Counter (PSPC) instrument aboard the ROSAT satellite. We have searched for X-ray and radio emission from previously-known SNRs identified in the optical using the [S II]/H-alpha method, and searched for new candidate X-ray and radio SNRs. We have found that remarkably few of the optically-identified SNRs possess counterparts at either of the other two wavelengths: of the 83 optically-identified SNRs in these galaxies, only four (N300-S10, N300-S26, N7793-S26 and N6946-S16) were also detected in the X-ray and the radio. N7793-S26 is a very noteworthy source: in the optical and radio it shows a remarkable filamentary structure approximately 450 parsecs in size, and its radio emission is nearly twice as luminous as the most radio-luminous Galactic SNR, Cassiopeia A. Three other optically-identified SNRs -- N300-S11, N7793-S11 and NGC 6946-S9 -- feature strong radio emission but no X-ray emission. Our search for new SNRs in NGC 300 and NGC 7793 has produced 21 candidates: fourteen candidate radio SNRs and two X-ray candidate SNRs in NGC 300, and five candidate radio SNRs in NGC 7793. Very limited intersection is seen between the sets of X-ray, optical and radio-selected SNRs in these three galaxies. These results indicate possible selection effects inherent in these surveys: optical surveys favor the detection of SNRs in low density regions which are nearly devoid of optical confusion. In contrast, radio and X-ray surveys are biased toward the detection of SNRs in high-density regions where optical surveys are severely impeded. Such selection effects may also indicate selection effects for the type of supernova that parents the SNR: the optical surveys are more likely to detect SNRs produced by the explosion of low mass stars in Type Ia supernovae, while radio and X-ray surveys are more likely to identify SNRs produced by the explosion of high mass stars in Type II supernovae. To investigate these selection effects

  13. High-latitude, Transluscent Molecular Clouds as Probes of Local Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Abrahams, Ryan D.; Paglione, Timothy A. D.

    2015-05-01

    We analyze the gamma ray emission from nine high latitude, translucent molecular clouds taken with the Fermi Large Area Telescope between 250 MeV and 10 GeV. Observations of gamma rays allow us to probe the density and spectrum of cosmic rays in the solar neighborhood. The clouds studied lie within ?270 pc from the Sun and are selected from the Planck all-sky CO map. Gamma rays in this energy range mostly result from cosmic-ray interactions with the interstellar medium, which is traced with three components: H i, CO, and dark gas. Every cloud is detected and shows significant, extended gamma ray emission from molecular gas. The gamma ray emission is dominated by the CO-emitting gas in some clouds, but by the CO-dark gas in others. The average emissivity and gamma ray power law index from H i above 1 GeV shows no evidence of a systematic variation. The CO-to-{{H}2} conversion factor shows no variation between clouds over this small spatial range, but shows significant variations within each cloud. The average CO-to-{{H}2} conversion factor suggests that the CO-dark gas is molecular as opposed to optically thick H i.

  14. X-ray emission from star-forming galaxies - signatures of cosmic rays and magnetic fields

    NASA Astrophysics Data System (ADS)

    Schober, J.; Schleicher, D. R. G.; Klessen, R. S.

    2015-01-01

    The evolution of magnetic fields in galaxies is still an open problem in astrophysics. In nearby galaxies the far-infrared-radio correlation indicates the coupling between magnetic fields and star formation. The correlation arises from the synchrotron emission of cosmic ray electrons travelling through the interstellar magnetic fields. However, with an increase of the interstellar radiation field (ISRF), inverse Compton scattering becomes the dominant energy loss mechanism of cosmic ray electrons with a typical emission frequency in the X-ray regime. The ISRF depends on the one hand on the star formation rate and becomes stronger in starburst galaxies, and on the other hand increases with redshift due to the higher temperature of the cosmic microwave background. With a model for the star formation rate of galaxies, the ISRF, and the cosmic ray spectrum, we can calculate the expected X-ray luminosity resulting from the inverse Compton emission. Except for galaxies with an active galactic nucleus the main additional contribution to the X-ray luminosity comes from X-ray binaries. We estimate this contribution with an analytical model as well as with an observational relation, and compare it to the pure inverse Compton luminosity. Using data from the Chandra Deep Field Survey and far-infrared observations from Atacama Large Millimeter/Submillimeter Array, we then determine upper limits for the cosmic ray energy. Assuming that the magnetic energy in a galaxy is in equipartition with the energy density of the cosmic rays, we obtain upper limits for the magnetic field strength. Our results suggest that the mean magnetic energy of young galaxies is similar to the one in local galaxies. This points towards an early generation of galactic magnetic fields, which is in agreement with current dynamo evolution models.

  15. Cosmic Rays as a Factor of Biosphere Evolution

    NASA Astrophysics Data System (ADS)

    Miroshnichenko, L. I.

    2014-11-01

    There are no doubts that the Earth's space environment in the past inevitably exerted direct and/or indirect influence [1--4] on the conditions of terrestrial life and biospheric evolution. Well-known cosmic factors are usually streams of cosmic dust and gas, comets and asteroids, cosmic rays (energetic particles of galactic and/or solar origin), interplanetary plasma (solar wind), and electromagnetic radiation of different energies, wavelengths, or frequencies. Of great interest are radiation conditions and their variations, especially in the remote past (over the geological time scales). The Sun, the most important and indispensable condition for the existence of the Earth's biosphere, is also a potential source of dangerous emissions. In continuation of (and in addition to) our review paper [3], below we summarize the observational data and results of theoretical works that have been carried out and/or published mainly after 2012. These studies are actually in the frontier region between the Astrobiology and Space Weather. Our main attention is paid to cosmic rays (CR) of galactic and solar origin (GCR and SCR, respectively).

  16. Impact of Fermi-LAT and AMS-02 results on cosmic-ray astrophysics

    E-print Network

    Dermer, Charles D

    2015-01-01

    This article reviews a few topics relevant to Galactic cosmic-ray astrophysics, focusing on the recent AMS-02 data release and Fermi Large Area Telescope data on the diffuse Galactic gamma-ray emissivity. Calculations are made of the diffuse cosmic-ray induced p+p --> pi^0 --> 2 gamma spectra, normalized to the AMS-02 cosmic-ray proton spectrum at ~ 10 - 100 GV, with and without a hardening in the cosmic-ray proton spectrum at rigidities R >~ 300 GV. A single power-law momentum "shock" spectrum for the local interstellar medium cosmic-ray proton spectrum cannot be ruled out from the gamma-ray emissivity data alone without considering the additional contribution of electron bremsstrahlung. Metallicity corrections are discussed, and a maximal range of nuclear enhancement factors from 1.52 to 1.92 is estimated.Origins of the 300 GV cosmic-ray proton and alpha-particle hardening are discussed.

  17. Time correlation of cosmic-ray-induced neutrons and gamma rays at sea level

    E-print Network

    Harilal, S. S.

    Time correlation of cosmic-ray-induced neutrons and gamma rays at sea level G. Miloshevsky n , A and evaporation processes of air nuclei are time-correlated. The occurrence of their counts in a fixed time interval is not a random (Poisson) distribution, but rather time-correlated bursts of counts

  18. The Galactic Diffuse Gamma-ray Spectrum from Cosmic-ray Proton Interactions

    E-print Network

    Masaki Mori

    1996-11-28

    A new calculation of the Galactic diffuse gamma-ray spectrum from the decay of secondary particles produced by interactions of cosmic-ray protons with interstellar matter is presented. The calculation utilizes the modern Monte Carlo event generators, Hadrin, Fritiof and Pythia, which simulate high-energy proton-proton collisions and are widely used in studies of nuclear and particle physics, in addition to scaling calculation. This study is motivated by the result on the Galactic diffuse gamma-ray flux observed by the EGRET detector on the Compton Gamma-ray Observatory, which indicates an excess above about 1 GeV of the observed intensity compared with a model prediction. The prediction is based on cosmic-ray interactions with interstellar matter, in which secondary pion productions are treated by a simple model. With the improved interaction model used here, however, the diffuse gamma-ray flux agrees rather well with previous calculations within uncertainties, which mainly come from the unobservable demodulated cosmic-ray spectrum in interstellar space. As a possible solution to the excess flux, flatter spectra of cosmic-ray protons have been tested and we found that the power-law spectrum with an index of about $-(2.4\\sim2.5)$ gives a better fit to the EGRET data, though the spectrum is not explained completely.

  19. On the spectrum of Ultrahigh Energy Cosmic Rays and the Gamma Ray Burst Origin Hypothesis

    E-print Network

    S. T. Scully; F. W. Stecker

    2001-03-21

    It has been suggested that cosmological gamma-ray bursts (GRBs) can produce the observed flux of cosmic rays at the highest energies. However, recent studies of GRBs indicate that their redshift distribution likely follows that of the average star formation rate and that GRBs were more numerous at high redshifts. As a consequence, we show that photomeson production energy losses suffered by ultrahigh energy cosmic rays coming from GRBs would produce too sharp a spectral high energy cutoff to be consistent with the air shower data. Furthermore, we show that cosmological GRBs fail to supply the energy input required to account for the cosmic ray flux above 10 EeV by a factor of 100-1000.

  20. Ultra-high energy cosmic rays and the extragalactic gamma ray flux

    E-print Network

    Erlykin, A D

    2014-01-01

    Ultra-high energy cosmic rays interacting with the radiation fields in the universe cause electromagnetic cascades resulting in a flux of extragalactic gamma rays, detectable to some 100 GeV. Recent precise measurements of the extragalactic gamma ray flux by Fermi-LAT, coupled with estimates of the background from active galactic nuclei of various types, allows limits to be set on the cascade component. By comparison with prediction and, making various assumptions, ie taking a particular model, limits can be set on the maximum energy to which ultra-high energy particle can be accelerated. If our model is correct, it is unlikely that the maximum energy is above 100 EeV, in turn, the apparent 'GZK' cut-off in the measured ultra-high energy spectrum could instead be due to a fall-off in the intrinsic emergent particle spectrum. However, it is not plausible to be dogmatic at the present time because of uncertainty in many of the parameters involved. We have used recent estimates of the range of parameters and hav...