Implications of new measurements of O-16 + p + C-12,13, N-14,15 for the abundances of C, N isotopes at the cosmic ray source

NASA Technical Reports Server (NTRS)

Guzik, T. G.; Wefel, J. P.; Crawford, H. J.; Greiner, D. E.; Lindstrom, P. J.; Schimmerling, W.; Symons, T. J. M.

1985-01-01

The fragmentation of a 225 MeV/n O-16 beam was investigated at the Bevalac. Preliminary cross sections for mass = 13, 14, 15 fragments are used to constrain the nuclear excitation functions employed in galactic propagation calculations. Comparison to cosmic ray isotonic data at low energies shows that in the cosmic ray source C-13/C approximately 2% and N-14/0=3-6%. No source abundance of N-15 is required with the current experimental results.

AMS Observations of Light Cosmic Ray Isotopes and Implications for their Production in the Galaxy

NASA Astrophysics Data System (ADS)

Tomassetti, Nicola

2012-08-01

Observations of light isotopes in cosmic rays provide information on their origin and propagation in the Galaxy. Using the data collected by AMS-01 in the STS-91 space mission, we report our final results on the isotopic composition of hydrogen and helium between 200 MeV and 1.4 GeV per nucleon. These measurements are in good agreement with the previous data and set new standards of precision. We discuss the role of isotopic composition data in modeling the cosmic ray production, acceleration and diffusive transport in the Galaxy.

Antarctic meteorites

NASA Astrophysics Data System (ADS)

Cassidy, W. A.; Rancitelli, L. A.

1982-04-01

An abundance of meteorites has been discovered on two sites in the Antarctic which may assist in the study of the origins of meteorites and the history of the solar system. Characteristics particular to those meteorites discovered in this region are explained. These specimens, being well preserved due to the climate, have implications in the study of the cosmic ray flux through time, the meteoroid complex in space, and cosmic ray exposure ages. Implications for the study of the Antarctic, particularly the ice flow, are also discussed. Further discoveries of meteorites in this region are anticipated.

Neutral particle background in cosmic ray telescopes composed of silicon solid state detectors

NASA Technical Reports Server (NTRS)

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

1977-01-01

The energy loss-spectrum of secondary charged particles produced by the interaction of gamma-rays and energetic neutrons in silicon solid state detectors has been measured with a satellite-borne cosmic ray telescope. In the satellite measurements presented here two distinct neutral background effects are identified: secondary protons and alpha particles with energies of about 2 to 100 MeV produced by neutron interactions, and secondary electrons with energies of about 0.2 to 10 MeV produced by X-ray interactions. The implications of this neutral background for satellite measurements of low energy cosmic rays are discussed, and suggestions are given for applying these results to other detector systems in order to estimate background contamination and optimize detector system design.

THE CENTAURUS A ULTRAHIGH-ENERGY COSMIC-RAY EXCESS AND THE LOCAL EXTRAGALACTIC MAGNETIC FIELD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yueksel, Hasan; Kronberg, Philipp P.; Stanev, Todor

2012-10-10

The ultrahigh-energy cosmic-ray (UHECR) anisotropies discovered by the Pierre Auger Observatory provide the potential to finally address both the particle origins and properties of the nearby extragalactic magnetic field (EGMF). We examine the implications of the excess of {approx}10{sup 20} eV events around the nearby radio galaxy Centaurus A. We find that, if Cen A is the source of these cosmic rays, the angular distribution of events constrains the EGMF strength within several Mpc of the Milky Way to {approx}> 20 nG for an assumed primary proton composition. Our conclusions suggest that either the observed excess is a statistical anomalymore » or the local EGMF is stronger than conventionally thought. We discuss several implications, including UHECR scattering from more distant sources, time delays from transient sources, and the possibility of using magnetic lensing signatures to attain tighter constraints.« less

Photonuclear interactions of ultrahigh energy cosmic rays and their astrophysical consequences

NASA Technical Reports Server (NTRS)

Puget, J. L.; Stecker, F. W.; Bredekamp, J. H.

1976-01-01

Results are presented for detailed Monte Carlo calculations of the interaction histories of ultrahigh-energy cosmic-ray nuclei with intergalactic radiation fields, using improved estimates of these fields and empirical determinations of photonuclear cross sections, including multinuclear disintegrations for nuclei up to Fe-56. Intergalactic and galactic energy-loss rates and nucleon-loss rates for nuclei up to Fe-56 are also given. Astrophysical implications are discussed in terms of expected features in the cosmic-ray spectrum between 10 to the 18th and 10 to the 21st power eV for the universal and supercluster origin hypotheses. The results of these calculations indicate that ultrahigh-energy cosmic rays cannot be universal in origin regardless of whether they are protons or nuclei. Both the supercluster and galactic origin hypotheses, however, are possible regardless of nuclear composition.

Cosmic-ray models for early Galactic Lithium, Beryllium, and Boron production

NASA Technical Reports Server (NTRS)

Fields, Brian D.; Olive, Keith A.; Schramm, David N.

1994-01-01

To understand better the early Galactic production of Li, Be, and B by comsmic-ray spallation and fusion reactions, the dependence of these production rates on cosmic-ray models and model parameters is examined. The sensitivity of elemental and isotopic production to the cosmic-ray path length magnitude and energy dependence, source spectrum, spallation kinematics, and cross section uncertainties is studied. Changes in these model features, particularly those features related to confinement, are shown to alter the Be- and B- versus-Fe slopes from a naive quadratic relation. The implications of our results for the diffuse gamma-ray background are examined, and the role of chemical evolution and its relation to our results is noted. It is also noted that the unmeasured high-energy behavior of alpha + alpha fusion can lead to effects as large as a factor of 2 in the resultant yields. Future data should enable Population II Li, Be, and B abundances to constrain cosmic-ray models for the early Galaxy.

Time-dependent evolution of cosmic-ray-modified shock structure: Transition to steady state

NASA Astrophysics Data System (ADS)

Donohue, D. J.; Zank, G. P.; Webb, G. M.

1994-03-01

Steady state solutions to the two-fluid equations of cosmic-ray-modified shock structure were investigated first by Drury and Volk (1981). Their analysis revealed, among other properties, that there exist regions of upstream parameter space where the equations possess three different downstream solutions for a given upstream state. In this paper we investigate whether or not all these solutions can occur as time-asymptotic states in a physically realistic evolution. To do this, we investigate the time-dependent evolution of the two-fluid cosmic-ray equations in going from a specified initial condition to a steady state. Our results indicate that the time-asymptotic solution is strictly single-valued, and it undergoes a transition from weakly to strongly cosmic-ray-modified at a critical value of the upstream cosmic ray energy density. The expansion of supernova remnant shocks is considered as an example, and it is shown that the strong to weak transition is in fact more likely. The third intermediate solution is shown to influence the time-dependent evolution of the shock, but it is not found to be a stable time-asymptotic state. Timescales for convergence to these states and their implications for the efficiency of shock acceleration are considered. We also investigate the effects of a recently introduced model for the injection of seed particles into the shock accelerated cosmic-ray population. The injection is found to result in a more strongly cosmic-ray-dominated shock, which supports our conclusion that for most classes of intermediate and strong cosmic-ray-modified shocks, the downstream cosmic-ray pressure component is at least as large as the thermal gas pressure, independent of the upstream state. As a result, cosmic rays almost always play a significant role in determining the shock structure and dissipation and they cannot be regarded as test particles.

Time-dependent evolution of cosmic-ray-modified shock structure: Transition to steady state

NASA Technical Reports Server (NTRS)

Donohue, D. J.; Zank, G. P.; Webb, G. M.

1994-01-01

Steady state solutions to the two-fluid equations of cosmic-ray-modified shock structure were investigated first by Drury and Volk (1981). Their analysis revealed, among other properties, that there exist regions of upstream parameter space where the equations possess three different downstream solutions for a given upstream state. In this paper we investigate whether or not all these solutions can occur as time-asymptotic states in a physically realistic evolution. To do this, we investigate the time-dependent evolution of the two-fluid cosmic-ray equations in going from a specified initial condition to a steady state. Our results indicate that the time-asymptotic solution is strictly single-valued, and it undergoes a transition from weakly to strongly cosmic-ray-modified at a critical value of the upstream cosmic ray energy density. The expansion of supernova remnant shocks is considered as an example, and it is shown that the strong to weak transition is in fact more likely. The third intermediate solution is shown to influence the time-dependent evolution of the shock, but it is not found to be a stable time-asymptotic state. Timescales for convergence to these states and their implications for the efficiency of shock acceleration are considered. We also investigate the effects of a recently introduced model for the injection of seed particles into the shock accelerated cosmic-ray population. The injection is found to result in a more strongly cosmic-ray-dominated shock, which supports our conclusion that for most classes of intermediate and strong cosmic-ray-modified shocks, the downstream cosmic-ray pressure component is at least as large as the thermal gas pressure, independent of the upstream state. As a result, cosmic rays almost always play a significant role in determining the shock structure and dissipation and they cannot be regarded as test particles.

Production of Na-22 and Other Radionuclides by Neutrons in Al, SiO2, Si, Ti, Fe and Ni Targets: Implications for Cosmic Ray Studies

NASA Technical Reports Server (NTRS)

Sisterson, J. M.; Jones, D. T. L.; Binns, P. J.; Langen, K.; Schroeder, I.; Buthelezi, Z.; Latti, E.; Brooks, F. D.; Buffler, A.; Allie, M. S.;

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.

Global Anisotropies in TeV Cosmic Rays Related to the Sun's Local Galactic Environment from IBEX

NASA Technical Reports Server (NTRS)

Schwadron, N. A.; Adams, F. C.; Christian, E. R.; Desiati, P.; Frisch, P.; Funsten, H. O.; Jokipii, J. R.; McComas, D. J.; Moebius, E.; Zank, G. P.

2014-01-01

Observations with the Interstellar Boundary Explorer (IBEX) have shown enhanced energetic neutral atom (ENA) emission from a narrow, circular ribbon likely centered on the direction of the local interstellar medium (LISM) magnetic field. Here, we show that recent determinations of the local interstellar velocity, based on interstellar atom measurements with IBEX, are consistent with the interstellar modulation of high-energy (tera-electron volts, TeV) cosmic rays and diffusive propagation from supernova sources revealed in global anisotropy maps of ground-based high-energy cosmic-ray observatories (Milagro, Asg, and IceCube). Establishing a consistent local interstellar magnetic field direction using IBEX ENAs at hundreds to thousands of eV and galactic cosmic rays at tens of TeV has wide-ranging implications for the structure of our heliosphere and its interactions with the LISM, which is particularly important at the time when the Voyager spacecraft are leaving our heliosphere.

Global anisotropies in TeV cosmic rays related to the Sun's local galactic environment from IBEX.

PubMed

Schwadron, N A; Adams, F C; Christian, E R; Desiati, P; Frisch, P; Funsten, H O; Jokipii, J R; McComas, D J; Moebius, E; Zank, G P

2014-02-28

Observations with the Interstellar Boundary Explorer (IBEX) have shown enhanced energetic neutral atom (ENA) emission from a narrow, circular ribbon likely centered on the direction of the local interstellar medium (LISM) magnetic field. Here, we show that recent determinations of the local interstellar velocity, based on interstellar atom measurements with IBEX, are consistent with the interstellar modulation of high-energy (tera-electron volts, TeV) cosmic rays and diffusive propagation from supernova sources revealed in global anisotropy maps of ground-based high-energy cosmic-ray observatories (Milagro, Asγ, and IceCube). Establishing a consistent local interstellar magnetic field direction using IBEX ENAs at hundreds to thousands of eV and galactic cosmic rays at tens of TeV has wide-ranging implications for the structure of our heliosphere and its interactions with the LISM, which is particularly important at the time when the Voyager spacecraft are leaving our heliosphere.

Hard X-ray irradiation of cosmic silicate analogs: structural evolution and astrophysical implications

NASA Astrophysics Data System (ADS)

Gavilan, L.; Jäger, C.; Simionovici, A.; Lemaire, J. L.; Sabri, T.; Foy, E.; Yagoubi, S.; Henning, T.; Salomon, D.; Martinez-Criado, G.

2016-03-01

Context. Protoplanetary disks, interstellar clouds, and active galactic nuclei contain X-ray-dominated regions. X-rays interact with the dust and gas present in such environments. While a few laboratory X-ray irradiation experiments have been performed on ices, X-ray irradiation experiments on bare cosmic dust analogs have been scarce up to now. Aims: Our goal is to study the effects of hard X-rays on cosmic dust analogs via in situ X-ray diffraction. By using a hard X-ray synchrotron nanobeam, we seek to simulate cumulative X-ray exposure on dust grains during their lifetime in these astrophysical environments and provide an upper limit on the effect of hard X-rays on dust grain structure. Methods: We prepared enstatite (MgSiO3) nanograins, which are analogs to cosmic silicates, via the melting-quenching technique. These amorphous grains were then annealed to obtain polycrystalline grains. These were characterized via scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) before irradiation. Powder samples were prepared in X-ray transparent substrates and were irradiated with hard X-rays nanobeams (29.4 keV) provided by beamline ID16B of the European Synchrotron Radiation Facility (Grenoble). X-ray diffraction images were recorded in transmission mode, and the ensuing diffractograms were analyzed as a function of the total X-ray exposure time. Results: We detected the amorphization of polycrystalline silicates embedded in an organic matrix after an accumulated X-ray exposure of 6.4 × 1027 eV cm-2. Pure crystalline silicate grains (without resin) do not exhibit amorphization. None of the amorphous silicate samples (pure and embedded in resin) underwent crystallization. We analyze the evolution of the polycrystalline sample embedded in an organic matrix as a function of X-ray exposure. Conclusions: Loss of diffraction peak intensity, peak broadening, and the disappearance of discrete spots and arcs reveal the amorphization of the resin embedded (originally polycrystalline) silicate sample. We explore the astrophysical implications of this laboratory result as an upper limit to the effect of X-rays on the structure of cosmic silicates.

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.

Fermi-LAT observations of the diffuse γ-ray emission: Implications for cosmic rays and the interstellar medium

DOE PAGES

Ackermann, M.; Ajello, M.; Atwood, W. B.; ...

2012-04-09

The γ-ray sky >100 MeV is dominated by the diffuse emissions from interactions of cosmic rays with the interstellar gas and radiation fields of the Milky Way. Our observations of these diffuse emissions provide a tool to study cosmic-ray origin and propagation, and the interstellar medium. We present measurements from the first 21 months of the Fermi Large Area Telescope (Fermi-LAT) mission and compare with models of the diffuse γ-ray emission generated using the GALPROP code. The models are fitted to cosmic-ray data and incorporate astrophysical input for the distribution of cosmic-ray sources, interstellar gas, and radiation fields. In ordermore » to assess uncertainties associated with the astrophysical input, a grid of models is created by varying within observational limits the distribution of cosmic-ray sources, the size of the cosmic-ray confinement volume (halo), and the distribution of interstellar gas. An all-sky maximum-likelihood fit is used to determine the X CO factor, the ratio between integrated CO-line intensity and H2 column density, the fluxes and spectra of the γ-ray point sources from the first Fermi-LAT catalog, and the intensity and spectrum of the isotropic background including residual cosmic rays that were misclassified as γ-rays, all of which have some dependency on the assumed diffuse emission model. The models are compared on the basis of their maximum-likelihood ratios as well as spectra, longitude, and latitude profiles. Here, we provide residual maps for the data following subtraction of the diffuse emission models. The models are consistent with the data at high and intermediate latitudes but underpredict the data in the inner Galaxy for energies above a few GeV. Possible explanations for this discrepancy are discussed, including the contribution by undetected point-source populations and spectral variations of cosmic rays throughout the Galaxy. In the outer Galaxy, we find that the data prefer models with a flatter distribution of cosmic-ray sources, a larger cosmic-ray halo, or greater gas density than is usually assumed. Our results in the outer Galaxy are consistent with other Fermi-LAT studies of this region that used different analysis methods than employed in this paper.« less

Fermi-LAT Observations of the Diffuse γ-Ray Emission: Implications for Cosmic Rays and the Interstellar Medium

NASA Astrophysics Data System (ADS)

Ackermann, M.; Ajello, M.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; de Angelis, A.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Silva, E. do Couto e.; Drell, P. S.; Drlica-Wagner, A.; Falletti, L.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fortin, P.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gaggero, D.; Gargano, F.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grove, J. E.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Horan, D.; Hou, X.; Hughes, R. E.; Jóhannesson, G.; Johnson, A. S.; Johnson, R. P.; Kamae, T.; Katagiri, H.; Kataoka, J.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lee, S.-H.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Parent, D.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Sadrozinski, H. F.-W.; Sgrò, C.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Strong, A. W.; Suson, D. J.; Takahashi, H.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Wood, M.; Yang, Z.; Ziegler, M.; Zimmer, S.

2012-05-01

The γ-ray sky >100 MeV is dominated by the diffuse emissions from interactions of cosmic rays with the interstellar gas and radiation fields of the Milky Way. Observations of these diffuse emissions provide a tool to study cosmic-ray origin and propagation, and the interstellar medium. We present measurements from the first 21 months of the Fermi Large Area Telescope (Fermi-LAT) mission and compare with models of the diffuse γ-ray emission generated using the GALPROP code. The models are fitted to cosmic-ray data and incorporate astrophysical input for the distribution of cosmic-ray sources, interstellar gas, and radiation fields. To assess uncertainties associated with the astrophysical input, a grid of models is created by varying within observational limits the distribution of cosmic-ray sources, the size of the cosmic-ray confinement volume (halo), and the distribution of interstellar gas. An all-sky maximum-likelihood fit is used to determine the X CO factor, the ratio between integrated CO-line intensity and H2 column density, the fluxes and spectra of the γ-ray point sources from the first Fermi-LAT catalog, and the intensity and spectrum of the isotropic background including residual cosmic rays that were misclassified as γ-rays, all of which have some dependency on the assumed diffuse emission model. The models are compared on the basis of their maximum-likelihood ratios as well as spectra, longitude, and latitude profiles. We also provide residual maps for the data following subtraction of the diffuse emission models. The models are consistent with the data at high and intermediate latitudes but underpredict the data in the inner Galaxy for energies above a few GeV. Possible explanations for this discrepancy are discussed, including the contribution by undetected point-source populations and spectral variations of cosmic rays throughout the Galaxy. In the outer Galaxy, we find that the data prefer models with a flatter distribution of cosmic-ray sources, a larger cosmic-ray halo, or greater gas density than is usually assumed. Our results in the outer Galaxy are consistent with other Fermi-LAT studies of this region that used different analysis methods than employed in this paper.

FERMI-LAT OBSERVATIONS OF THE DIFFUSE {gamma}-RAY EMISSION: IMPLICATIONS FOR COSMIC RAYS AND THE INTERSTELLAR MEDIUM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ackermann, M.; Ajello, M.; Bechtol, K.

The {gamma}-ray sky >100 MeV is dominated by the diffuse emissions from interactions of cosmic rays with the interstellar gas and radiation fields of the Milky Way. Observations of these diffuse emissions provide a tool to study cosmic-ray origin and propagation, and the interstellar medium. We present measurements from the first 21 months of the Fermi Large Area Telescope (Fermi-LAT) mission and compare with models of the diffuse {gamma}-ray emission generated using the GALPROP code. The models are fitted to cosmic-ray data and incorporate astrophysical input for the distribution of cosmic-ray sources, interstellar gas, and radiation fields. To assess uncertaintiesmore » associated with the astrophysical input, a grid of models is created by varying within observational limits the distribution of cosmic-ray sources, the size of the cosmic-ray confinement volume (halo), and the distribution of interstellar gas. An all-sky maximum-likelihood fit is used to determine the X{sub CO} factor, the ratio between integrated CO-line intensity and H{sub 2} column density, the fluxes and spectra of the {gamma}-ray point sources from the first Fermi-LAT catalog, and the intensity and spectrum of the isotropic background including residual cosmic rays that were misclassified as {gamma}-rays, all of which have some dependency on the assumed diffuse emission model. The models are compared on the basis of their maximum-likelihood ratios as well as spectra, longitude, and latitude profiles. We also provide residual maps for the data following subtraction of the diffuse emission models. The models are consistent with the data at high and intermediate latitudes but underpredict the data in the inner Galaxy for energies above a few GeV. Possible explanations for this discrepancy are discussed, including the contribution by undetected point-source populations and spectral variations of cosmic rays throughout the Galaxy. In the outer Galaxy, we find that the data prefer models with a flatter distribution of cosmic-ray sources, a larger cosmic-ray halo, or greater gas density than is usually assumed. Our results in the outer Galaxy are consistent with other Fermi-LAT studies of this region that used different analysis methods than employed in this paper.« less

Fermi-LAT observations of the diffuse γ-ray emission: Implications for cosmic rays and the interstellar medium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ackermann, M.; Ajello, M.; Atwood, W. B.

The γ-ray sky >100 MeV is dominated by the diffuse emissions from interactions of cosmic rays with the interstellar gas and radiation fields of the Milky Way. Our observations of these diffuse emissions provide a tool to study cosmic-ray origin and propagation, and the interstellar medium. We present measurements from the first 21 months of the Fermi Large Area Telescope (Fermi-LAT) mission and compare with models of the diffuse γ-ray emission generated using the GALPROP code. The models are fitted to cosmic-ray data and incorporate astrophysical input for the distribution of cosmic-ray sources, interstellar gas, and radiation fields. In ordermore » to assess uncertainties associated with the astrophysical input, a grid of models is created by varying within observational limits the distribution of cosmic-ray sources, the size of the cosmic-ray confinement volume (halo), and the distribution of interstellar gas. An all-sky maximum-likelihood fit is used to determine the X CO factor, the ratio between integrated CO-line intensity and H2 column density, the fluxes and spectra of the γ-ray point sources from the first Fermi-LAT catalog, and the intensity and spectrum of the isotropic background including residual cosmic rays that were misclassified as γ-rays, all of which have some dependency on the assumed diffuse emission model. The models are compared on the basis of their maximum-likelihood ratios as well as spectra, longitude, and latitude profiles. Here, we provide residual maps for the data following subtraction of the diffuse emission models. The models are consistent with the data at high and intermediate latitudes but underpredict the data in the inner Galaxy for energies above a few GeV. Possible explanations for this discrepancy are discussed, including the contribution by undetected point-source populations and spectral variations of cosmic rays throughout the Galaxy. In the outer Galaxy, we find that the data prefer models with a flatter distribution of cosmic-ray sources, a larger cosmic-ray halo, or greater gas density than is usually assumed. Our results in the outer Galaxy are consistent with other Fermi-LAT studies of this region that used different analysis methods than employed in this paper.« less

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

NASA Astrophysics Data System (ADS)

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

1994-03-01

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 a cosmic-ray lifetime for escape of 27 (+19, -9) x 106 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.

The galactic gamma-ray distribution: Implications for galactic structure and the radial cosmic ray gradient

NASA Technical Reports Server (NTRS)

Harding, A. K.; Stecker, F. W.

1984-01-01

The radial distribution of gamma ray emissivity in the Galaxy was derived from flux longitude profiles, using both the final SAS-2 results and the recently corrected COS-B results and analyzing the northern and southern galactic regions separately. The recent CO surveys of the Southern Hemisphere, were used in conjunction with the Northern Hemisphere data, to derive the radial distribution of cosmic rays on both sides of the galactic plane. In addition to the 5 kpc ring, there is evidence from the radial asymmetry for spiral features which are consistent with those derived from the distribution of bright HII regions. Positive evidence was also found for a strong increase in the cosmic ray flux in the inner Galaxy, particularly in the 5 kpc region in both halves of the plane.

Terrestrial effects of high energy cosmic rays

NASA Astrophysics Data System (ADS)

Atri, Dimitra

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

Cosmic ray electrons, positrons and the synchrotron emission of the Galaxy: consistent analysis and implications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernardo, Giuseppe Di; Evoli, Carmelo; Gaggero, Daniele

2013-03-01

A multichannel analysis of cosmic ray electron and positron spectra and of the diffuse synchrotron emission of the Galaxy is performed by using the DRAGON code. This study is aimed at probing the interstellar electron source spectrum down to E ∼< 1GeV and at constraining several propagation parameters. We find that above 4GeV the e{sup −} source spectrum is compatible with a power-law of index ∼ 2.5. Below 4GeV instead it must be significantly suppressed and the total lepton spectrum is dominated by secondary particles. The positron spectrum and fraction measured below a few GeV are consistently reproduced only withinmore » low reacceleration models. We also constrain the scale-height z{sub t} of the cosmic-ray distribution using three independent (and, in two cases, original) arguments, showing that values of z{sub t} ∼< 2kpc are excluded. This result may have strong implications for particle dark matter searches.« less

Cosmological Implications of the Effects of X-Ray Clusters on the Cosmic Microwave Background

NASA Technical Reports Server (NTRS)

Forman, William R.

1996-01-01

We have been carrying forward a program to confront X-ray observations of clusters and their evolution as derived from X-ray observatories with observations of the cosmic microwave background radiation (CMBR). In addition to the material covered in our previous reports (including three published papers), most recently we have explored the effects of a cosmological constant on the predicted Sunyaev-Zel'dovich effect from the ensemble of clusters. In this report we summarize that work from which a paper will be prepared.

The Outer Heliosphere: Solar Wind, Cosmic Ray and VLF Radio Emission Variations

NASA Technical Reports Server (NTRS)

McNutt, Ralph L., Jr.

1995-01-01

The Voyager 1 and 2 spacecraft now 45 astronomical units (AU) from Earth continue to monitor the outer heliosphere field and particles environment on a daily basis during their journey to the termination shock of the solar wind. Strong transient shocks continue to be detected in the solar wind plasma. The largest of these are associated with Global Merged Interaction Regions (GMIR's) which, in turn, block cosmic ray entry into the inner heliosphere and are apparently responsible for triggering the two major episodes of VLF radio emissions now thought to come from the heliopause. Distance estimates to the termination shock are consistent with those determined from observations of anomalous cosmic rays. Current observations and implications for heliospheric structure are discussed.

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.

Modulation of galactic and anomalous cosmic rays in the inner heliosphere

NASA Astrophysics Data System (ADS)

Heber, B.

Our knowledge on how galactic and anomalous cosmic rays are modulated in the inner heliosphere has been dramatically enlarged due to measurements provided by several missions launched in the past ten years. The current paradigma of singly charged anomalous cosmic rays has been confirmed by recent measurements from the SAMPEX and ACE satelite. Ulysses explored the inner heliosphere at polar regions during the last solar minimum period and is heading again to high heliographic latitudes during the time of the conference in July, 2000. The Sun approaches maximum activity when the spacecraft is at high heliographic latitudes giving us for the first time the possibility to explore modulation of cosmic rays in the inner three-dimensional heliosphere during such conditions. Ulysses electron measurements in addition to the 1 AU ICE electron and IMP helium measurements allows us to investigate charge sign dependent modulation over a full 22-year solar magnetic cycle. Implications of these observations for our understanding of different modulation processes in the inner three-dimensional heliosphere are presented.

Cosmic rays and terrestrial life: A brief review

NASA Astrophysics Data System (ADS)

Atri, Dimitra; Melott, Adrian L.

2014-01-01

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

Cosmic Rays and Gamma-Rays in Large-Scale Structure

NASA Astrophysics Data System (ADS)

Inoue, Susumu; Nagashima, Masahiro; Suzuki, Takeru K.; Aoki, Wako

2004-12-01

During the hierarchical formation of large scale structure in the universe, the progressive collapse and merging of dark matter should inevitably drive shocks into the gas, with nonthermal particle acceleration as a natural consequence. Two topics in this regard are discussed, emphasizing what important things nonthermal phenomena may tell us about the structure formation (SF) process itself. 1. Inverse Compton gamma-rays from large scale SF shocks and non-gravitational effects, and the implications for probing the warm-hot intergalactic medium. We utilize a semi-analytic approach based on Monte Carlo merger trees that treats both merger and accretion shocks self-consistently. 2. Production of 6Li by cosmic rays from SF shocks in the early Galaxy, and the implications for probing Galaxy formation and uncertain physics on sub-Galactic scales. Our new observations of metal-poor halo stars with the Subaru High Dispersion Spectrograph are highlighted.

The cosmic-ray antiproton spectrum from dark matter annihilation and its astrophysical implications - A new look

NASA Technical Reports Server (NTRS)

Stecker, F. W.; Tylka, A. J.

1989-01-01

The spectrum of antiprotons from dark matter annihilation are calculated using the Lund Monte Carlo program, and simple analytic expressions for the spectrum and low-energy antiproton/proton ratio are derived. Comparing the results with recent upper limits on low energy antiprotons, it is concluded that the reported 4-13 GeV antiproton flux cannot be accounted for by dark matter annihilation. The new upper limits do not provide useful constraints on dark matter particles. They restrict the annihilation rate and imply that annihilation gamma ray and e(+) fluxes would be far below the fluxes produced by cosmic-ray collisions. It may be possible to look for a dark matter halo annihilation signal at antiprotons energies below 0.5 GeV, where the flux from cosmic-ray collisions is expected to be negligible.

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

NASA Technical Reports Server (NTRS)

Moiseev, Alexander

2010-01-01

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

Background Underground at WIPP

NASA Astrophysics Data System (ADS)

Esch, Ernst-Ingo; Hime, A.; Bowles, T. J.

2001-04-01

Recent interest to establish a dedicated underground laboratory in the United States prompted an experimental program at to quantify the enviromental backgrounds underground at the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico. An outline of this program is provided along with recent experimental data on the cosmic ray muon flux at the 650 meter level of WIPP. The implications of the cosmic ray muon and fast neutron background at WIPP will be discussed in the context of new generation, low background experiments envisioned in the future.

The Andromeda galaxy in gamma-rays

NASA Technical Reports Server (NTRS)

Oezel, M. E.; Berkhuijsen, E. M.

1987-01-01

Implications of high-energy gamma-ray observations of the Andromeda galaxy with the next generation of satellites Gamma-1 and GRO are discussed in the context of the origin of cosmic rays and gamma-ray processes. The present estimate of the total gamma-ray flux of this galaxy at energies above 100 MeV is a factor of about three less than previous estimates.

Relativistic Interaction of 22Ne and 26Mg in Hydrogen and the Cosmic-Ray Implications

NASA Astrophysics Data System (ADS)

Chen, C.-X.; Albergo, S.; Caccia, Z.; Costa, S.; Crawford, H. J.; Cronqvist, M.; Engelage, J.; Greiner, L.; Guzik, T. G.; Insolia, A.; Knott, C. N.; Lindstrom, P. J.; McMahon, M.; Mitchell, J. W.; Potenza, R.; Russo, G. V.; Soutoul, A.; Testard, O.; Tull, C. E.; Tuvé, C.; Waddington, C. J.; Webber, W. R.; Wefel, J. P.

1997-04-01

The isotopic production cross sections for 22Ne projectiles at 377,581, and 894 MeV nucleon-1 and 26Mg projectiles at 371 and 576 MeV nucleon-1 interacting in a liquid hydrogen target have been measured by the Transport Collaboration at the Lawrence Berkeley Laboratory Heavy-Ion Spectrometer System (LBL HISS) facility. These cross sections are compared with those predicted by semi-empirical formulae. The systematics are studied to develop suitable inputs for calculations of galactic cosmic-ray interstellar transport. These calculations are used to unfold the transport effects from available observations of cosmic-ray CNO isotopes to extract the underlying source composition. With these new cross section measurements, the previously reported enhancement of 18O at the cosmic-ray source, which is sensitive to the cross sections for production from 22Ne and 26Mg and the uncertainties in cross section prediction formulae, may be explained. There is no evidence for an enhancement of 18O when these new cross sections are used in a weighted slab propagation calculation.

High-energy cosmic ray nuclei from tidal disruption events: Origin, survival, and implications

NASA Astrophysics Data System (ADS)

Zhang, B. Theodore; Murase, Kohta; Oikonomou, Foteini; Li, Zhuo

2017-09-01

Tidal disruption events (TDEs) by supermassive or intermediate mass black holes have been suggested as candidate sources of ultrahigh-energy cosmic rays (UHECRs) and high-energy neutrinos. Motivated by the recent measurements from the Pierre Auger Observatory, which indicates a metal-rich cosmic-ray composition at ultrahigh energies, we investigate the fate of UHECR nuclei loaded in TDE jets. First, we consider the production and survival of UHECR nuclei at internal shocks, external forward and reverse shocks, and nonrelativistic winds. Based on the observations of Swift J 1644 +57 , we show that the UHECRs can survive for external reverse and forward shocks, and disk winds. On the other hand, UHECR nuclei are significantly disintegrated in internal shocks, although they could survive for low-luminosity TDE jets. Assuming that UHECR nuclei can survive, we consider implications of different composition models of TDEs. We find that the tidal disruption of main sequence stars or carbon-oxygen white dwarfs does not successfully reproduce UHECR observations, namely the observed composition or spectrum. The observed mean depth of the shower maximum and its deviation could be explained by oxygen-neon-magnesium white dwarfs, although they may be too rare to be the sources of UHECRs.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moharana, Reetanjali; Razzaque, Soebur, E-mail: reetanjalim@uj.ac.za, E-mail: srazzaque@uj.ac.za

2015-08-01

Cosmic neutrino events detected by the IceCube Neutrino Observatory with energy 0∼> 3 TeV have poor angular resolutions to reveal their origin. Ultrahigh-energy cosmic rays (UHECRs), with better angular resolutions at 0>6 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 0≥ 10 EeV UHECR arrival directions at confidence level ≈ 90%. The strengthmore » of the correlation decreases with decreasing UHECR energy and no correlation exists at energy 0∼ 6 EeV . A search in astrophysical databases within 3{sup o} of the arrival directions of UHECRs with energy 0≥ 10 EeV, that are correlated with the IceCube cosmic neutrinos, resulted in 18 sources from the Swift-BAT X-ray catalog with redshift z≤ 0.06. We also found 3 objects in the Kühr 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 Kühr catalogs. We compare these luminosities with the X-ray luminosity of the corresponding sources and discuss possibilities of accelerating protons to 0∼> 10 EeV and produce neutrinos in these sources.« less

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)

Constraints on the gamma-ray emission from the cluster-scale AGN outburst in the Hydra A galaxy cluster

NASA Astrophysics Data System (ADS)

HESS Collaboration; Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker, J.; Bernlöhr, K.; Birsin, E.; Biteau, J.; Bochow, A.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Büsching, I.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Charbonnier, A.; Chaves, R. C. G.; Cheesebrough, A.; Cologna, G.; Conrad, J.; Couturier, C.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; O'C. Drury, L.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Gast, H.; Gérard, L.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Göring, D.; Grondin, M.-H.; Häffner, S.; Hague, J. D.; Hahn, J.; Hampf, D.; Harris, J.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Krayzel, F.; Laffon, H.; Lamanna, G.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Moderski, R.; Mohamed, M.; Moulin, E.; Naumann, C. L.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nekrassov, D.; Nguyen, N.; Nicholas, B.; Niemiec, J.; Nolan, S. J.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sheidaei, F.; Skilton, J. L.; Sol, H.; Spengler, G.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Terrier, R.; Tluczykont, M.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorobiov, S.; Vorster, M.; Wagner, S. J.; Ward, M.; White, R.; Wierzcholska, A.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.; Ali, M. O.

2012-09-01

Context. In some galaxy clusters, powerful active galactic nuclei (AGN) have blown bubbles with cluster scale extent into the ambient medium. The main pressure support of these bubbles is not known to date, but cosmic rays are a viable possibility. For such a scenario copious gamma-ray emission is expected as a tracer of cosmic rays from these systems. Aims: Hydra A, the closest galaxy cluster hosting a cluster scale AGN outburst, located at a redshift of 0.0538, is investigated for being a gamma-ray emitter with the High Energy Stereoscopic System (H.E.S.S.) array and the Fermi Large Area Telescope (Fermi-LAT). Methods: Data obtained in 20.2 h of dedicated H.E.S.S. observations and 38 months of Fermi-LAT data, gathered by its usual all-sky scanning mode, have been analyzed to search for a gamma-ray signal. Results: No signal has been found in either data set. Upper limits on the gamma-ray flux are derived and are compared to models. These are the first limits on gamma-ray emission ever presented for galaxy clusters hosting cluster scale AGN outbursts. Conclusions: The non-detection of Hydra A in gamma-rays has important implications on the particle populations and physical conditions inside the bubbles in this system. For the case of bubbles mainly supported by hadronic cosmic rays, the most favorable scenario, which involves full mixing between cosmic rays and embedding medium, can be excluded. However, hadronic cosmic rays still remain a viable pressure support agent to sustain the bubbles against the thermal pressure of the ambient medium. The largest population of highly-energetic electrons, which are relevant for inverse-Compton gamma-ray production is found in the youngest inner lobes of Hydra A. The limit on the inverse-Compton gamma-ray flux excludes a magnetic field below half of the equipartition value of 16 μG in the inner lobes.

Lorentz symmetry violation and UHECR experiments

NASA Astrophysics Data System (ADS)

Gonzalez-Mestres, L.

2001-08-01

Lorentz symmetry violation (LSV) at Planck scale can be tested through ultra-high energy cosmic rays (UHECR). We discuss deformed Lorentz symmetry (DLS) and energy non-conservation (ENC) patterns where the effective LSV parameter varies like the square of the momentum scale (e.g. quadratically de-formed relativistic kinematics, QDRK). In such patterns, a ≈ 106 LSV at Planck scale would be enough to produce observable effects on the properties of cosmic rays at the ≈ 1020 eV scale: absence of GZK cutoff, stability of unstable particles, lower interaction rates, kinematical failure of any parton model and of standard formulae for Lorentz contraction and time dilation... Its phenomeno-logical implications are compatible with existing data. Precise signatures are discussed in several patterns. If the effective LSV or ENC parameter is taken to vary linearly with the momentum scale (e.g. linearly deformed relativistic kinematics, LDRK), contradictions seem to arise with UHECR data. Conse-quences are important for UHECR and high-energy gamma-ray exper iments, as well as for high-energy cosmic rays and gravitational waves.

Probe of the solar magnetic field using the "cosmic-ray shadow" of the sun.

PubMed

Amenomori, M; Bi, X J; Chen, D; Chen, T L; Chen, W Y; Cui, S W; Danzengluobu; Ding, L K; Feng, C F; Feng, Zhaoyang; Feng, Z Y; Gou, Q B; Guo, Y Q; Hakamada, K; He, H H; He, Z T; Hibino, K; Hotta, N; Hu, Haibing; Hu, H B; Huang, J; Jia, H Y; Jiang, L; Kajino, F; Kasahara, K; Katayose, Y; Kato, C; Kawata, K; Labaciren; Le, G M; Li, A F; Li, H J; Li, W J; Liu, C; Liu, J S; Liu, M Y; Lu, H; Meng, X R; Mizutani, K; Munakata, K; Nanjo, H; Nishizawa, M; Ohnishi, M; Ohta, I; Onuma, H; Ozawa, S; Qian, X L; Qu, X B; Saito, T; Saito, T Y; Sakata, M; Sako, T K; Shao, J; Shibata, M; Shiomi, A; Shirai, T; Sugimoto, H; Takita, M; Tan, Y H; Tateyama, N; Torii, S; Tsuchiya, H; Udo, S; Wang, H; Wu, H R; Xue, L; Yamamoto, Y; Yang, Z; Yasue, S; Yuan, A F; Yuda, T; Zhai, L M; Zhang, H M; Zhang, J L; Zhang, X Y; Zhang, Y; Zhang, Yi; Zhang, Ying; Zhaxisangzhu; Zhou, X X

2013-07-05

We report on a clear solar-cycle variation of the Sun’s shadow in the 10 TeV cosmic-ray flux observed by the Tibet air shower array during a full solar cycle from 1996 to 2009. In order to clarify the physical implications of the observed solar cycle variation, we develop numerical simulations of the Sun’s shadow, using the potential field source surface model and the current sheet source surface (CSSS) model for the coronal magnetic field. We find that the intensity deficit in the simulated Sun’s shadow is very sensitive to the coronal magnetic field structure, and the observed variation of the Sun’s shadow is better reproduced by the CSSS model. This is the first successful attempt to evaluate the coronal magnetic field models by using the Sun’s shadow observed in the TeV cosmic-ray flux.

Progress report on the ultra heavy cosmic ray experiment (AO178)

NASA Technical Reports Server (NTRS)

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

1993-01-01

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 employing sixteen peripheral Long Duration Exposure Facility (LDEF) trays. The extended duration of the LDEF mission has resulted in a greatly enhanced scientific yield from the UHCRE. 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 degrees. 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 (Z greater than 88) cosmic rays. Results to date are presented including details 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 +/- 0.8 e for uranium and +/- 0.6 e for the platinum-lead group. The precision of charge assignment as a function of energy is derived and evidence for remarkably good charge resolution achieved in the UHCRE is considered. Astrophysical implications of the UHCRE charge spectrum are discussed.

Voyager measurements of the isotopic composition of cosmic-ray aluminum and implications for the propagation of cosmic rays

NASA Technical Reports Server (NTRS)

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

1994-01-01

We report a new measurement of the cosmic-ray isotopic composition of aluminum in the low-energy range form 75 to 206 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 1993 with an average solar modulation level about 497 MV, roughly the same as at Earth near sunspot minimum. We obtain approximately 430 Al events of which approximately 35 are Al-26 and 395 are Al-27. The Al isotopes were separated with an average mass resolution sigma of 0.35 amu. Our interpretation of the isotopic composition of cosmic-ray aluminum is based on a standard Leaky-Box model for the interstellar propagation of cosmic-ray nuclei using the latest cross sections of the New Mexico-Saclay collaboration as well as a disk-halo diffusion model. From our observed ratio Al-26/Al-27 of 8.3 +/- 2.4 % we deduce an average interstellar density of about 0.52 (+0.26, -0.2) atoms per cu cm. This density is larger than the value of 0.28 (+0.14, -0.11) atoms per cu cm we found from an analysis of the observed abundance of the longer lived Be-10 made using data from the Voyager detectors over almost the same time interval and using essentially the same propagation program.

A Numerical Assessment of Cosmic-Ray Energy Diffusion through Turbulent Media

NASA Astrophysics Data System (ADS)

Fatuzzo, M.; Melia, F.

2014-04-01

How and where cosmic rays are produced, and how they diffuse through various turbulent media, represent fundamental problems in astrophysics with far-reaching implications, both in terms of our theoretical understanding of high-energy processes in the Milky Way and beyond, and the successful interpretation of space-based and ground based GeV and TeV observations. For example, recent and ongoing detections, e.g., by Fermi (in space) and HESS (in Namibia), of γ-rays produced in regions of dense molecular gas hold important clues for both processes. In this paper, we carry out a comprehensive numerical investigation of relativistic particle acceleration and transport through turbulent magnetized environments in order to derive broadly useful scaling laws for the energy diffusion coefficients.

High energy gamma-ray astronomy; Proceedings of the International Conference, ANN Arbor, MI, Oct. 2-5, 1990

NASA Astrophysics Data System (ADS)

Matthews, James

The present volume on high energy gamma-ray astronomy discusses the composition and properties of heavy cosmic rays greater than 10 exp 12 eV, implications of the IRAS Survey for galactic gamma-ray astronomy, gamma-ray emission from young neutron stars, and high-energy diffuse gamma rays. Attention is given to observations of TeV photons at the Whipple Observatory, TeV gamma rays from millisecond pulsars, recent data from the CYGNUS experiment, and recent results from the Woomera Telescope. Topics addressed include bounds on a possible He/VHE gamma-ray line signal of Galactic dark matter, albedo gamma rays from cosmic ray interactions on the solar surface, source studies, and the CANGAROO project. Also discussed are neural nets and other methods for maximizing the sensitivity of a low-threshold VHE gamma-ray telescope, a prototype water-Cerenkov air-shower detector, detection of point sources with spark chamber gamma-ray telescopes, and real-time image parameterization in high energy gamma-ray astronomy using transputers. (For individual items see A93-25002 to A93-25039)

Measuring the Local Diffusion Coefficient with H.E.S.S. Observations of Very High-Energy Electrons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hooper, Dan; Linden, Tim

2017-11-20

The HAWC Collaboration has recently reported the detection of bright and spatially extended multi-TeV gamma-ray emission from Geminga, Monogem, and a handful of other nearby, middle-aged pulsars. The angular profile of the emission observed from these pulsars is surprising, in that it implies that cosmic-ray diffusion is significantly inhibited within ~25 pc of these objects, compared to the expectations of standard Galactic diffusion models. This raises the important question of whether the diffusion coefficient in the local interstellar medium is also low, or whether it is instead better fit by the mean Galactic value. Here, we utilize recent observations ofmore » the cosmic-ray electron spectrum (extending up to ~20 TeV) by the H.E.S.S. Collaboration to show that the local diffusion coefficient cannot be as low as it is in the regions surrounding Geminga and Monogem. Instead, we conclude that cosmic rays efficiently diffuse through the bulk of the local interstellar medium. Among other implications, this further supports the conclusion that pulsars significantly contribute to the observed positron excess.« less

Calculation of Cosmic Ray Induced Single Event Upsets: Program CRUP, Cosmic Ray Upset Program

DTIC Science & Technology

1983-09-14

1.., 0 .j ~ u M ~ t R A’- ~~ ’ .~ ; I .: ’ 1 J., ) ’- CALCULATION OF COSMIC RAY INDUCED SINGLE EVEI’o"T UPSETS: PROGRAM CRUP , COSMIC RAY UPSET...neceuety end Identity by blo..;k number) 0Thls report documents PROGR.Al\\1 CRUP , COSMIC RAY UPSET PROGRAM. The computer program calculates cosmic...34. » » •-, " 1 » V »1T"~ Calculation of Cosmic Ray Induced Single Event Upsets: PROGRAM CRUP , COSMIC RAY UPSET PROGRAM I. INTRODUCTION Since the

The PAMELA experiment on satellite and its capability in cosmic rays measurements

NASA Astrophysics Data System (ADS)

Adriani, O.; Ambriola, M.; Barbarino, G.; Barbier, L. M.; Bartalucci, S.; Bazilevskaja, G.; Bellotti, R.; Bertazzoni, S.; Bidoli, V.; Boezio, M.; Bogomolov, E.; Bonechi, L.; Bonvicini, V.; Boscherini, M.; Bravar, U.; Cafagna, F.; Campana, D.; Carlson, P.; Casolino, M.; Castellano, M.; Castellini, G.; Christian, E. R.; Ciacio, F.; Circella, M.; D'Alessandro, R.; De Marzo, C. N.; De Pascale, M. P.; Finetti, N.; Furano, G.; Gabbanini, A.; Galper, A. M.; Giglietto, N.; Grandi, M.; Grigorjeva, A.; Guarino, F.; Hof, M.; Koldashov, S. V.; Korotkov, M. G.; Krizmanic, J. F.; Krutkov, S.; Lund, J.; Marangelli, B.; Marino, L.; Menn, W.; Mikhailov, V. V.; Mirizzi, N.; Mitchell, J. W.; Mocchiutti, E.; Moiseev, A. A.; Morselli, A.; Mukhametshin, R.; Ormes, J. F.; Osteria, G.; Ozerov, J. V.; Papini, P.; Pearce, M.; Perego, A.; Piccardi, S.; Picozza, P.; Ricci, M.; Salsano, A.; Schiavon, P.; Scian, G.; Simon, M.; Sparvoli, R.; Spataro, B.; Spillantini, P.; Spinelli, P.; Stephens, S. A.; Stochaj, S. J.; Stozhkov, Y.; Straulino, S.; Streitmatter, R. E.; Taccetti, F.; Tesi, M.; Vacchi, A.; Vannuccini, E.; Vasiljev, G.; Vignoli, V.; Voronov, S. A.; Yurkin, Y.; Zampa, G.; Zampa, N.

2002-02-01

The PAMELA& equipment will be assembled in 2001 and installed on board the Russian satellite Resurs. PAMELA is conceived mainly to study the antiproton and positron fluxes in cosmic rays up to high energy (190GeV for p¯ and 270GeV for e+) and to search antinuclei, up to 30GeV/n, with a sensitivity of 10-7 in the He/He ratio. The PAMELA telescope consists of: a magnetic spectrometer made up of a permanent magnet system equipped with double sided microstrip silicon detectors; a transition radiation detector made up of active layers of proportional straw tubes interleaved with carbon fibre radiators; and a silicon-tungsten imaging calorimeter made up of layers of tungsten absorbers and silicon detector planes. A time-of-flight system and anti-coincidence counters complete the PAMELA equipment. In the past years, tests have been done on each subdetector of PAMELA; the main results are presented and their implications on the anti-particles identification capability in cosmic rays are discussed here.

Estimating Cosmic-Ray Spectral Parameters from Simulated Detector Responses with Detector Design Implications

NASA Technical Reports Server (NTRS)

Howell, L. W.

2001-01-01

A simple power law model consisting of a single spectral index (alpha-1) is believed to be an adequate description of the galactic cosmic-ray (GCR) proton flux at energies below 10(exp 13) eV, with a transition at knee energy (E(sub k)) to a steeper spectral index alpha-2 > alpha-1 above E(sub k). The maximum likelihood procedure is developed for estimating these three spectral parameters of the broken power law energy spectrum from simulated detector responses. These estimates and their surrounding statistical uncertainty are being used to derive the requirements in energy resolution, calorimeter size, and energy response of a proposed sampling calorimeter for the Advanced Cosmic-ray Composition Experiment for the Space Station (ACCESS). This study thereby permits instrument developers to make important trade studies in design parameters as a function of the science objectives, which is particularly important for space-based detectors where physical parameters, such as dimension and weight, impose rigorous practical limits to the design envelope.

Solar-Heliospheric-Interstellar Cosmic Ray Tour with the NASA Virtual Energetic Particle Observatory and the Space Physics Data Facility

NASA Astrophysics Data System (ADS)

Cooper, John F.; Papitashvili, Natalia E.; Johnson, Rita C.; Lal, Nand; McGuire, Robert E.

2015-04-01

NASA now has a large collection of solar, heliospheric, and local interstellar (Voyager 1) cosmic ray particle data sets that can be accessed through the data system services of the NASA Virtual Energetic Particle Observatory (VEPO) in collaboration with the NASA Space Physics Data Facility SPDF), respectively led by the first and last authors. The VEPO services were developed to enhance the long-existing OMNIWeb solar wind and energetic particle services of SPDF for on-line browse, correlative, and statistical analysis of NASA and ESA mission fields, plasma, and energetic particle data. In this presentation we take of tour through VEPO and SPDF of SEP reservoir events, the outer heliosphere earlier surveyed by the Pioneer, Voyager, and Ulysses spacecraft and now being probed by New Horizons, and the heliosheath-heliopause-interstellar regions now being explored by the Voyagers and IBEX. Implications of the latter measurements are also considered for the flux spectra of low to high energy cosmic rays in interstellar space.

Do supernovae of type 1 paly a role in cosmic-ray production?

NASA Technical Reports Server (NTRS)

Shapiro, M. M.

1985-01-01

A model of cosmic-ray origin is suggested which aims to account for some salient features of the composition. Relative to solar abundances, the Galactic cosmic rays (GCR) are deficient in hydrogen and helim (H and He) by an order of magnitude when the two compositions are normalized at iron. Our conjectural model implicates supernovae of Type I (SN-I) as sources of some of the GCR. SN-I occur approximately as often as SN-II, through their genesis is thought to be different. Recent studies of nucleosynthesis in SN-I based on accreting white dwarfs, find that the elements from Si to Fe are produced copiously. On the other hand, SN-I are virtually devoid of hydrogen, and upper limits deduced for He are low. If SN-I contribute significantly to the pool of GCR by injecting energetic particles into the interstellar medium (ISM), then this could explain why the resulting GCR is relatively deficient in H and He. A test of the model is proposed, and difficulties are discussed.

The microphysics and macrophysics of cosmic rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zweibel, Ellen G.

2013-05-15

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

Calculation of cosmic ray induced single event upsets: Program CRUP (Cosmic Ray Upset Program)

NASA Astrophysics Data System (ADS)

Shapiro, P.

1983-09-01

This report documents PROGRAM CRUP, COSMIC RAY UPSET PROGRAM. The computer program calculates cosmic ray induced single-event error rates in microelectronic circuits exposed to several representative cosmic-ray environments.

The origin of cosmic rays

NASA Technical Reports Server (NTRS)

Eichler, D.

1986-01-01

Data related to the development of cosmic rays are discussed. The relationship between cosmic ray production and the steady-state Boltzmann equation is analyzed. The importance of the power-law spectrum, the scattering rate, the theory of shock acceleration, anisotropic instabilities, and cosmic ray diffusion in the formation of cosmic rays is described. It is noted that spacecraft observations at the earth's bow shock are useful for studying cosmic rays and that the data support the collisionless shock-wave theory of cosmic ray origin.

Prospects to verify a possible dark matter hint in cosmic antiprotons with antideuterons and antihelium

NASA Astrophysics Data System (ADS)

Korsmeier, Michael; Donato, Fiorenza; Fornengo, Nicolao

2018-05-01

Cosmic rays are an important tool to study dark matter (DM) annihilation in our Galaxy. Recently, a possible hint for dark matter annihilation was found in the antiproton spectrum measured by AMS-02, even though the result might be affected by theoretical uncertainties. A complementary way to test its dark matter interpretation would be the observation of low-energy antinuclei in cosmic rays. We determine the chances to observe antideuterons with GAPS and AMS-02 and the implications for the ongoing AMS-02 antihelium searches. We find that the corresponding antideuteron signal is within the GAPS and AMS-02 detection potential. If, more conservatively, the putative signal was considered as an upper limit on DM annihilation, our results would indicate the highest possible fluxes for antideuterons and antihelium compatible with current antiproton data.

Implication of EAS data for the study of primary cosmic rays above 10 to the 5th power GeV

NASA Technical Reports Server (NTRS)

Popova, L.; Wdowczyk, J.

1985-01-01

Due to the strong decrease of the energetic cosmic ray flux its direct detection at the top of atmosphere with aircraft is limited at the present time to about 100,000 GeV. The intensity of all primary particles can be approximated in the range 100 to 100,000 GeV by power function with power index 2.65. There are predominantly protons and the rest is represented by several groups of nuclei. In the range of 100,000 to 10 to the 8th power GeV considerable disagreement is most probably connected with the uncertainity of the indirect derivation of the parameters of extensive air showers. Results for the primary spectrum in the range to the 8th power GeV, obtained by implication of extensive air showers (EAS) data from mountain altitudes are discussed.

Cosmic ray modulation with a Fisk-type heliospheric magnetic field and a latitude-dependent solar wind speed

NASA Astrophysics Data System (ADS)

Hitge, M.; Burger, R. A.

2010-01-01

The effect of a latitude-dependent solar wind speed on a Fisk heliospheric magnetic field [Fisk, L. A. Motion of the footpoints of heliospheric magnetic field lines at the Sun: implications for recurrent energetic particle events at high heliographic latitudes. J. Geophys. Res. 101, 15547-15553, 1996] was first discussed by Schwadron and Schwadron and McComas [Schwadron, N.A. An explanation for strongly underwound magnetic field in co-rotating rarefaction regions and its relationship to footpoint motion on the the sun. Geophys. Res. Lett. 29, 1-8, 2002. and Schwadron, N.A., McComas, D.J. Heliospheric “FALTS”: favored acceleration locations at the termination shock. Geophys. Res. Lett. 30, 41-1, 2003]. Burger and Sello [Burger, R.A., Sello, P.C. The effect on cosmic ray modulation of a Parker field modified by a latitudinal-dependent solar wind speed. Adv. Space Res. 35, 643-646, 2005] found a significant effect for a simplified 2D version of a latitude-dependent Fisk-type field while Miyake and Yanagita [Miyake, S., Yanagita, S. The effect of a modified Parker field on the modulation of the galactic cosmic rays. In: Proceedings of 30th International Cosmic Ray Conference. Merida, Mexico, vol. 1, 445-448, 2007] found a smaller effect. The current report improves on a previous attempt Hitge and Burger [Hitge, M., Burger, R.A. The effect of a latitude-dependent solar wind speed on cosmic-ray modulation in a Fisk-type heliospheric magnetic field. In: Proceedings of 30th International Cosmic Ray Conference. Merida, Mexico, vol. 1, pp. 449-450, 2007] where the global change in the solar wind speed and not the local speed gradient was emphasized. The sheared Fisk field of Schwadron and McComas [Schwadron, N.A., McComas, D.J. Heliospheric “FALTS”: Favored acceleration locations at the termination shock. Geophys. Res. Lett. 30, 41-1, 2003.) is similar to the current Schwadron-Parker hybrid field. Little difference is found between the effects of a Parker field and a Schwadron-Parker hybrid field on cosmic-ray modulation, in contrast to the results of Burger and Sello and Miyake and Yanagita [Burger, R.A., Sello, P.C. The effect on cosmic ray modulation of a Parker field modified by a latitudinal-dependent solar wind speed. Adv. Space Res. 35, 643-646, 2005 and Miyake, S., Yanagita, S. The effect of a modified Parker field on the modulation of the galactic cosmic rays. In: Proceedings of 30th International Cosmic Ray Conference. Merida, Mexico, vol. 1, pp. 445-448, 2007]. The two-dimensional approximation used by these authors is therefore inadequate to model the complexities of the actual three-dimensional field. We also show that a Fisk-type field with a latitude-dependent solar wind speed (Schwadron-Parker hybrid field) decreases both the relative amplitude of recurrent cosmic ray intensity variations and latitude gradients and yields similar constants of proportionality for these quantities as for the constant solar wind speed case.

ATCA 16 cm observation of CIZA J1358.9-4750: Implication of merger stage and constraint on non-thermal properties

NASA Astrophysics Data System (ADS)

Akahori, Takuya; Kato, Yuichi; Nakazawa, Kazuhiro; Ozawa, Takeaki; Gu, Liyi; Takizawa, Motokazu; Fujita, Yutaka; Nakanishi, Hiroyuki; Okabe, Nobuhiro; Makishima, Kazuo

2018-06-01

We report the Australia Telescope Compact Array 16 cm observation of CIZA J1358.9-4750. Recent X-ray studies imply that this galaxy cluster is composed of merging, binary clusters. Using the EW367 configuration, we found no significant diffuse radio emission in and around the cluster. An upper limit of the total radio power at 1.4 GHz is ˜1.1 × 1022 W Hz-1 in 30 square arcminutes, which is a typical size for radio relics. It is known that an empirical relation holds between the total radio power and X-ray luminosity of the host cluster. The upper limit is about one order of magnitude lower than the power expected from the relation. Very young (˜70 Myr) shocks with low Mach numbers (˜1.3), which are often seen at an early stage of merger simulations, are suggested by the previous X-ray observation. The shocks may generate cosmic-ray electrons with a steep energy spectrum, which is consistent with non-detection of bright (>1023 W Hz-1) relic in this 16 cm band observation. Based on the assumption of energy equipartition, the upper limit gives a magnetic field strength of below 0.68f(Dlos/1 Mpc)-1(γmin/200)-1 μG, where f is the cosmic-ray total energy density over the cosmic-ray electron energy density, Dlos is the depth of the shock wave along the sightline, and γmin is the lower cutoff Lorentz factor of the cosmic-ray electron energy spectrum.

An RXTE Study of M87 and the Core of the Virgo Cluster

NASA Technical Reports Server (NTRS)

Reynolds, Christopher S.; Heinz, Sebastian; Fabian, Andrew C.; Begelman, Mitchell C.

1998-01-01

We present hard X-ray observations of the nearby radio galaxy M87 and the core of the Virgo cluster using the Rossi X-ray Timing Explorer. These are the first hard X-ray observations of M87 not affected by contamination from the nearby Seyfert 2 galaxy NGC 4388. Thermal emission from Virgo's intracluster medium is clearly detected and has a spectrum indicative of kT approx. = 2.5 keV plasma with approximately 25% cosmic abundances. No non-thermal (power-law) emission from M87 is detected in the hard X-ray band, with fluctuations in the Cosmic X-ray Background being the limiting factor. Combining with ROSAT data, we infer that the X-ray spectrum of the M87 core and jet must be steep (Gamma(sub core) greater than 1.90 and Gamma(sub jet) greater than 1.75), and we discuss the implications of this result. In particular, these results are consistent with M87 being a mis-aligned BL-Lac object.

An RXTE Study of M87 and the Core of the Virgo Cluster

NASA Technical Reports Server (NTRS)

Reynolds, Christopher S.; Heinz, Sebastian; Fabian, Andrew C.; Begelman, Mitchell C.

1998-01-01

We present hard X-ray observations of the nearby radio galaxy M87 and the core of the Virgo cluster using the Rossi X-ray 7Tming Explorer. These are the first hard X-ray observations of M87 not affected by contamination from the nearby Seyfert 2 galaxy NGC 4388. Thermal emission from Virgo's intracluster medium is clearly detected and has a spectrum indicative of kT is approximately equal to 2.5 keV plasma with approximately 25% cosmic abundances. No non-thermal (power-law) emission from M87 is detected in the hard X-ray band, with fluctuations in the Cosmic X-ray Background being the limiting factor. Combining with ROSAT data, we infer that the X-ray spectrum of the M87 core and jet must be steep (Gamma (sub core) > 1.90 and Gamma (sub jet) > 1.75), and we discuss the implications of this result. In particular, these results are consistent with M87 being a mis-aligned BL-Lac object.

International Cosmic Ray Conference, 13th, University of Denver, Denver, Colo., August 17-30, 1973, Proceedings. Volume 5

NASA Technical Reports Server (NTRS)

1974-01-01

An X-ray observation of the Norma-Lupus region, charge and isotope measurements of heavy cosmic ray nuclei and their role in the determination of cosmic ray age, and the possibility of a contribution to primary cosmic ray spectra from pulsars are among the topics covered in papers concerned with some of the results of recent cosmic ray research. Other topics covered include multiple scattering of charged particles in magnetic fields, absorption of primary cosmic rays in the atmosphere, and phase lag effects on cosmic ray modulation during a recent solar cycle. Individual items are announced in this issue.

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.

Acoustic instability driven by cosmic-ray streaming

NASA Technical Reports Server (NTRS)

Begelman, Mitchell C.; Zweibel, Ellen G.

1994-01-01

We study the linear stability of compressional waves in a medium through which cosmic rays stream at the Alfven speed due to strong coupling with Alfven waves. Acoustic waves can be driven unstable by the cosmic-ray drift, provided that the streaming speed is sufficiently large compared to the thermal sound speed. Two effects can cause instability: (1) the heating of the thermal gas due to the damping of Alfven waves driven unstable by cosmic-ray streaming; and (2) phase shifts in the cosmic-ray pressure perturbation caused by the combination of cosmic-ray streaming and diffusion. The instability does not depend on the magnitude of the background cosmic-ray pressure gradient, and occurs whether or not cosmic-ray diffusion is important relative to streaming. When the cosmic-ray pressure is small compared to the gas pressure, or cosmic-ray diffusion is strong, the instability manifests itself as a weak overstability of slow magnetosonic waves. Larger cosmic-ray pressure gives rise to new hybrid modes, which can be strongly unstable in the limits of both weak and strong cosmic-ray diffusion and in the presence of thermal conduction. Parts of our analysis parallel earlier work by McKenzie & Webb (which were brought to our attention after this paper was accepted for publication), but our treatment of diffusive effects, thermal conduction, and nonlinearities represent significant extensions. Although the linear growth rate of instability is independent of the background cosmic-ray pressure gradient, the onset of nonlinear eff ects does depend on absolute value of DEL (vector differential operator) P(sub c). At the onset of nonlinearity the fractional amplitude of cosmic-ray pressure perturbations is delta P(sub C)/P(sub C) approximately (kL) (exp -1) much less than 1, where k is the wavenumber and L is the pressure scale height of the unperturbed cosmic rays. We speculate that the instability may lead to a mode of cosmic-ray transport in which plateaus of uniform cosmic-ray pressure are separated by either laminar or turbulent jumps in which the thermal gas is subject to intense heating.

Determination and study of the cosmic-ray composition above 100 TeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinnis, G.; Haines, T.J.; Hoffman, C.M.

1998-11-01

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project was to develop a new technique using ground-based measurements to determine the cosmic-ray composition at energies around 10{sup 15} eV (the knee in the cosmic-ray spectrum). Cosmic rays are high-energy nuclei that continuously bombard the earth. Though cosmic rays were first detected in the 1870s it wasn`t until 1915 that their cosmic origin was established. At present, the authors still do not know the source of cosmic rays. At energies above 50 TeVmore » (1 TeV = 1 trillion electron-volts) they do not know the composition of the cosmic rays. At about 5 PeV (1PeV = 10{sup 15} eV) the cosmic ray spectrum steepens. Knowledge of the composition above and below this point can help determine the origin of cosmic rays.« less

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.

Cancer Risk from Exposure to Galactic Cosmic Rays - Implications for Human Space Exploration

NASA Technical Reports Server (NTRS)

Cucinotta, Francis A.; Durant, marco

2006-01-01

Current space programs are shifting toward planetary exploration, and in particular towards human missions to the moon and Mars. However, space radiation is a major barrier to human exploration of the solar system because the biological effects of high-energy and charge (HZE) ions, which are the main contributors to radiation risks in deep space, are poorly understood. Predictions of the nature and magnitude of the risks posed by space radiation are subject to very large uncertainties. Great efforts have been dedicated worldwide in recent years toward a better understanding of the oncogenic potential of galactic cosmic rays. A review of the new results in this field will be presented here.

Mass ejection by strange star mergers and observational implications.

PubMed

Bauswein, A; Janka, H-T; Oechslin, R; Pagliara, G; Sagert, I; Schaffner-Bielich, J; Hohle, M M; Neuhäuser, R

2009-07-03

We determine the Galactic production rate of strangelets as a canonical input to calculations of the measurable cosmic ray flux of strangelets by performing simulations of strange star mergers and combining the results with recent estimates of stellar binary populations. We find that the flux depends sensitively on the bag constant of the MIT bag model of QCD and disappears for high values of the bag constant and thus more compact strange stars. In the latter case, strange stars could coexist with ordinary neutron stars as they are not converted by the capture of cosmic ray strangelets. An unambiguous detection of an ordinary neutron star would then not rule out the strange matter hypothesis.

The spectrum of galactic electrons with energies between 10 and 900 GeV

NASA Technical Reports Server (NTRS)

Mueller, D.; Meyer, P.

1973-01-01

A cosmic-ray electron detector has been exposed during 1970 in three high-altitude balloon flights from Palestine, Texas. The data analysis is based on results from accelerator calibrations with electrons and pions at SLAC. Discrimination against a contamination of the electron data due to interacting protons has been achieved by statistical methods. The resulting differential energy spectrum of cosmic-ray electrons can be well described by a single power law with spectral index 2.66 plus or minus 0.1 up to energies around 250 GeV. Within the experimental uncertainty, no change in this spectral slope up to almost 1000 GeV can be detected. Some implications of these results are discussed.

Cosmic gamma-rays and cosmic nuclei above 1 TeV

NASA Technical Reports Server (NTRS)

Watson, A. A.

1986-01-01

Work on cosmic gamma rays and cosmic nuclei above I TeV is described and evaluated. The prospect that gamma ray astronomy above I TeV will give new insights into high energy cosmic ray origin within our galaxy is particularly bright.

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,

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…

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…

Cosmic ray propagation and containment

NASA Technical Reports Server (NTRS)

Parker, E. N.

1976-01-01

The cosmic rays, an active gaseous component of the disk of the galaxy, are considered along with their propagation and containment as a part of the general dynamics of the disk. The sources of cosmic rays are a matter of speculation. The disk is inflated by the cosmic ray gas pressure comparable to the magnetic pressure, but the rate of inflation is unknown. The time spent by the individual cosmic ray particles in the disk is inversely proportional to the cosmic ray production rate. It is evident from the decay of Be(1c) that the cosmic rays circulate through a volume of space perhaps ten times the thickness of the gaseous disk, suggesting a magnetic halo extending out approximately 1 kpc from either face of the disk. The cosmic rays may be responsible for the halo by inflating the magnetic fields of the disk. Extension of the fields to 1 kpc would imply a high production rate and short life of cosmic rays in the dense gaseous disk of the galaxy.

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.

Cosmic Gamma-Rays

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Gamma-Ray, Cosmic Ray and Neutrino Tests of Lorentz Invariance and Quantum Gravity Models

NASA Technical Reports Server (NTRS)

Stecker, Floyd

2011-01-01

High-energy astrophysics observations provide the best possibilities to detect a very small violation of Lorentz invariance such as may be related to the structure of space-time near the Planck scale of approximately 10(exp -35) m. I will discuss here the possible signatures of Lorentz invariance violation (LIV) from observations of the spectra, polarization, and timing of gamma-rays from active galactic nuclei and gamma-ray bursts. Other sensitive tests are provided by observations of the spectra of ultrahigh energy cosmic rays and neutrinos. Using the latest data from the Pierre Auger Observatory one can already derive an upper limit of 4.5 x 10(exp -23) to the amount of LIV of at a proton Lorentz factor of approximately 2 x 10(exp 11). This result has fundamental implications for quantum gravity models. I will also discuss the possibilities of using more sensitive space based detection techniques to improve searches for LIV in the future.

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

NASA Technical Reports Server (NTRS)

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

1975-01-01

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

REVIEWS OF TOPICAL PROBLEMS: Astrophysical aspects of cosmic-ray research (first 75 years and outlook for the future)

NASA Astrophysics Data System (ADS)

Ginzburg, Vitalii L.

1988-06-01

(Invited talk at the 20th International Cosmic Ray Conference, Moscow, 2-15 August 1987) The basic topics discussed here are the primary cosmic rays near the earth, cosmic rays in the universe, the origin of cosmic rays, a galactic model with a halo, and some prospects for future research.

The Parker Instability with Cosmic-Ray Streaming

NASA Astrophysics Data System (ADS)

Heintz, Evan; Zweibel, Ellen G.

2018-06-01

Recent studies have found that cosmic-ray transport plays an important role in feedback processes such as star formation and the launching of galactic winds. Although cosmic-ray buoyancy is widely held to be a destabilizing force in galactic disks, the effect of cosmic-ray transport on the stability of stratified systems has yet to be analyzed. We perform a stability analysis of a stratified layer for three different cosmic-ray transport models: decoupled (Classic Parker), coupled with γ c = 4/3 but not streaming (Modified Parker), and finally coupled with streaming at the Alfvén speed. When the compressibility of the cosmic rays is decreased the system becomes much more stable, but the addition of cosmic-ray streaming to the Parker instability severely destabilizes it. Through comparison of these three cases and analysis of the work contributions for the perturbed quantities of each system, we demonstrate that cosmic-ray heating of the gas is responsible for the destabilization of the system. We find that a 3D system is unstable over a larger range of wavelengths than the 2D system. Therefore, the Parker instability with cosmic-ray streaming may play an important role in cosmic-ray feedback.

Searching for New Physics with Ultrahigh Energy Cosmic Rays

NASA Technical Reports Server (NTRS)

Stecker, Floyd W.; Scully, Sean T.

2009-01-01

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 approximately 10 (exp -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 x 10 (exp -23) ,corresponding to an upper limit of 4.5 x 10-23 at a proton Lorentz factor of approximately 2 x 10(exp 11) . This result has fundamental implications for quantum gravity models.

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

NASA Astrophysics Data System (ADS)

Huang, C.-Y.; Pohl, M.

This talk present 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. The results will be compared with calculations made with other propagation models.

Explaining TeV cosmic-ray anisotropies with non-diffusive cosmic-ray propagation

DOE PAGES

Harding, James Patrick; Fryer, Chris Lee; Mendel, Susan Marie

2016-05-11

Constraining the behavior of cosmic ray data observed at Earth requires a precise understanding of how the cosmic rays propagate in the interstellar medium. The interstellar medium is not homogeneous; although turbulent magnetic fields dominate over large scales, small coherent regions of magnetic field exist on scales relevant to particle propagation in the nearby Galaxy. Guided propagation through a coherent field is significantly different from random particle diffusion and could be the explanation of spatial anisotropies in the observed cosmic rays. We present a Monte Carlo code to propagate cosmic particle through realistic magnetic field structures. We discuss the detailsmore » of the model as well as some preliminary studies which indicate that coherent magnetic structures are important effects in local cosmic-ray propagation, increasing the flux of cosmic rays by over two orders of magnitude at anisotropic locations on the sky. Furthermore, the features induced by coherent magnetic structure could be the cause of the observed TeV cosmic-ray anisotropy.« less

EXPLAINING TEV COSMIC-RAY ANISOTROPIES WITH NON-DIFFUSIVE COSMIC-RAY PROPAGATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harding, J. Patrick; Fryer, Chris L.; Mendel, Susan, E-mail: jpharding@lanl.gov, E-mail: fryer@lanl.gov, E-mail: smendel@lanl.gov

2016-05-10

Constraining the behavior of cosmic ray data observed at Earth requires a precise understanding of how the cosmic rays propagate in the interstellar medium. The interstellar medium is not homogeneous; although turbulent magnetic fields dominate over large scales, small coherent regions of magnetic field exist on scales relevant to particle propagation in the nearby Galaxy. Guided propagation through a coherent field is significantly different from random particle diffusion and could be the explanation of spatial anisotropies in the observed cosmic rays. We present a Monte Carlo code to propagate cosmic particle through realistic magnetic field structures. We discuss the detailsmore » of the model as well as some preliminary studies which indicate that coherent magnetic structures are important effects in local cosmic-ray propagation, increasing the flux of cosmic rays by over two orders of magnitude at anisotropic locations on the sky. The features induced by coherent magnetic structure could be the cause of the observed TeV cosmic-ray anisotropy.« less

Galactic cosmic ray composition and energy spectra

NASA Technical Reports Server (NTRS)

Mewaldt, R. A.

1994-01-01

Galactic cosmic ray nuclei represent a significant risk to long-duration spaceflight outside the magnetosphere. We review briefly existing measurements of the composition and energy spectra of heavy cosmic ray nuclei, pointing out which species and energy ranges are most critical to assessing cosmic ray risks for spaceflight. Key data sets are identified and a table of cosmic ray abundances is presented for elements from H to Ni (Z = 1 to 28). Because of the 22-year nature of the solar modulation cycle, data from the approaching 1998 solar minimum is especially important to reducing uncertainties in the cosmic ray radiation hazard. It is recommended that efforts to model this hazard take advantage of approaches that have been developed to model the astrophysical aspects of cosmic rays.

Cosmic-ray propagation and containment

NASA Technical Reports Server (NTRS)

Parker, E. N.

1977-01-01

The cosmic rays are an active gaseous component of the disk of the galaxy, and their propagation and containment is a part of the general dynamics of the disk. The sources of cosmic rays are a matter of speculation. The disk is inflated by the cosmic-ray gas pressure, P, comparable to the magnetic pressure B super 2/ 8 pi, but the rate of inflation is unknown. The time spent by the individual cosmic-ray particles in the disk is inversely proportional to the cosmic-ray production rate and may be anything from 100,000 to more than 10 million years. It is evident from the decay of Be(10) that the cosmic rays circulate through a volume of space perhaps ten times the thickness of the gaseous disk, suggesting a magnetic halo extending out approximately 1 kpc from either face of the disk. The cosmic rays may be responsible for the halo by inflating the magnetic fields of the disk. Extension of the fields to 1 kpc would imply a high production rate and short life of cosmic rays in the dense gaseous disk of the galaxy.

Cosmic Ray Studies with the Fermi Gamma-ray Space Telescope Large Area Telescope

NASA Technical Reports Server (NTRS)

Thompson, David J.; Baldini, L.; Uchiyama, Y.

2012-01-01

The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope provides both direct and indirect measurements of galactic cosmic rays (CR). The LAT high-statistics observations of the 7 GeV - 1 TeV electron plus positron spectrum and limits on spatial anisotropy constrain models for this cosmic-ray component. On a galactic scale, the LAT observations indicate that cosmic-ray sources may be more plentiful in the outer Galaxy than expected or that the scale height of the cosmic-ray diffusive halo is larger than conventional models. Production of cosmic rays in supernova remnants (SNR) is supported by the LAT gamma-ray studies of several of these, both young SNR and those interacting with molecular clouds.

Cosmic Ray Studies with the Fermi Gamma-ray Space Telescope Large Area Telescope

NASA Technical Reports Server (NTRS)

Thompson, D. J.; Baldini, L.; Uchiyama, Y.

2011-01-01

The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope provides both direct and indirect measurements of Galactic cosmic rays (CR). The LAT high-statistics observations of the 7 GeV - 1 TcV electron plus positron spectrum and limits on spatial anisotropy constrain models for this cosmic-ray component. On a Galactic scale, the LAT observations indicate that cosmic-ray sources may be more plentiful in the outer Galaxy than expected or that the scale height of the cosmic-ray diffusive halo is larger than conventional models. Production of cosmic rays in supernova remnants (SNR) is supported by the LAT gamma-ray studies of several of these, both young SNR and those interacting with molecular clouds.

Noble Gases in Dust Returned by Hayabusa — Clues to Asteroid Itokawa's History?

NASA Astrophysics Data System (ADS)

Busemann, H.; Alwmark, C.; Bajt, S.; Böttger, U.; Crowther, S. A.; Gilmour, J. D.; Heitmann, U.; Hübers, H.-W.; Meier, M. M. M.; Pavlov, S.; Schade, U.; Spring, N. H.; Weber, I.

2014-09-01

We discuss the first detection of Xe in asteroid Itokawa dust, the uniformly short exposure of the dust to cosmic rays, possibly resulting from the extremely fast erosion present on small asteroids, and potential implications for Itokawa’s history.

Cosmic Ray Induced Neutron Irradiation

NASA Astrophysics Data System (ADS)

Overholt, Andrew

2011-11-01

After cancer studies performed on flight crews during the 1970s, it was found that cosmic rays produce a signficant flux of thermal neutrons at airplane altitudes. In the case of high energy cosmic rays these biologically threatening neutrons are increased at ground level. Our work models the flux of neutrons produced by high energy cosmic rays, exploring the possibility of biological impact due to extended periods of increase high energy cosmic ray flux.

Cosmic ray experimental observations

NASA Technical Reports Server (NTRS)

Balasubrahmanyan, V. K.; Mcdonald, F. B.

1974-01-01

The current experimental situation in cosmic ray studies is discussed, with special emphasis on the development of new detector systems. Topics covered are the techniques for particle identification, energy measurements, gas Cerenkov counters, magnet spectrometers, ionization spectrometers, track detectors, nuclear emulsions, multiparameter analysis using arrays of detectors, the Goddard ionization spectrometer, charge spectra, relative abundances, isotope composition, antinuclei in cosmic rays, electrons, the measurement of cosmic ray arrival directions, and the prehistory of cosmic rays.

Cosmic Rays Astrophysics: The Discipline, Its Scope, and Its Applications

NASA Technical Reports Server (NTRS)

Barghouty, A. F.

2009-01-01

This slide presentation gives an overview of the discipline surrounding cosmic ray astrophysics. It includes information on recent assertions surrounding cosmic rays, exposure levels, and a short history with specific information on the origin, acceleration, transport, and modulation of cosmic rays.

Atmospheric neutrinos and discovery of neutrino oscillations

PubMed Central

Kajita, Takaaki

2010-01-01

Neutrino oscillation was discovered through studies of neutrinos produced by cosmic-ray interactions in the atmosphere. These neutrinos are called atmospheric neutrinos. They are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron-neutrinos and muon-neutrinos are produced mainly by the decay chain of charged pions to muons to electrons. Atmospheric neutrino experiments observed zenith-angle and energy dependent deficit of muon-neutrino events. Neutrino oscillations between muon-neutrinos and tau-neutrinos explain these data well. Neutrino oscillations imply that neutrinos have small but non-zero masses. The small neutrino masses have profound implications to our understanding of elementary particle physics and the Universe. This article discusses the experimental discovery of neutrino oscillations. PMID:20431258

Connecting blazars with ultrahigh-energy cosmic rays and astrophysical neutrinos

NASA Astrophysics Data System (ADS)

Resconi, E.; Coenders, S.; Padovani, P.; Giommi, P.; Caccianiga, L.

2017-06-01

We present a strong hint of a connection between high-energy γ-ray emitting blazars, very high energy neutrinos, and ultrahigh-energy cosmic rays. We first identify potential hadronic sources by filtering γ-ray emitters in spatial coincidence with the high-energy neutrinos detected by IceCube. The neutrino filtered γ-ray emitters are then correlated with the ultrahigh-energy cosmic rays from the Pierre Auger Observatory and the Telescope Array by scanning in γ-ray flux (Fγ) and angular separation (θ) between sources and cosmic rays. A maximal excess of 80 cosmic rays (42.5 expected) is found at θ ≤ 10° from the neutrino-filtered γ-ray emitters selected from the second hard Fermi-LAT catalogue (2FHL) and for Fγ(>50 GeV) ≥ 1.8 × 10-11 ph cm-2 s-1. The probability for this to happen is 2.4 × 10-5, which translates to ˜2.4 × 10-3 after compensation for all the considered trials. No excess of cosmic rays is instead observed for the complement sample of γ-ray emitters (I.e. not in spatial connection with IceCube neutrinos). A likelihood ratio test comparing the connection between the neutrino-filtered and the complement source samples with the cosmic rays favours a connection between neutrino-filtered emitters and cosmic rays with a probability of ˜1.8 × 10-3 (2.9σ) after compensation for all the considered trials. The neutrino-filtered γ-ray sources that make up the cosmic rays excess are blazars of the high synchrotron peak type. More statistics is needed to further investigate these sources as candidate cosmic ray and neutrino emitters.

A Shifting Shield Provides Protection Against Cosmic Rays

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-12-01

The Sun plays an important role in protecting us from cosmic rays, energetic particles that pelt us from outside our solar system. But can we predict when and how it will provide the most protection, and use this to minimize the damage to both pilotedand roboticspace missions?The Challenge of Cosmic RaysSpacecraft outside of Earths atmosphere and magnetic field are at risk of damage from cosmic rays. [ESA]Galactic cosmic rays are high-energy, charged particles that originate from astrophysical processes like supernovae or even distant active galactic nuclei outside of our solar system.One reason to care about the cosmic rays arriving near Earth is because these particles can provide a significant challenge for space missions traveling above Earths protective atmosphere and magnetic field. Since impacts from cosmic rays can damage human DNA, this risk poses a major barrier to plans for interplanetary travel by crewed spacecraft. And roboticmissions arent safe either: cosmic rays can flip bits, wreaking havoc on spacecraft electronics as well.The magnetic field carried by the solar wind provides a protective shield, deflecting galactic cosmic rays from our solar system. [Walt Feimer/NASA GSFCs Conceptual Image Lab]Shielded by the SunConveniently, we do have some broader protection against galactic cosmic rays: a built-in shield provided by the Sun. The interplanetary magnetic field, which is embedded in the solar wind, deflects low-energy cosmic rays from us at the outer reaches of our solar system, decreasing the flux of these cosmic rays that reach us at Earth.This shield, however, isnt stationary; instead, it moves and changes as the strength and direction of the solar wind moves and changes. This results in a much lower cosmic-ray flux at Earth when solar activity is high i.e., at the peak of the 11-year solar cycle than when solar activity is low. This visible change in local cosmic-ray flux with solar activity is known as solar modulation of the cosmic ray flux at Earth.In a new study, a team of scientists led by Nicola Tomassetti (University of Perugia, Italy) has modeled this solar modulation to better understand the process by which the Suns changing activity influences the cosmic ray flux that reaches us at Earth.Modeling a LagTomassetti and collaborators model uses two solar-activity observables as inputs: the number of sunspots and the tilt angle of the heliospheric current sheet. By modeling basic transport processes in the heliosphere, the authors then track the impact that the changing solar properties have on incoming galactic cosmic rays. In particular, the team explores the time lag between when solar activity changes and when we see the responding change in the cosmic-ray flux.Cosmic-ray flux observations are best fit by the authors model when an 8-month lag is included (red bold line). A comparison model with no lag (black dashed line) is included. [Tomassetti et al. 2017]By comparing their model outputs to the large collection of time-dependent observations of cosmic-ray fluxes, Tomassetti and collaborators show that the best fit to data occurs with an 8-month lag between changing solar activity and local cosmic-ray flux modulation.This is an important outcome for studying the processes that affect the cosmic-ray flux that reaches Earth. But theres an additional intriguing consequence of this result: knowledge of the current solar activity could allow us to predict the modulation that will occur for cosmic rays near Earth an entire 8 months from now! If this model is correct, it brings us one step closer to being able to plan safer space missions for the future.CitationNicola Tomassetti et al 2017 ApJL 849 L32. doi:10.3847/2041-8213/aa9373

Cosmic rays: a review for astrobiologists.

PubMed

Ferrari, Franco; Szuszkiewicz, Ewa

2009-05-01

Cosmic rays represent one of the most fascinating research themes in modern astronomy and physics. Significant progress is being made toward an understanding of the astrophysics of the sources of cosmic rays and the physics of interactions in the ultrahigh-energy range. This is possible because several new experiments in these areas have been initiated. Cosmic rays may hold answers to a great number of fundamental questions, but they also shape our natural habitat and influence the radiation environment of our planet Earth. The importance of the study of cosmic rays has been acknowledged in many fields, including space weather science and astrobiology. Here, we concentrate on the astrobiological aspects of cosmic rays with regard to the enormous amount of new data available, some of which may, in fact, improve our knowledge about the radiation of cosmic origin on Earth. We focus on fluxes arriving at Earth and doses received, and will guide the reader through the wealth of scientific literature on cosmic rays. We have prepared a concise and self-contained source of data and recipes useful for performing interdisciplinary research in cosmic rays and their effects on life on Earth.

The effects of low solar activity upon the cosmic radiation and the interplanetary magnetic field over the past 10,000 years, and implications for the future. (Invited)

NASA Astrophysics Data System (ADS)

McCracken, K. G.; McDonald, F. B.; Beer, J.; Abreu, J.; Steinhilber, F.

2009-12-01

The paleo-cosmic ray records based on the radionuclides 10Be and 14 C show that the Sun has experienced twenty two extended periods of low activity (similar to, or longer than the Maunder Minimum) in the past 10,000 years, and many more periods of reduced activity for 2 or more solar cycles similar to the period 1880-1910. The 10,000 yr record shows that solar activity has exhibited three persistent periodicities that modulate the amplitude of the Hale (11/22 year) cycle. They are the Gleissberg (~85 yr); the de Vries (~208 yr); and the Hallstatt (~2200 yr) periodicities. It is possible that the Sun is entering a somewhat delayed Gleissberg repetition of the 1880-1910 period of reduced activity or a de Vries repetition of the Dalton Minimum of 1800-1820; or a combination of both. The historic record shows that the cosmic ray intensity at sunspot minimum increases substantially during periods of reduced solar activity- during the Dalton minimum it was twice the present-day sunspot minimum intensity at 2GeV/nucleon ; and 10 times greater at 100 MeV/nucleon. The Hale cycle of solar activity continued throughout the Spoerer (1420-1540) and Maunder Minima, and it appears possible that the local interstellar cosmic ray spectrum was occasionally incident on Earth. Using the cosmic ray transport equation to invert the paleo-cosmic ray record shows that the magnetic field was <1nT at Hale minima during the Spoerer Minimum and late in the Maunder Minimum. The Sun was at a minimum of the Hallstatt (2200yr) cycle of activity in the 15th century, and is now on a steadily rising plane of activity. Paleo-cosmic ray evidence suggests that there was a greater production of impulsive solar energetic particle events in the solar cycles of reduced solar activity 1880-1910. Based on these observations, three scenarios for the next several decades will be outlined- (a) a single, deep sunspot minimum followed by an active sun; (b) several cycles of reduced solar activity similar to 1880-1910; and (c) a “Grand Minimum” with one or more 11 year cycles of very low activity similar to the Dalton Minimum.

CosmicSIG science and plans

NASA Astrophysics Data System (ADS)

Olinto, Angela V.

2014-03-01

Recent activities of the Cosmic Ray Science Interest Group (CosmicSIG) of the Physics of the Cosmos PAG will be reviewed. CosmicSIG was formed to provide an assessment to NASA HQ and the PCOS program office of the status of current and future missions in the area of cosmic-ray astrophysics. CosmicSIG also strives to act as a focal point and forum for the cosmic ray community.

Primary gamma rays. [resulting from cosmic ray interaction with interstellar matter

NASA Technical Reports Server (NTRS)

Fichtel, C. E.

1974-01-01

Within this galaxy, cosmic rays reveal their presence in interstellar space and probably in source regions by their interactions with interstellar matter which lead to gamma rays with a very characteristic energy spectrum. From the study of the intensity of the high energy gamma radiation as a function of galactic longitude, it is already clear that cosmic rays are almost certainly not uniformly distributed in the galaxy and are not concentrated in the center of the galaxy. The galactic cosmic rays appear to be tied to galactic structural features, presumably by the galactic magnetic fields which are in turn held by the matter in the arm segments and the clouds. On the extragalactic scale, it is now possible to say that cosmic rays are not universal at the density seen near the earth. The diffuse celestial gamma ray spectrum that is observed presents the interesting possibility of cosmological studies and possible evidence for a residual universal cosmic ray density, which is much lower than the present galactic cosmic ray density.

Supernova Origin of Cosmic Rays from a γ-Ray Signal in the Constellation III Region of the Large Magellanic Cloud.

PubMed

Neronov, Andrii

2017-11-10

Cosmic rays could be produced via shock acceleration powered by supernovae. The supernova hypothesis implies that each supernova injects, on average, some 10^{50}  erg in cosmic rays, while the shock acceleration model predicts a power law cosmic ray spectrum with the slope close to 2. Verification of these predictions requires measurement of the spectrum and power of cosmic ray injection from supernova population(s). Here, we obtain such measurements based on γ-ray observation of the Constellation III region of the Large Magellanic Cloud. We show that γ-ray emission from this young star formation region originates from cosmic rays injected by approximately two thousand supernovae, rather than by a massive star wind powered by a superbubble predating supernova activity. Cosmic ray injection power is found to be (1.1_{-0.2}^{+0.5})×10^{50}  erg/supernova (for the estimated interstellar medium density 0.3  cm^{-3}). The spectrum is a power law with slope 2.09_{-0.07}^{+0.06}. This agrees with the model of particle acceleration at supernova shocks and provides a direct proof of the supernova origin of cosmic rays.

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

NASA Astrophysics Data System (ADS)

Gelfand, Joseph; Slane, Patrick; Hughes, John; Temim, Tea; Castro, Daniel; Rakowski, Cara

Supernova remnant are believed to be the dominant source of cosmic rays protons below the "knee" in the energy spectrum. However, relatively few supernova remnants have been identified as efficient producers of cosmic ray protons. In this talk, I will present evidence that the production of cosmic ray protons is required to explain the broadband non-thermal spectrum of supernova remnant Kes 17 (SNR G304.6+0.1). 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 and similar sources are important for understanding how cosmic rays are accelerated in supernova remnants.

Cosmic Ray Helium Intensities over the Solar Cycle from ACE

NASA Technical Reports Server (NTRS)

DeNolfo, G. A.; Yanasak, N. E.; Binns, W. R.; Cohen, C. M. S.; Cummings, A. C.; Davis, A. J.; George, J. S.; Hink. P. L.; Israel, M. H.; Lave, K.;

Terrestrial Effects of High Energy Cosmic Rays

NASA Astrophysics Data System (ADS)

Atri, Dimitra

2011-01-01

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

Long term variability of the cosmic ray intensity

NASA Technical Reports Server (NTRS)

Bhat, C. L.; Houston, B. P.; Mayer, C. J.; Wolfendale, A. W.

1985-01-01

In a previous paper Bhat, et al., assess the evidence for the continuing acceleration of cosmic rays in the Loop I supernova remnant. The enhanced gamma-ray emission is found consistent with the Blandford and Cowie model for particle acceleration at the remnant shock wave. The contributions of other supernovae remnants to the galactic cosmic ray energy density are now considered, paying anisotropy of cosmic rays accelerated by local supernovae ( 100 pc). The results are compared with geophysical data on the fluctuations in the cosmic ray intensity over the previous one billion years.

Difference between even and odd 11-year cycles in cosmic ray intensity

NASA Technical Reports Server (NTRS)

Otaola, J. A.; Perez-Enriquez, R.; Valdes-Galicia, J. F.

1985-01-01

Cosmic ray data for the period 1946-1984 are used to determine the run of the cosmic ray intensity over three complete solar cycles. The analysis shows a tendency towards a regular alternation of cosmic ray intensity cycles with double and single maxima. Whereas a saddle-like shape is characteristic of even cycles, odd cycles are characterized by a peak-like shape. The importance of this behavior is discussed in terms of different processes influencing cosmic ray transport in the heliosphere.

The basis for cosmic ray feedback: Written on the wind

PubMed Central

Zweibel, Ellen G.

2017-01-01

Star formation and supermassive black hole growth in galaxies appear to be self-limiting. The mechanisms for self-regulation are known as feedback. Cosmic rays, the relativistic particle component of interstellar and intergalactic plasma, are among the agents of feedback. Because cosmic rays are virtually collisionless in the plasma environments of interest, their interaction with the ambient medium is primarily mediated by large scale magnetic fields and kinetic scale plasma waves. Because kinetic scales are much smaller than global scales, this interaction is most conveniently described by fluid models. In this paper, I discuss the kinetic theory and the classical theory of cosmic ray hydrodynamics (CCRH) which follows from assuming cosmic rays interact only with self-excited waves. I generalize CCRH to generalized cosmic ray hydrodynamics, which accommodates interactions with extrinsic turbulence, present examples of cosmic ray feedback, and assess where progress is needed. PMID:28579734

The basis for cosmic ray feedback: Written on the wind

NASA Astrophysics Data System (ADS)

Zweibel, Ellen G.

2017-05-01

Star formation and supermassive black hole growth in galaxies appear to be self-limiting. The mechanisms for self-regulation are known as feedback. Cosmic rays, the relativistic particle component of interstellar and intergalactic plasma, are among the agents of feedback. Because cosmic rays are virtually collisionless in the plasma environments of interest, their interaction with the ambient medium is primarily mediated by large scale magnetic fields and kinetic scale plasma waves. Because kinetic scales are much smaller than global scales, this interaction is most conveniently described by fluid models. In this paper, I discuss the kinetic theory and the classical theory of cosmic ray hydrodynamics (CCRH) which follows from assuming cosmic rays interact only with self-excited waves. I generalize CCRH to generalized cosmic ray hydrodynamics, which accommodates interactions with extrinsic turbulence, present examples of cosmic ray feedback, and assess where progress is needed.

The basis for cosmic ray feedback: Written on the wind.

PubMed

Zweibel, Ellen G

2017-05-01

Star formation and supermassive black hole growth in galaxies appear to be self-limiting. The mechanisms for self-regulation are known as feedback . Cosmic rays, the relativistic particle component of interstellar and intergalactic plasma, are among the agents of feedback. Because cosmic rays are virtually collisionless in the plasma environments of interest, their interaction with the ambient medium is primarily mediated by large scale magnetic fields and kinetic scale plasma waves. Because kinetic scales are much smaller than global scales, this interaction is most conveniently described by fluid models. In this paper, I discuss the kinetic theory and the classical theory of cosmic ray hydrodynamics (CCRH) which follows from assuming cosmic rays interact only with self-excited waves. I generalize CCRH to generalized cosmic ray hydrodynamics, which accommodates interactions with extrinsic turbulence, present examples of cosmic ray feedback, and assess where progress is needed.

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.

Cosmic ray interactions in the ground: Temporal variations in cosmic ray intensities and geophysical studies

NASA Technical Reports Server (NTRS)

Lal, D.

1986-01-01

Temporal variations in cosmic ray intensity have been deduced from observations of products of interactions of cosmic ray particles in the Moon, meteorites, and the Earth. Of particular interest is a comparison between the information based on Earth and that based on other samples. Differences are expected at least due to: (1) differences in the extent of cosmic ray modulation, and (2) changes in the geomagnetic dipole field. Any information on the global changes in the terrestrial cosmic ray intensity is therefore of importance. In this paper a possible technique for detecting changes in cosmic ray intensity is presented. The method involves human intervention and is applicable for the past 10,000 yrs. Studies of changes over longer periods of time are possible if supplementary data on age and history of the sample are available using other methods. Also discussed are the possibilities of studying certain geophysical processes, e.g., erosion, weathering, tectonic events based on studies of certain cosmic ray-produced isotopes for the past several million years.

Observation of New Properties of Secondary Cosmic Rays Lithium, Beryllium, and Boron by the Alpha Magnetic Spectrometer on the International Space Station.

PubMed

Aguilar, M; Ali Cavasonza, L; Ambrosi, G; Arruda, L; Attig, N; Aupetit, S; Azzarello, P; Bachlechner, A; Barao, F; Barrau, A; Barrin, L; Bartoloni, A; Basara, L; Başeğmez-du Pree, S; Battarbee, M; Battiston, R; Becker, U; Behlmann, M; Beischer, B; Berdugo, J; Bertucci, B; Bindel, K F; Bindi, V; de Boer, W; Bollweg, K; Bonnivard, V; Borgia, B; Boschini, M J; Bourquin, M; Bueno, E F; Burger, J; Burger, W J; Cadoux, F; Cai, X D; Capell, M; Caroff, S; Casaus, J; Castellini, G; Cervelli, F; Chae, M J; Chang, Y H; Chen, A I; Chen, G M; Chen, H S; Cheng, L; Chou, H Y; Choumilov, E; Choutko, V; Chung, C H; Clark, C; Clavero, R; Coignet, G; Consolandi, C; Contin, A; Corti, C; Creus, W; Crispoltoni, M; Cui, Z; Dadzie, K; Dai, Y M; Datta, A; Delgado, C; Della Torre, S; Demirköz, M B; Derome, L; Di Falco, S; Dimiccoli, F; Díaz, C; von Doetinchem, P; Dong, F; Donnini, F; Duranti, M; D'Urso, D; Egorov, A; Eline, A; Eronen, T; Feng, J; Fiandrini, E; Fisher, P; Formato, V; Galaktionov, Y; Gallucci, G; García-López, R J; Gargiulo, C; Gast, H; Gebauer, I; Gervasi, M; Ghelfi, A; Giovacchini, F; Gómez-Coral, D M; Gong, J; Goy, C; Grabski, V; Grandi, D; Graziani, M; Guo, K H; Haino, S; Han, K C; He, Z H; Heil, M; Hsieh, T H; Huang, H; Huang, Z C; Huh, C; Incagli, M; Ionica, M; Jang, W Y; Jia, Yi; Jinchi, H; Kang, S C; Kanishev, K; Khiali, B; Kim, G N; Kim, K S; Kirn, Th; Konak, C; Kounina, O; Kounine, A; Koutsenko, V; Kulemzin, A; La Vacca, G; Laudi, E; Laurenti, G; Lazzizzera, I; Lebedev, A; Lee, H T; Lee, S C; Leluc, C; Li, H S; Li, J Q; Li, Q; Li, T X; Li, Y; Li, Z H; Li, Z Y; Lim, S; Lin, C H; Lipari, P; Lippert, T; Liu, D; Liu, Hu; Lordello, V D; Lu, S Q; Lu, Y S; Luebelsmeyer, K; Luo, F; Luo, J Z; Lyu, S S; Machate, F; Mañá, C; Marín, J; Martin, T; Martínez, G; Masi, N; Maurin, D; Menchaca-Rocha, A; Meng, Q; Mikuni, V M; Mo, D C; Mott, P; Nelson, T; Ni, J Q; Nikonov, N; Nozzoli, F; Oliva, A; Orcinha, M; Palermo, M; Palmonari, F; Palomares, C; Paniccia, M; Pauluzzi, M; Pensotti, S; Perrina, C; Phan, H D; Picot-Clemente, N; Pilo, F; Pizzolotto, C; Plyaskin, V; Pohl, M; Poireau, V; Quadrani, L; Qi, X M; Qin, X; Qu, Z Y; Räihä, T; Rancoita, P G; Rapin, D; Ricol, J S; Rosier-Lees, S; Rozhkov, A; Rozza, D; Sagdeev, R; Schael, S; Schmidt, S M; Schulz von Dratzig, A; Schwering, G; Seo, E S; Shan, B S; Shi, J Y; Siedenburg, T; Son, D; Song, J W; Tacconi, M; Tang, X W; Tang, Z C; Tescaro, D; Ting, Samuel C C; Ting, S M; Tomassetti, N; Torsti, J; Türkoğlu, C; Urban, T; Vagelli, V; Valente, E; Valtonen, E; Vázquez Acosta, M; Vecchi, M; Velasco, M; Vialle, J P; Vitale, V; Wang, L Q; Wang, N H; Wang, Q L; Wang, X; Wang, X Q; Wang, Z X; Wei, C C; Weng, Z L; Whitman, K; Wu, H; Wu, X; Xiong, R Q; Xu, W; Yan, Q; Yang, J; Yang, M; Yang, Y; Yi, H; Yu, Y J; Yu, Z Q; Zannoni, M; Zeissler, S; Zhang, C; Zhang, F; Zhang, J; Zhang, J H; Zhang, S W; Zhang, Z; Zheng, Z M; Zhuang, H L; Zhukov, V; Zichichi, A; Zimmermann, N; Zuccon, P

2018-01-12

We report on the observation of new properties of secondary cosmic rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary cosmic rays has also been observed in the AMS measurement of primary cosmic rays He, C, and O but the rigidity dependences of primary cosmic rays and of secondary cosmic rays are distinctly different. In particular, above 200 GV, the secondary cosmic rays harden more than the primary cosmic rays.

Observation of New Properties of Secondary Cosmic Rays Lithium, Beryllium, and Boron by the Alpha Magnetic Spectrometer on the International Space Station

NASA Astrophysics Data System (ADS)

Aguilar, M.; Ali Cavasonza, L.; Ambrosi, G.; Arruda, L.; Attig, N.; Aupetit, S.; Azzarello, P.; Bachlechner, A.; Barao, F.; Barrau, A.; Barrin, L.; Bartoloni, A.; Basara, L.; Başeǧmez-du Pree, S.; Battarbee, M.; Battiston, R.; Becker, U.; Behlmann, M.; Beischer, B.; Berdugo, J.; Bertucci, B.; Bindel, K. F.; Bindi, V.; de Boer, W.; Bollweg, K.; Bonnivard, V.; Borgia, B.; Boschini, M. J.; Bourquin, M.; Bueno, E. F.; Burger, J.; Burger, W. J.; Cadoux, F.; Cai, X. D.; Capell, M.; Caroff, S.; Casaus, J.; Castellini, G.; Cervelli, F.; Chae, M. J.; Chang, Y. H.; Chen, A. I.; Chen, G. M.; Chen, H. S.; Cheng, L.; Chou, H. Y.; Choumilov, E.; Choutko, V.; Chung, C. H.; Clark, C.; Clavero, R.; Coignet, G.; Consolandi, C.; Contin, A.; Corti, C.; Creus, W.; Crispoltoni, M.; Cui, Z.; Dadzie, K.; Dai, Y. M.; Datta, A.; Delgado, C.; Della Torre, S.; Demirköz, M. B.; Derome, L.; Di Falco, S.; Dimiccoli, F.; Díaz, C.; von Doetinchem, P.; Dong, F.; Donnini, F.; Duranti, M.; D'Urso, D.; Egorov, A.; Eline, A.; Eronen, T.; Feng, J.; Fiandrini, E.; Fisher, P.; Formato, V.; Galaktionov, Y.; Gallucci, G.; García-López, R. J.; Gargiulo, C.; Gast, H.; Gebauer, I.; Gervasi, M.; Ghelfi, A.; Giovacchini, F.; Gómez-Coral, D. M.; Gong, J.; Goy, C.; Grabski, V.; Grandi, D.; Graziani, M.; Guo, K. H.; Haino, S.; Han, K. C.; He, Z. H.; Heil, M.; Hsieh, T. H.; Huang, H.; Huang, Z. C.; Huh, C.; Incagli, M.; Ionica, M.; Jang, W. Y.; Jia, Yi; Jinchi, H.; Kang, S. C.; Kanishev, K.; Khiali, B.; Kim, G. N.; Kim, K. S.; Kirn, Th.; Konak, C.; Kounina, O.; Kounine, A.; Koutsenko, V.; Kulemzin, A.; La Vacca, G.; Laudi, E.; Laurenti, G.; Lazzizzera, I.; Lebedev, A.; Lee, H. T.; Lee, S. C.; Leluc, C.; Li, H. S.; Li, J. Q.; Li, Q.; Li, T. X.; Li, Y.; Li, Z. H.; Li, Z. Y.; Lim, S.; Lin, C. H.; Lipari, P.; Lippert, T.; Liu, D.; Liu, Hu; Lordello, V. D.; Lu, S. Q.; Lu, Y. S.; Luebelsmeyer, K.; Luo, F.; Luo, J. Z.; Lyu, S. S.; Machate, F.; Mañá, C.; Marín, J.; Martin, T.; Martínez, G.; Masi, N.; Maurin, D.; Menchaca-Rocha, A.; Meng, Q.; Mikuni, V. M.; Mo, D. C.; Mott, P.; Nelson, T.; Ni, J. Q.; Nikonov, N.; Nozzoli, F.; Oliva, A.; Orcinha, M.; Palermo, M.; Palmonari, F.; Palomares, C.; Paniccia, M.; Pauluzzi, M.; Pensotti, S.; Perrina, C.; Phan, H. D.; Picot-Clemente, N.; Pilo, F.; Pizzolotto, C.; Plyaskin, V.; Pohl, M.; Poireau, V.; Quadrani, L.; Qi, X. M.; Qin, X.; Qu, Z. Y.; Räihä, T.; Rancoita, P. G.; Rapin, D.; Ricol, J. S.; Rosier-Lees, S.; Rozhkov, A.; Rozza, D.; Sagdeev, R.; Schael, S.; Schmidt, S. M.; Schulz von Dratzig, A.; Schwering, G.; Seo, E. S.; Shan, B. S.; Shi, J. Y.; Siedenburg, T.; Son, D.; Song, J. W.; Tacconi, M.; Tang, X. W.; Tang, Z. C.; Tescaro, D.; Ting, Samuel C. C.; Ting, S. M.; Tomassetti, N.; Torsti, J.; Türkoǧlu, C.; Urban, T.; Vagelli, V.; Valente, E.; Valtonen, E.; Vázquez Acosta, M.; Vecchi, M.; Velasco, M.; Vialle, J. P.; Vitale, V.; Wang, L. Q.; Wang, N. H.; Wang, Q. L.; Wang, X.; Wang, X. Q.; Wang, Z. X.; Wei, C. C.; Weng, Z. L.; Whitman, K.; Wu, H.; Wu, X.; Xiong, R. Q.; Xu, W.; Yan, Q.; Yang, J.; Yang, M.; Yang, Y.; Yi, H.; Yu, Y. J.; Yu, Z. Q.; Zannoni, M.; Zeissler, S.; Zhang, C.; Zhang, F.; Zhang, J.; Zhang, J. H.; Zhang, S. W.; Zhang, Z.; Zheng, Z. M.; Zhuang, H. L.; Zhukov, V.; Zichichi, A.; Zimmermann, N.; Zuccon, P.; AMS Collaboration

2018-01-01

We report on the observation of new properties of secondary cosmic rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4 ×106 nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li /Be flux ratio of 2.0 ±0.1 . The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary cosmic rays has also been observed in the AMS measurement of primary cosmic rays He, C, and O but the rigidity dependences of primary cosmic rays and of secondary cosmic rays are distinctly different. In particular, above 200 GV, the secondary cosmic rays harden more than the primary cosmic rays.

Implications of the IRAS data for galactic gamma ray astronomy and EGRET

NASA Technical Reports Server (NTRS)

Stecker, Floyd W.

1990-01-01

Using the results of gamma-ray, millimeter wave and far surveys of the galaxy, logically consistent picture of the large scale distribution of galactic gas and cosmic rays was derived, tied to the overall processes of stellar birth and destruction on a galactic scale. Using the results of the IRAS far-infrared survey of te galaxy, the large scale radial distributions of galactic far-infrared emission independently was obtained for both the Northern and Southern Hemisphere sides of the Galaxy. The dominant feature in these distributions was found to be a broad peak coincident with the 5 kpc molecular gas cloud ring. Evidence was found for spiral arm features. Strong correlations are evident between the large scale galactic distributions of far-infrared emission, gamma-ray emission and total CO emission. There is particularly tight correlation between the distribution of warm molecular clouds and far-infrared emission on a galactic scale. The 5 kpc ring was evident in existing galactic gamma-ray data. The extent to which the more detailed spiral arm features are evident in the more resolved EGRET (Energetic Gamma-Ray Experimental Telescope) data will help to determine more precisely the propagation characteristics of cosmic rays.

A physical model of the infrared-to-radio correlation in galaxies

NASA Technical Reports Server (NTRS)

Helou, G.; Bicay, M. D.

1993-01-01

We explore the implications of the IR-radio correlation in star-forming galaxies, using a simple physical model constrained by the constant global ratio q of IR to radio emission and by the radial falloff of this ratio in disks of galaxies. The modeling takes into account the diffusion, radiative decay, and escape of cosmic-ray electrons responsible for the synchrotron emission, and the full range of optical depths to dust-heating photons. We introduce two assumptions: that dust-heating photons and radio-emitting cosmic-ray electrons are created in constant proportion to each other as part of the star formation activity, and that gas and magnetic field are well coupled locally, expressed as B proportional to n exp beta, with beta between 1/3 and 2/3. We conclude that disk galaxies would maintain the observed constant ratio q under these assumptions if the disk scale height h(0) and the escape scale length l(esc) for cosmic-ray electrons followed a relation of the form l(esc) proportional to h(0) exp 1/2; the IR-to-radio ratio will then depend very weakly on interstellar density, and, therefore, on magnetic field strength or mean optical depth.

Nineteenth International Cosmic Ray Conference. Conference Papers: Invited Rapporteur, Highlight, Miscellaneous, Volume 9

NASA Technical Reports Server (NTRS)

Jones, F. C. (Compiler)

1986-01-01

Invited talks, rapporteur talks, and highlight talks are included. Topics of the invited and highlight talks include astrophysical jets, gamma-ray line astronomy, cosmic rays and gamma rays in astrophysics, the early universe, elementary particle physics, solar flares and acceleration of energetic particles, cosmogenic nuclei, extragalactic astronomy, composition of solar flare particles, very high energy gamma ray sources, gamma-ray bursts, shock acceleration in the solar wind, cosmic rays in deep underground detectors, spectrum of cosmic rays at 10 to the 19th power eV, and nucleus-nucleus interactions.

Mars' surface radiation environment measured with the Mars Science Laboratory's Curiosity rover.

PubMed

Hassler, Donald M; Zeitlin, Cary; Wimmer-Schweingruber, Robert F; Ehresmann, Bent; Rafkin, Scot; Eigenbrode, Jennifer L; Brinza, David E; Weigle, Gerald; Böttcher, Stephan; Böhm, Eckart; Burmeister, Soenke; Guo, Jingnan; Köhler, Jan; Martin, Cesar; Reitz, Guenther; Cucinotta, Francis A; Kim, Myung-Hee; Grinspoon, David; Bullock, Mark A; Posner, Arik; Gómez-Elvira, Javier; Vasavada, Ashwin; Grotzinger, John P

2014-01-24

The Radiation Assessment Detector (RAD) on the Mars Science Laboratory's Curiosity rover began making detailed measurements of the cosmic ray and energetic particle radiation environment on the surface of Mars on 7 August 2012. We report and discuss measurements of the absorbed dose and dose equivalent from galactic cosmic rays and solar energetic particles on the martian surface for ~300 days of observations during the current solar maximum. These measurements provide insight into the radiation hazards associated with a human mission to the surface of Mars and provide an anchor point with which to model the subsurface radiation environment, with implications for microbial survival times of any possible extant or past life, as well as for the preservation of potential organic biosignatures of the ancient martian environment.

Next Steps Forward in Understanding Martian Surface and Subsurface Chemistry

NASA Astrophysics Data System (ADS)

Carrier, Brandi L.

2017-09-01

The presence of oxidants such as hydrogen peroxide (H2O2) and perchlorate (ClO4-), which have been detected on Mars, has significant implications for chemistry and astrobiology. These oxidants can increase the reactivity of the Martian soil, accelerate the decomposition of organic molecules, and depress the freezing point of water. The study by Crandall et al. "Can Perchlorates be Transformed to Hydrogen Peroxide Products by Cosmic Rays on the Martian Surface" reveals a new formation mechanism by which hydrogen peroxide and other potential oxidants can be generated via irradiation of perchlorate by cosmic rays. This study represents an important next step in developing a full understanding of Martian surface and subsurface chemistry, particularly with respect to degradation of organic molecules and potential biosignatures.

Cosmic Ray investigations on peak Musala in Bulgaria: A memoir

NASA Astrophysics Data System (ADS)

Kavlakov, S.

2009-11-01

A very brief historical description of the Bulgarian Cosmic Ray investigations, in the Cosmic Ray Station on peak Musala (2925 m.a.s.l.) is presented. Difficulties of the high mountain measurements that time are mentioned, together with the hard emotional and successful work done by a small staff of young Bulgarian cosmic ray scientists.

Transient cosmic ray increase associated with a geomagnetic storm

NASA Technical Reports Server (NTRS)

Kudo, S.; Wada, M.; Tanskanen, P.; Kodama, M.

1985-01-01

On the basis of worldwide network data of cosmic ray nucleonic components, the transient cosmic ray increase due to the depression of cosmic ray cutoff rigidity during a severe geomagnetic storm was investigated in terms of the longitudinal dependence. Multiple correlation analysis among isotropic and diurnal terms of cosmic ray intensity variations and Dst term of the geomagnetic field is applied to each of various station's data. It is shown that the amplitude of the transient cosmic ray increase associated with Dst depends on the local time of the station, and that its maximum phase is found in the evening sector. This fact is consistent with the theoretical estimation based on the azimuthally asymmetric ring current model for the magnetic DS field.

Ultra high energy gamma rays, cosmic rays and neutrinos from accreting degenerate stars

NASA Technical Reports Server (NTRS)

Brecher, K.; Chanmugam, G.

1985-01-01

Super-Eddington accretion for a recently proposed unipolar induction model of cosmic ray acceleration in accreting binary star systems containing magnetic white dwarfs or neutron stars is considered. For sufficiently high accretion rates and low magnetic fields, the model can account for: (1) acceleration of cosmic ray nuclei up to energies of 10 to the 19th power eV; (2) production of more or less normal solar cosmic ray composition; (3) the bulk of cosmic rays observed with energies above 1 TeV, and probably even down to somewhat lower energies as well; and (4) possibly the observed antiproton cosmic ray flux. It can also account for the high ultra high energy (UHE) gamma ray flux observed from several accreting binary systems (including Cygnus X-3), while allowing the possibility of an even higher neutrino flux from these sources, with L sub nu/L sub gamma is approximately 100.

Lightning Initiation and Propagation

DTIC Science & Technology

2009-08-22

ray (gamma ray ) and multiple-station (>24) cosmic - ray - muon detection network (TERA) pl:esently in place. Upgrade TERA with LaBr3 detectors to...DATES COVERED 4. TITLE AND SUBTITLE Lightning Initistion and Propagation Including the Role of X- Rays , Gamma Rays , and Cosmic Rays 5a... rays , gamma rays , and cosmic rays in the initiation and propagation of lightning and in the phenomenology of thunderclouds. The experimental

Cosmic ray transport in astrophysical plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schlickeiser, R.

2015-09-15

Since the development of satellite space technology about 50 years ago the solar heliosphere is explored almost routinely by several spacecrafts carrying detectors for measuring the properties of the interplanetary medium including energetic charged particles (cosmic rays), solar wind particle densities, and electromagnetic fields. In 2012, the Voyager 1 spacecraft has even left what could be described as the heliospheric modulation region, as indicated by the sudden disappearance of low energy heliospheric cosmic ray particles. With the available in-situ measurements of interplanetary turbulent electromagnetic fields and of the momentum spectra of different cosmic ray species in different interplanetary environments, themore » heliosphere is the best cosmic laboratory to test our understanding of the transport and acceleration of cosmic rays in space plasmas. I review both the historical development and the current state of various cosmic ray transport equations. Similarities and differences to transport theories for terrestrial fusion plasmas are highlighted. Any progress in cosmic ray transport requires a detailed understanding of the electromagnetic turbulence that is responsible for the scattering and acceleration of these particles.« less

Re-evaluation of cosmic ray cutoff terminology

NASA Technical Reports Server (NTRS)

Cooke, D. J.; Humble, J. E.; Shea, M. A.; Smart, D. F.; Lund, N.; Rasmussen, I. L.; Byrnak, B.; Goret, P.; Petrou, N.

1985-01-01

The study of cosmic ray access to locations inside the geomagnetic field has evolved in a manner that has led to some misunderstanding and misapplication of the terminology originally developed to describe particle access. This paper presents what is believed to be a useful set of definitions for cosmic ray cutoff terminology for use in theoretical and experimental cosmic ray studies.

A Demonstration Device for Cosmic Rays Telescopes

ERIC Educational Resources Information Center

Esposito, Salvatore

2018-01-01

We describe a hands-on accurate demonstrator for cosmic rays realized by six high school students. The main aim is to show the relevance and the functioning of the principal parts of a cosmic ray telescope (muon detector), with the help of two large sized wooden artefacts. The first one points out how cosmic rays can be tracked in a muon…

Influence of the backreaction of streaming cosmic rays on magnetic field generation and thermal instability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nekrasov, Anatoly K.; Shadmehri, Mohsen, E-mail: anekrasov@ifz.ru, E-mail: nekrasov.anatoly@gmail.com, E-mail: m.shadmehri@gu.ac.ir

2014-06-10

Using a multifluid approach, we investigate streaming and thermal instabilities of the electron-ion plasma with homogeneous cold cosmic rays propagating perpendicular to the background magnetic field. Perturbations are also considered to be across the magnetic field. The backreaction of cosmic rays resulting in strong streaming instabilities is taken into account. It is shown that, for sufficiently short wavelength perturbations, the growth rates can exceed the growth rate of cosmic-ray streaming instability along the magnetic field, found by Nekrasov and Shadmehri, which is in turn considerably larger than the growth rate of the Bell instability. The thermal instability is shown notmore » to be subject to the action of cosmic rays in the model under consideration. The dispersion relation for the thermal instability has been derived, which includes sound velocities of plasma and cosmic rays and Alfvén and cosmic-ray streaming velocities. The relation between these parameters determines the kind of thermal instability ranging from the Parker to the Field instabilities. The results obtained can be useful for a more detailed investigation of electron-ion astrophysical objects, such as supernova remnant shocks, galaxy clusters, and others, including the dynamics of streaming cosmic rays.« less

Results from Two Low Mass Cosmic Ray Experiments Flown on the HASP Platform

NASA Astrophysics Data System (ADS)

Fontenot, R. S.; Hollerman, W. A.; Tittsworth, M.; Fountain, W.; Christl, M.; Thibodaux, C.; Broussard, B. M.

2009-03-01

The High Altitude Student Payload (HASP) program is designed to carry twelve student experiments to an altitude of about 123,000 feet (˜37 km). In 2006, students participated in the first HASP launch to measure cosmic ray intensities using traditional film and absorbers. This 10 kg payload flew from Fort Sumner, New Mexico in early September 2006 and was a great success. In 2007, students participated in the second HASP flight to measure the cosmic ray intensity and flux using a traditional film and absorber stack with five layers of optically stimulated luminescent (OSL) dosimeters. Results from both payloads showed that the cosmic ray flux decreases as a function of payload depth. As the cosmic rays go through the stack, they deposit their energy in the payload material. Determining cosmic ray flux is a tedious task. It involves digitizing the film and determining the real cosmic ray density. For the first HASP payload, students used a program known as GlobalLab to count particles. For the second payload, the students decided to use a combination of the GREYCStoration image regularization algorithm, an embossing filter, and a depth-merging filter to reconstruct the paths of the cosmic rays.

The responses of three kinds of passive dosimeters to secondary cosmic rays in the lower atmosphere.

PubMed

Yang, Zhen; Chen, Bo; Zhuo, Weihai; Fan, Dunhuang; Zhao, Chao; Zhang, Yu

2015-12-01

For accurate measurements of the secondary cosmic rays by using passive dosimeters, the relative responses of the thermoluminescence dosimeter (TLD), optically stimulated luminescence (OSL) dosimeter, and radiophotoluminescent glass dosimeter (RPLGD) were studied. The cosmic-ray shower generator was used to simulate the secondary cosmic rays at the sea level. Monte Carlo simulations were performed to calculate the air kerma and absorbed doses in each kind of dosimeter. The results showed that compared with their responses to gamma rays of (137)Cs, the relative responses of the TLD, OSL, and RPLGD were 0.786, 0.707, and 0.735 to the hard component of cosmic rays, respectively, and the values were 0.904, 0.838, and 0.857 to the soft component of cosmic rays, respectively. To verify the simulations results, an in situ measurement with the three kinds of dosimeters was performed at the same place. The results indicated that the secondary cosmic rays monitored with the three kinds of dosimeters were well consistent with each other provided their relative responses were taken into account.

The responses of three kinds of passive dosimeters to secondary cosmic rays in the lower atmosphere

NASA Astrophysics Data System (ADS)

Yang, Zhen; Chen, Bo; Zhuo, Weihai; Fan, Dunhuang; Zhao, Chao; Zhang, Yu

2015-12-01

For accurate measurements of the secondary cosmic rays by using passive dosimeters, the relative responses of the thermoluminescence dosimeter (TLD), optically stimulated luminescence (OSL) dosimeter, and radiophotoluminescent glass dosimeter (RPLGD) were studied. The cosmic-ray shower generator was used to simulate the secondary cosmic rays at the sea level. Monte Carlo simulations were performed to calculate the air kerma and absorbed doses in each kind of dosimeter. The results showed that compared with their responses to gamma rays of 137Cs, the relative responses of the TLD, OSL, and RPLGD were 0.786, 0.707, and 0.735 to the hard component of cosmic rays, respectively, and the values were 0.904, 0.838, and 0.857 to the soft component of cosmic rays, respectively. To verify the simulations results, an in situ measurement with the three kinds of dosimeters was performed at the same place. The results indicated that the secondary cosmic rays monitored with the three kinds of dosimeters were well consistent with each other provided their relative responses were taken into account.

Diffuse Galactic gamma rays from shock-accelerated cosmic rays.

PubMed

Dermer, Charles D

2012-08-31

A shock-accelerated particle flux is proportional to p(-s), where p is the particle momentum, follows from simple theoretical considerations of cosmic-ray acceleration at nonrelativistic shocks followed by rigidity-dependent escape into the Galactic halo. A flux of shock-accelerated cosmic-ray protons with s≈2.8 provides an adequate fit to the Fermi Large Area Telescope γ-ray emission spectra of high-latitude and molecular cloud gas when uncertainties in nuclear production models are considered. A break in the spectrum of cosmic-ray protons claimed by Neronov, Semikoz, and Taylor [Phys. Rev. Lett. 108, 051105 (2012)] when fitting the γ-ray spectra of high-latitude molecular clouds is a consequence of using a cosmic-ray proton flux described by a power law in kinetic energy.

Evaluation of Galactic Cosmic Ray Models

NASA Technical Reports Server (NTRS)

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

2009-01-01

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

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.;

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.

Observation of a large-scale anisotropy in the arrival directions of cosmic rays above 8 × 1018 eV

NASA Astrophysics Data System (ADS)

Pierre Auger Collaboration; Aab, A.; Abreu, P.; Aglietta, M.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Anastasi, G. A.; Anchordoqui, L.; Andrada, B.; Andringa, S.; Aramo, C.; Arqueros, F.; Arsene, N.; Asorey, H.; Assis, P.; Aublin, J.; Avila, G.; Badescu, A. M.; Balaceanu, A.; Barbato, F.; Barreira Luz, R. J.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Biteau, J.; Blaess, S. G.; Blanco, A.; Blazek, J.; Bleve, C.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Borodai, N.; Botti, A. M.; Brack, J.; Brancus, I.; Bretz, T.; Bridgeman, A.; Briechle, F. L.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, L.; Cancio, A.; Canfora, F.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Chavez, A. G.; Chinellato, J. A.; Chudoba, J.; Clay, R. W.; Cobos, A.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Consolati, G.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Cronin, J.; D'Amico, S.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Jong, S. J.; De Mauro, G.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; Debatin, J.; Deligny, O.; Di Giulio, C.; Di Matteo, A.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; D'Olivo, J. C.; Dorosti, Q.; dos Anjos, R. C.; Dova, M. T.; Dundovic, A.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Fenu, F.; Fick, B.; Figueira, J. M.; Filipčič, A.; Fratu, O.; Freire, M. M.; Fujii, T.; Fuster, A.; Gaior, R.; García, B.; Garcia-Pinto, D.; Gaté, F.; Gemmeke, H.; Gherghel-Lascu, A.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Głas, D.; Glaser, C.; Golup, G.; Gómez Berisso, M.; Gómez Vitale, P. F.; González, N.; Gorgi, A.; Gorham, P.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huege, T.; Hulsman, J.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Johnsen, J. A.; Josebachuili, M.; Jurysek, J.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Katkov, I.; Keilhauer, B.; Kemmerich, N.; Kemp, E.; Kemp, J.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kuempel, D.; Kukec Mezek, G.; Kunka, N.; Kuotb Awad, A.; LaHurd, D.; Lauscher, M.; Legumina, R.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lo Presti, D.; Lopes, L.; López, R.; López Casado, A.; Luce, Q.; Lucero, A.; Malacari, M.; Mallamaci, M.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Mariş, I. C.; Marsella, G.; Martello, D.; Martinez, H.; Martínez Bravo, O.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melo, D.; Menshikov, A.; Merenda, K.-D.; Michal, S.; Micheletti, M. I.; Middendorf, L.; Miramonti, L.; Mitrica, B.; Mockler, D.; Mollerach, S.; Montanet, F.; Morello, C.; Mostafá, M.; Müller, A. L.; Müller, G.; Muller, M. A.; Müller, S.; Mussa, R.; Naranjo, I.; Nellen, L.; Nguyen, P. H.; Niculescu-Oglinzanu, M.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Núñez, L. A.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Palatka, M.; Pallotta, J.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pedreira, F.; Pkala, J.; Pelayo, R.; Peña-Rodriguez, J.; Pereira, L. A. S.; Perlín, M.; Perrone, L.; Peters, C.; Petrera, S.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Ramos-Pollan, R.; Rautenberg, J.; Ravignani, D.; Revenu, B.; Ridky, J.; Riehn, F.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rogozin, D.; Roncoroni, M. J.; Roth, M.; Roulet, E.; Rovero, A. C.; Ruehl, P.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santos, E. M.; Santos, E.; Sarazin, F.; Sarmento, R.; Sarmiento, C. A.; Sato, R.; Schauer, M.; Scherini, V.; Schieler, H.; Schimp, M.; Schmidt, D.; Scholten, O.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sigl, G.; Silli, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sonntag, S.; Sorokin, J.; Squartini, R.; Stanca, D.; Stanič, S.; Stasielak, J.; Stassi, P.; Strafella, F.; Suarez, F.; Suarez Durán, M.; Sudholz, T.; Suomijärvi, T.; Supanitsky, A. D.; Šupík, J.; Swain, J.; Szadkowski, Z.; Taboada, A.; Taborda, O. A.; Tapia, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Tomankova, L.; Tomé, B.; Torralba Elipe, G.; Travnicek, P.; Trini, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, R. A.; Veberič, D.; Ventura, C.; Vergara Quispe, I. D.; Verzi, V.; Vicha, J.; Villaseñor, L.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weindl, A.; Wiencke, L.; Wilczyński, H.; Wirtz, M.; Wittkowski, D.; Wundheiler, B.; Yang, L.; Yushkov, A.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zimmermann, B.; Ziolkowski, M.; Zong, Z.; Zuccarello, F.

2017-09-01

Cosmic rays are high-energy particles arriving from space; some have energies far beyond those that human-made particle accelerators can achieve. The sources of higher-energy cosmic rays remain under debate, although we know that lower-energy cosmic rays come from the solar wind. The Pierre Auger Collaboration reports the observation of thousands of cosmic rays with ultrahigh energies of several exa–electron volts (about a Joule per particle), arriving in a slightly dipolar distribution (see the Perspective by Gallagher and Halzen). The direction of the rays indicates that the particles originated in other galaxies and not from nearby sources within our own Milky Way Galaxy.

Cosmic Ray Propagation through the Magnetic Fields of the Galaxy with Extended Halo

NASA Technical Reports Server (NTRS)

Zhang, Ming

2005-01-01

In this project we perform theoretical studies of 3-dimensional cosmic ray propagation in magnetic field configurations of the Galaxy with an extended halo. We employ our newly developed Markov stochastic process methods to solve the diffusive cosmic ray transport equation. We seek to understand observations of cosmic ray spectra, composition under the constraints of the observations of diffuse gamma ray and radio emission from the Galaxy. The model parameters are directly are related to properties of our Galaxy, such as the size of the Galactic halo, particle transport in Galactic magnetic fields, distribution of interstellar gas, primary cosmic ray source distribution and their confinement in the Galaxy. The core of this investigation is the development of software for cosmic ray propagation models with the Markov stochastic process approach. Values of important model parameters for the halo diffusion model are examined in comparison with observations of cosmic ray spectra, composition and the diffuse gamma-ray background. This report summarizes our achievement in the grant period at the Florida Institute of Technology. Work at the co-investigator's institution, the University of New Hampshire, under a companion grant, will be covered in detail by a separate report.

Measurement of cosmic-ray muons with the Distributed Electronic Cosmic-ray Observatory, a network of smartphones

NASA Astrophysics Data System (ADS)

Vandenbroucke, J.; BenZvi, S.; Bravo, S.; Jensen, K.; Karn, P.; Meehan, M.; Peacock, J.; Plewa, M.; Ruggles, T.; Santander, M.; Schultz, D.; Simons, A. L.; Tosi, D.

2016-04-01

Solid-state camera image sensors can be used to detect ionizing radiation in addition to optical photons. We describe the Distributed Electronic Cosmic-ray Observatory (DECO), an app and associated public database that enables a network of consumer devices to detect cosmic rays and other ionizing radiation. In addition to terrestrial background radiation, cosmic-ray muon candidate events are detected as long, straight tracks passing through multiple pixels. The distribution of track lengths can be related to the thickness of the active (depleted) region of the camera image sensor through the known angular distribution of muons at sea level. We use a sample of candidate muon events detected by DECO to measure the thickness of the depletion region of the camera image sensor in a particular consumer smartphone model, the HTC Wildfire S. The track length distribution is fit better by a cosmic-ray muon angular distribution than an isotropic distribution, demonstrating that DECO can detect and identify cosmic-ray muons despite a background of other particle detections. Using the cosmic-ray distribution, we measure the depletion thickness to be 26.3 ± 1.4 μm. With additional data, the same method can be applied to additional models of image sensor. Once measured, the thickness can be used to convert track length to incident polar angle on a per-event basis. Combined with a determination of the incident azimuthal angle directly from the track orientation in the sensor plane, this enables direction reconstruction of individual cosmic-ray events using a single consumer device. The results simultaneously validate the use of cell phone camera image sensors as cosmic-ray muon detectors and provide a measurement of a parameter of camera image sensor performance which is not otherwise publicly available.

Cosmic ray impact on extrasolar earth-like planets in close-in habitable zones.

PubMed

Griessmeier, J-M; Stadelmann, A; Motschmann, U; Belisheva, N K; Lammer, H; Biernat, H K

2005-10-01

Because of their different origins, cosmic rays can be subdivided into galactic cosmic rays and solar/stellar cosmic rays. The flux of cosmic rays to planetary surfaces is mainly determined by two planetary parameters: the atmospheric density and the strength of the internal magnetic moment. If a planet exhibits an extended magnetosphere, its surface will be protected from high-energy cosmic ray particles. We show that close-in extrasolar planets in the habitable zone of M stars are synchronously rotating with their host star because of the tidal interaction. For gravitationally locked planets the rotation period is equal to the orbital period, which is much longer than the rotation period expected for planets not subject to tidal locking. This results in a relatively small magnetic moment. We found that an Earth-like extrasolar planet, tidally locked in an orbit of 0.2 AU around an M star of 0.5 solar masses, has a rotation rate of 2% of that of the Earth. This results in a magnetic moment of less than 15% of the Earth's current magnetic moment. Therefore, close-in extrasolar planets seem not to be protected by extended Earth-like magnetospheres, and cosmic rays can reach almost the whole surface area of the upper atmosphere. Primary cosmic ray particles that interact with the atmosphere generate secondary energetic particles, a so-called cosmic ray shower. Some of the secondary particles can reach the surface of terrestrial planets when the surface pressure of the atmosphere is on the order of 1 bar or less. We propose that, depending on atmospheric pressure, biological systems on the surface of Earth-like extrasolar planets at close-in orbital distances can be strongly influenced by secondary cosmic rays.

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.

First spectroscopy of a short-hard GRB: the environment of a compact object merger

NASA Astrophysics Data System (ADS)

de Ugarte Postigo, Antonio; Thöne, Christina C.; Rowllinson, Antonia; Benito, Rubén García; Levan, Andrew J.; Gorosabel, Javier; Goldoni, Paolo; Schulze, Steve

2015-03-01

Short gamma-ray bursts (GRBs) are an extremely elusive family of cosmic explosions. They are thought to be related to the violent merger of compact objects (such as a neutron stars or black holes). Their optical counterparts were not discovered until 2005, and since then, there had been no successful spectroscopic observations. Here we present the first spectra of a short GRB, which we use to study the environment and derive implications on the progenitors of these cosmic explosions. This poster is based on the work by de Ugarte Postigo et al. (2014).

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.

Cosmic ray interactions with lunar materials - Nature and composition of species formed

NASA Technical Reports Server (NTRS)

Mukherjee, N. R.

1976-01-01

The paper discusses the effect of cosmic-ray proton interactions with lunar material, the nature and composition of the species resulting from these interactions, and the contribution of these species to the lunar atmosphere. It is shown that hydrogen atoms resulting from cosmic-ray proton neutralization escape into the atmosphere mostly as H2, that only a small fraction of the very small amount of OH and H2O produced by cosmic-ray protons escapes into the atmosphere, and that cosmic-ray protons play a very minor role, as compared with solar-wind protons, in producing lunar atmospheric hydrogen and hydrogenated species. It is concluded that the atmospheric contributions of H2, H, OH, and H2O produced by cosmic-ray protons are about three orders of magnitude less than those due to solar-wind protons.

THE COSMIC-RAY INTENSITY NEAR THE ARCHEAN EARTH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cohen, O.; Drake, J. J.; Kota, J.

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 themore » 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.« less

Understanding the spectral hardenings and radial distribution of Galactic cosmic rays and Fermi diffuse γ rays with spatially-dependent propagation

NASA Astrophysics Data System (ADS)

Guo, Yi-Qing; Yuan, Qiang

2018-03-01

Recent direct measurements of Galactic cosmic ray spectra by balloon/space-borne detectors reveal spectral hardenings of all major nucleus species at rigidities of a few hundred GV. The all-sky diffuse γ -ray emissions measured by the Fermi Large Area Telescope also show spatial variations of the intensities and spectral indices of cosmic rays. These new observations challenge the traditional simple acceleration and/or propagation scenario of Galactic cosmic rays. In this work, we propose a spatially dependent diffusion scenario to explain all these phenomena. The diffusion coefficient is assumed to be anticorrelated with the source distribution, which is a natural expectation from the charged particle transportation in a turbulent magnetic field. The spatially dependent diffusion model also gives a lower level of anisotropies of cosmic rays, which are consistent with observations by underground muons and air shower experiments. The spectral variations of cosmic rays across the Galaxy can be properly reproduced by this model.

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.

X-Ray Binary Populations in a Cosmological Context, Including NuSTAR Predictions

NASA Technical Reports Server (NTRS)

Cardiff, Ann Hornschemeier

2011-01-01

The new ultradeep 4 Ms Chandra Deep Field South has afforded the deepest view ever of X-ray binary populations. We report on the latest results on both LMXB and HMXB evolution out to redshifts of approximately four, including comparison with the latest theoretical models, using this deepest-ever view of the X-ray universe with Chandra. The upcoming NuSTAR mission will open up X-ray binary populations in the hard X-ray band, similar to the pioneering work of Fabbiano et al. in the Einstein era. We report on plans to study both Local Group and starburst galaxies as well as the implications those observations may have for X-ray binary populations in galaxies contributing to the Cosmic X-ray Background.

A local recent supernova - Evidence from X-rays, Al-26 radioactivity and cosmic rays

NASA Technical Reports Server (NTRS)

Clayton, Donald D.; Cox, Donald P.; Michel, Curtis F.

1986-01-01

Possible ways in which cosmic rays could have been contaminated by a local recent supernova are discussed, and ways in which this contamination may be affecting interpretation of Al-26 gamma radiation and locally observed cosmic rays as samples of the average Galactic distribution are considered. Mass spectra of cosmic rays are examined to see whether there is enrichment by a population arising from supernova preacceleration. The reinterpretation of the anomalous component in terms of a local supernova model is addressed.

Long-Term Solar and Cosmic Radiation Data Bases

DTIC Science & Technology

1991-01-01

determine the magnitude of the variations in the cosmic ray intensity caused by solar activity. Neutron monitors, with their much lower energy threshold...expression that neutron monitors are sensors on spacecraft EARTH. Here we will consider cosmic ray detectors to measure two components of cosmic ...A comparison with the solar cycle as illustrated by the sunspot number in Fig. 1. shows that the maximum cosmic ray intensity occurs near sunspot

Underground measurements on secondary cosmic rays

NASA Technical Reports Server (NTRS)

Wilson, C. W.; Fenton, A. G.; Fenton, K. B.

1985-01-01

Measurements made at the Poatina cosmic ray station (41.8 S 149.9 E, 347 m.w.e.) from August 1983 to July 1984 are summarized. The cosmic ray primary particles responsible for events detected at the station have a median primary energy of 1.2 TeV. The motivation for part of this work came from the reported detection of narrow angle anisotropies in the arrival direction of cosmic rays.

Cosmic Ray Observation at Mount Chacaltaya for beyond the Knee Region

NASA Astrophysics Data System (ADS)

Tsunesada, Y.; Kakimoto, F.; Furuhata, F.; Matsumoto, H.; Sugawara, T.; Wakamatsu, H.; Gotoh, E.; Nakatani, H.; Nishi, K.; Tajima, N.; Yamada, Y.; Shimoda, S.; Yoshii, H.; Kaneko, T.; Ogio, S.; Matsubara, Y.; Kadota, K.; Tokuno, H.; Mizumoto, Y.; Shirasaki, Y.; Toyoda, Y.; Burgoa, O.; Flores, V.; Miranda, P.; Salinas, J.; Velarde, A.

We have installed a new air shower array at Mount Chacaltaya (5,200m above sea level) to observe primary cosmic rays with energies greater than 1015 eV. In our previous experiments, we measured energy spectrum and nuclear composition of primary cosmic rays around the knee region. Above all, we obtained the cosmic ray composition with three independent techniques, namely from the equi-intensity cuts, the arrival time distributions of Cherenkov lights associated with air showers, and the lateral distributions of Cherenkov photons around the shower axis. All the results from these experiments are in agreement and show that the average mass of cosmic ray nuclei increases with energies below and above the knee, and dominated by heavier nuclei as iron at 1016 eV. This result is consistent with the confinement and rigidity dependent acceleration models, and suggests that the cosmic ray origins are supernova remnants of massive population as Wolf-Rayet stars. It is of quite interest whether the mass of cosmic ray nuclei continues to increase with energies, or decreases by contributions of lighter components expected from the extra-galactic cosmic ray models. In this paper, we describe the characteristics of the new array and preliminary results from the first observation.

Cosmic ray interactions in starbursting galaxies

NASA Astrophysics Data System (ADS)

Yoast-Hull, Tova M.

High quality gamma-ray and radio observations of nearby galaxies offer an unprecedented opportunity to quantitatively study the properties of their cosmic ray populations. Accounting for various interactions and energy losses, I developed a multi-component, single-zone model of the cosmic ray populations in the central molecular zones of star-forming galaxies. Using observational knowledge of the interstellar medium and star formation, I successfully predicted the radio, gamma-ray, and neutrino spectra for nearby starbursts. Using chi-squared tests to compare the models with observational radio and gamma-ray data, I placed constraints on magnetic field strengths, cosmic ray energy densities, and galactic wind (advection) speeds. The initial models were applied to and tested on the prototypical starburst galaxy M82. To further test the model and to explore the differences in environment between starbursts and active galactic nuclei, I studied NGC 253 and NGC 1068, both nearby giant spiral galaxies which have been detected in gamma-rays. Additionally, I demonstrated that the excess GeV energy gamma-ray emission in the Galactic Center is likely not diffuse emission from an additional population of cosmic rays accelerated in supernova remnants. Lastly, I investigated cosmic ray populations in the starburst nuclei of Arp 220, a nearby ultraluminous infrared galaxy which displays a high-intensity mode of star formation more common in young galaxies, and I showed that the nuclei are efficient cosmic-ray proton calorimeters.

Testing cosmic ray acceleration with radio relics: a high-resolution study using MHD and tracers

NASA Astrophysics Data System (ADS)

Wittor, D.; Vazza, F.; Brüggen, M.

2017-02-01

Weak shocks in the intracluster medium may accelerate cosmic-ray protons and cosmic-ray electrons differently depending on the angle between the upstream magnetic field and the shock normal. In this work, we investigate how shock obliquity affects the production of cosmic rays in high-resolution simulations of galaxy clusters. For this purpose, we performed a magnetohydrodynamical simulation of a galaxy cluster using the mesh refinement code ENZO. We use Lagrangian tracers to follow the properties of the thermal gas, the cosmic rays and the magnetic fields over time. We tested a number of different acceleration scenarios by varying the obliquity-dependent acceleration efficiencies of protons and electrons, and by examining the resulting hadronic γ-ray and radio emission. We find that the radio emission does not change significantly if only quasi-perpendicular shocks are able to accelerate cosmic-ray electrons. Our analysis suggests that radio-emitting electrons found in relics have been typically shocked many times before z = 0. On the other hand, the hadronic γ-ray emission from clusters is found to decrease significantly if only quasi-parallel shocks are allowed to accelerate cosmic ray protons. This might reduce the tension with the low upper limits on γ-ray emission from clusters set by the Fermi satellite.

A cosmic-ray-mediated shock in the solar system

NASA Technical Reports Server (NTRS)

Eichler, D.

1981-01-01

It is pointed out that the flare-induced blast wave of Aug. 4, 1972, the most violent disturbance in the solar wind on record, produced cosmic rays with an efficiency of about 50%. Such a high efficiency is predicted by the self-regulating production model of cosmic-ray origin in shocks. Most interplanetary shocks, according to simple theoretical analysis, are not strong enough to produce cosmic rays efficiently. However, if shock strength is the key parameter governing efficiency, as present interplanetary data suggest, then shocks from supernova blasts, quasar outbursts, and other violent astrophysical phenomena should be extremely efficient sources of cosmic rays.

Study of cosmic rays reveals secrets of solar-terrestrial science

NASA Astrophysics Data System (ADS)

Jokipii, J. R.

For many years cosmic rays provided the most important source of energetic particles for studies of subatomic physics. Today, cosmic rays are being studied as a natural phenomenon that can tell us much about both the Earth's environment in space and distant astrophysical processes. Cosmic rays are naturally occurring energetic particles—mainly ions—with kinetic energies extending from just above thermal energies to more than 1020 electron volts (eV). They constantly bombard the Earth from all directions, with more than 1018 particles having energies >1 MeV striking the top of the Earth's atmosphere each second. Figure 1 illustrates the continuous cosmic ray energy spectrum.

The influence of cosmic rays on the stability and large-scale dynamics of the interstellar medium

NASA Astrophysics Data System (ADS)

Kuznetsov, V. D.

1986-06-01

The diffusion-convection formulation is used to study the influence of galactic cosmic rays on the stability and dynamics of the interstellar medium which is supposedly kept in equilibrium by the gravitational field of stars. It is shown that the influence of cosmic rays on the growth rate of MHD instability depends largely on a dimensionless parameter expressing the ratio of the characteristic acoustic time scale to the cosmic-ray diffusion time. If this parameter is small, the cosmic rays will decelerate the build-up of instabilities, thereby stabilizing the system; in contrast, if the parameter is large, the system will be destabilized.

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.

Cosmic Ray Astronomy

NASA Technical Reports Server (NTRS)

Wu, S. T.

2000-01-01

The cosmic ray division participation in the cooperative agreement was activated in the second year. The scientific goals will be analysis of cosmic ray data from the Japanese-American Cooperative Emulsion Experiments (JACEE). Measurements of primary cosmic rays in the JACEE emulsion chambers will be made to derive for each detected particle the deposited energy in the chamber and the primary charge (atomic number). The data will be corrected to the primary flux above the atmosphere, and the composition and energy spectra will be derived. The spectra of the individual elements will be interpreted in context with the supernova shock and other models of cosmic ray acceleration. Additional information is contained in the original extended abstract.

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.

Evolution of Hot Gas in Elliptical Galaxies

NASA Technical Reports Server (NTRS)

Mathews, William G.

2004-01-01

This theory grant was awarded to study the curious nature, origin and evolution of hot gas in elliptical galaxies and their surrounding groups. Understanding the properties of this X-ray emitting gas has profound implications over the broad landscape of modern astrophysics: cosmology, galaxy formation, star formation, cosmic metal enrichment, galactic structure and dynamics, and the physics of hot gases containing dust and magnetic fields. One of our principal specific objectives was to interpret the marvelous new observations from the XMM and Chandru satellite X-ray telescopes.

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). )

Cosmic-ray anisotropy studies with IceCube

NASA Astrophysics Data System (ADS)

McNally, Frank

2014-03-01

The IceCube neutrino observatory detects tens of billions of energetic muons per year produced by cosmic-ray interactions with the atmosphere. The size of this sample has allowed IceCube to observe a significant anisotropy in arrival direction for cosmic rays with median energies between 20 and 400 TeV. This anisotropy is characterized by a large scale structure of per-mille amplitude accompanied by structures with smaller amplitudes and with typical angular sizes between 10° and 20°. IceTop, the surface component of IceCube, has observed a similar anisotropy in the arrival direction distribution of cosmic rays, extending the study to PeV energies. The better energy resolution of IceTop allows for additional studies of the anisotropy, for example a comparison of the energy spectrum in regions of a cosmic-ray excess or deficit to the rest of the sky. We present an update on the cosmic-ray anisotropy observed with IceCube and IceTop and the results of first studies of the energy spectrum at locations of cosmic-ray excess or deficit.

SPECTRAL INTENSITIES OF ANTIPROTONS AND THE NESTED LEAKY-BOX MODEL FOR COSMIC RAYS IN THE GALAXY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cowsik, R.; Madziwa-Nussinov, T., E-mail: cowsik@physics.wustl.edu

2016-08-20

In this paper we note that the spectral intensities of antiprotons observed in Galactic cosmic rays in the energy range ∼1–300 GeV by BESS, PAMELA, and AMS instruments display nearly the same spectral shape as that generated by primary cosmic rays through their interaction with matter in the interstellar medium, without any significant modifications. More importantly, a constant residence time of ∼2.3 ± 0.7 million years in the Galactic volume, independent of the energy of cosmic rays, matches the observed intensities. A small additional component of secondary antiprotons in the energy range below 10 GeV, generated in cocoon-like regions surroundingmore » the cosmic-ray sources, seems to be present. We discuss this result in the context of observations of other secondary components such as positrons and boron, and the bounds on anisotropy of cosmic rays. In the nested leaky-box model the spectral intensities of antiprotons and positrons can be interpreted as secondary products of cosmic-ray interactions.« less

A predictive analytic model for the solar modulation of cosmic rays

DOE PAGES

Cholis, Ilias; Hooper, Dan; Linden, Tim

2016-02-23

An important factor limiting our ability to understand the production and propagation of cosmic rays pertains to the effects of heliospheric forces, commonly known as solar modulation. The solar wind is capable of generating time- and charge-dependent effects on the spectrum and intensity of low-energy (≲10 GeV) cosmic rays reaching Earth. Previous analytic treatments of solar modulation have utilized the force-field approximation, in which a simple potential is adopted whose amplitude is selected to best fit the cosmic-ray data taken over a given period of time. Making use of recently available cosmic-ray data from the Voyager 1 spacecraft, along withmore » measurements of the heliospheric magnetic field and solar wind, we construct a time-, charge- and rigidity-dependent model of solar modulation that can be directly compared to data from a variety of cosmic-ray experiments. Here, we provide a simple analytic formula that can be easily utilized in a variety of applications, allowing us to better predict the effects of solar modulation and reduce the number of free parameters involved in cosmic-ray propagation models.« less

Constraining the p¯/p ratio in TeV cosmic rays with observations of the Moon shadow by HAWC

NASA Astrophysics Data System (ADS)

Abeysekara, A. U.; Albert, A.; Alfaro, R.; Alvarez, C.; Álvarez, J. D.; Arceo, R.; Arteaga-Velázquez, J. C.; Avila Rojas, D.; Ayala Solares, H. A.; Belmont-Moreno, E.; BenZvi, S. Y.; Braun, J.; Brisbois, C.; Caballero-Mora, K. S.; Capistrán, T.; Carramiñana, A.; Casanova, S.; Castillo, M.; Cotti, U.; Cotzomi, J.; Coutiño de León, S.; De León, C.; De la Fuente, E.; Diaz Hernandez, R.; Dichiara, S.; Dingus, B. L.; DuVernois, M. A.; Ellsworth, R. W.; Engel, K.; Enríquez-Rivera, O.; Fleischhack, H.; Fraija, N.; Galván-Gámez, A.; García-González, J. A.; González Muñoz, A.; González, M. M.; Hampel-Arias, Z.; Harding, J. P.; Hernandez, S.; Hona, B.; Hueyotl-Zahuantitla, F.; Hui, C. M.; Hüntemeyer, P.; Iriarte, A.; Jardin-Blicq, A.; Joshi, V.; Kaufmann, S.; Lara, A.; Lee, W. H.; León Vargas, H.; Linnemann, J. T.; Longinotti, A. L.; Luis-Raya, G.; Luna-García, R.; López-Coto, R.; Malone, K.; Marinelli, S. S.; Martinez, O.; Martinez-Castellanos, I.; Martínez-Castro, J.; Martínez-Huerta, H.; Matthews, J. A.; Miranda-Romagnoli, P.; Moreno, E.; Mostafá, M.; Nellen, L.; Newbold, M.; Nisa, M. U.; Noriega-Papaqui, R.; Pelayo, R.; Pretz, J.; Pérez-Pérez, E. G.; Ren, Z.; Rho, C. D.; Rivière, C.; Rosa-González, D.; Rosenberg, M.; Ruiz-Velasco, E.; Salesa Greus, F.; Sandoval, A.; Schneider, M.; Schoorlemmer, H.; Seglar Arroyo, M.; Sinnis, G.; Smith, A. J.; Springer, R. W.; Surajbali, P.; Taboada, I.; Tibolla, O.; Torres, I.; Villaseñor, L.; Weisgarber, T.; Westerhoff, S.; Wood, J.; Yapici, T.; Yodh, G. B.; Zepeda, A.; Zhou, H.; HAWC Collaboration

2018-05-01

An indirect measurement of the antiproton flux in cosmic rays is possible as the particles undergo deflection by the geomagnetic field. This effect can be measured by studying the deficit in the flux, or shadow, created by the Moon as it absorbs cosmic rays that are headed toward the Earth. The shadow is displaced from the actual position of the Moon due to geomagnetic deflection, which is a function of the energy and charge of the cosmic rays. The displacement provides a natural tool for momentum/charge discrimination that can be used to study the composition of cosmic rays. Using 33 months of data comprising more than 80 billion cosmic rays measured by the High Altitude Water Cherenkov observatory, we have analyzed the Moon shadow to search for TeV antiprotons in cosmic rays. We present our first upper limits on the p ¯/p fraction, which in the absence of any direct measurements provide the tightest available constraints of ˜1 % on the antiproton fraction for energies between 1 and 10 TeV.

Linear growth of the Kelvin-Helmholtz instability with an adiabatic cosmic-ray gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suzuki, Akihiro; Takahashi, Hiroyuki R.; Kudoh, Takahiro

2014-06-01

We investigate effects of cosmic rays on the linear growth of the Kelvin-Helmholtz instability. Cosmic rays are treated as an adiabatic gas and allowed to diffuse along magnetic field lines. We calculated the dispersion relation of the instability for various sets of two free parameters, the ratio of the cosmic-ray pressure to the thermal gas pressure, and the diffusion coefficient. Including cosmic-ray effects, a shear layer is more destabilized and the growth rates can be enhanced in comparison with the ideal magnetohydrodynamical case. Whether the growth rate is effectively enhanced or not depends on the diffusion coefficient of cosmic rays.more » We obtain the criterion for effective enhancement by comparing the growing timescale of the instability with the diffusion timescale of cosmic rays. These results can be applied to various astrophysical phenomena where a velocity shear is present, such as outflows from star-forming galaxies, active galactic nucleus jet, channel flows resulting from the nonlinear development of the magnetorotational instability, and galactic disks.« less

Galactic Cosmic Rays in the Outer Heliosphere

NASA Technical Reports Server (NTRS)

Florinski, V.; Washimi, H.; Pogorelov, N. V.; Adams, J. H.

2010-01-01

We report a next generation model of galactic cosmic ray (GCR) transport in the three dimensional heliosphere. Our model is based on an accurate three-dimensional representation of the heliospheric interface. This representation is obtained by taking into account the interaction between partially ionized, magnetized plasma flows of the solar wind and the local interstellar medium. Our model reveals that after entering the heliosphere GCRs are stored in the heliosheath for several years. The preferred GCR entry locations are near the nose of the heliopause and at high latitudes. Low-energy (hundreds of MeV) galactic ions observed in the heliosheath have spent, on average, a longer time in the solar wind than those observed in the inner heliosphere, which would explain their cooled-off spectra at these energies. We also discuss radial gradients in the heliosheath and the implications for future Voyager observations

Extrapolating cosmic ray variations and impacts on life: Morlet wavelet analysis

NASA Astrophysics Data System (ADS)

Zarrouk, N.; Bennaceur, R.

2009-07-01

Exposure to cosmic rays may have both a direct and indirect effect on Earth's organisms. The radiation may lead to higher rates of genetic mutations in organisms, or interfere with their ability to repair DNA damage, potentially leading to diseases such as cancer. Increased cloud cover, which may cool the planet by blocking out more of the Sun's rays, is also associated with cosmic rays. They also interact with molecules in the atmosphere to create nitrogen oxide, a gas that eats away at our planet's ozone layer, which protects us from the Sun's harmful ultraviolet rays. On the ground, humans are protected from cosmic particles by the planet's atmosphere. In this paper we give estimated results of wavelet analysis from solar modulation and cosmic ray data incorporated in time-dependent cosmic ray variation. Since solar activity can be described as a non-linear chaotic dynamic system, methods such as neural networks and wavelet methods should be very suitable analytical tools. Thus we have computed our results using Morlet wavelets. Many have used wavelet techniques for studying solar activity. Here we have analysed and reconstructed cosmic ray variation, and we have better depicted periods or harmonics other than the 11-year solar modulation cycles.

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.

The Interstellar 7Li/6Li Ratio in the Diffuse Gas Near IC 443

NASA Astrophysics Data System (ADS)

Ritchey, A. M.; Taylor, C. J.; Federman, S. R.; Lambert, D. L.

2010-11-01

Supernova remnants are believed to be the primary acceleration sites of Galactic cosmic rays (GCR), which are essential to gas-phase interstellar chemistry since they are a major source of ionization in both diffuse and dense environments. The interaction of accelerated particles with interstellar gas will also synthesize isotopes of the light elements Li, Be, and B through the spallation of CNO nuclei (producing all stable LiBeB isotopes) and through α+α fusion (yielding 6Li and 7Li, only). Type II supernovae may provide an additional source of 7Li and 11B during core collapse through neutrino-induced spallation in the He and C shells of the progenitor star (the ν-process). However, direct observational evidence for light element synthesis resulting from cosmic-ray or neutrino-induced spallation is rare. Here, we examine 7Li/6Li isotope ratios along four lines of sight through the supernova remnant IC 443 using observations of the Li I λ6707 doublet made with the Hobby-Eberly Telescope (HET) at McDonald Observatory. The 7Li/6Li ratio in the general interstellar medium is expected to be similar to the ratio of ~12 that characterizes solar system material. A local enhancement in the cosmic-ray flux will act to lower 7Li/6Li, yielding a ratio of ~2 when cosmic rays dominate Li synthesis. Gamma-ray emission from IC 443 provides strong evidence for the interaction of cosmic rays accelerated by the remnant with the ambient atomic and molecular gas. Yet this material has also been contaminated by the ejecta of a Type II supernova, which should be enriched in 7Li. We are seeking 7Li/6Li ratios that are either higher than the solar system ratio as a result of the ν-process or lower due to cosmic-ray spallation. Since the fine structure separation of the Li I doublet is comparable to the isotope shift (~7 km s-1) and each fine structure line is further split into hyperfine components, the velocity structure along the line of sight must be carefully constrained if meaningful 7Li/6Li ratios are to be determined. In our analysis, the strongest components seen in K I and CH are used to synthesize the complex Li I profiles. We will discuss the implications of our results on 7Li/6Li (and Li/K) ratios in the context of Li production by Type II supernovae.

Cosmic-Ray Source Composition Determined from ACE

NASA Technical Reports Server (NTRS)

Wiedenbeck, M.

2000-01-01

The cosmic rays arriving at Earth comprise a mix of material produced by stellar sources and ejected into the interstellar medium (primary cosmic rays) and particles produced by fragmentation of heavier nuclei during transport through the Galaxy.

Compact cosmic ray detector for unattended atmospheric ionization monitoring

NASA Astrophysics Data System (ADS)

Aplin, K. L.; Harrison, R. G.

2010-12-01

Two vertical cosmic ray telescopes for atmospheric cosmic ray ionization event detection are compared. Counter A, designed for low power remote use, was deployed in the Welsh mountains; its event rate increased with altitude as expected from atmospheric cosmic ray absorption. Independently, Counter B's event rate was found to vary with incoming particle acceptance angle. Simultaneous co-located comparison of both telescopes exposed to atmospheric ionization showed a linear relationship between their event rates.

Definition of parameters of daily anisotropy of cosmic rays according to the world network of neutron monitors

NASA Astrophysics Data System (ADS)

Grigoryev, V. G.; Starodubtsev, S. A.; Potapova, V. D.

2013-02-01

In our previous works we have created the method of determination of parameters of cosmic ray daily anisotropy in the interplanetary environment based on the data provided by only single station - cosmic ray spectrograph named after A.I.Kuzmin. This method allows to predict the ingress of the Earth into large-scale solar wind disturbances with a probability of more than 70% and in advance time of about from several hours up to 2 days. Now it became possible to use the data of the neutron monitor networks, which can be seen in the neutron monitor database (NMDB) in real time. In this case the well-known method of global survey is applied for determination of cosmic ray anisotropy. Usage of the data of the cosmic ray station network allows to determine parameters of daily cosmic ray anisotropy with a greater accuracy.

Muon and neutron observations in connection with the corotating interaction regions

NASA Astrophysics Data System (ADS)

da Silva, M. R.; Dal Lago, A.; Echer, E.; de Lucas, A.; Gonzalez, W. D.; Schuch, N. J.; Munakata, K.; Vieira, L. E. A.; Guarnieri, F. L.

Ground cosmic ray observations are used for studying several kinds of interplanetary structures. The cosmic ray data has different responses to each kind of interplanetary structure. This article has as objective to study cosmic ray muon and neutron signatures due to the passage of corotating interaction region (CIR) in the interplanetary medium, and identify the signatures in the cosmic ray data due to these events. The cosmic ray muon data used in this work are recorded by the multidirectional muon detector installed at INPE’s Observatório Espacial do Sul OES/CRSPE/INPE-MCT, in São Martinho da Serra, RS (Brazil) and the neutron data was recorded by the neutron monitor installed in Newark (USA). The CIR events were selected in the period from 2001 to 2004. CIRs clearly affect cosmic ray density in the interplanetary medium in the Earth’s vicinity, where the magnetic field plays an important role.

THE COSMIC RAY EQUATOR AND THE GEOMAGNETISM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakurai, K.

1960-01-01

It was formerly thought that the disagreement of the position of geomagnetic dipole equator with that of the cosmic ray equator was caused by 45 deg westward shifting of the latter. Referring to the theory of geomagnetic effect on cosmic rays, it was determined whether such westward shifting could be existent or not. It was found that the deviation of the cosmic ray equator from the geomagnetic dipole equator is negligible even if the magnetic cavity is present around the earth's outer atmosphere. Taking into account such results, the origin of the cosmic ray equator was investigated. It was foundmore » that this equater could be produced by the higher harmonic components combined with the dipole component of geomagnetism. The relation of the origin of the cosmic ray equater to the eccentric dipoles, near the outer pant of the earth's core, contributing to the secular variation of geomagnetism was considered. (auth)« less

Progress in high-energy cosmic ray physics

NASA Astrophysics Data System (ADS)

Mollerach, S.; Roulet, E.

2018-01-01

We review some of the recent progress in our knowledge about high-energy cosmic rays, with an emphasis on the interpretation of the different observational results. We discuss the effects that are relevant to shape the cosmic ray spectrum and the explanations proposed to account for its features and for the observed changes in composition. The physics of air-showers is summarized and we also present the results obtained on the proton-air cross section and on the muon content of the showers. We discuss the cosmic ray propagation through magnetic fields, the effects of diffusion and of magnetic lensing, the cosmic ray interactions with background radiation fields and the production of secondary neutrinos and photons. We also consider the cosmic ray anisotropies, both at large and small angular scales, presenting the results obtained from the TeV up to the highest energies and discuss the models proposed to explain their origin.

Expectations for high energy diffuse galactic neutrinos for different cosmic ray distributions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pagliaroli, Giulia; Evoli, Carmelo; Villante, Francesco Lorenzo, E-mail: giulia.pagliaroli@gssi.infn.it, E-mail: carmelo.evoli@gssi.infn.it, E-mail: francesco.villante@lngs.infn.it

2016-11-01

The interaction of cosmic rays with the gas contained in our Galaxy is a guaranteed source of diffuse high energy neutrinos. We provide expectations for this component by considering different assumptions for the cosmic ray distribution in the Galaxy which are intended to cover the large uncertainty in cosmic ray propagation models. We calculate the angular dependence of the diffuse galactic neutrino flux and the corresponding rate of High Energy Starting Events in IceCube by including the effect of detector angular resolution. Moreover we discuss the possibility to discriminate the galactic component from an isotropic astrophysical flux. We show thatmore » a statistically significant excess of events from the galactic plane in present IceCube data would disfavour models in which the cosmic ray density is uniform , thus bringing relevant information on the cosmic ray radial distribution.« less

Millisecond Pulsars at Gamma-Ray Energies: Fermi Detections and Implications

NASA Technical Reports Server (NTRS)

Harding, Alice K.

2011-01-01

The Fermi Gamma-Ray Space Telescope has revolutionized the study of pulsar physics with the discovery of new populations of radio quiet and millisecond gamma-ray pulsars. The Fermi Large Area Telescope has so far discovered approx.20 new gamma-ray millisecond pulsars (MSPs) by both folding at periods of known radio MSPs or by detecting them as gamma-ray sources that are followed up by radio pulsar searches. The second method has resulted in a phenomenally successful synergy, with -30 new radio MSPs (to date) having been discovered at Fermi unidentified source locations and the gamma-ray pulsations having then been detected in a number of these using the radio timing solutions. Many of the newly discovered MSPs may be suitable for addition to the collection of very stable MSPs used for gravitational wave detection. Detection of such a large number of MSPs was surprising, given that most have relatively low spin-down luminosity and surface field strength. I will discuss their properties and the implications for pulsar particle acceleration and emission, as well as their potential contribution to gamma-ray backgrounds and Galactic cosmic rays.

Space-atmospheric interactions of energetic cosmic rays

NASA Astrophysics Data System (ADS)

Isar, Paula Gina

2015-02-01

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

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 γ-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.

An absence of neutrinos associated with cosmic-ray acceleration in γ-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.; Hülβ, 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 (γ-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 γ-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.

Charge 4/3 leptons in cosmic rays

NASA Technical Reports Server (NTRS)

Wada, T.; Yamashita, Y.; Imaeda, K.; Yamamoto, I.

1985-01-01

A cosmic ray counter telescope has been operated at zenith angles of 0, 40, 44, and 60 degs in order to look for charge 4/3 particles. A few million clean single cosmic rays of each zenith angle are analyzed.

Propagation of Galactic cosmic rays: the influence of anisotropic diffusion

NASA Astrophysics Data System (ADS)

AL-Zetoun, A.; Achterberg, A.

2018-06-01

We consider the anisotropic diffusion of cosmic rays in the large-scale Galactic magnetic field, where diffusion along the field and diffusion across the field proceeds at different rates. To calculate this diffusion, we use stochastic differential equations to describe the cosmic ray propagation, solving these numerically. The Galactic magnetic field is described using the Jansson-Farrar model for the Galactic magnetic field. In this paper, we study the influence of perpendicular diffusion on the residence time of cosmic rays in the Galaxy. This provides an estimate for the influence of anisotropic diffusion on the residence time and the amount of matter (grammage) that a typical cosmic ray traverses during its residence in the Galaxy.

A Novel Study Connecting Ultra-High Energy Cosmic Rays, Neutrinos, and Gamma-Rays

NASA Astrophysics Data System (ADS)

Coenders, Stefan; Resconi, Elisa; Padovani, Paolo; Giommi, Paolo; Caccianiga, Lorenzo

We present a novel study connecting ultra-high energy cosmic rays, neutrinos, and gamma-rays with the objective to identify common counterparts of the three astrophysical messengers. In the test presented here, we first identify potential hadronic sources by filtering gamma-ray emitters that are in spatial coincidence with IceCube neutrinos. Subsequently, these objects are correlated against ultra-high energy cosmic rays detected by the Pierre Auger Observatory and the Telescope Array, scanning in gamma-ray flux and angular separation between sources and cosmic rays. A maximal excess of 80 cosmic rays (41.9 expected) is observed for the second catalog of hard Fermi-LAT objects of blazars of the high synchrotron peak type. This corresponds to a deviation from the null-hypothesis of 2.94σ . No excess is observed for objects not in spatial connection with neutrinos. The gamma-ray sources that make up the excess are blazars of the high synchrotron peak type.

Spectrum measurement with the Telescope Array Low Energy Extension (TALE) fluorescence detector

NASA Astrophysics Data System (ADS)

Zundel, Zachary James

The Telescope Array (TA) experiment is the largest Ultra High Energy cosmic ray observatory in the northern hemisphere and is designed to be sensitive to cosmic ray air showers above 1018eV. Despite the substantial measurements made by TA and AUGER (the largest cosmic ray observatory in the southern hemisphere), there remains uncertainty about whether the highest energy cosmic rays are galactic or extragalactic in origin. Locating features in the cosmic ray energy spectrum below 1018eV that indicate a transition from galactic to extragalactic sources would clarify the interpretation of measurements made at the highest energies. The Telescope Array Low Energy Extension (TALE) is designed to extend the energy threshold of the TA observatory down to 1016.5eV in order to make such measurements. This dissertation details the construction, calibration, and operation of the TALE flu- orescence detector. A measurement of the flux of cosmic rays in the energy range of 1016.5 -- 1018.5eV is made using the monocular data set taken between September 2013 and January 2014. The TALE fluorescence detector observes evidence for a softening of the cosmic spectrum at 1017.25+/-0.5eV. The evidence of a change in the spectrum motivates continued study of 1016.5 -- 1018.5eV cosmic rays.

Toward a descriptive model of galactic cosmic rays in the heliosphere

NASA Technical Reports Server (NTRS)

Mewaldt, R. A.; Cummings, A. C.; Adams, James H., Jr.; Evenson, Paul; Fillius, W.; Jokipii, J. R.; Mckibben, R. B.; Robinson, Paul A., Jr.

1988-01-01

Researchers review the elements that enter into phenomenological models of the composition, energy spectra, and the spatial and temporal variations of galactic cosmic rays, including the so-called anomalous cosmic ray component. Starting from an existing model, designed to describe the behavior of cosmic rays in the near-Earth environment, researchers suggest possible updates and improvements to this model, and then propose a quantitative approach for extending such a model into other regions of the heliosphere.

Feasibility of Cosmic-Ray Muon Intensity Measurements for Tunnel Detection

DTIC Science & Technology

1990-06-01

BUR-’TR-3110 TECHNICAL REPORT BRL-TR-3110 mBRL I• FEASIBILITY OF COSMIC - RAY MUON INTENSITY MEASUREMENTS FOR TUNNEL DETECTION AIVARS CELIN. , JUNE...Feasibility of Cosmic - Ray Muon Intensity Measurements f or Tunnel Detection 612786H20001 4.AUTNOR(S) Aivars Celmins 7. PERORMING ORGANIZATION NAMe(S) AND... cosmic - ray muon intensity depends on the amount, of material above the point of reference and is therefore influenced by anomalies in rock density

Ultrahigh Energy Cosmic Rays: Old Physics or New Physics?

NASA Technical Reports Server (NTRS)

Stecker, F. W.

2004-01-01

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

The responses of three kinds of passive dosimeters to secondary cosmic rays in the lower atmosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Zhen; Chen, Bo, E-mail: bochenfys@fudan.edu.cn; Zhuo, Weihai

For accurate measurements of the secondary cosmic rays by using passive dosimeters, the relative responses of the thermoluminescence dosimeter (TLD), optically stimulated luminescence (OSL) dosimeter, and radiophotoluminescent glass dosimeter (RPLGD) were studied. The cosmic-ray shower generator was used to simulate the secondary cosmic rays at the sea level. Monte Carlo simulations were performed to calculate the air kerma and absorbed doses in each kind of dosimeter. The results showed that compared with their responses to gamma rays of {sup 137}Cs, the relative responses of the TLD, OSL, and RPLGD were 0.786, 0.707, and 0.735 to the hard component of cosmicmore » rays, respectively, and the values were 0.904, 0.838, and 0.857 to the soft component of cosmic rays, respectively. To verify the simulations results, an in situ measurement with the three kinds of dosimeters was performed at the same place. The results indicated that the secondary cosmic rays monitored with the three kinds of dosimeters were well consistent with each other provided their relative responses were taken into account.« less

Efficient cold outflows driven by cosmic rays in high-redshift galaxies and their global effects on the IGM

NASA Astrophysics Data System (ADS)

Samui, Saumyadip; Subramanian, Kandaswamy; Srianand, Raghunathan

2018-05-01

We present semi-analytical models of galactic outflows in high-redshift galaxies driven by both hot thermal gas and non-thermal cosmic rays. Thermal pressure alone may not sustain a large-scale outflow in low-mass galaxies (i.e. M ˜ 108 M⊙), in the presence of supernovae feedback with large mass loading. We show that inclusion of cosmic ray pressure allows outflow solutions even in these galaxies. In massive galaxies for the same energy efficiency, cosmic ray-driven winds can propagate to larger distances compared to pure thermally driven winds. On an average gas in the cosmic ray-driven winds has a lower temperature which could aid detecting it through absorption lines in the spectra of background sources. Using our constrained semi-analytical models of galaxy formation (that explains the observed ultraviolet luminosity functions of galaxies), we study the influence of cosmic ray-driven winds on the properties of the intergalactic medium (IGM) at different redshifts. In particular, we study the volume filling factor, average metallicity, cosmic ray and magnetic field energy densities for models invoking atomic cooled and molecular cooled haloes. We show that the cosmic rays in the IGM could have enough energy that can be transferred to the thermal gas in presence of magnetic fields to influence the thermal history of the IGM. The significant volume filling and resulting strength of IGM magnetic fields can also account for recent γ-ray observations of blazars.

A Study of Heavy Trans-Iron Primary Cosmic Rays (Z More than or Equal to 55) with a Fast Film Cerenkov Detector. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Pinsky, L. S.

1972-01-01

The detection and measurement of the cosmic ray charge spectrum for nuclei heavier than iron (Fe, Z = 26) are discussed. These trans-iron nuclei are of great interest for several reasons. They promise to be one of the more sensitive clocks for use in determining the age of cosmic rays. The discovery of radioactive nuclides and their decay products in the primary flux, will allow an estimation of the elapsed time since these cosmic rays were synthesized. In addition, the relatively short interaction length of the very heavy trans-iron particles makes their relative abundance a source of information regarding the amount of interstellar matter that they had to traverse to reach the earth. A study of the trans-iron cosmic rays may provide clues as to the very processes of nucleosyntheses by which the bulk of the trans-iron nuclei in the universe are produced. This in turn may shed light on the mechanics of the supernova, which is postulated to be the major source of all cosmic rays. Finally, trans-iron cosmic ray experiments may demonstrate the existence of the recently postulated super-heavy nuclei.

Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cholis, Ilias; Hooper, Dan; Linden, Tim

2017-01-16

The antiproton-to-proton ratio in the cosmic-ray spectrum is a sensitive probe of new physics. Using recent measurements of the cosmic-ray antiproton and proton fluxes in the energy range of 1-1000 GeV, we study the contribution to themore » $$\\bar{p}/p$$ ratio from secondary antiprotons that are produced and subsequently accelerated within individual supernova remnants. We consider several well-motivated models for cosmic-ray propagation in the interstellar medium and marginalize our results over the uncertainties related to the antiproton production cross section and the time-, charge-, and energy-dependent effects of solar modulation. We find that the increase in the $$\\bar{p}/p$$ ratio observed at rigidities above $$\\sim$$ 100 GV cannot be accounted for within the context of conventional cosmic-ray propagation models, but is consistent with scenarios in which cosmic-ray antiprotons are produced and subsequently accelerated by shocks within a given supernova remnant. In light of this, the acceleration of secondary cosmic rays in supernova remnants is predicted to substantially contribute to the cosmic-ray positron spectrum, accounting for a significant fraction of the observed positron excess.« less

Constraints on cosmic ray and PeV neutrino production in blazars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, B. Theodore; Li, Zhuo, E-mail: zhangbing91@pku.edu.cn, E-mail: zhuo.li@pku.edu.cn

2017-03-01

IceCube has detected a cumulative flux of PeV neutrinos, which origin is unknown. Blazars, active galactic nuclei with relativistic jets pointing to us, are long and widely expected to be one of the strong candidates of high energy neutrino sources. The neutrino production depends strongly on the cosmic ray power of blazar jets, which is largely unknown. The recent null results in stacking searches of neutrinos for several blazar samples by IceCube put upper limits on the neutrino fluxes from these blazars. Here we compute the cosmic ray power and PeV neutrino flux of Fermi-LAT blazars, and find that themore » upper limits for known blazar sources give stringent constraint on the cosmic ray loading factor of blazar jets (i.e., the ratio of the cosmic ray to bolometric radiation luminosity of blazar jets), ξ{sub cr} ∼< (2–10)ζ{sup −1} (with ζ ∼< 1 the remained fraction of cosmic ray energy when propagate into the blazar broad line region) for flat cosmic ray spectrum, and that the cumulative PeV neutrino flux contributed by all-sky blazars is a fraction ∼< (10–50)% of the IceCube detected flux.« less

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.

Blazar Jet Physics in the Age of Fermi

DTIC Science & Technology

2010-11-23

in colliding shells, and whether blazars are sources of ultra-high energy cosmic rays . Keywords. galaxies: jets, gamma rays : observations, gamma rays ...colliding shells ejected from the central supermassive black hole are made. The likelihood that blazars accelerate ultra-high energy cosmic rays is...colliding shells, and whether blazars are sources of ultra-high energy cosmic rays . 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

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.

Cosmic-ray detectors on the Moon

NASA Technical Reports Server (NTRS)

Linsley, John

1988-01-01

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

Balloon test project: Cosmic Ray Antimatter Calorimeter (CRAC)

NASA Technical Reports Server (NTRS)

Christy, J. C.; Dhenain, G.; Goret, P.; Jorand, J.; Masse, P.; Mestreau, P.; Petrou, N.; Robin, A.

1984-01-01

Cosmic ray observations from balloon flights are discussed. The cosmic ray antimatter calorimeter (CRAC) experiment attempts to measure the flux of antimatter in the 200-600 Mev/m energy range and the isotopes of light elements between 600 and 1,000 Mev/m.

Nineteenth International Cosmic Ray Conference. SH Sessions, Volume 5

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 addressing cosmic ray gradients in the heliosphere; siderial, diurnal, and long term modulations; geomagnetic and atmospheric effects; cosmogenic nuclides; solar neutrinos; and detection techniques.

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.

Signatures of cosmic-ray interactions on the solar surface

NASA Technical Reports Server (NTRS)

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

1991-01-01

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

The distribution of cosmic rays in the galaxy and their dynamics as deduced from recent gamma ray observations. [noting maximum in toroidal region between 4 and 5 kpc from galactic center

NASA Technical Reports Server (NTRS)

Puget, J. L.; Stecker, F. W.

1974-01-01

Data from SAS-2 on the galactic gamma ray line flux as a function of longitude is examined. It is shown that the gamma ray emissivity varies with galactocentric distance and is about an order of magnitude higher than the local value in a toroidal region between 4 and 5 kpc from the galactic center. This enhancement is accounted for in part by first-order Fermi acceleration, compression, and trapping of cosmic rays consistent with present ideas of galactic dynamics and galactic structure theory. Calculations indicate that cosmic rays in the 4 to 5 kpc region are trapped and accelerated over a mean time of the order of a few million years or about 2 to 4 times the assumed trapping time in the solar region of the galaxy on the assumption that only an increased cosmic ray flux is responsible for the observed emission. Cosmic ray nucleons, cosmic ray electrons, and ionized hydrogen gas were found to have a strikingly similar distribution in the galaxy according to both the observational data and the theoretical model discussed.

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

PubMed

2009-12-10

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 gamma-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 gamma-ray emission. Here we report the detection of >700-GeV gamma-rays from M82. From these data we determine a cosmic-ray density of 250 eV cm(-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.

Steady state and dynamical structure of a cosmic-ray-modified termination shock

NASA Technical Reports Server (NTRS)

Donohue, D. J.; Zank, G. P.

1993-01-01

A hydrodynamic model is developed for the structure of a cosmic-ray-modified termination shock. The model is based on the two-fluid equations of diffuse shock acceleration (Drury and Volk, 1981). Both the steady state structure of the shock and its interaction with outer heliospheric disturbances are considered. Under the assumption that the solar wind is decelerated by diffusing interstellar cosmic rates, it is shown that the natural state of the termination shock is a gradual deceleration and compression, followed by a discontinuous jump to a downstream state which is dominated by the pressure contribution of the cosmic rays. A representative model is calculated for the steady state which incorporates both interstellar cosmic ray mediation and diffusively accelerated anomalous ions through a proposed thermal leakage mechanism. The interaction of large-scale disturbances with the equilibrium termination shock model is shown to result in some unusual downstream structure, including transmitted shocks and cosmic-ray-modified contact discontinuities. The structure observed may be connected to the 2-kHz outer heliospheric radio emission (Cairns et al., 1992a, b). The time-dependent simulations also demonstrate that interaction with solar wind compressible turbulence (e.g., traveling interplanetary shocks, etc.) could induce the termination shock to continually fluctuate between cosmic-ray-dominated and gas-dynamic states. This fluctuation may represent a partial explanation of the galactic cosmic ray modulation effect and illustrates that the Pioneer and Voyager satellites will encounter an evolving shock whose structure and dynamic properties are strongly influence by the mediation of interstellar and anomalous cosmic rays.

Steady state and dynamical structure of a cosmic-ray-modified termination shock

NASA Astrophysics Data System (ADS)

Donohue, D. J.; Zank, G. P.

1993-11-01

A hydrodynamic model is developed for the structure of a cosmic-ray-modified termination shock. The model is based on the two-fluid equations of diffuse shock acceleration (Drury and Volk, 1981). Both the steady state structure of the shock and its interaction with outer heliospheric disturbances are considered. Under the assumption that the solar wind is decelerated by diffusing interstellar cosmic rates, it is shown that the natural state of the termination shock is a gradual deceleration and compression, followed by a discontinuous jump to a downstream state which is dominated by the pressure contribution of the cosmic rays. A representative model is calculated for the steady state which incorporates both interstellar cosmic ray mediation and diffusively accelerated anomalous ions through a proposed thermal leakage mechanism. The interaction of large-scale disturbances with the equilibrium termination shock model is shown to result in some unusual downstream structure, including transmitted shocks and cosmic-ray-modified contact discontinuities. The structure observed may be connected to the 2-kHz outer heliospheric radio emission (Cairns et al., 1992a, b). The time-dependent simulations also demonstrate that interaction with solar wind compressible turbulence (e.g., traveling interplanetary shocks, etc.) could induce the termination shock to continually fluctuate between cosmic-ray-dominated and gas-dynamic states. This fluctuation may represent a partial explanation of the galactic cosmic ray modulation effect and illustrates that the Pioneer and Voyager satellites will encounter an evolving shock whose structure and dynamic properties are strongly influence by the mediation of interstellar and anomalous cosmic rays.

Heliospheric influence on the anisotropy of TeV cosmic rays

DOE PAGES

Zhang, Ming; Zuo, Pingbing; Pogorelov, Nikolai

2014-06-26

This article provides a theory of using Liouville's theorem to map the anisotropy of TeV cosmic rays seen at Earth using the particle distribution function in the local interstellar medium (LISM). The ultimate source of cosmic ray anisotropy is the energy, pitch angle, and spatial dependence of the cosmic ray distribution function in the LISM. Because young nearby cosmic ray sources can make a special contribution to the cosmic ray anisotropy, the anisotropy depends on the source age, distance and magnetic connection, and particle diffusion of these cosmic rays, all of which make the anisotropy sensitive to the particle energy.more » When mapped through the magnetic and electric field of a magnetohydrodynamic model heliosphere, the large-scale dipolar and bidirectional interstellar anisotropy patterns become distorted if they are seen from Earth, resulting in many small structures in the observations. Best fits to cosmic ray anisotropy measurements have allowed us to estimate the particle density gradient and pitch angle anisotropies in the LISM. It is found that the heliotail, hydrogen deflection plane, and the plane perpendicular to the LISM magnetic field play a special role in distorting cosmic ray anisotropy. These features can lead to an accurate determination of the LISM magnetic field direction and polarity. The effects of solar cycle variation, the Sun's coronal magnetic field, and turbulence in the LISM and heliospheric magnetic fields are minor but clearly visible at a level roughly equal to a fraction of the overall anisotropy amplitude. Lastly, the heliospheric influence becomes stronger at lower energies. Below 1 TeV, the anisotropy is dominated by small-scale patterns produced by disturbances in the heliosphere.« less

Heliospheric influence on the anisotropy of TeV cosmic rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Ming; Zuo, Pingbing; Pogorelov, Nikolai, E-mail: mzhang@fit.edu

2014-07-20

This paper provides a theory of using Liouville's theorem to map the anisotropy of TeV cosmic rays seen at Earth using the particle distribution function in the local interstellar medium (LISM). The ultimate source of cosmic ray anisotropy is the energy, pitch angle, and spatial dependence of the cosmic ray distribution function in the LISM. Because young nearby cosmic ray sources can make a special contribution to the cosmic ray anisotropy, the anisotropy depends on the source age, distance and magnetic connection, and particle diffusion of these cosmic rays, all of which make the anisotropy sensitive to the particle energy.more » When mapped through the magnetic and electric field of a magnetohydrodynamic model heliosphere, the large-scale dipolar and bidirectional interstellar anisotropy patterns become distorted if they are seen from Earth, resulting in many small structures in the observations. Best fits to cosmic ray anisotropy measurements have allowed us to estimate the particle density gradient and pitch angle anisotropies in the LISM. It is found that the heliotail, hydrogen deflection plane, and the plane perpendicular to the LISM magnetic field play a special role in distorting cosmic ray anisotropy. These features can lead to an accurate determination of the LISM magnetic field direction and polarity. The effects of solar cycle variation, the Sun's coronal magnetic field, and turbulence in the LISM and heliospheric magnetic fields are minor but clearly visible at a level roughly equal to a fraction of the overall anisotropy amplitude. The heliospheric influence becomes stronger at lower energies. Below 1 TeV, the anisotropy is dominated by small-scale patterns produced by disturbances in the heliosphere.« less

Cosmic Rays in Intermittent Magnetic Fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shukurov, Anvar; Seta, Amit; Bushby, Paul J.

The propagation of cosmic rays in turbulent magnetic fields is a diffusive process driven by the scattering of the charged particles by random magnetic fluctuations. Such fields are usually highly intermittent, consisting of intense magnetic filaments and ribbons surrounded by weaker, unstructured fluctuations. Studies of cosmic-ray propagation have largely overlooked intermittency, instead adopting Gaussian random magnetic fields. Using test particle simulations, we calculate cosmic-ray diffusivity in intermittent, dynamo-generated magnetic fields. The results are compared with those obtained from non-intermittent magnetic fields having identical power spectra. The presence of magnetic intermittency significantly enhances cosmic-ray diffusion over a wide range of particlemore » energies. We demonstrate that the results can be interpreted in terms of a correlated random walk.« less

Apollo-Soyuz pamphlet no. 6: Cosmic ray dosage. [experimental designiradiation hazards and dosage

NASA Technical Reports Server (NTRS)

Page, L. W.; From, T. P.

1977-01-01

The radiation hazard inside spacecraft is discussed with emphasis on its effects on the crew, biological specimens, and spacecraft instruments. The problem of light flash sensations in the eyes of astronauts is addressed and experiment MA-106 is described. In this experiment, light flashes seen by blindfolded astronauts were counted and high energy cosmic ray intensity in the command module cabin were measured. The damage caused by cosmic ray hits on small living organisms was investigated in the Biostack 3 experiment (MA-107). Individual cosmic rays were tracked through layers of bacterial spores, small seeds, and eggs interleaved with layers of AgCl-crystal wafers, special plastic, and special photographic film that registered each cosmic ray particle passed.

The STScI STIS Pipeline V: Cosmic Ray Rejection

NASA Astrophysics Data System (ADS)

Baum, Stefi; Hsu, J. C.; Hodge, Phil; Ferguson, Harry

1996-07-01

In this ISR we describe calstis-2, the calstis calibration module which combines CRSPLIT exposures to produce a single cosmic ray rejected image. Cosmic ray rejection in the STIS pipeline will follow the same basic philosophy as does the STSDAS task crrej - a series of separate CRSPLIT exposures are combined to produce a single summed image, where discrepant (different by some number of sigma from the guess value) are discarded in forming the output image. The calstis pipeline is able to perform this cosmic ray rejection because the individually commanded exposures are associated together into a single dataset by TRANS and generic conversion. The crrej will also exist as a task in STSDAS to allow users to reperform the cosmic ray rejection, altering the input parameters.

Cosmic ray antimatter and baryon symmetric cosmology

NASA Technical Reports Server (NTRS)

Stecker, F. W.; Protheroe, R. J.; Kazanas, D.

1982-01-01

The relative merits and difficulties of the primary and secondary origin hypotheses for the observed cosmic-ray antiprotons, including the new low-energy measurement of Buffington, et al. We conclude that the cosmic-ray antiproton data may be evidence for antimatter galaxies and baryon symmetric cosmology. The present bar P data are consistent with a primary extragalactic component having /p=/equiv 1+/- 3.2/0.7x10 = to the -4 independent of energy. We propose that the primary extragalactic cosmic ray antiprotons are most likely from active galaxies and that expected disintegration of bar alpha/alpha ban alpha/alpha. We further predict a value for ban alpha/alpha =/equiv 10 to the -5, within range of future cosmic ray detectors.

Measurement of the flux of ultra high energy cosmic rays by the stereo technique

NASA Astrophysics Data System (ADS)

High Resolution Fly'S Eye Collaboration; Abbasi, R. U.; Abu-Zayyad, T.; Al-Seady, M.; Allen, M.; Amann, J. F.; Archbold, G.; Belov, K.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Brusova, O. A.; Burt, G. W.; Cannon, C.; Cao, Z.; Deng, W.; Fedorova, Y.; Findlay, J.; Finley, C. B.; Gray, R. C.; Hanlon, W. F.; Hoffman, C. M.; Holzscheiter, M. H.; Hughes, G.; Hüntemeyer, P.; Ivanov, D.; Jones, B. F.; Jui, C. C. H.; Kim, K.; Kirn, M. A.; Loh, E. C.; Maestas, M. M.; Manago, N.; Marek, L. J.; Martens, K.; Matthews, J. A. J.; Matthews, J. N.; Moore, S. A.; O'Neill, A.; Painter, C. A.; Perera, L.; Reil, K.; Riehle, R.; Roberts, M. D.; Rodriguez, D.; Sasaki, M.; Schnetzer, S. R.; Scott, L. M.; Sinnis, G.; Smith, J. D.; Snow, R.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Thomas, J. R.; Thomas, S. B.; Thomson, G. B.; Tupa, D.; Wiencke, L. R.; Zech, A.; Zhang, B. K.; Zhang, X.; Zhang, Y.; High Resolution Fly's Eye Collaboration

2009-08-01

The High Resolution Fly’s Eye (HiRes) experiment has measured the flux of ultrahigh energy cosmic rays using the stereoscopic air fluorescence technique. The HiRes experiment consists of two detectors that observe cosmic ray showers via the fluorescence light they emit. HiRes data can be analyzed in monocular mode, where each detector is treated separately, or in stereoscopic mode where they are considered together. Using the monocular mode the HiRes collaboration measured the cosmic ray spectrum and made the first observation of the Greisen-Zatsepin-Kuzmin cutoff. In this paper we present the cosmic ray spectrum measured by the stereoscopic technique. Good agreement is found with the monocular spectrum in all details.

Elemental composition and energy spectra of galactic cosmic rays

NASA Technical Reports Server (NTRS)

Mewaldt, R. A.

1988-01-01

A brief review is presented of the major features of the elemental composition and energy spectra of galactic cosmic rays. The requirements for phenomenological models of cosmic ray composition and energy spectra are discussed, and possible improvements to an existing model are suggested.

An investigation of techniques for the measurement and interpretation of cosmic ray isotopic abundances. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Wiedenbeck, M. E.

1977-01-01

An instrument, the Caltech High Energy Isotope Spectrometer Telescope was developed to measure isotopic abundances of cosmic ray nuclei by employing an energy loss - residual energy technique. A detailed analysis was made of the mass resolution capabilities of this instrument. A formalism, based on the leaky box model of cosmic ray propagation, was developed for obtaining isotopic abundance ratios at the cosmic ray sources from abundances measured in local interstellar space for elements having three or more stable isotopes, one of which is believed to be absent at the cosmic ray sources. It was shown that the dominant sources of uncertainty in the derived source ratios are uncorrelated errors in the fragmentation cross sections and statistical uncertainties in measuring local interstellar abundances. These results were applied to estimate the extent to which uncertainties must be reduced in order to distinguish between cosmic ray production in a solar-like environment and in various environments with greater neutron enrichments.

The Need for Direct High-Energy Cosmic-Ray Measurements

NASA Technical Reports Server (NTRS)

Jones, Frank C.; Streitmatter, Robert

2004-01-01

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

Relative distribution of cosmic rays and magnetic fields

NASA Astrophysics Data System (ADS)

Seta, Amit; Shukurov, Anvar; Wood, Toby S.; Bushby, Paul J.; Snodin, Andrew P.

2018-02-01

Synchrotron radiation from cosmic rays is a key observational probe of the galactic magnetic field. Interpreting synchrotron emission data requires knowledge of the cosmic ray number density, which is often assumed to be in energy equipartition (or otherwise tightly correlated) with the magnetic field energy. However, there is no compelling observational or theoretical reason to expect such a tight correlation to hold across all scales. We use test particle simulations, tracing the propagation of charged particles (protons) through a random magnetic field, to study the cosmic ray distribution at scales comparable to the correlation scale of the turbulent flow in the interstellar medium (≃100 pc in spiral galaxies). In these simulations, we find that there is no spatial correlation between the cosmic ray number density and the magnetic field energy density. In fact, their distributions are approximately statistically independent. We find that low-energy cosmic rays can become trapped between magnetic mirrors, whose location depends more on the structure of the field lines than on the field strength.

Experimental Summary: Very High Energy Cosmic Rays and their Interactions

NASA Astrophysics Data System (ADS)

Kampert, Karl-Heinz

2013-06-01

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

A demonstration device for cosmic rays telescopes

NASA Astrophysics Data System (ADS)

Esposito, Salvatore

2018-01-01

We describe a hands-on accurate demonstrator for cosmic rays realized by six high school students. The main aim is to show the relevance and the functioning of the principal parts of a cosmic ray telescope (muon detector), with the help of two large sized wooden artefacts. The first one points out how cosmic rays can be tracked in a muon telescope, while the other one shows the key avalanche process of electronic ionization that effectively allows muon detection through a photomultiplier. Incoming cosmic rays are visualized in terms of laser beams, whose 3D trajectory is highlighted by turning on LEDs on two orthogonal matrices. Instead the avalanche ionization process is demonstrated through the avalanche falling off glass marbles on an inclined plane, finally turning on a LED. A pictured poster accompanying the demonstrator is as effective in assisting cosmic ray demonstration and its detection. The success of the demonstrator has been fully proven by the general public during a science festival, in which the corresponding project won the Honorable Mention in a dedicated competition.

UH cosmic rays and solar system material - The elements just beyond iron

NASA Technical Reports Server (NTRS)

Wefel, J. P.; Schramm, D. N.; Blake, J. B.

1977-01-01

The nucleosynthesis of cosmic-ray elements between the iron peak and the rare-earth region is examined, and compositional changes introduced by propagation in interstellar space are calculated. Theories on the origin of elements heavier than iron are reviewed, a supernova model of explosive nucleosynthesis is adopted for the ultraheavy (UH) cosmic rays, and computational results for different source distributions are compared with experimental data. It is shown that both the cosmic-ray data and the nucleosynthesis calculations are not yet of sufficient precision to pinpoint the processes occurring in cosmic-ray source regions, that the available data do provide boundary conditions for cosmic-ray nucleosynthesis, and that these limits may apply to the origin of elements in the solar system. Specifically, it is concluded that solar-system abundances appear to be consistent with a superposition of the massive-star core-helium-burning s-process plus explosive-carbon-burning synthesis for the elements from Cu to As and are explained adequately by the s- and r-processes for heavier elements.

The KASCADE-Grande observatory and the composition of very high-energy cosmic rays

NASA Astrophysics Data System (ADS)

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

2015-11-01

KASCADE-Grande is an air-shower observatory devoted to the detection of cosmic rays with energies in the range of 1016 to 1018 eV. This energy region is of particular interest for the cosmic ray astrophysics, since it is the place where some models predict the existence of a transition from galactic to extragalactic origin of cosmic rays and the presence of a break in the flux of its heavy component. The detection of these features requires detailed and simultaneous measurements of the energy and composition of cosmic rays with sufficient statistics. These kinds of studies are possible for the first time in KASCADE-Grande due to the accurate measurements of several air-shower observables, i.e., the number of charged particles, electrons and muons in the shower, using the different detector systems of the observatory. In this contribution, a detailed look into the composition of 1016 — 1018 eV cosmic rays with KASCADE-Grande is presented.

Cosmic ray composition and energy spectrum from 1-30 PeV using the 40-string configuration of IceTop and IceCube

NASA Astrophysics Data System (ADS)

IceCube Collaboration; Abbasi, R.; Abdou, Y.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Altmann, D.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Baum, V.; Bay, R.; 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.; Bruijn, R.; Brunner, J.; Buitink, S.; Caballero-Mora, K. S.; Carson, M.; Casey, J.; Casier, M.; Chirkin, D.; Christy, B.; Clevermann, F.; Cohen, S.; Cowen, D. F.; Silva, A. H. Cruz; Danninger, M.; Daughhetee, J.; Davis, J. C.; De Clercq, C.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; DeYoung, T.; Díaz-Vélez, J. C.; Dreyer, J.; Dumm, J. P.; Dunkman, M.; Eagan, R.; 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.; Frantzen, K.; Fuchs, T.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Goodman, J. A.; Góra, D.; Grant, D.; Groß, A.; Grullon, S.; Gurtner, M.; Ha, C.; Ismail, A. Haj; Hallgren, A.; Halzen, F.; Hanson, K.; Heereman, D.; Heimann, P.; Heinen, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Homeier, A.; Hoshina, K.; Huelsnitz, W.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobi, E.; Jacobsen, J.; Japaridze, G. S.; Jlelati, O.; Johansson, H.; Kappes, A.; Karg, T.; Karle, A.; Kiryluk, J.; Kislat, F.; Kläs, J.; Klein, S. R.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krasberg, M.; Kroll, G.; Kunnen, J.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Laihem, K.; Landsman, H.; Larson, M. J.; Lauer, R.; Lesiak-Bzdak, M.; Lünemann, J.; Madsen, J.; Maruyama, R.; Mase, K.; Matis, H. S.; McNally, F.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Miarecki, S.; Middell, E.; Milke, N.; Miller, J.; Mohrmann, L.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Naumann, U.; Nowicki, S. C.; Nygren, D. R.; Obertacke, A.; Odrowski, S.; Olivas, A.; Olivo, M.; O'Murchadha, A.; Panknin, S.; Paul, L.; Pepper, J. A.; de los Heros, C. Pérez; Pieloth, D.; Pirk, N.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Rädel, L.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Richman, M.; Riedel, B.; Rodrigues, J. P.; Rothmaier, F.; Rott, C.; Ruhe, T.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Salameh, T.; Sander, H.-G.; Santander, M.; Sarkar, S.; Saba, S. M.; Schatto, K.; Scheel, M.; Scheriau, F.; Schmidt, T.; Schmitz, M.; Schoenen, S.; Schöneberg, S.; Schönherr, L.; Schönwald, A.; Schukraft, A.; Schulte, L.; Schulz, O.; Seckel, D.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Smith, M. W. E.; Soiron, M.; Soldin, D.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stasik, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Strahler, E. A.; Ström, R.; Sullivan, G. W.; Taavola, H.; Taboada, I.; Tamburro, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Toscano, S.; Usner, M.; van Eijndhoven, N.; van der Drift, D.; 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.; 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.; Ziemann, J.; Zilles, A.; Zoll, M.

2013-02-01

The mass composition of high energy cosmic rays depends on their production, acceleration, and propagation. The study of cosmic ray composition can therefore reveal hints of the origin of these particles. At the South Pole, the IceCube Neutrino Observatory is capable of measuring two components of cosmic ray air showers in coincidence: the electromagnetic component at high altitude (2835 m) using the IceTop surface array, and the muonic component above ˜1 TeV using the IceCube array. This unique detector arrangement provides an opportunity for precision measurements of the cosmic ray energy spectrum and composition in the region of the knee and beyond. We present the results of a neural network analysis technique to study the cosmic ray composition and the energy spectrum from 1 PeV to 30 PeV using data recorded using the 40-string/40-station configuration of the IceCube Neutrino Observatory.

The Cosmic Ray Observatory Project: Results of a Summer High-School Student, Teacher, University Scientist Partnership Using a Capstone Research Experience

NASA Astrophysics Data System (ADS)

Shell, Duane F.; Snow, Gregory R.; Claes, Daniel R.

2011-04-01

This paper reports results from evaluation of the Cosmic Ray Observatory Project (CROP), a student, teacher, scientist partnership to engage high-school students and teachers in school based cosmic ray research. Specifically, this study examined whether an intensive summer workshop experience could effectively prepare teacher—student teams to engage in cutting edge high-energy physics research. Results showed that teachers and students could acquire enough knowledge about cosmic ray physics and self-efficacy for conducting cosmic ray research during a summer workshop to be full participants in an SSP conducting research in their schools, and a capstone anchoring approach using an authentic research activity was effective for motivating student engagement in didactic classroom learning. CROP demonstrated "proof of concept" that setting up cosmic ray detector arrays in schools run by teachers and students was feasible, but found that set-up and operation in a high-school was technically difficult.

A measurement of the cosmic ray elements C to Fe in the two energy intervals 0.5-2.0 GeV/n and 20-60 GeV/n

NASA Technical Reports Server (NTRS)

Derrickson, J. H.; Parnell, T. A.; Watts, J. W.; Gregory, J. C.

1985-01-01

The study of the cosmic ray abundances beyond 20 GeV/n provides additional information on the propagation and containment of the cosmic rays in the galaxy. Since the average amount of interstellar material traversed by cosmic rays decreases as its energy increases, the source composition undergoes less distortion in this higher energy region. However, data over a wide energy range is necessary to study propagation parameters. Some measurements of some of the primary cosmic ray abundance ratios at both low (near 2 GeV/n) and high (above 20 GeV/n) energy are given and compared to the predictions of the leaky box mode. In particular, the integrated values (above 23.7 GeV/n) for the more abundant cosmic ray elements in the interval C through Fe and the differential flux for carbon, oxygen, and the Ne, Mg, Si group are presented. Limited statistics prevented the inclusion of the odd Z elements.

Lateral distribution of muons in IceCube cosmic ray events

NASA Astrophysics Data System (ADS)

Abbasi, R.; Abdou, Y.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Altmann, D.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Baum, V.; Bay, R.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker Tjus, J.; 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.; Bruijn, R.; Brunner, J.; Buitink, S.; Carson, M.; Casey, J.; Casier, M.; Chirkin, D.; Christy, B.; Clevermann, F.; Cohen, S.; Cowen, D. F.; Cruz Silva, A. H.; Danninger, M.; Daughhetee, J.; Davis, J. C.; De Clercq, C.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; DeYoung, T.; Díaz-Vélez, J. C.; Dreyer, J.; Dumm, J. P.; Dunkman, M.; Eagan, R.; 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.; Frantzen, K.; Fuchs, T.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Goodman, J. A.; Góra, D.; Grant, D.; Groß, A.; Grullon, S.; Gurtner, M.; Ha, C.; Haj Ismail, A.; Hallgren, A.; Halzen, F.; Hanson, K.; Heereman, D.; Heimann, P.; Heinen, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Homeier, A.; Hoshina, K.; Huelsnitz, W.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobi, E.; Jacobsen, J.; Japaridze, G. S.; Jlelati, O.; Kappes, A.; Karg, T.; Karle, A.; Kiryluk, J.; Kislat, F.; Kläs, J.; Klein, S. R.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krasberg, M.; Kroll, G.; Kunnen, J.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Laihem, K.; Landsman, H.; Larson, M. J.; Lauer, R.; Lesiak-Bzdak, M.; Lünemann, J.; Madsen, J.; Maruyama, R.; Mase, K.; Matis, H. S.; McNally, F.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Miarecki, S.; Middell, E.; Milke, N.; Miller, J.; Mohrmann, L.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Naumann, U.; Nowicki, S. C.; Nygren, D. R.; Obertacke, A.; Odrowski, S.; Olivas, A.; Olivo, M.; O'Murchadha, A.; Panknin, S.; Paul, L.; Pepper, J. A.; Pérez de los Heros, C.; Pieloth, D.; Pirk, N.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Rädel, L.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Richman, M.; Riedel, B.; Rodrigues, J. P.; Rothmaier, F.; Rott, C.; Ruhe, T.; Ruzybayev, B.; Ryckbosch, D.; Saba, S. M.; Salameh, T.; Sander, H.-G.; Santander, M.; Sarkar, S.; Schatto, K.; Scheel, M.; Scheriau, F.; Schmidt, T.; Schmitz, M.; Schoenen, S.; Schöneberg, S.; Schönherr, L.; Schönwald, A.; Schukraft, A.; Schulte, L.; Schulz, O.; Seckel, D.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Smith, M. W. E.; Soiron, M.; Soldin, D.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stasik, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Strahler, E. A.; Ström, R.; Sullivan, G. W.; Taavola, H.; Taboada, I.; Tamburro, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Toscano, S.; Usner, M.; van der Drift, 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.; 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.; Ziemann, J.; Zilles, A.; Zoll, M.

2013-01-01

In cosmic ray air showers, the muon lateral separation from the center of the shower is a measure of the transverse momentum that the muon parent acquired in the cosmic ray interaction. IceCube has observed cosmic ray interactions that produce muons laterally separated by up to 400 m from the shower core, a factor of 6 larger distance than previous measurements. These muons originate in high pT (>2GeV/c) interactions from the incident cosmic ray, or high-energy secondary interactions. The separation distribution shows a transition to a power law at large values, indicating the presence of a hard pT component that can be described by perturbative quantum chromodynamics. However, the rates and the zenith angle distributions of these events are not well reproduced with the cosmic ray models tested here, even those that include charm interactions. This discrepancy may be explained by a larger fraction of kaons and charmed particles than is currently incorporated in the simulations.

An estimation of Canadian population exposure to cosmic rays.

PubMed

Chen, Jing; Timmins, Rachel; Verdecchia, Kyle; Sato, Tatsuhiko

2009-08-01

The worldwide average exposure to cosmic rays contributes to about 16% of the annual effective dose from natural radiation sources. At ground level, doses from cosmic ray exposure depend strongly on altitude, and weakly on geographical location and solar activity. With the analytical model PARMA developed by the Japan Atomic Energy Agency, annual effective doses due to cosmic ray exposure at ground level were calculated for more than 1,500 communities across Canada which cover more than 85% of the Canadian population. The annual effective doses from cosmic ray exposure in the year 2000 during solar maximum ranged from 0.27 to 0.72 mSv with the population-weighted national average of 0.30 mSv. For the year 2006 during solar minimum, the doses varied between 0.30 and 0.84 mSv, and the population-weighted national average was 0.33 mSv. Averaged over solar activity, the Canadian population-weighted average annual effective dose due to cosmic ray exposure at ground level is estimated to be 0.31 mSv.

High energy physics in cosmic rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Lawrence W.

2013-02-07

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

Ninteenth International Cosmic Ray Conference. OG Sessions, Volume 1

NASA Technical Reports Server (NTRS)

Jones, F. C. (Compiler)

1985-01-01

Contributed papers addressing cosmic ray origin and galactic phenomena are compiled. The topic areas covered in this volume include gamma ray bursts, gamma rays from point sources, and diffuse gamma ray emission.

Gamma rays from Centaurus A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, Nayantara, E-mail: nayan@phy.iitb.ac.in

2008-06-15

Centaurus A, the cosmic ray accelerator a few Mpc away from us, is possibly one of the nearest sources of extremely high energy cosmic rays. We investigate whether the gamma ray data currently available from Centaurus A in the GeV-TeV energy band can be explained with only proton-proton interactions. We show that for a single power law proton spectrum, mechanisms of {gamma}-ray production other than proton-proton interactions are needed inside this radio-galaxy to explain the gamma ray flux observed by EGRET, upper limits from HESS/CANGAROO-III and the correlated extremely energetic cosmic ray events observed by the Pierre Auger experiment. Inmore » future, with better {gamma}-ray data, and simultaneous observation with {gamma}-ray and cosmic ray detectors, it will be possible to carry out such studies on different sources in more detail.« less

Leptophilic dark matter in gauged U(1)_{L{_e}-L_{μ }} model in light of DAMPE cosmic ray {e{^+}} + {e{^-}} excess

NASA Astrophysics Data System (ADS)

Duan, Guang Hua; He, Xiao-Gang; Wu, Lei; Yang, Jin Min

2018-04-01

Motivated by the very recent cosmic-ray electron+positron excess observed by DAMPE collaboration, we investigate a Dirac fermion dark matter (DM) in the gauged {{L_e} - {L_μ }} model. DM interacts with the electron and muon via the U(1)_{e-μ } gauge boson Z^' . The model can explain the DAMPE data well. Although a non-zero DM-nucleon cross section is only generated at one loop level and there is a partial cancellation between Z^' }ee and Z^' }μ μ couplings, we find that a large portion of Z' mass is ruled out from direct DM detection limit leaving the allowed Z^' } mass to be close to two times of the DM mass. Implications for pp → Z^' } → 2ℓ and pp → 2ℓ + Z^' }, and muon g-2 anomaly are also studied.

Characterising encapsulated nuclear waste using cosmic-ray muon tomography

NASA Astrophysics Data System (ADS)

Clarkson, A.; Hamilton, D. J.; Hoek, M.; Ireland, D. G.; Johnstone, J. R.; Kaiser, R.; Keri, T.; Lumsden, S.; Mahon, D. F.; McKinnon, B.; Murray, M.; Nutbeam-Tuffs, S.; Shearer, C.; Yang, G.; Zimmerman, C.

2015-03-01

Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons have been shown previously to successfully identify and characterise low- and high-Z materials within an air matrix using a prototype scintillating-fibre tracker system. Those studies were performed as the first in a series to assess the feasibility of this technology and image reconstruction techniques in characterising the potential high-Z contents of legacy nuclear waste containers for the U.K. Nuclear Industry. The present work continues the feasibility study and presents the first images reconstructed from experimental data collected using this small-scale prototype system of low- and high-Z materials encapsulated within a concrete-filled stainless-steel container. Clear discrimination is observed between the thick steel casing, the concrete matrix and the sample materials assayed. These reconstructed objects are presented and discussed in detail alongside the implications for future industrial scenarios.

Cosmic Ray Modulation in the Outer Heliosphere During the Minimum of Solar Cycle 23/24

NASA Technical Reports Server (NTRS)

Adams, James H., Jr.; Florinski, V.; Washimi, H.; Pogorelov, N. V.

2011-01-01

We report a next generation model of galactic cosmic ray (GCR) transport in the three dimensional heliosphere. Our model is based on an accurate three-dimensional representation of the heliospheric interface. This representation is obtained by taking into account the interaction between partially ionized, magnetized plasma flows of the solar wind and the local interstellar medium. Our model reveals that after entering the heliosphere GCRs are stored in the heliosheath for several years. The preferred GCR entry locations are near the nose of the heliopause and at high latitudes. Low-energy (hundreds of MeV) galactic ions observed in the heliosheath have spent, on average, a longer time in the solar wind than those observed in the inner heliosphere, which would explain their cooled-off spectra at these energies. We also discuss radial gradients in the heliosheath and the implications for future Voyager observations.

Do cosmic ray air showers initiate lightning?: A statistical analysis of cosmic ray air showers and lightning mapping array data

NASA Astrophysics Data System (ADS)

Hare, B. M.; Dwyer, J. R.; Winner, L. H.; Uman, M. A.; Jordan, D. M.; Kotovsky, D. A.; Caicedo, J. A.; Wilkes, R. A.; Carvalho, F. L.; Pilkey, J. T.; Ngin, T. K.; Gamerota, W. R.; Rassoul, H. K.

2017-08-01

It has been argued in the technical literature, and widely reported in the popular press, that cosmic ray air showers (CRASs) can initiate lightning via a mechanism known as relativistic runaway electron avalanche (RREA), where large numbers of high-energy and low-energy electrons can, somehow, cause the local atmosphere in a thundercloud to transition to a conducting state. In response to this claim, other researchers have published simulations showing that the electron density produced by RREA is far too small to be able to affect the conductivity in the cloud sufficiently to initiate lightning. In this paper, we compare 74 days of cosmic ray air shower data collected in north central Florida during 2013-2015, the recorded CRASs having primary energies on the order of 1016 eV to 1018 eV and zenith angles less than 38°, with Lightning Mapping Array (LMA) data, and we show that there is no evidence that the detected cosmic ray air showers initiated lightning. Furthermore, we show that the average probability of any of our detected cosmic ray air showers to initiate a lightning flash can be no more than 5%. If all lightning flashes were initiated by cosmic ray air showers, then about 1.6% of detected CRASs would initiate lightning; therefore, we do not have enough data to exclude the possibility that lightning flashes could be initiated by cosmic ray air showers.

Numerical Model for Cosmic Rays Species Production and Propagation in the Galaxy

NASA Technical Reports Server (NTRS)

Farahat, Ashraf; Zhang, Ming; Rassoul, Hamid; Connell, J. J.

2005-01-01

In recent years, considerable progress has been made in studying the propagation and origin of cosmic rays, as new and more accurate data have become available. Many models have been developed to study cosmic ray interactions and propagation showed flexibility in resembling various astrophysical conditions and good agreement with observational data. However, some astrophysical problems cannot be addressed using these models, such as the stochastic nature of the cosmic rays source, small-scale structures and inhomogeneities in the interstellar gas that can affect radioactive secondary abundance in cosmic rays. We have developed a new model and a corresponding computer code that can address some of these limitations. The model depends on the expansion of the backward stochastic solution of the general diffusion transport equation (Zhang 1999) starting from an observer position to solve a group of diffusion transport equations each of which represents a particular element or isotope of cosmic ray nuclei. In this paper we are focusing on key abundance ratios such as B/C, sub-Fe/Fe, (10)Be/(9)Be, (26)Al/(27)Al, (36)Cl/(37)Cl and (54)Mn/(55)Mn, which all have well established cross sections, to evaluate our model. The effect of inhomogeneity in the interstellar medium is investigated. The contribution of certain cosmic ray nuclei to the production of other nuclei is addressed. The contribution of various galactic locations to the production of cosmic ray nuclei observed at solar system is also investigated.

Modulation of Cosmic Ray Precipitation Related to Climate

NASA Technical Reports Server (NTRS)

Feynman, J.; Ruzmaikin, A.

1998-01-01

High energy cosmic rays may influence the formation of clouds, and thus can have an impact on weather and climate. Cosmic rays in the solar wind are incident on the magnetosphere boundary and are then transmitted through the magnetosphere and atmosphere to reach the upper troposphere.

Investigation of the properties of galactic cosmic rays with the KASCADE-Grande experiment

NASA Astrophysics Data System (ADS)

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

2011-02-01

The properties of galactic cosmic rays are investigated with the KASCADE-Grande experiment in the energy range between 1014 and 1018 eV. Recent results are discussed. They concern mainly the all-particle energy spectrum and the elemental composition of cosmic rays.

Impact of particles on the Planck HFI detectors: Ground-based measurements and physical interpretation

NASA Astrophysics Data System (ADS)

Catalano, A.; Ade, P.; Atik, Y.; Benoit, A.; Bréele, E.; Bock, J. J.; Camus, P.; Chabot, M.; Charra, M.; Crill, B. P.; Coron, N.; Coulais, A.; Désert, F.-X.; Fauvet, L.; Giraud-Héraud, Y.; Guillaudin, O.; Holmes, W.; Jones, W. C.; Lamarre, J.-M.; Macías-Pérez, J.; Martinez, M.; Miniussi, A.; Monfardini, A.; Pajot, F.; Patanchon, G.; Pelissier, A.; Piat, M.; Puget, J.-L.; Renault, C.; Rosset, C.; Santos, D.; Sauvé, A.; Spencer, L. D.; Sudiwala, R.

2014-09-01

The Planck High Frequency Instrument (HFI) surveyed the sky continuously from August 2009 to January 2012. Its noise and sensitivity performance were excellent (from 11 to 40 aW Hz-1), but the rate of cosmic-ray impacts on the HFI detectors was unexpectedly higher than in other instruments. Furthermore, collisions of cosmic rays with the focal plane produced transient signals in the data (glitches) with a wide range of characteristics and a rate of about one glitch per second. A study of cosmic-ray impacts on the HFI detector modules has been undertaken to categorize and characterize the glitches, to correct the HFI time-ordered data, and understand the residual effects on Planck maps and data products. This paper evaluates the physical origins of glitches observed by the HFI detectors. To better understand the glitches observed by HFI in flight, several ground-based experiments were conducted with flight-spare HFI bolometer modules. The experiments were conducted between 2010 and 2013 with HFI test bolometers in different configurations using varying particles and impact energies. The bolometer modules were exposed to 23 MeV protons from the Orsay IPN Tandem accelerator, and to 241Am and 244Cm α-particle and 55Fe radioactive X-ray sources. The calibration data from the HFI ground-based preflight tests were used to further characterize the glitches and compare glitch rates with statistical expectations under laboratory conditions. Test results provide strong evidence that the dominant family of glitches observed in flight are due to cosmic-ray absorption by the silicon die substrate on which the HFI detectors reside. Glitch energy is propagated to the thermistor by ballistic phonons, while thermal diffusion also contributes. The average ratio between the energy absorbed, per glitch, in the silicon die and thatabsorbed in the bolometer is equal to 650. We discuss the implications of these results for future satellite missions, especially those in the far-infrared to submillimeter and millimeter regions of the electromagnetic spectrum.

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.

Selected Theoretical Studies Group contributions to the 14th International Cosmic Ray conference. [including studies on galactic molecular hydrogen, interstellar reddening, and on the origin of cosmic rays

NASA Technical Reports Server (NTRS)

1975-01-01

The galactic distribution of H2 was studied through gamma radiation and through X-ray, optical, and infrared absorption measurements from SAS-2 and other sources. A comparison of the latitude distribution of gamma-ray intensity with reddening data shows reddening data to give the best estimate of interstellar gas in the solar vicinity. The distribution of galactic cosmic ray nucleons was determined and appears to be identical to the supernova remnant distribution. Interactions between ultrahigh energy cosmic-ray nuclei and intergalactic photon radiation fields were calculated, using the Monte Carlo method.

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.

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.

Cosmic ray modulation by high-speed solar wind fluxes

NASA Technical Reports Server (NTRS)

Dorman, L. I.; Kaminer, N. S.; Kuzmicheva, A. E.; Mymrina, N. V.

1985-01-01

Cosmic ray intensity variations connected with recurrent high-speed fluxes (HSF) of solar wind are investigated. The increase of intensity before the Earth gets into a HSF, north-south anisotropy and diurnal variation of cosmic rays inside a HSF as well as the characteristics of Forbush decreases are considered.

Elemental composition, isotopes, electrons and positrons in cosmic rays

NASA Technical Reports Server (NTRS)

Balasubrahmanyan, V. K.

1979-01-01

Papers presented at the 16th International Cosmic Ray Conference, Kyoto, Japan, dealing with the composition of cosmic rays are reviewed. Particular interest is given to data having bearing on nucleosynthesis sites, supernovae, gamma-process, comparison with solar system composition, multiplicity of sources, and the energy dependence of composition.

Badhwar-O'Neil 2007 Galactic Cosmic Ray (GCR) Model Using Advanced Composition Explorer (ACE) Measurements for Solar Cycle 23

NASA Technical Reports Server (NTRS)

ONeill, P. M.

2007-01-01

Advanced Composition Explorer (ACE) satellite measurements of the galactic cosmic ray flux and correlation with the Climax Neutron Monitor count over Solar Cycle 23 are used to update the Badhwar O'Neill Galactic Cosmic Ray (GCR) model.

Testing Galactic Cosmic Ray Models

NASA Technical Reports Server (NTRS)

Adams, James H., Jr.

2009-01-01

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

Testing Galactic Cosmic Ray Models

NASA Technical Reports Server (NTRS)

Adams, James H., Jr.

2010-01-01

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

Rossi and high-energy astronomy

NASA Astrophysics Data System (ADS)

Clark, George W.

2012-03-01

The contributions of Bruno Rossi to high-energy astronomy began in Italy in the 1930s with investigations concerning the nature of cosmic rays in theory and in hands-on experiments at the universities of Florence and Padua. Recent discoveries had cast doubt on Robert Millikan's idea that the primary cosmic rays are gamma rays created in the production of the elements by fusion of hydrogen atoms in interstellar space. Rossi entered the field with a prediction published in 1930 of a difference between the intensity of cosmic rays from the east and the west that would occur if the primary cosmic rays were charged particles of one sign. In the same year he invented the first practical electronic coincidence circuit, which he used in a series of fundamental particle experiments and in an unsuccessful attempt to detect an east-west effect at Florence. Expecting by theory that the effect would be greater at high altitude near the equator, he took his experiment to Eritrea in 1934 where his measurements demonstrated that the primary cosmic rays are predominantly positive particles. In the report of his expedition he also described his discovery of extensive cosmic-ray air showers. After WWII and his work at Los Alamos, Rossi resumed his cosmic-ray research, now at MIT, in a new style best described in his own words: ``Now I had the responsibility of an entire group, and what mattered was no longer my own work, but the work of the group.'' He suggested the new methods of ``density sampling'' and ``fast timing'' for air shower studies, and promoted their application in numerous experiments on the nature and origins of the highest energy cosmic rays. In 1959 he initiated and participated as a consultant in the work of Riccardo Giacconi that led to the discovery of the first x-ray star, Sco X-1, and the development of the first imaging x-ray telescopes. At MIT, members of the Rossi Cosmic Ray Group took the early steps in gamma-ray astronomy, first with balloon experiments that set lower and lower limits on the intensity of primary gamma rays, and then with the satellite experiments led by William Kraushaar that discovered the galactic and extra-galactic components of cosmic gamma rays. After Sco X-1, Rossi focused his efforts on exploring the solar wind and the interplanetary plasma while leaving his younger colleagues to pursue the new field of extra-solar x-ray astronomy with balloon, rocket, and satellite experiments.

Cosmic-ray electrons and galactic radio emission - A conflict

NASA Technical Reports Server (NTRS)

Badhwar, G. D.; Daniel, R. R.; Stephens, S. A.

1977-01-01

An analysis which takes into account the observed energy spectrum of cosmic-ray electrons above 5 GeV and calculated mean magnetic field data shows that the observed spectral index of the radio continuum in the Galaxy is in conflict with some of the cosmic-ray electron measurements. It is found that the absolute intensities of cosmic-ray electrons measured by some of the experimenters are so low that they cannot be reconciled either with the interstellar magnetic field limits or with the extent of the galactic disk toward the anticenter.

11- and 22-year variations of the cosmic ray density and of the solar wind speed

NASA Technical Reports Server (NTRS)

Chirkov, N. P.

1985-01-01

Cosmic ray density variations for 17-21 solar activity cycles and the solar wind speed for 20-21 events are investigated. The 22-year solar wind speed recurrence was found in even and odd cycles. The 22-year variations of cosmic ray density were found to be opposite that of solar wind speed and solar activity. The account of solar wind speed in 11-year variations significantly decreases the modulation region of cosmic rays when E = 10-20 GeV.

Cosmic rays in the heliosphere

NASA Technical Reports Server (NTRS)

Webber, William R.

1987-01-01

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

The effect of the neutral sheet structure of the interplanetary magnetic field on cosmic ray distribution in space

NASA Technical Reports Server (NTRS)

Alania, M. V.; Aslamazashvili, R. G.; Bochorishvili, T.; Djapiashvili, T. V.; Tkemaladze, V. S.

1985-01-01

Results of the numerical solution of the anistoropic diffusion equation are presented. The modulation depth of galactic cosmic rays is defined by the degree of curvature of the neutral current sheet in the heliosphere. The effect of the regular interplanetary magnetic field (IMF) on cosmic ray anisotropy in the period of solar activity minimum (in 1976) is analyzed by the data of the neutron super-monitors of the world network, and the heliolatitudinal gradient and cosmic ray diffusion coefficient are defined.

Viscosity and inertia in cosmic-ray transport - Effects of an average magnetic field

NASA Technical Reports Server (NTRS)

Williams, L. L.; Jokipii, J. R.

1991-01-01

A generalized transport equation is introduced which describes the transport and propagation of cosmic rays in a magnetized, collisionless medium. The equation is valid if the cosmic-ray distribution function is nearly isotropic in momentum, if the ratio of fluid speed to fluid-flow particle speed is small, and if the ratio of collision time to time for change in the macroscopic flow is small. Five independent cosmic-ray viscosity coefficients are found, and the ralationship of this viscosity to particle orbits in a magnetic field is presented.

Cosmic ray spectrum, composition, and anisotropy measured with IceCube

NASA Astrophysics Data System (ADS)

Tamburro, Alessio

2014-04-01

Analysis of cosmic ray surface data collected with the IceTop array of Cherenkov detectors at the South Pole provides an accurate measurement of the cosmic ray spectrum and its features in the "knee" region up to energies of about 1 EeV. IceTop is part of the IceCube Observatory that includes a deep-ice cubic kilometer detector that registers signals of penetrating muons and other particles. Surface and in-ice signals detected in coincidence provide clear insights into the nuclear composition of cosmic rays. IceCube already measured an increase of the average primary mass as a function of energy. We present preliminary results on both IceTop-only and coincident events analysis. Furthermore, we review the recent measurement of the cosmic ray anisotropy with IceCube.

Cosmic Rays - A Word-Wide Student Laboratory

NASA Astrophysics Data System (ADS)

Adams, Mark

2017-01-01

The QuarkNet program has distributed hundreds of cosmic ray detectors for use in high schools and research facilities throughout the world over the last decade. Data collected by those students has been uploaded to a central server where web-based analysis tools enable users to characterize and to analyze everyone's cosmic ray data. Since muons rain down on everyone in the world, all students can participate in this free, high energy particle environment. Through self-directed inquiry students have designed their own experiments: exploring cosmic ray rates and air shower structure; and using muons to measure their speed, time dilation, lifetime, and affects on biological systems. We also plan to expand our annual International Muon Week project to create a large student-led collaboration where similar cosmic ray measurements are performed simultaneously throughout the world.

Cosmic Rays and Their Radiative Processes in Numerical Cosmology

NASA Technical Reports Server (NTRS)

Ryu, Dongsu; Miniati, Francesco; Jones, Tom W.; Kang, Hyesung

2000-01-01

A cosmological hydrodynamic code is described, which includes a routine to compute cosmic ray acceleration and transport in a simplified way. The routine was designed to follow explicitly diffusive, acceleration at shocks, and second-order Fermi acceleration and adiabatic loss in smooth flows. Synchrotron cooling of the electron population can also be followed. The updated code is intended to be used to study the properties of nonthermal synchrotron emission and inverse Compton scattering from electron cosmic rays in clusters of galaxies, in addition to the properties of thermal bremsstrahlung emission from hot gas. The results of a test simulation using a grid of 128 (exp 3) cells are presented, where cosmic rays and magnetic field have been treated passively and synchrotron cooling of cosmic ray electrons has not been included.

Cosmic Rays and Their Radiative Processes in Numerical Cosmology

NASA Astrophysics Data System (ADS)

Ryu, D.; Miniati, F.; Jones, T. W.; Kang, H.

2000-05-01

A cosmological hydrodynamic code is described, which includes a routine to compute cosmic ray acceleration and transport in a simplified way. The routine was designed to follow explicitly diffusive acceleration at shocks, and second-order Fermi acceleration and adiabatic loss in smooth flows. Synchrotron cooling of the electron population can also be followed. The updated code is intended to be used to study the properties of nonthermal synchrotron emission and inverse Compton scattering from electron cosmic rays in clusters of galaxies, in addition to the properties of thermal bremsstrahlung emission from hot gas. The results of a test simulation using a grid of 1283 cells are presented, where cosmic rays and magnetic field have been treated passively and synchrotron cooling of cosmic ray electrons has not been included.

The shape of the extragalactic cosmic ray spectrum from galaxy clusters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harari, Diego; Mollerach, Silvia; Roulet, Esteban, E-mail: harari@cab.cnea.gov.ar, E-mail: mollerach@cab.cnea.gov.ar, E-mail: roulet@cab.cnea.gov.ar

2016-08-01

We study the diffusive escape of cosmic rays from a central source inside a galaxy cluster to obtain the suppression in the outgoing flux appearing when the confinement times get comparable or larger than the age of the sources. We also discuss the attenuation of the flux due to the interactions of the cosmic rays with the cluster medium, which can be sizeable for heavy nuclei. The overall suppression in the total cosmic ray flux expected on Earth is important to understand the shape of the extragalactic contribution to the cosmic ray spectrum for E / Z < 1 EeVmore » . This suppression can also be relevant to interpret the results of fits to composition-sensitive observables measured at ultra-high energies.« less

Cosmic ray modulation and radiation dose of aircrews during the solar cycle 24/25

NASA Astrophysics Data System (ADS)

Miyake, Shoko; Kataoka, Ryuho; Sato, Tatsuhiko

2017-04-01

Weak solar activity and high cosmic ray flux during the coming solar cycle are qualitatively anticipated by the recent observations that show the decline in the solar activity levels. We predict the cosmic ray modulation and resultant radiation exposure at flight altitude by using the time-dependent and three-dimensional model of the cosmic ray modulation. Our galactic cosmic ray (GCR) model is based on the variations of the solar wind speed, the strength of the heliospheric magnetic field, and the tilt angle of the heliospheric current sheet. We reproduce the 22 year variation of the cosmic ray modulation from 1980 to 2015 taking into account the gradient-curvature drift motion of GCRs. The energy spectra of GCR protons obtained by our model show good agreement with the observations by the Balloon-borne Experiment with a Superconducting magnetic rigidity Spectrometer (BESS) and the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) except for a discrepancy at the solar maximum. Five-year annual radiation dose around the solar minimum at the solar cycle 24/25 will be approximately 19% higher than that in the last cycle. This is caused by the charge sign dependence of the cosmic ray modulation, such as the flattop profiles in a positive polarity.

Models of Cosmic-Ray Origin

NASA Astrophysics Data System (ADS)

Shapiro, M. M.

2001-08-01

Two models of cosmic-ray genesis are compared: (a) the author s red-dwarf hypothesis requiring the injection of seed particles from coronal mass ejections (CME) prior to shock acceleration, and (b) the direct acceleration of thermal ions and of grains in the ISM, proposed by Meyer, Drury and Ellison. Both models agree that shocks in the expanding envelopes of supernova remnants are principally responsible for acceleration to cosmic-ray energies. Both are designed to overcome the mismatch between the source composition of the Galactic cosmic rays (GCR) and the composition of the thermal ISM gas. Model (a) utilizes the prolific emissions of energetic particles from active dMe and dKe stars via their CME as the agents of seed-particle injection into the ISM. The composition of these seed particles is governed by the FIP (first-ionization potential) selection mechanism that operates for both Galactic cosmic rays and solar energetic particles. Hence it is consistent with the cosmic-ray source composition. Model (b) relies on the sputtering and acceleration of grains in the ISM (along with acceleration of thermal ions) to provide the known source composition. This model considers the FIP ordering of GCR abundances as purely coincidental, and it attributes the relative source abundances to selection according to volatility. Recent cosmic-ray observations in favor of each model are cited.

Spaced-based Cosmic Ray Astrophysics

NASA Astrophysics Data System (ADS)

Seo, Eun-Suk

2016-03-01

The bulk of cosmic ray data has been obtained with great success by balloon-borne instruments, particularly with NASA's long duration flights over Antarctica. More recently, PAMELA on a Russian Satellite and AMS-02 on the International Space Station (ISS) started providing exciting measurements of particles and anti-particles with unprecedented precision upto TeV energies. In order to address open questions in cosmic ray astrophysics, future missions require spaceflight exposures for rare species, such as isotopes, ultra-heavy elements, and high (the ``knee'' and above) energies. Isotopic composition measurements up to about 10 GeV/nucleon that are critical for understanding interstellar propagation and origin of the elements are still to be accomplished. The cosmic ray composition in the knee (PeV) region holds a key to understanding the origin of cosmic rays. Just last year, the JAXA-led CALET ISS mission, and the DAMPE Chinese Satellite were launched. NASA's ISS-CREAM completed its final verification at GSFC, and was delivered to KSC to await launch on SpaceX. In addition, a EUSO-like mission for ultrahigh energy cosmic rays and an HNX-like mission for ultraheavy nuclei could accomplish a vision for a cosmic ray observatory in space. Strong support of NASA's Explorer Program category of payloads would be needed for completion of these missions over the next decade.

Cosmic-Ray Extremely Distributed Observatory: a global cosmic ray detection framework

NASA Astrophysics Data System (ADS)

Sushchov, O.; Homola, P.; Dhital, N.; Bratek, Ł.; Poznański, P.; Wibig, T.; Zamora-Saa, J.; Almeida Cheminant, K.; Alvarez Castillo, D.; Góra, D.; Jagoda, P.; Jałocha, J.; Jarvis, J. F.; Kasztelan, M.; Kopański, K.; Krupiński, M.; Michałek, M.; Nazari, V.; Smelcerz, K.; Smolek, K.; Stasielak, J.; Sułek, M.

2017-12-01

The main objective of the Cosmic-Ray Extremely Distributed Observatory (CREDO) is the detection and analysis of extended cosmic ray phenomena, so-called super-preshowers (SPS), using existing as well as new infrastructure (cosmic-ray observatories, educational detectors, single detectors etc.). The search for ensembles of cosmic ray events initiated by SPS is yet an untouched ground, in contrast to the current state-of-the-art analysis, which is focused on the detection of single cosmic ray events. Theoretical explanation of SPS could be given either within classical (e.g., photon-photon interaction) or exotic (e.g., Super Heavy Dark Matter decay or annihilation) scenarios, thus detection of SPS would provide a better understanding of particle physics, high energy astrophysics and cosmology. The ensembles of cosmic rays can be classified based on the spatial and temporal extent of particles constituting the ensemble. Some classes of SPS are predicted to have huge spatial distribution, a unique signature detectable only with a facility of the global size. Since development and commissioning of a completely new facility with such requirements is economically unwarranted and time-consuming, the global analysis goals are achievable when all types of existing detectors are merged into a worldwide network. The idea to use the instruments in operation is based on a novel trigger algorithm: in parallel to looking for neighbour surface detectors receiving the signal simultaneously, one should also look for spatially isolated stations clustered in a small time window. On the other hand, CREDO strategy is also aimed at an active engagement of a large number of participants, who will contribute to the project by using common electronic devices (e.g., smartphones), capable of detecting cosmic rays. It will help not only in expanding the geographical spread of CREDO, but also in managing a large manpower necessary for a more efficient crowd-sourced pattern recognition scheme to identify and classify SPS. A worldwide network of cosmic-ray detectors could not only become a unique tool to study fundamental physics, it will also provide a number of other opportunities, including space-weather or geophysics studies. Among the latter one has to list the potential to predict earthquakes by monitoring the rate of low energy cosmic-ray events. The diversity of goals motivates us to advertise this concept across the astroparticle physics community.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1970-01-01

This schematic details the third High Energy Astronomy Observatory (HEAO)-3. The HEAO-3's mission was to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit.

Solar induced long- and short-term variations of the cosmic ray intensity in the past, and predictions and opportunities for the future

NASA Astrophysics Data System (ADS)

McCracken, K. G.; McDonald, F. B.; Beer, J.

2009-12-01

The cosmogenic radionuclide data from the past 10,000 years, and the instrumental cosmic ray data since 1936 provide detailed information on the possible consequences of the present long and deep solar minimum. Furthermore, the cosmic ray transport equation has been used to estimate the strength of the interplanetary magnetic field (IMF) throughout the past 10,000 years. This paper presents a series of figures that document the behavior of both the cosmic radiation and the IMF at Earth in the past. In particular, the 11-year cycles in both quantities for the past 600 years are displayed; and estimates given of the cosmic ray spectrum at Earth for situations that history tells us may occur in the near future. Over the longer term, a minimum of the Hallstatt cycle (2200 yr periodicity) of solar activity occurred ~500 years ago and the Sun is now on a steadily rising plane of activity. The historic record shows that the cosmic ray intensity has decreased extremely rapidly after earlier prolonged deep minima and this suggests rapid and large changes in the heliospheric conditions that we may see replicated. The paper will also display data from the deep, isolated solar minimum of 1956 that exhibited unusual low energy cosmic ray fluxes, and a highly anomalous cosmic ray gradient in the inner heliosphere. Paleo-cosmic ray evidence will also be displayed of an episode of intense solar energetic particle (SEP) events in the interval of reduced solar activity, 1892-1900, that may possibly be repeated. If the present long, deep solar minimum is a precursor to a “Grand Minimum” such as the Dalton minimum, it will provide a much improved insight into the spectrum of the cosmic radiation in interstellar space, and to the cosmic ray modulation process in the heliosphere. With this in mind, the paper suggests key measurements, and speculates on experimental conditions that may be markedly different from those encountered in the instrumental era.

Constraints on the Galactic Halo Dark Matter from Fermi-LAT Diffuse Measurements

NASA Technical Reports Server (NTRS)

Ackermann, M.; Ajello, M.; Atwood, W. B.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Blandford, R. D.; Bloom, E. D.;

Radiation Environments on Mars and Their Implications for Terrestrial Planetary Habitability

NASA Astrophysics Data System (ADS)

Schneider, I.; Kasting, J. F.

2009-12-01

The understanding of the surface and subsurface radiation environments of a terrestrial planet such as Mars is crucial to its potential past and/or present habitability. Despite this, the subject of high energy radiation is rarely contemplated within the field of Astrobiology as an essential factor determining the realistic parameter space for the development and preservation of life. Furthermore, not much is known of the radiation environment on the surface of Mars due to the fact that no real data exist on this contribution. There are no direct measurements available as no surface landers/probes have ever carried nuclear radiation detection equipment to characterize the interactions arising from cosmic ray bombardment, solar particle events and the atmosphere striking the planetary surface. The first mission set to accomplish this task, the Mars Science Laboratory, is not scheduled to launch until 2011. Presented here are some of such simulations performed with the HZETRN NASA code offering radiation depth profiles as well as a characterization of the diverse radiation environments. A discussion of the implications that these projected doses would have on terrestrial planetary habitability on Mars is presented as well as its implications for the habitability of terrestrial planets elsewhere. This work does not provide an estimate of the UV radiation fields on the Martian surface instead it focuses on the high energy radiation fields as composed by galactic cosmic rays (GCRs)

Influence of Sun and Other Cosmic Factors on Environment of the Earth

DTIC Science & Technology

2010-01-07

of the secondary cosmic rays (mostly muons , electrons, neutrons and gammas) can provide highly cost-effective information on the key characteristics...Coronal mass ejection (CME) from the Sun the impact on the Galactic Cosmic rays (GCR) will be observed. Particle detector is vital for measuring the...modulation effects the sun poses on the ambient population of the Galactic Cosmic Rays (GCR). The known agents of these modulation effects are Solar Flares

Response of Atmospheric Biomarkers to NOx-Induced Photochemistry Generated by Stellar Cosmic Rays for Earth-like Planets in the Habitable Zone of M Dwarf Stars

PubMed Central

Grießmeier, Jean-Mathias; von Paris, Philip; Patzer, A. Beate C.; Lammer, Helmut; Stracke, Barbara; Gebauer, Stefanie; Schreier, Franz; Rauer, Heike

2012-01-01

Abstract Understanding whether M dwarf stars may host habitable planets with Earth-like atmospheres and biospheres is a major goal in exoplanet research. If such planets exist, the question remains as to whether they could be identified via spectral signatures of biomarkers. Such planets may be exposed to extreme intensities of cosmic rays that could perturb their atmospheric photochemistry. Here, we consider stellar activity of M dwarfs ranging from quiet up to strong flaring conditions and investigate one particular effect upon biomarkers, namely, the ability of secondary electrons caused by stellar cosmic rays to break up atmospheric molecular nitrogen (N2), which leads to production of nitrogen oxides (NOx) in the planetary atmosphere, hence affecting biomarkers such as ozone (O3). We apply a stationary model, that is, without a time dependence; hence we are calculating the limiting case where the atmospheric chemistry response time of the biomarkers is assumed to be slow and remains constant compared with rapid forcing by the impinging stellar flares. This point should be further explored in future work with time-dependent models. We estimate the NOx production using an air shower approach and evaluate the implications using a climate-chemical model of the planetary atmosphere. O3 formation proceeds via the reaction O+O2+M→O3+M. At high NOx abundances, the O atoms arise mainly from NO2 photolysis, whereas on Earth this occurs via the photolysis of molecular oxygen (O2). For the flaring case, O3 is mainly destroyed via direct titration, NO+O3→NO2+O2, and not via the familiar catalytic cycle photochemistry, which occurs on Earth. For scenarios with low O3, Rayleigh scattering by the main atmospheric gases (O2, N2, and CO2) became more important for shielding the planetary surface from UV radiation. A major result of this work is that the biomarker O3 survived all the stellar-activity scenarios considered except for the strong case, whereas the biomarker nitrous oxide (N2O) could survive in the planetary atmosphere under all conditions of stellar activity considered here, which clearly has important implications for missions that aim to detect spectroscopic biomarkers. Key Words: M dwarf—Atmosphere—Earth-like—Biomarkers—Stellar cosmic rays. Astrobiology 12, 1109–1122. PMID:23215581

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.

The Heavy Nuclei eXplorer (HNX) Mission

NASA Astrophysics Data System (ADS)

Krizmanic, John; Mitchell, John; Binns, W. Robert; Hams, Thomas; Israel, Martin; Link, Jason; Rauch, Brian; Sakai, Kenichi; Sasaki, Makoto; Westphal, Andrew; Wiedenbeck, Mark; Heavy Nuclei eXplorer Collaboration

2016-03-01

The Heavy Nuclei eXplorer (HNX) will use two large high-precision instruments, the Extremely-heavy Cosmic-ray Composition Observer (ECCO) and the Cosmic-ray Trans-Iron Galactic Element Recorder (CosmicTIGER), designed to fly in a SpaceX DragonLab Capsule, to measure the cosmic-ray abundance of every individual element in the periodic table from carbon through curium, providing the first measurement of many of these elements. These measurements provide an investigation on the nature of the source material of cosmic rays, the processes that inject them into cosmic accelerators, and the acceleration mechanisms. HNX will measure several thousand ultra-heavy galactic cosmic ray (UHGCR) nuclei with Z >= 30 , including about 50 actinides (Z >= 79). These data allow for a measurement of the mix of new and old material that is accelerated to GCRs, determine their age, measure the mix of nucleosynthesis processes responsible for the UHGCRs, determine how UHGCR elements are selected for acceleration, and measure the mean integrated pathlength traversed by UHGCRs before observation. The scientific motivation and instrumentation of HNX will be discussed as well as recent beam test results.

A Multi-Variate Fit to the Chemical Composition of the Cosmic-Ray Spectrum

NASA Astrophysics Data System (ADS)

Eisch, Jonathan

Since the discovery of cosmic rays over a century ago, evidence of their origins has remained elusive. Deflected by galactic magnetic fields, the only direct evidence of their origin and propagation remain encoded in their energy distribution and chemical composition. Current models of galactic cosmic rays predict variations of the energy distribution of individual elements in an energy region around 3x1015 eV known as the knee. This work presents a method to measure the energy distribution of individual elemental groups in the knee region and its application to a year of data from the IceCube detector. The method uses cosmic rays detected by both IceTop, the surface-array component, and the deep-ice component of IceCube during the 2009-2010 operation of the IC-59 detector. IceTop is used to measure the energy and the relative likelihood of the mass composition using the signal from the cosmic-ray induced extensive air shower reaching the surface. IceCube, 1.5 km below the surface, measures the energy of the high-energy bundle of muons created in the very first interactions after the cosmic ray enters the atmosphere. These event distributions are fit by a constrained model derived from detailed simulations of cosmic rays representing five chemical elements. The results of this analysis are evaluated in terms of the theoretical uncertainties in cosmic-ray interactions and seasonal variations in the atmosphere. The improvements in high-energy cosmic ray hadronic-interaction models informed by this analysis, combined with increased data from subsequent operation of the IceCube detector, could provide crucial limits on the origin of cosmic rays and their propagation through the galaxy. In the course of developing this method, a number of analysis and statistical techniques were developed to deal with the difficulties inherent in this type of measurement. These include a composition-sensitive air shower reconstruction technique, a method to model simulated event distributions with limited statistics, and a method to optimize and estimate the error on a regularized fit.

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.

Ionization Processes in the Atmosphere of Titan (Research Note). III. Ionization by High-Z Nuclei Cosmic Rays

NASA Technical Reports Server (NTRS)

Gronoff, G.; Mertens, C.; Lilensten, J.; Desorgher, L.; Fluckiger, E.; Velinov, P.

2011-01-01

Context. The Cassini-Huygens mission has revealed the importance of particle precipitation in the atmosphere of Titan thanks to in-situ measurements. These ionizing particles (electrons, protons, and cosmic rays) have a strong impact on the chemistry, hence must be modeled. Aims. We revisit our computation of ionization in the atmosphere of Titan by cosmic rays. The high-energy high-mass ions are taken into account to improve the precision of the calculation of the ion production profile. Methods. The Badhwahr and O Neill model for cosmic ray spectrum was adapted for the Titan model. We used the TransTitan model coupled with the Planetocosmics model to compute the ion production by cosmic rays. We compared the results with the NAIRAS/HZETRN ionization model used for the first time for a body that differs from the Earth. Results. The cosmic ray ionization is computed for five groups of cosmic rays, depending on their charge and mass: protons, alpha, Z = 8 (oxygen), Z = 14 (silicon), and Z = 26 (iron) nucleus. Protons and alpha particles ionize mainly at 65 km altitude, while the higher mass nucleons ionize at higher altitudes. Nevertheless, the ionization at higher altitude is insufficient to obscure the impact of Saturn s magnetosphere protons at a 500 km altitude. The ionization rate at the peak (altitude: 65 km, for all the different conditions) lies between 30 and 40/cu cm/s. Conclusions. These new computations show for the first time the importance of high Z cosmic rays on the ionization of the Titan atmosphere. The updated full ionization profile shape does not differ significantly from that found in our previous calculations (Paper I: Gronoff et al. 2009, 506, 955) but undergoes a strong increase in intensity below an altitude of 400 km, especially between 200 and 400 km altitude where alpha and heavier particles (in the cosmic ray spectrum) are responsible for 40% of the ionization. The comparison of several models of ionization and cosmic ray spectra (in intensity and composition) reassures us about the stability of the altitude of the ionization peak (65 km altitude) with respect to the solar activity.

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

PubMed

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

2013-07-26

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

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.

PLASMA EFFECTS ON EXTRAGALACTIC ULTRAHIGH-ENERGY COSMIC-RAY HADRON BEAMS IN COSMIC VOIDS. II. KINETIC INSTABILITY OF PARALLEL ELECTROSTATIC WAVES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krakau, S.; Schlickeiser, R., E-mail: steffen.krakau@rub.de, E-mail: rsch@tp4.rub.de

2016-02-20

The linear instability of an ultrarelativistic hadron beam in the unmagnetized intergalactic medium (IGM) is investigated with respect to the excitation of parallel electrostatic and electromagnetic fluctuations. This analysis is important for the propagation of extragalactic ultrarelativistic cosmic rays from their distant sources to Earth. As opposed to the previous paper, we calculate the minimum instability growth time for Lorentz-distributed cosmic rays which traverse the hot IGM. The growth times are orders of magnitude higher than the cosmic-ray propagation time in the IGM. Since the backreaction of the generated plasma fluctuations (plateauing) lasts longer than the propagation time, the cosmic-raymore » hadron beam can propagate to the Earth without losing a significant amount of energy to electrostatic turbulence.« less

Cosmic ray albedo gamma rays from the quiet sun

NASA Technical Reports Server (NTRS)

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

1992-01-01

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

Early history of cosmic rays at Chicago

NASA Astrophysics Data System (ADS)

Yodh, Gaurang B.

2013-02-01

Cosmic ray studies at the University of Chicago were started by Arthur Compton during the late 1920s. The high points of cosmic ray studies at Chicago under Compton and Marcel Schein are the focus of this report, which summarizes the research done at Chicago up to the end of World War II.

Cosmic ray modulation and turbulent interaction regions near 11 AU

NASA Technical Reports Server (NTRS)

Burlaga, L. F.; Mcdonald, F. B.; Goldstein, M. L.; Lazarus, A. J.

1985-01-01

When Voyager 2 was near 11 AU, the counting rate of nuclei approx 75 MeV/nucleon decreased during the interval from July, 1982 to November, 1982, and it increased thereafter until August, 1983. A decrease in cosmic ray flux was generally associated with the passage of an interaction region in which the magnetic field strength B was higher than that predicted by the spiral field model, B sub p. Several large enhancements in B/B sup p were associated with merged interaction regions which probably resulted from the interaction of two or more distinct flows. During the passage of interaction regions the cosmic ray intensity decreased at a rate proportional to (B/B sup p -1), and during the passage of rarefaction regions (where B/B sup p 1) the cosmic ray intensity increased at a constant rate. The general form of the cosmic ray intensity profile during this approx 13 month minicycle can be described by integrating these relations using the observed B(t). Latitudinal variations of the interaction regions and of the short-term cosmic ray variations were identified.

COMPARISON OF COSMIC-RAY ENVIRONMENTS ON EARTH, MOON, MARS AND IN SPACECARFT USING PHITS.

PubMed

Sato, Tatsuhiko; Nagamatsu, Aiko; Ueno, Haruka; Kataoka, Ryuho; Miyake, Shoko; Takeda, Kazuo; Niita, Koji

2017-09-29

Estimation of cosmic-ray doses is of great importance not only in aircrew and astronaut dosimetry but also in evaluation of background radiation exposure to public. We therefore calculated the cosmic-ray doses on Earth, Moon and Mars as well as inside spacecraft, using Particle and Heavy Ion Transport code System PHITS. The same cosmic-ray models and dose conversion coefficients were employed in the calculation to properly compare between the simulation results for different environments. It is quantitatively confirmed that the thickness of physical shielding including the atmosphere and soil of the planets is the most important parameter to determine the cosmic-ray doses and their dominant contributors. The comparison also suggests that higher solar activity significantly reduces the astronaut doses particularly for the interplanetary missions. The information obtained from this study is useful in the designs of the future space missions as well as accelerator-based experiments dedicated to cosmic-ray research. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Observation of Anisotropy in the Galactic Cosmic-Ray Arrival Directions at 400 TeV with IceCube

NASA Astrophysics Data System (ADS)

Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Allen, M. 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.; 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.; Brown, A. M.; Buitink, S.; Caballero-Mora, K. S.; Carson, 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.; Demirörs, L.; 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.; Fox, B. D.; 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.; Heinen, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoffmann, B.; Homeier, A.; Hoshina, K.; Huelsnitz, W.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobi, E.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kenny, P.; 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.; 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.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; O'Murchadha, A.; Panknin, S.; Paul, L.; Pérez de los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Porrata, R.; Posselt, J.; Price, C. C.; Price, P. B.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Richman, M.; 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.; Schönwald, A.; Schukraft, A.; Schultes, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; 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.; Swillens, Q.; Taavola, H.; Taboada, I.; Tamburro, A.; Tepe, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Toscano, S.; Tosi, D.; van Eijndhoven, N.; Vandenbroucke, J.; Van Overloop, A.; van Santen, J.; Vehring, M.; Voge, M.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; 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

2012-02-01

In this paper we report the first observation in the Southern hemisphere of an energy dependence in the Galactic cosmic-ray anisotropy up to a few hundred TeV. This measurement was performed using cosmic-ray-induced muons recorded by the partially deployed IceCube observatory between 2009 May and 2010 May. The data include a total of 33 × 109 muon events with a median angular resolution of ~3°. A sky map of the relative intensity in arrival direction over the Southern celestial sky is presented for cosmic-ray median energies of 20 and 400 TeV. The same large-scale anisotropy observed at median energies around 20 TeV is not present at 400 TeV. Instead, the high-energy sky map shows a different anisotropy structure including a deficit with a post-trial significance of -6.3σ. This anisotropy reveals a new feature of the Galactic cosmic-ray distribution, which must be incorporated into theories of the origin and propagation of cosmic rays.

Model structure of a cosmic-ray mediated stellar or solar wind

NASA Technical Reports Server (NTRS)

Lee, M. A.; Axford, W. I.

1988-01-01

An idealized hydrodynamic model is presented for the mediation of a free-streaming stellar wind by galactic cosmic rays or energetic particles accelerated at the stellar wind termination shock. The spherically-symmetric stellar wind is taken to be cold; the only body force is the cosmic ray pressure gradient. The cosmic rays are treated as a massless fluid with an effective mean diffusion coefficient k proportional to radial distance r. The structure of the governing equations is investigated both analytically and numerically. Solutions for a range of values of k are presented which describe the deceleration of the stellar wind and a transition to nearly incompressible flow and constant cosmic ray pressure at large r. In the limit of small k the transition steepens to a strong stellar wind termination shock. For large k the stellar wind is decelerated gradually with no shock transition. It is argued that the solutions provide a simple model for the mediation of the solar wind by interstellar ions as both pickup ions and the cosmic ray anomalous component which together dominate the pressure of the solar wind at large r.

Modification of the parallel scattering mean free path of cosmic rays in the presence of adiabatic focusing

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, H.-Q.; Schlickeiser, R., E-mail: hqhe@mail.iggcas.ac.cn, E-mail: rsch@tp4.rub.de

The cosmic ray mean free path in a large-scale nonuniform guide magnetic field with superposed magnetostatic turbulence is calculated to clarify some conflicting results in the literature. A new, exact integro-differential equation for the cosmic-ray anisotropy is derived from the Fokker-Planck transport equation. A perturbation analysis of this integro-differential equation leads to an analytical expression for the cosmic ray anisotropy and the focused transport equation for the isotropic part of the cosmic ray distribution function. The derived parallel spatial diffusion coefficient and the associated cosmic ray mean free path include the effect of adiabatic focusing and reduce to the standardmore » forms in the limit of a uniform guide magnetic field. For the illustrative case of isotropic pitch angle scattering, the derived mean free path agrees with the earlier expressions of Beeck and Wibberenz, Bieber and Burger, Kota, and Litvinenko, but disagrees with the result of Shalchi. The disagreement with the expression of Shalchi is particularly strong in the limit of strong adiabatic focusing.« less

Anomalous Transport of Cosmic Rays in a Nonlinear Diffusion Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Litvinenko, Yuri E.; Fichtner, Horst; Walter, Dominik

2017-05-20

We investigate analytically and numerically the transport of cosmic rays following their escape from a shock or another localized acceleration site. Observed cosmic-ray distributions in the vicinity of heliospheric and astrophysical shocks imply that anomalous, superdiffusive transport plays a role in the evolution of the energetic particles. Several authors have quantitatively described the anomalous diffusion scalings, implied by the data, by solutions of a formal transport equation with fractional derivatives. Yet the physical basis of the fractional diffusion model remains uncertain. We explore an alternative model of the cosmic-ray transport: a nonlinear diffusion equation that follows from a self-consistent treatmentmore » of the resonantly interacting cosmic-ray particles and their self-generated turbulence. The nonlinear model naturally leads to superdiffusive scalings. In the presence of convection, the model yields a power-law dependence of the particle density on the distance upstream of the shock. Although the results do not refute the use of a fractional advection–diffusion equation, they indicate a viable alternative to explain the anomalous diffusion scalings of cosmic-ray particles.« less

Enhancements of energetic particles near the heliospheric termination shock.

PubMed

McDonald, Frank B; Stone, Edward C; Cummings, Alan C; Heikkila, Bryant; Lal, Nand; Webber, William R

2003-11-06

The spacecraft Voyager 1 is at a distance greater than 85 au from the Sun, in the vicinity of the termination shock that marks the abrupt slowing of the supersonic solar wind and the beginning of the extended and unexplored distant heliosphere. This shock is expected to accelerate 'anomalous cosmic rays', as well as to re-accelerate Galactic cosmic rays and low-energy particles from the inner Solar System. Here we report a significant increase in the numbers of energetic ions and electrons that persisted for seven months beginning in mid-2002. This increase differs from any previously observed in that there was a simultaneous increase in Galactic cosmic ray ions and electrons, anomalous cosmic rays and low-energy ions. The low-intensity level and spectral energy distribution of the anomalous cosmic rays, however, indicates that Voyager 1 still has not reached the termination shock. Rather, the observed increase is an expected precursor event. We argue that the radial anisotropy of the cosmic rays is expected to be small in the foreshock region, as is observed.

Observation of Anisotropy in the Galactic Cosmic Ray Arrival Directions at 400 TEV With IceCube

NASA Technical Reports Server (NTRS)

Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Allen, M. M.; Altmann, D.; Andeen, K.;

Astrophysical Sources of Cosmic Rays and Related Measurements with the Pierre Auger Observatory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abraham, : J.; Abreu, P.; Aglietta, M.

2009-06-01

These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Correlation of the highest energy cosmic rays with nearby extragalactic objects in Pierre Auger Observatory data; (2) Discriminating potential astrophysical sources of the highest energy cosmic rays with the Pierre Auger Observatory; (3) Intrinsic anisotropy of the UHECR from the Pierre Auger Observatory; (4) Ultra-high energy photon studies with the Pierre Auger Observatory; (5) Limits on the flux of diffuse ultra high energy neutrinos set using the Pierre Auger Observatory; (6) Search for siderealmore » modulation of the arrival directions of events recorded at the Pierre Auger Observatory; (7) Cosmic Ray Solar Modulation Studies in the Pierre Auger Observatory; (8) Investigation of the Displacement Angle of the Highest Energy Cosmic Rays Caused by the Galactic Magnetic Field; (9) Search for coincidences with astrophysical transients in Pierre Auger Observatory data; and (10) An alternative method for determining the energy of hybrid events at the Pierre Auger Observatory.« less

Observation of an Anisotropy in the Galactic Cosmic Ray Arrival Direction at 400 TeV with IceCube

NASA Technical Reports Server (NTRS)

Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Allen, M. M.; Altmann, D.; Andeen, K.;

Discovery of very-high-energy gamma-rays from the Galactic Centre ridge.

PubMed

Aharonian, F; Akhperjanian, A G; Bazer-Bachi, A R; Beilicke, M; Benbow, W; Berge, D; Bernlöhr, K; Boisson, C; Bolz, O; Borrel, V; Braun, I; Breitling, F; Brown, A M; Chadwick, P M; Chounet, L-M; Cornils, R; Costamante, L; Degrange, B; Dickinson, H J; Djannati-Ataï, A; Drury, L O'C; Dubus, G; Emmanoulopoulos, D; Espigat, P; Feinstein, F; Fontaine, G; Fuchs, Y; Funk, S; Gallant, Y A; Giebels, B; Gillessen, S; Glicenstein, J F; Goret, P; Hadjichristidis, C; Hauser, D; Hauser, M; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hofmann, W; Holleran, M; Horns, D; Jacholkowska, A; de Jager, O C; Khélifi, B; Klages, S; Komin, Nu; Konopelko, A; Latham, I J; Le Gallou, R; Lemière, A; Lemoine-Goumard, M; Leroy, N; Lohse, T; Marcowith, A; Martin, J M; Martineau-Huynh, O; Masterson, C; McComb, T J L; de Naurois, M; Nolan, S J; Noutsos, A; Orford, K J; Osborne, J L; Ouchrif, M; Panter, M; Pelletier, G; Pita, S; Pühlhofer, G; Punch, M; Raubenheimer, B C; Raue, M; Raux, J; Rayner, S M; Reimer, A; Reimer, O; Ripken, J; Rob, L; Rolland, L; Rowell, G; Sahakian, V; Saugé, L; Schlenker, S; Schlickeiser, R; Schuster, C; Schwanke, U; Siewert, M; Sol, H; Spangler, D; Steenkamp, R; Stegmann, C; Tavernet, J-P; Terrier, R; Théoret, C G; Tluczykont, M; van Eldik, C; Vasileiadis, G; Venter, C; Vincent, P; Völk, H J; Wagner, S J

2006-02-09

The source of Galactic cosmic rays (with energies up to 10(15) eV) remains unclear, although it is widely believed that they originate in the shock waves of expanding supernova remnants. At present the best way to investigate their acceleration and propagation is by observing the gamma-rays produced when cosmic rays interact with interstellar gas. Here we report observations of an extended region of very-high-energy (> 10(11) eV) gamma-ray emission correlated spatially with a complex of giant molecular clouds in the central 200 parsecs of the Milky Way. The hardness of the gamma-ray spectrum and the conditions in those molecular clouds indicate that the cosmic rays giving rise to the gamma-rays are likely to be protons and nuclei rather than electrons. The energy associated with the cosmic rays could have come from a single supernova explosion around 10(4) years ago.

Variation of cosmic rays and solar wind properties with respect to the heliospheric current sheet. II - Rigidity dependence of the latitudinal gradient of cosmic rays at 1 AU

NASA Technical Reports Server (NTRS)

Newkirk, G., Jr.; Asbridge, J.; Lockwood, J. A.; Garcia-Munoz, M.; Simpson, J. A.

1986-01-01

The role which empirical determinations of the latitudinal variation of cosmic rays with respect to the current sheet may have in illuminating the importance of the cross-field drift of particles in the large-scale heliospheric magnetic field is discussed. Using K coronameter observations and measured solar wind speeds, the latitudinal gradients have been determined with respect to the current sheet for cosmic rays in four rigidity ranges. Gradients vary between approximately -2 and -50 pct/AU. The rigidity dependence of the decrease of cosmic ray flux with distance from the current sheet lies between the -0.72 to -0.86 power of the rigidity, with the exact dependence being determined by the definition used for the median rigidity of each monitor.

The local time dependence of the anisotropic solar cosmic ray flux.

PubMed

Smart, D F; Shea, M A

2003-01-01

The distribution of the solar cosmic radiation flux over the earth is not uniform, but the result of complex phenomena involving the interplanetary magnetic field, the geomagnetic field and latitude and longitude of locations on the earth. The latitude effect relates to the geomagnetic shield; the longitude effect relates to local time. For anisotropic solar cosmic ray events the maximum particle flux is always along the interplanetary magnetic field direction, sometimes called the Archimedean spiral path from the sun to the earth. During anisotropic solar cosmic ray event, the locations on the earth viewing "sunward" into the interplanetary magnetic field direction will observe the largest flux (when adjustments are made for the magnetic latitude effect). To relate this phenomena to aircraft routes, for anisotropic solar cosmic ray events that occur during "normal quiescent" conditions, the maximum solar cosmic ray flux (and corresponding solar particle radiation dose) will be observed in the dawn quadrant, ideally at about 06 hours local time. Published by Elsevier Ltd on behalf of COSPAR.

Radio-wave detection of ultra-high-energy neutrinos and cosmic rays

NASA Astrophysics Data System (ADS)

Huege, Tim; Besson, Dave

2017-12-01

Radio waves, perhaps because our terrestrial atmosphere and the cosmos beyond are uniquely transparent to them, or perhaps because they are macroscopic, so the basic instruments of detection (antennas) are easily constructible, arguably occupy a privileged position within the electromagnetic spectrum, and, correspondingly, receive disproportionate attention experimentally. Detection of radio-frequency radiation, at macroscopic wavelengths, has blossomed within the last decade as a competitive method for the measurement of cosmic particles, particularly charged cosmic rays and neutrinos. Cosmic-ray detection via radio emission from extensive air showers has been demonstrated to be a reliable technique that has reached a reconstruction quality of the cosmic-ray parameters competitive with more traditional approaches. Radio detection of neutrinos in dense media seems to be the most promising technique to achieve the gigantic detection volumes required to measure neutrinos at energies beyond the PeV-scale flux established by IceCube. In this article, we review radio detection both of cosmic rays in the atmosphere, as well as neutrinos in dense media.

What is your Cosmic Connection to the Elements?

NASA Technical Reports Server (NTRS)

White, Nicholas E. (Technical Monitor); Lochner, James; Rohrbach, Gail; Cochrane, Kim

2003-01-01

This information and activity booklet describes the roles of the Big Bang, types of stars, supernovae, cosmic ray interactions, and radioactive decay in the formation of the elements. The booklet includes instructions for the following classroom activities, intended for students in Grades 9-12: Grandma's Apple Pie; Cosmic Shuffle; Nickel-odeon; Kinesthetic Big Bang; Elemental Haiku; Cosmic Ray Collisions; Cosmic Abundances; and What's Out There.

On the Slow time Geomagnetic field Modulation of Cosmic Rays

NASA Astrophysics Data System (ADS)

Okpala, K. C.; Egbunu, F.

2016-12-01

Cosmic rays of galactic origin are modulated by both heliospheric and geomagnetic conditions. The mutual (and mutually exclusive) contribution of both heliospheric and geomagnetic conditions to galactic cosmic rays (GCR) modulation is still an open question. While the rapid-time association of the galactic cosmic ray variation with different heliophysical and geophysical phenomena has been well studied, not so much attention has been paid to slow-time variations especially with regards to local effects. In this work, we employed monthly means of cosmic ray count rates from two mid latitude (Hermanus and Rome), and two higher latitude (Inuvik and Oulu) neutron monitors (NM), and compared their variability with geomagnetic stations that are in close proximity to the NMs. The data spans 1966 to 2008 and covers four (4) solar cycles. The difference (CRdiff)between the mean count rate of all days and the mean of the five quietest days for each month was compared with the Dst-related disturbance (Hdiff) derived from the nearby geomagnetic stations. Zeroth- and First- correlation between the cosmic ray parameters and geomagnetic parameters was performed to ascertain statistical association and test for spurious association. Our results show that solar activity is generally strongly correlated (>0.75) with mean strength of GCR count rate and geomagnetic field during individual solar cycles. The correlation between mean strength of cosmic ray intensity and Geomagnetic field strength is spurious and is basically moderated by the solar activity. The signature of convection driven disturbances at high latitude geomagnetic stations was evident during the declining phase of the solar cycles close to the solar minimums. The absence of this feature in the slow-time varying cosmic ray count rates in all stations, and in the mid latitude geomagnetic stations suggest that the local geomagnetic disturbance do not play a significant role in modulating the cosmic ray flux.

Cosmic ray variations of solar origin in relation to human physiological state during the December 2006 solar extreme events

NASA Astrophysics Data System (ADS)

Papailiou, M.; Mavromichalaki, H.; Vassilaki, A.; Kelesidis, K. M.; Mertzanos, G. A.; Petropoulos, B.

2009-02-01

There is an increasing amount of evidence linking biological effects to solar and geomagnetic disturbances. A series of studies is published referring to the changes in human physiological responses at different levels of geomagnetic activity. In this study, the possible relation between the daily variations of cosmic ray intensity, measured by the Neutron Monitor at the Cosmic Ray Station of the University of Athens (http://cosray.phys.uoa.gr) and the average daily and hourly heart rate variations of persons, with no symptoms or hospital admission, monitored by Holter electrocardiogram, is considered. This work refers to a group of persons admitted to the cardiological clinic of the KAT Hospital in Athens during the time period from 4th to 24th December 2006 that is characterized by extreme solar and geomagnetic activity. A series of Forbush decreases started on 6th December and lasted until the end of the month and a great solar proton event causing a Ground Level Enhancement (GLE) of the cosmic ray intensity on 13th December occurred. A sudden decrease of the cosmic ray intensity on 15th December, when a geomagnetic storm was registered, was also recorded in Athens Neutron Monitor station (cut-off rigidity 8.53 GV) with amplitude of 4%. It is noticed that during geomagnetically quiet days the heart rate and the cosmic ray intensity variations are positively correlated. When intense cosmic ray variations, like Forbush decreases and relativistic proton events produced by strong solar phenomena occur, cosmic ray intensity and heart rate get minimum values and their variations, also, coincide. During these events the correlation coefficient of these two parameters changes and follows the behavior of the cosmic ray intensity variations. This is only a small part of an extended investigation, which has begun using data from the year 2002 and is still in progress.

A large light-mass component of cosmic rays at 10(17)-10(17.5) electronvolts from radio observations.

PubMed

Buitink, S; Corstanje, A; Falcke, H; Hörandel, J R; Huege, T; Nelles, A; Rachen, J P; Rossetto, L; Schellart, P; Scholten, O; ter Veen, S; Thoudam, S; Trinh, T N G; Anderson, J; Asgekar, A; Avruch, I M; Bell, M E; Bentum, M J; Bernardi, G; Best, P; Bonafede, A; Breitling, F; Broderick, J W; Brouw, W N; Brüggen, M; Butcher, H R; Carbone, D; Ciardi, B; Conway, J E; de Gasperin, F; de Geus, E; Deller, A; Dettmar, R-J; van Diepen, G; Duscha, S; Eislöffel, J; Engels, D; Enriquez, J E; Fallows, R A; Fender, R; Ferrari, C; Frieswijk, W; Garrett, M A; Grießmeier, J M; Gunst, A W; van Haarlem, M P; Hassall, T E; Heald, G; Hessels, J W T; Hoeft, M; Horneffer, A; Iacobelli, M; Intema, H; Juette, E; Karastergiou, A; Kondratiev, V I; Kramer, M; Kuniyoshi, M; Kuper, G; van Leeuwen, J; Loose, G M; Maat, P; Mann, G; Markoff, S; McFadden, R; McKay-Bukowski, D; McKean, J P; Mevius, M; Mulcahy, D D; Munk, H; Norden, M J; Orru, E; Paas, H; Pandey-Pommier, M; Pandey, V N; Pietka, M; Pizzo, R; Polatidis, A G; Reich, W; Röttgering, H J A; Scaife, A M M; Schwarz, D J; Serylak, M; Sluman, J; Smirnov, O; Stappers, B W; Steinmetz, M; Stewart, A; Swinbank, J; Tagger, M; Tang, Y; Tasse, C; Toribio, M C; Vermeulen, R; Vocks, C; Vogt, C; van Weeren, R J; Wijers, R A M J; Wijnholds, S J; Wise, M W; Wucknitz, O; Yatawatta, S; Zarka, P; Zensus, J A

2016-03-03

Cosmic rays are the highest-energy particles found in nature. Measurements of the mass composition of cosmic rays with energies of 10(17)-10(18) electronvolts are essential to understanding whether they have galactic or extragalactic sources. It has also been proposed that the astrophysical neutrino signal comes from accelerators capable of producing cosmic rays of these energies. Cosmic rays initiate air showers--cascades of secondary particles in the atmosphere-and their masses can be inferred from measurements of the atmospheric depth of the shower maximum (Xmax; the depth of the air shower when it contains the most particles) or of the composition of shower particles reaching the ground. Current measurements have either high uncertainty, or a low duty cycle and a high energy threshold. Radio detection of cosmic rays is a rapidly developing technique for determining Xmax (refs 10, 11) with a duty cycle of, in principle, nearly 100 per cent. The radiation is generated by the separation of relativistic electrons and positrons in the geomagnetic field and a negative charge excess in the shower front. Here we report radio measurements of Xmax with a mean uncertainty of 16 grams per square centimetre for air showers initiated by cosmic rays with energies of 10(17)-10(17.5) electronvolts. This high resolution in Xmax enables us to determine the mass spectrum of the cosmic rays: we find a mixed composition, with a light-mass fraction (protons and helium nuclei) of about 80 per cent. Unless, contrary to current expectations, the extragalactic component of cosmic rays contributes substantially to the total flux below 10(17.5) electronvolts, our measurements indicate the existence of an additional galactic component, to account for the light composition that we measured in the 10(17)-10(17.5) electronvolt range.

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.

High energy particles and quanta in astrophysics

NASA Technical Reports Server (NTRS)

Mcdonald, F. B. (Editor); Fichtel, C. E.

1974-01-01

The various subdisciplines of high-energy astrophysics are surveyed in a series of articles which attempt to give an overall view of the subject as a whole by emphasizing the basic physics common to all fields in which high-energy particles and quanta play a role. Successive chapters cover cosmic ray experimental observations, the abundances of nuclei in the cosmic radiation, cosmic electrons, solar modulation, solar particles (observation, relationship to the sun acceleration, interplanetary medium), radio astronomy, galactic X-ray sources, the cosmic X-ray background, and gamma ray astronomy. Individual items are announced in this issue.

Latest AMS Results on elementary particles in cosmic rays

NASA Astrophysics Data System (ADS)

Kounine, Andrei; AMS Collaboration

2017-01-01

AMS-02 is a particle physics detector collecting data on the International Space Station since May 2011. Precision measurements of all elementary charged cosmic ray particles have been performed by AMS using a data sample of 85 billion cosmic ray events collected during the first five years of operations on the Station. The latest AMS results on the fluxes and flux ratios of the elementary cosmic ray particles are presented. They show unique features that require accurate theoretical interpretation as to their origin, be it from dark matter collisions or new astrophysical sources. On behalf of the AMS Collaboration.

The Galactic Magnetic Field and Ultra-High Energy Cosmic Rays

NASA Astrophysics Data System (ADS)

Urban, Federico R.

The Galactic Magnetic Field is a peeving and importune screen between Ultra-High Energy Cosmic Rays and us cosmologists, engaged in the combat to unveil their properties and origin, as it deviates their paths towards the Earth in unpredictable ways. I will, in this order: briefly review the available field models on the market; explain a little trick which allows one to obtain cosmic rays deflection variances without even knowing what the (random) GMF model is; and argue that there is a lack of anisotropy in the large scales cosmic rays signal, which the Galactic field can do nothing about.

Cosmic-ray antimatter - A primary origin hypothesis

NASA Technical Reports Server (NTRS)

Stecker, F. W.; Protheroe, R. J.; Kazanas, D.

1983-01-01

The present investigation is concerned with the possibility that the observed cosmic-ray protons are of primary extragalactic origin, taking into account the significance of the current antiproton data. Attention is given to questions regarding primary antiprotons, antihelium fluxes, and the propagation of extragalactic cosmic rays. It is concluded that the primary origin hypothesis should be considered as a serious alternative explanation for the cosmic-ray antiproton fluxes. Such extragalactic primary origin can be considered in the context of a baryon symmetric domain cosmology. The fluxes and propagation characteristics suggested are found to be in rough agreement with the present antiproton data.

Calculations of cosmic-ray helium transport in shielding materials

NASA Technical Reports Server (NTRS)

Cucinotta, Francis A.

1993-01-01

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

A lower bound on the number of cosmic ray events required to measure source catalogue correlations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dolci, Marco; Romero-Wolf, Andrew; Wissel, Stephanie, E-mail: marco.dolci@polito.it, E-mail: Andrew.Romero-Wolf@jpl.nasa.gov, E-mail: swissel@calpoly.edu

2016-10-01

Recent analyses of cosmic ray arrival directions have resulted in evidence for a positive correlation with active galactic nuclei positions that has weak significance against an isotropic source distribution. In this paper, we explore the sample size needed to measure a highly statistically significant correlation to a parent source catalogue. We compare several scenarios for the directional scattering of ultra-high energy cosmic rays given our current knowledge of the galactic and intergalactic magnetic fields. We find significant correlations are possible for a sample of >1000 cosmic ray protons with energies above 60 EeV.

A new method for imaging nuclear threats using cosmic ray muons

NASA Astrophysics Data System (ADS)

Morris, C. L.; Bacon, Jeffrey; Borozdin, Konstantin; Miyadera, Haruo; Perry, John; Rose, Evan; Watson, Scott; White, Tim; Aberle, Derek; Green, J. Andrew; McDuff, George G.; Lukić, Zarija; Milner, Edward C.

2013-08-01

Muon tomography is a technique that uses cosmic ray muons to generate three dimensional images of volumes using information contained in the Coulomb scattering of the muons. Advantages of this technique are the ability of cosmic rays to penetrate significant overburden and the absence of any additional dose delivered to subjects under study above the natural cosmic ray flux. Disadvantages include the relatively long exposure times and poor position resolution and complex algorithms needed for reconstruction. Here we demonstrate a new method for obtaining improved position resolution and statistical precision for objects with spherical symmetry.

Alfven wave transport effects in the time evolution of parallel cosmic-ray modified shocks

NASA Technical Reports Server (NTRS)

Jones, T. W.

1993-01-01

Some of the issues associated with a more complete treatment of Alfven transport in cosmic ray shocks are explored qualitatively. The treatment is simplified in some important respects, but some new issues are examined and for the first time a nonlinear, time dependent study of plane cosmic ray mediated shocks with both the entropy producing effects of wave dissipation and effects due to the Alfven wave advection of the cosmic ray relative to the gas is included. Examination of the direct consequences of including the pressure and energy of the Alfven waves in the formalism began.

An estimation of Canadian population exposure to cosmic rays from air travel.

PubMed

Chen, Jing; Newton, Dustin

2013-03-01

Based on air travel statistics in 1984, it was estimated that less than 4 % of the population dose from cosmic ray exposure would result from air travel. In the present study, cosmic ray doses were calculated for more than 3,000 flights departing from more than 200 Canadian airports using actual flight profiles. Based on currently available air travel statistics, the annual per capita effective dose from air transportation is estimated to be 32 μSv for Canadians, about 10 % of the average cosmic ray dose received at ground level (310 μSv per year).

A new method for imaging nuclear threats using cosmic ray muons

DOE PAGES

Morris, C. L.; Bacon, Jeffrey; Borozdin, Konstantin; ...

2013-08-29

Muon tomography is a technique that uses cosmic ray muons to generate three-dimensional images of volumes using information contained in the Coulomb scattering of the muons. Advantages of this technique are the ability of cosmic rays to penetrate significant overburden and the absence of any additional dose delivered to subjects under study beyond the natural cosmic ray flux. Disadvantages include the relatively long exposure times and poor position resolution and complex algorithms needed for reconstruction. Furthermore, we demonstrate a new method for obtaining improved position resolution and statistical precision for objects with spherical symmetry.

Anisotropy of low-energy Galactic cosmic rays in the outer heliosheath

NASA Astrophysics Data System (ADS)

Zhang, M.; Pogorelov, N.

2017-12-01

Since Voyager 1 crossed the heliopause into the local interstellar medium in August 2012, it has been observing nearly unmodulated low-energy Galactic cosmic rays for over 5 years and 18 AU beyond the heliopause. The angular distribution of these cosmic rays is not isotropic, showing a slight depletion at 90-degree pitch-angle to the magnetic field lines. The anisotropy was interrupted episodically by solar disturbances transmitting through the heliopause into the local interstellar medium of outer heliosheath. These observations indicate the heliosphere still affects cosmic rays in the local interstellar medium. The paper presents a theoretical analysis of the particle transport mechanisms responsible for the observed anisotropy. In order to explain the phenomenon, we argue that cosmic rays of near 90-degree pitch angles do not a quick access to the interstellar cosmic-ray source and in the meantime, they experience some loss in the outer heliosheath. Magnetic field barriers on the both sides of the observer may reduce the access to cosmic ray source, but it still requires that pitch scattering of these particles is very weak in the magnetic field of the outer heliosheath. A possible particle loss mechanism is diffusion into the heliospheric magnetic field where they get modulated by the solar wind plasma. Our model simulation will put constraints on the rates of particle scattering and cross-field diffusion in the interstellar magnetic field of the outer heliosheath.

Cosmic-Ray Propagation in Turbulent Spiral Magnetic Fields Associated with Young Stellar Objects

NASA Astrophysics Data System (ADS)

Fatuzzo, Marco; Adams, Fred C.

2018-04-01

External cosmic rays impinging upon circumstellar disks associated with young stellar objects provide an important source of ionization, and, as such, play an important role in disk evolution and planet formation. However, these incoming cosmic rays are affected by a variety of physical processes internal to stellar/disk systems, including modulation by turbulent magnetic fields. Globally, these fields naturally provide both a funneling effect, where cosmic rays from larger volumes are focused into the disk region, and a magnetic mirroring effect, where cosmic rays are repelled due to the increasing field strength. This paper considers cosmic-ray propagation in the presence of a turbulent spiral magnetic field, analogous to that produced by the solar wind. The interaction of this wind with the interstellar medium defines a transition radius, analogous to the heliopause, which provides the outer boundary to this problem. We construct a new coordinate system where one coordinate follows the spiral magnetic field lines and consider magnetic perturbations to the field in the perpendicular directions. The presence of magnetic turbulence replaces the mirroring points with a distribution of values and moves the mean location outward. Our results thus help quantify the degree to which cosmic-ray fluxes are reduced in circumstellar disks by the presence of magnetic field structures that are shaped by stellar winds. The new coordinate system constructed herein should also be useful in other astronomical applications.

The extreme solar cosmic ray particle event on 20 January 2005 and its influence on the radiation dose rate at aircraft altitude.

PubMed

Bütikofer, R; Flückiger, E O; Desorgher, L; Moser, M R

2008-03-01

In January 2005 toward the end of solar activity cycle 23 the Sun was very active. Between 15 and 20 January 2005, the solar active region NOAA AR 10720 produced five powerful solar flares. In association with this major solar activity several pronounced variations in the ground-level cosmic ray intensity were observed. The fifth of these flares (X7.1) produced energetic solar cosmic rays that caused a giant increase in the count rates of the ground-based cosmic ray detectors (neutron monitors). At southern polar neutron monitor stations the increase of the count rate reached several thousand percent. From the recordings of the worldwide network of neutron monitors, we determined the characteristics of the solar particle flux near Earth. In the initial phase of the event, the solar cosmic ray flux near Earth was extremely anisotropic. The energy spectrum of the solar cosmic rays was fairly soft during the main and the decay phase. We investigated also the flux of different secondary particle species in the atmosphere and the radiation dosage at flight altitude. Our analysis shows a maximum increment of the effective dose rate due to solar cosmic rays in the south polar region around 70 degrees S and 130 degrees E at flight altitude of almost three orders of magnitude.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1979-09-20

This Atlas/Centaur launch vehicle, carrying the High Energy Astronomy Observatory (HEAO)-3, lifted off on September 20, 1979. The HEAO-3's mission was to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit.

Determination of magnetic helicity in the solar wind and implications for cosmic ray propagation

NASA Technical Reports Server (NTRS)

Matthaeus, W. H.; Goldstein, M. L.

1981-01-01

The mean value of the correlation between local magnetic field and vector potential, known as the magnetic helicity, is a measure of the lack of mirror reflection symmetry of magnetic covariances in a turbulent medium. A method is presented for extraction of helicity spectra from magnetometer data, and applied to an evaluation of the magnetic helicity of interplanetary magnetic fluctuations.

Measurement of cosmic-ray reconstruction efficiencies in the MicroBooNE LArTPC using a small external cosmic-ray counter

NASA Astrophysics Data System (ADS)

Acciarri, R.; Adams, C.; An, R.; Anthony, J.; Asaadi, J.; Auger, M.; Bagby, L.; Balasubramanian, S.; Baller, B.; Barnes, C.; Barr, G.; Bass, M.; Bay, F.; Bishai, M.; Blake, A.; Bolton, T.; Camilleri, L.; Caratelli, D.; Carls, B.; Castillo Fernandez, R.; Cavanna, F.; Chen, H.; Church, E.; Cianci, D.; Cohen, E.; Collin, G. H.; Conrad, J. M.; Convery, M.; Crespo-Anadón, J. I.; Del Tutto, M.; Devitt, D.; Dytman, S.; Eberly, B.; Ereditato, A.; Escudero Sanchez, L.; Esquivel, J.; Fadeeva, A. A.; Fleming, B. T.; Foreman, W.; Furmanski, A. P.; Garcia-Gamez, D.; Garvey, G. T.; Genty, V.; Goeldi, D.; Gollapinni, S.; Graf, N.; Gramellini, E.; Greenlee, H.; Grosso, R.; Guenette, R.; Hackenburg, A.; Hamilton, P.; Hen, O.; Hewes, J.; Hill, C.; Ho, J.; Horton-Smith, G.; Hourlier, A.; Huang, E.-C.; James, C.; de Vries, J. Jan; Jen, C.-M.; Jiang, L.; Johnson, R. A.; Joshi, J.; Jostlein, H.; Kaleko, D.; Kalousis, L. N.; Karagiorgi, G.; Ketchum, W.; Kirby, B.; Kirby, M.; Kobilarcik, T.; Kreslo, I.; Lange, G.; Laube, A.; Li, Y.; Lister, A.; Littlejohn, B. R.; Lockwitz, S.; Lorca, D.; Louis, W. C.; Luethi, M.; Lundberg, B.; Luo, X.; Marchionni, A.; Mariani, C.; Marshall, J.; Martinez Caicedo, D. A.; Meddage, V.; Miceli, T.; Mills, G. B.; Moon, J.; Mooney, M.; Moore, C. D.; Mousseau, J.; Murrells, R.; Naples, D.; Nienaber, P.; Nowak, J.; Palamara, O.; Paolone, V.; Papavassiliou, V.; Pate, S. F.; Pavlovic, Z.; Pelkey, R.; Piasetzky, E.; Porzio, D.; Pulliam, G.; Qian, X.; Raaf, J. L.; Rafique, A.; Rochester, L.; von Rohr, C. Rudolf; Russell, B.; Schmitz, D. W.; Schukraft, A.; Seligman, W.; Shaevitz, M. H.; Sinclair, J.; Smith, A.; Snider, E. L.; Soderberg, M.; Söldner-Rembold, S.; Soleti, S. R.; Spentzouris, P.; Spitz, J.; John, J. St.; Strauss, T.; Szelc, A. M.; Tagg, N.; Terao, K.; Thomson, M.; Toups, M.; Tsai, Y.-T.; Tufanli, S.; Usher, T.; Van De Pontseele, W.; Van de Water, R. G.; Viren, B.; Weber, M.; Wickremasinghe, D. A.; Wolbers, S.; Wongjirad, T.; Woodruff, K.; Yang, T.; Yates, L.; Zeller, G. P.; Zennamo, J.; Zhang, C.

2017-12-01

The MicroBooNE detector is a liquid argon time projection chamber at Fermilab designed to study short-baseline neutrino oscillations and neutrino-argon interaction cross-section. Due to its location near the surface, a good understanding of cosmic muons as a source of backgrounds is of fundamental importance for the experiment. We present a method of using an external 0.5 m (L) × 0.5 m (W) muon counter stack, installed above the main detector, to determine the cosmic-ray reconstruction efficiency in MicroBooNE. Data are acquired with this external muon counter stack placed in three different positions, corresponding to cosmic rays intersecting different parts of the detector. The data reconstruction efficiency of tracks in the detector is found to be epsilondata=(97.1±0.1 (stat) ± 1.4 (sys))%, in good agreement with the Monte Carlo reconstruction efficiency epsilonMC = (97.4±0.1)%. This analysis represents a small-scale demonstration of the method that can be used with future data coming from a recently installed cosmic-ray tagger system, which will be able to tag ≈80% of the cosmic rays passing through the MicroBooNE detector.

Measurement of cosmic-ray reconstruction efficiencies in the MicroBooNE LArTPC using a small external cosmic-ray counter

DOE PAGES

Acciarri, R.; Adams, C.; An, R.; ...

2017-12-01

The MicroBooNE detector is a liquid argon time projection chamber at Fermilab designed to study short-baseline neutrino oscillations and neutrino-argon interaction cross-section. Due to its location near the surface, a good understanding of cosmic muons as a source of backgrounds is of fundamental importance for the experiment. We present a method of using an external 0.5 m (L) x 0.5 m (W) muon counter stack, installed above the main detector, to determine the cosmic-ray reconstruction efficiency in MicroBooNE. Data are acquired with this external muon counter stack placed in three different positions, corresponding to cosmic rays intersecting different parts of the detector. The data reconstruction efficiency of tracks in the detector is found to bemore » $$\\epsilon_{\\mathrm{data}}=(97.1\\pm0.1~(\\mathrm{stat}) \\pm 1.4~(\\mathrm{sys}))\\%$$, in good agreement with the Monte Carlo reconstruction efficiency $$\\epsilon_{\\mathrm{MC}} = (97.4\\pm0.1)\\%$$. This analysis represents a small-scale demonstration of the method that can be used with future data coming from a recently installed cosmic-ray tagger system, which will be able to tag $$\\approx80\\%$$ of the cosmic rays passing through the MicroBooNE detector.« less

Measurement of cosmic-ray reconstruction efficiencies in the MicroBooNE LArTPC using a small external cosmic-ray counter

DOE PAGES

Acciarri, R.; Adams, C.; An, R.; ...

2017-12-20

The MicroBooNE detector is a liquid argon time projection chamber at Fermilab designed to study short-baseline neutrino oscillations and neutrino-argon interaction cross-section. Due to its location near the surface, a good understanding of cosmic muons as a source of backgrounds is of fundamental importance for the experiment. In this paper, we present a method of using an external 0.5 m (L) × 0.5 m (W) muon counter stack, installed above the main detector, to determine the cosmic-ray reconstruction efficiency in MicroBooNE. Data are acquired with this external muon counter stack placed in three different positions, corresponding to cosmic rays intersectingmore » different parts of the detector. The data reconstruction efficiency of tracks in the detector is found to be ϵ data=(97.1±0.1 (stat) ± 1.4 (sys))%, in good agreement with the Monte Carlo reconstruction efficiency ϵ MC = (97.4±0.1)%. In conclusion, this analysis represents a small-scale demonstration of the method that can be used with future data coming from a recently installed cosmic-ray tagger system, which will be able to tag ≈80% of the cosmic rays passing through the MicroBooNE detector.« less

Measurement of cosmic-ray reconstruction efficiencies in the MicroBooNE LArTPC using a small external cosmic-ray counter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acciarri, R.; Adams, C.; An, R.

The MicroBooNE detector is a liquid argon time projection chamber at Fermilab designed to study short-baseline neutrino oscillations and neutrino-argon interaction cross-section. Due to its location near the surface, a good understanding of cosmic muons as a source of backgrounds is of fundamental importance for the experiment. In this paper, we present a method of using an external 0.5 m (L) × 0.5 m (W) muon counter stack, installed above the main detector, to determine the cosmic-ray reconstruction efficiency in MicroBooNE. Data are acquired with this external muon counter stack placed in three different positions, corresponding to cosmic rays intersectingmore » different parts of the detector. The data reconstruction efficiency of tracks in the detector is found to be ϵ data=(97.1±0.1 (stat) ± 1.4 (sys))%, in good agreement with the Monte Carlo reconstruction efficiency ϵ MC = (97.4±0.1)%. In conclusion, this analysis represents a small-scale demonstration of the method that can be used with future data coming from a recently installed cosmic-ray tagger system, which will be able to tag ≈80% of the cosmic rays passing through the MicroBooNE detector.« less

Measurement of cosmic-ray reconstruction efficiencies in the MicroBooNE LArTPC using a small external cosmic-ray counter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acciarri, R.; et al.

2017-07-31

The MicroBooNE detector is a liquid argon time projection chamber at Fermilab designed to study short-baseline neutrino oscillations and neutrino-argon interaction cross-section. Due to its location near the surface, a good understanding of cosmic muons as a source of backgrounds is of fundamental importance for the experiment. We present a method of using an external 0.5 m (L) x 0.5 m (W) muon counter stack, installed above the main detector, to determine the cosmic-ray reconstruction efficiency in MicroBooNE. Data are acquired with this external muon counter stack placed in three different positions, corresponding to cosmic rays intersecting different parts of the detector. The data reconstruction efficiency of tracks in the detector is found to bemore » $$\\epsilon_{\\mathrm{data}}=(97.1\\pm0.1~(\\mathrm{stat}) \\pm 1.4~(\\mathrm{sys}))\\%$$, in good agreement with the Monte Carlo reconstruction efficiency $$\\epsilon_{\\mathrm{MC}} = (97.4\\pm0.1)\\%$$. This analysis represents a small-scale demonstration of the method that can be used with future data coming from a recently installed cosmic-ray tagger system, which will be able to tag $$\\approx80\\%$$ of the cosmic rays passing through the MicroBooNE detector.« less

Constraints on the Galactic Halo Dark Matter From FERMI-LAT Diffuse Measurements

DOE PAGES

Ackermann, M.; Ajello, M.; Atwood, W. B.; ...

2012-11-28

For this study, we have performed an analysis of the diffuse gamma-ray emission with the Fermi Large Area Telescope (LAT) in the Milky Way halo region, searching for a signal from dark matter annihilation or decay. In the absence of a robust dark matter signal, constraints are presented. We consider both gamma rays produced directly in the dark matter annihilation/decay and produced by inverse Compton scattering of the e +/e – produced in the annihilation/decay. Conservative limits are derived requiring that the dark matter signal does not exceed the observed diffuse gamma-ray emission. A second set of more stringent limitsmore » is derived based on modeling the foreground astrophysical diffuse emission using the GALPROP code. Uncertainties in the height of the diffusive cosmic-ray halo, the distribution of the cosmic-ray sources in the Galaxy, the index of the injection cosmic-ray electron spectrum, and the column density of the interstellar gas are taken into account using a profile likelihood formalism, while the parameters governing the cosmic-ray propagation have been derived from fits to local cosmic-ray data. In conclusion, the resulting limits impact the range of particle masses over which dark matter thermal production in the early universe is possible, and challenge the interpretation of the PAMELA/Fermi-LAT cosmic ray anomalies as the annihilation of dark matter.« less

Superbubbles and Local Cosmic Rays

NASA Technical Reports Server (NTRS)

Streitmatter, Robert E.; Jones, Frank C.

2005-01-01

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

Multidirectional Cosmic Ray Ion Detector for Deep Space CubeSats

NASA Technical Reports Server (NTRS)

Wrbanek, John D.; Wrbanek, Susan Y.

2016-01-01

NASA Glenn Research Center has proposed a CubeSat-based instrument to study solar and cosmic ray ions in lunar orbit or deep space. The objective of Solar Proton Anisotropy and Galactic cosmic ray High Energy Transport Instrument (SPAGHETI) is to provide multi-directional ion data to further understand anisotropies in SEP and GCR flux.

The Cosmic Connection

Science.gov Websites

Macy High School We have a simple cosmic ray detector that can be built by high school teachers. This cosmic rays vary with elevation. In addition, it is a valuable tool to teach elementary measurement

Inconstant sun: how solar evolution has affected cosmic and ultraviolet radiation exposure over the history of life on Earth.

PubMed

Karam, P Andrew

2003-03-01

Four billion years ago, sea-level UV exposure was more than 400 times as intense as today, the dose from solar cosmic rays was five times present levels, and galactic cosmic rays accounted for only about 10% their current contribution to sea-level radiation doses. Exposure to cosmic radiation accounts for about 10% of natural background radiation exposure today and includes dose from galactic cosmic rays and solar charged particles. There is little exposure to ionizing wavelengths of UV due to absorption by ozone. The sun has evolved significantly over its life; in the past there were higher levels of particulate radiation and lower UV emissions from the sun, and a stronger solar wind reduced radiation dose in the inner solar system from galactic cosmic rays. Finally, since the early atmosphere contained little to no oxygen, surface levels of UV radiation were far higher in the past.

Cosmic-ray antiprotons as a probe of a photino-dominated universe

NASA Technical Reports Server (NTRS)

Silk, J.; Srednicki, M.

1984-01-01

Observational tests of the hypothesis that the universe is flat and dominated by dark matter in the form of massive photinos include the production of significant fluxes of cosmic rays and gamma rays in our galactic halo. Specification of the cosmological photino density and the masses of scalar quarks and leptons determines the present annihilation rate. The predicted number of low-energy cosmic-ray antiprotons is comparable to the observed flux.

Search for patterns by combining cosmic-ray energy and arrival directions at the Pierre Auger Observatory.

PubMed

Aab, A; Abreu, P; Aglietta, M; Ahn, E J; Samarai, I Al; Albuquerque, I F M; Allekotte, I; Allen, J; Allison, P; Almela, A; Castillo, J Alvarez; Alvarez-Muñiz, J; Batista, R Alves; Ambrosio, M; Aminaei, A; Anchordoqui, L; Andringa, S; Aramo, C; Aranda, V M; Arqueros, F; Asorey, H; Assis, P; Aublin, J; Ave, M; Avenier, M; Avila, G; Awal, N; Badescu, A M; Barber, K B; 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; Blaess, S; Blanco, M; Bleve, C; Blümer, H; Boháčová, M; Boncioli, D; Bonifazi, C; Bonino, R; Borodai, N; Brack, J; Brancus, I; Bridgeman, A; Brogueira, P; Brown, W C; Buchholz, P; Bueno, A; Buitink, S; Buscemi, M; Caballero-Mora, K S; Caccianiga, B; Caccianiga, L; Candusso, M; Caramete, L; Caruso, R; Castellina, A; Cataldi, G; Cazon, L; Cester, R; Chavez, A G; Chiavassa, A; Chinellato, J A; Chudoba, J; Cilmo, M; Clay, R W; Cocciolo, G; Colalillo, R; Coleman, A; Collica, L; Coluccia, M R; 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; Almeida, R M de; Domenico, M De; Jong, S J de; Neto, J R T de Mello; Mitri, I De; Oliveira, J de; Souza, V de; Peral, L Del; Deligny, O; Dembinski, H; Dhital, N; Giulio, C Di; Matteo, A Di; Diaz, J C; Castro, M L Díaz; Diogo, F; Dobrigkeit, C; Docters, W; D'Olivo, J C; Dorofeev, A; Hasankiadeh, Q Dorosti; Dova, M T; Ebr, J; Engel, R; Erdmann, M; Erfani, M; Escobar, C O; Espadanal, J; Etchegoyen, A; Luis, P Facal San; Falcke, H; Fang, K; Farrar, G; Fauth, A C; Fazzini, N; Ferguson, A P; Fernandes, M; Fick, B; Figueira, J M; Filevich, A; Filipčič, A; Fox, B D; Fratu, O; Fröhlich, U; Fuchs, B; Fujii, T; Gaior, R; García, B; Roca, S T Garcia; Garcia-Gamez, D; Garcia-Pinto, D; Garilli, G; Bravo, A Gascon; Gate, F; Gemmeke, H; Ghia, P L; Giaccari, U; Giammarchi, M; Giller, M; Glaser, C; Glass, H; Berisso, M Gómez; Vitale, P F Gómez; Gonçalves, P; Gonzalez, J G; González, N; Gookin, B; Gordon, J; Gorgi, A; Gorham, P; Gouffon, P; Grebe, S; Griffith, N; Grillo, A F; Grubb, T D; Guarino, F; Guedes, G P; Hampel, M R; Hansen, P; Harari, D; Harrison, T A; Hartmann, S; Harton, J L; Haungs, A; Hebbeker, T; Heck, D; Heimann, P; Herve, A E; Hill, G C; Hojvat, C; Hollon, N; Holt, E; Homola, P; Hörandel, J R; Horvath, P; Hrabovský, M; Huber, D; Huege, T; Insolia, A; Isar, P G; 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; LaHurd, D; Latronico, L; Lauer, R; Lauscher, M; Lautridou, P; Coz, S Le; Leão, M S A B; Lebrun, D; Lebrun, P; Oliveira, M A Leigui de; Letessier-Selvon, A; Lhenry-Yvon, I; Link, K; López, R; Agüera, A Lopez; Louedec, K; Bahilo, J Lozano; Lu, L; Lucero, A; Ludwig, M; Malacari, M; Maldera, S; Mallamaci, M; Maller, J; Mandat, D; Mantsch, P; Mariazzi, A G; Marin, V; Mariş, I C; Marsella, G; Martello, D; Martin, L; Martinez, H; Bravo, O Martínez; Martraire, D; Meza, J J Masías; Mathes, H J; Mathys, S; Matthews, J; Matthews, J A J; Matthiae, G; Maurel, D; Maurizio, D; Mayotte, E; Mazur, P O; Medina, C; Medina-Tanco, G; Meissner, R; Melissas, M; Melo, D; Menshikov, A; Messina, S; Meyhandan, R; Mićanović, S; Micheletti, M I; Middendorf, L; Minaya, I A; Miramonti, L; Mitrica, B; Molina-Bueno, L; Mollerach, S; Monasor, M; Ragaigne, D Monnier; Montanet, F; Morello, C; Mostafá, M; Moura, C A; Muller, M A; Müller, G; Müller, S; Münchmeyer, M; Mussa, R; Navarra, G; Navas, S; Necesal, P; Nellen, L; Nelles, A; Neuser, J; Nguyen, P; Niechciol, M; Niemietz, L; Niggemann, T; Nitz, D; Nosek, D; Novotny, V; Nožka, L; Ochilo, L; Olinto, A; Oliveira, M; Pacheco, N; Selmi-Dei, D Pakk; Palatka, M; Pallotta, J; Palmieri, N; Papenbreer, P; Parente, G; Parra, A; Paul, T; Pech, M; Pȩkala, J; Pelayo, R; Pepe, I M; Perrone, L; Petermann, E; Peters, C; Petrera, S; Petrov, Y; Phuntsok, J; Piegaia, R; Pierog, T; Pieroni, P; Pimenta, M; Pirronello, V; Platino, M; Plum, M; Porcelli, A; Porowski, C; Prado, R R; Privitera, P; Prouza, M; Purrello, V; Quel, E J; Querchfeld, S; Quinn, S; Rautenberg, J; Ravel, O; Ravignani, D; Revenu, B; Ridky, J; Riggi, S; Risse, M; Ristori, P; Rizi, V; Carvalho, W Rodrigues de; Cabo, I Rodriguez; Fernandez, G Rodriguez; Rojo, J Rodriguez; Rodríguez-Frías, M D; Rogozin, D; Ros, G; Rosado, J; Rossler, T; Roth, M; Roulet, E; Rovero, A C; Saffi, S J; Saftoiu, A; Salamida, F; Salazar, H; Saleh, A; Greus, F Salesa; Salina, G; Sánchez, F; Sanchez-Lucas, P; Santo, C E; Santos, E; Santos, E M; Sarazin, F; Sarkar, B; Sarmento, R; Sato, R; Scharf, N; Scherini, V; Schieler, H; Schiffer, P; Schmidt, D; Schröder, F G; Scholten, O; Schoorlemmer, H; Schovánek, P; Schulz, A; Schulz, J; Schumacher, J; Sciutto, S J; Segreto, A; Settimo, M; Shadkam, A; Shellard, R C; Sidelnik, I; Sigl, G; Sima, O; Kowski, A Śmiał; Šmída, R; Snow, G R; Sommers, P; Sorokin, J; Squartini, R; Srivastava, Y N; Stanič, S; Stapleton, J; Stasielak, J; Stephan, M; Stutz, A; Suarez, F; Suomijärvi, T; Supanitsky, A D; Sutherland, M S; Swain, J; Szadkowski, Z; Szuba, M; Taborda, O A; Tapia, A; Tartare, M; Tepe, A; Theodoro, V M; Timmermans, C; Peixoto, C J Todero; Toma, G; Tomankova, L; Tomé, B; Tonachini, A; Elipe, G Torralba; Machado, D Torres; Travnicek, P; Trovato, E; Tueros, M; Ulrich, R; Unger, M; Urban, M; Galicia, J F Valdés; Valiño, I; Valore, L; Aar, G van; Bodegom, P van; Berg, A M van den; Velzen, S van; Vliet, A van; Varela, E; Vargas Cárdenas, B; Varner, G; Vázquez, J R; Vázquez, R A; Veberič, D; Verzi, V; Vicha, J; Videla, M; Villaseñor, L; Vlcek, B; Vorobiov, S; Wahlberg, H; Wainberg, O; Walz, D; Watson, A A; Weber, M; Weidenhaupt, K; Weindl, A; Werner, F; Widom, A; Wiencke, L; Wilczyńska, B; Wilczyński, H; Will, M; Williams, C; Winchen, T; Wittkowski, D; Wundheiler, B; Wykes, S; Yamamoto, T; Yapici, T; Yuan, G; Yushkov, A; Zamorano, B; Zas, E; Zavrtanik, D; Zavrtanik, M; Zaw, I; Zepeda, A; Zhou, J; Zhu, Y; Silva, M Zimbres; Ziolkowski, M; Zuccarello, F

Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with [Formula: see text] eV by analyzing cosmic rays with energies above [Formula: see text] eV arriving within an angular separation of approximately 15[Formula: see text]. We characterize the energy distributions inside these regions by two independent methods, one searching for angular dependence of energy-energy correlations and one searching for collimation of energy along the local system of principal axes of the energy distribution. No significant patterns are found with this analysis. The comparison of these measurements with astrophysical scenarios can therefore be used to obtain constraints on related model parameters such as strength of cosmic-ray deflection and density of point sources.

Lightning Discharges, Cosmic Rays and Climate

NASA Astrophysics Data System (ADS)

Kumar, Sanjay; Siingh, Devendraa; Singh, R. P.; Singh, A. K.; Kamra, A. K.

2018-03-01

The entirety of the Earth's climate system is continuously bombarded by cosmic rays and exhibits about 2000 thunderstorms active at any time of the day all over the globe. Any linkage among these vast systems should have global consequences. Numerous studies done in the past deal with partial links between some selected aspects of this grand linkage. Results of these studies vary from weakly to strongly significant and are not yet complete enough to justify the physical mechanism proposed to explain such links. This review is aimed at presenting the current understanding, based on the past studies on the link between cosmic ray, lightning and climate. The deficiencies in some proposed links are pointed out. Impacts of cosmic rays on engineering systems and the possible effects of cosmic rays on human health are also briefly discussed. Also enumerated are some problems for future work which may help in developing the grand linkage among these three vast systems.

Cosmic Ray Acceleration from Multiple Galactic Wind Shocks

NASA Astrophysics Data System (ADS)

Cotter, Cory; Bustard, Chad; Zweibel, Ellen

2018-01-01

Cosmic rays still have an unknown origin. Many mechanisms have been suggested for their acceleration including quasars, pulsars, magnetars, supernovae, supernova remnants, and galactic termination shocks. The source of acceleration may be a mixture of these and a different mixture in different energy regimes. Using numerical simulations, we investigate multiple shocks in galactic winds as potential cosmic rays sources. By having shocks closer to the parent galaxy, more particles may diffuse back to the disk instead of being blown out in the wind, as found in Bustard, Zweibel, and Cotter (2017, ApJ) and also Merten, Bustard, Zweibel, and Tjus (to be submitted to ApJ). Specifically, this flux of cosmic rays could contribute to the unexplained "shin" region between the well-known "knee" and "ankle" of the cosmic ray spectrum. We would like to acknowledge support from the National Science Foundation (NSF) Graduate Research Fellowship Program under grant No. DGE-125625 and NSF grant No. AST-1616037.

Cosmic ray physics in space: the role of Sergey Vernov's scientific school

NASA Astrophysics Data System (ADS)

Panasyuk, M. I.

2011-04-01

Cosmic rays were discovered almost 100 years ago. Since then the scientific world has learned a lot from their nature: the particles nascent in the Universe, both in our Galaxy and outside, the basic mechanisms of their acceleration, transfer in the interstellar environment and the interaction of the primary cosmic rays with the atmosphere surrounding the Earth. Before 1957, i.e., the beginning of the Space Era, researchers' capabilities were limited to experiments performed on the ground, underground and in near-ground atmosphere to flight altitudes of aerostats, airplanes and rockets, i.e., where only secondary radiation is in existence, this is the result of the interaction of cosmic rays with the Earth's atmosphere. The launching of spacecraft allowed the scientists to commence exploring the Universe's primordial matter itself outside the atmosphere, i.e., the primary cosmic rays. Sergey Vernov, the Russian scientist, was among them.

The evolution of cosmic-ray-mediated magnetohydrodynamic shocks: A two-fluid approach

NASA Astrophysics Data System (ADS)

Jun, Byung-Il; Clarke, David A.; Norman, Michael L.

1994-07-01

We study the shock structure and acceleration efficiency of cosmic-ray mediated Magnetohydrodynamic (MHD) shocks both analytically and numerically by using a two-fluid model. Our model includes the dynamical effect of magnetic fields and cosmic rays on a background thermal fluid. The steady state solution is derived by following the technique of Drury & Voelk (1981) and compared to numerical results. We explore the time evolution of plane-perpendicular, piston-driven shocks. From the results of analytical and numerical studies, we conclude that the mean magnetic field plays an important role in the structure and acceleration efficiency of cosmic-ray mediated MHD shocks. The acceleration of cosmic-ray particles becomes less efficient in the presence of strong magnetic pressure since the field makes the shock less compressive. This feature is more prominent at low Mach numbers than at high Mach numbers.

Cosmic Rays Variation Before Changes in Sun-Earth Environment

NASA Astrophysics Data System (ADS)

Mukherjee, S.

2011-12-01

Influence of cosmic rays variations on the Sun-Earth Environment has been observed before the changes in the atmospheric temperature, outbreak of influenza, cyclone, earthquake and tsunami. It has been recorded by Sun Observatory Heleospheric Observatory (SOHO) satellite data. Before the earthquake and tsunami the planetary indices (Kp) and Electron flux (E-flux) shows sudden changes followed by the atmospheric perturbations including very high temperature rise to sudden fall resulting snowfall in high altitude and rainfall in tropical areas. The active fault zones shows sudden faulting after the sudden drop in cosmic ray intensity and rise in Kp and E-flux. Besides the geo-environment the extraterrestrial influence on outbreak of H1N1 influenza has also been recorded based on the Mexico Cosmic ray data and its correlation with SOHO records. Distant stars have the potential to influence the heliophysical parameters by showering cosmic rays.

The evolution of cosmic-ray-mediated magnetohydrodynamic shocks: A two-fluid approach

NASA Technical Reports Server (NTRS)

Jun, Byung-Il; Clarke, David A.; Norman, Michael L.

1994-01-01

We study the shock structure and acceleration efficiency of cosmic-ray mediated Magnetohydrodynamic (MHD) shocks both analytically and numerically by using a two-fluid model. Our model includes the dynamical effect of magnetic fields and cosmic rays on a background thermal fluid. The steady state solution is derived by following the technique of Drury & Voelk (1981) and compared to numerical results. We explore the time evolution of plane-perpendicular, piston-driven shocks. From the results of analytical and numerical studies, we conclude that the mean magnetic field plays an important role in the structure and acceleration efficiency of cosmic-ray mediated MHD shocks. The acceleration of cosmic-ray particles becomes less efficient in the presence of strong magnetic pressure since the field makes the shock less compressive. This feature is more prominent at low Mach numbers than at high Mach numbers.

Search for patterns by combining cosmic-ray energy and arrival directions at the Pierre Auger Observatory

DOE PAGES

Aab, Alexander

2015-06-20

Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with E ≥ 6×10 19 eV by analyzing cosmic rays with energies above E ≥ 5×10 18 eV arriving within an angular separation of approximately 15°. We characterize the energy distributions inside these regions by two independent methods, one searching for angular dependence of energy-energy correlations and one searching for collimation of energy along the local system of principal axes of the energy distribution. No significant patterns are found with this analysis.more » As a result, the comparison of these measurements with astrophysical scenarios can therefore be used to obtain constraints on related model parameters such as strength of cosmic-ray deflection and density of point sources.« less

Ultrahigh energy cosmic rays from nearby starburst galaxies

NASA Astrophysics Data System (ADS)

Attallah, Reda; Bouchachi, Dallel

2018-04-01

Ultrahigh energy cosmic rays are the most energetic of any subatomic particles ever observed in nature. The quest for their mysterious origin is currently a major scientific challenge. Here we explore the possibility that these particles originate from nearby starburst galaxies, a scenario that matches the recent observation by the Telescope Array experiment of a cosmic-ray hotspot above 57 EeV not far from the direction of the starburst galaxy M82. Specifically, we study the stochastic propagation in space of ultrahigh energy cosmic rays through the state-of-the-art simulation framework CRPropa 3, taking into account all relevant particle interactions as well as deflections by the intervening magnetic fields. To ensure a comprehensive understanding of this model, we consider the energy spectrum, the cosmogenic neutrinos and gamma rays, and the distribution of arrival directions. The starburst galaxy scenario reproduces well observations from both the Telescope Array and Pierre Auger Observatories, making it very attractive for explaining the origin of cosmic rays at the highest energies.

Ultrahigh energy cosmic rays from nearby starburst galaxies

NASA Astrophysics Data System (ADS)

Attallah, Reda; Bouchachi, Dallel

2018-07-01

Ultrahigh energy cosmic rays are the most energetic of any subatomic particles ever observed in nature. The quest for their mysterious origin is currently a major scientific challenge. Here we explore the possibility that these particles originate from nearby starburst galaxies, a scenario that matches the recent observation by the Telescope Array experiment of a cosmic ray hotspot above 57 EeV not far from the direction of the starburst galaxy M82. Specifically, we study the stochastic propagation in space of ultrahigh ENERGY cosmic rays through the state-of-the-art simulation framework CRPROPA 3, taking into account all relevant particle interactions as well as deflections by the intervening magnetic fields. To ensure a comprehensive understanding of this model, we consider the energy spectrum, the cosmogenic neutrinos and gamma rays, and the distribution of arrival directions. The starburst galaxy scenario reproduces well observations from both the Telescope Array and Pierre Auger Observatories, making it very attractive for explaining the origin of cosmic rays at the highest energies.

Implications of the pseudo-Dirac scenario for ultra high energy neutrinos from GRBs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Esmaili, Arman; Farzan, Yasaman, E-mail: aesmaili@ifi.unicamp.br, E-mail: yasaman@theory.ipm.ac.ir

2012-12-01

The source of Ultra High Energy Cosmic Rays (UHECR) is still an unresolved mystery. Up until recently, sources of Gamma Ray Bursts (GRBs) had been considered as a suitable source for UHECR. Within the fireball model, the UHECR produced at GRBs should be accompanied with a neutrino flux detectable at the neutrino telescope such as IceCube. Recently, IceCube has set an upper bound on the neutrino flux accompanied by GRBs about 3.7 times below the prediction. We investigate whether this deficit can be explained by the oscillation of the active neutrinos to sterile neutrinos en route from the source tomore » the detectors within the pseudo-Dirac scenario. We then discuss the implication of this scenario for diffuse supernova relic neutrinos.« less

Linking high-energy cosmic particles by black-hole jets embedded in large-scale structures

NASA Astrophysics Data System (ADS)

Fang, Ke; Murase, Kohta

2018-04-01

The origin of ultrahigh-energy cosmic rays (UHECRs) is a half-century-old enigma1. The mystery has been deepened by an intriguing coincidence: over ten orders of magnitude in energy, the energy generation rates of UHECRs, PeV neutrinos and isotropic sub-TeV γ-rays are comparable, which hints at a grand unified picture2. Here we report that powerful black hole jets in aggregates of galaxies can supply the common origin for all of these phenomena. Once accelerated by a jet, low-energy cosmic rays confined in the radio lobe are adiabatically cooled; higher-energy cosmic rays leaving the source interact with the magnetized cluster environment and produce neutrinos and γ-rays; the highest-energy particles escape from the host cluster and contribute to the observed cosmic rays above 100 PeV. The model is consistent with the spectrum, composition and isotropy of the observed UHECRs, and also explains the IceCube neutrinos and the non-blazar component of the Fermi γ-ray background, assuming a reasonable energy output from black hole jets in clusters.

Using the information of cosmic rays to predict influence epidemic

NASA Astrophysics Data System (ADS)

Yu, Z. D.

1985-08-01

A correlation between the incidence of influenza pandemics and increased cosmic ray activity is made. A correlation is also made between the occurrence of these pandemics and the appearance of bright novae, e.g., Nova Eta Car. Four indices based on increased cosmic ray activity and novae are proposed to predict future influenza pandemics and viral antigenic shifts.

Cross section parameterizations for cosmic ray nuclei. 1: Single nucleon removal

NASA Technical Reports Server (NTRS)

Norbury, John W.; Townsend, Lawrence W.

1992-01-01

Parameterizations of single nucleon removal from electromagnetic and strong interactions of cosmic rays with nuclei are presented. These parameterizations are based upon the most accurate theoretical calculations available to date. They should be very suitable for use in cosmic ray propagation through interstellar space, the Earth's atmosphere, lunar samples, meteorites, spacecraft walls and lunar and martian habitats.

Using the information of cosmic rays to predict influence epidemic

NASA Technical Reports Server (NTRS)

Yu, Z. D.

1985-01-01

A correlation between the incidence of influenza pandemics and increased cosmic ray activity is made. A correlation is also made between the occurrence of these pandemics and the appearance of bright novae, e.g., Nova Eta Car. Four indices based on increased cosmic ray activity and novae are proposed to predict future influenza pandemics and viral antigenic shifts.

The Cosmic Ray Observatory Project: Results of a Summer High-School Student, Teacher, University Scientist Partnership Using a Capstone Research Experience

ERIC Educational Resources Information Center

Shell, Duane F.; Snow, Gregory R.; Claes, Daniel R.

2011-01-01

This paper reports results from evaluation of the Cosmic Ray Observatory Project (CROP), a student, teacher, scientist partnership to engage high-school students and teachers in school based cosmic ray research. Specifically, this study examined whether an intensive summer workshop experience could effectively prepare teacher-student teams to…

An Educational Study of the Barometric Effect of Cosmic Rays with a Geiger Counter

ERIC Educational Resources Information Center

Famoso, Barbara; La Rocca, Paola; Riggi, Francesco

2005-01-01

An educational study of the barometric effect of cosmic rays was carried out using an inexpensive experimental set-up that allowed for long-term monitoring of atmospheric pressure and cosmic ray flux as measured in a Geiger counter. The investigation was intended as a pilot study in view of ongoing involvements of high-school teams operating…

A simulation of high energy cosmic ray propagation 2

NASA Technical Reports Server (NTRS)

Honda, M.; Kamata, K.; Kifune, T.; Matsubara, Y.; Mori, M.; Nishijima, K.

1985-01-01

The cosmic ray propagation in the Galactic arm is simulated. The Galactic magnetic fields are known to go along with so called Galactic arms as a main structure with turbulences of the scale about 30pc. The distribution of cosmic ray in Galactic arm is studied. The escape time and the possible anisotropies caused by the arm structure are discussed.

Fermilab Education: Data-based Investigations

Science.gov Websites

Cosmic Rays Study cosmic rays with data from classrooom cosmic ray detectors. CMS e-Lab Study CMS Data using the CMS e-Lab from I2U2. LIGO Study seismic activity with data from LIGO (Laser Interferometer data from D0 - an example of conservation of momentum. Sky Server Study data from the Sloan Digital Sky

Does electromagnetic radiation accelerate galactic cosmic rays

NASA Technical Reports Server (NTRS)

Eichler, D.

1977-01-01

The 'reactor' theories of Tsytovich and collaborators (1973) of cosmic-ray acceleration by electromagnetic radiation are examined in the context of galactic cosmic rays. It is shown that any isotropic synchrotron or Compton reactors with reasonable astrophysical parameters can yield particles with a maximum relativistic factor of only about 10,000. If they are to produce particles with higher relativistic factors, the losses due to inverse Compton scattering of the electromagnetic radiation in them outweigh the acceleration, and this violates the assumptions of the theory. This is a critical restriction in the context of galactic cosmic rays, which have a power-law spectrum extending up to a relativistic factor of 1 million.

How cosmic rays were discovered and why they received this misnomer

NASA Astrophysics Data System (ADS)

Dorman, I. V.; Dorman, L. I.

2014-05-01

As many great discoveries, the phenomenon of cosmic rays was discovered mainly accidentally, during investigations that sought to answer another question: what are sources of air ionization? This problem became interesting for science about 230 years ago in the end of the 18th century, when physics met with a problem of leakage of electrical charge from very good isolated bodies. We describe the history how step by step cosmic rays was discovered and why this phenomenon received misnomer, how in cosmic rays was discovered the first antiparticle - positron. These discoveries were recognized among greatest in the 20th Century and were awarded by Nobel Prize.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandez T, Arturo

The use of the sophisticated and large underground detectors at CERN for cosmic ray studies has been considered by several groups, e.g. UA1, LEP and LHC detectors. They offer the opportunity to provide large sensitivity area with magnetic analysis which allow a precise determination of the direction of cosmic ray muons as well as their momentum up to the order of some TeV. The aim of this article is to review the observation of high energy cosmic ray muons using precise spectrometers at CERN, mainly LEP detectors as well as the possibility of improve those measurements with LHC apparatus, givingmore » special emphasis to the ACORDE-ALICE cosmic ray physics program.« less

Acceleration and propagation of cosmic rays

NASA Astrophysics Data System (ADS)

Fransson, C.; Epstein, R. I.

1980-11-01

Two general categories of cosmic ray models are discussed, concomitant acceleration and propagation (CAP) models and sequential acceleration and propagation (SAP) models. These normally correspond to the cosmic rays being continuously accelerated in the interstellar medium or being rapidly produced by discrete sources or strong shock waves, respectively. For the CAP models it is found that the ratio of the predominantly secondary nuclei (Li + Be + B + N) to the predominantly primary nuclei (C + O) varies by less than a factor of 1.5 between 1 and 100 GeV per nucleon. This is at variance with current measurements. It thus appears that the evolution of cosmic rays is best described by SAP models.

The beta(+) decay and cosmic-ray half-life of Mn-54

NASA Astrophysics Data System (ADS)

Dacruz, M. T. F.; Norman, E. B.; Chan, Y. D.; Garcia, A.; Larimer, R. M.; Lesko, K. T.; Stokstad, R. G.; Wietfeldt, F. E.

1993-03-01

We performed a search for the beta(+) branch of Mn-54 decay. As a cosmic ray, Mn-54, deprived of its atomic electrons, can decay only via beta(+) and beta(-) decay, with a half-life of the order of 106 yr. This turns Mn-54 into a suitable cosmic chronometer for the study of cosmic-ray confinement times. We searched for coincident back-to-back 511-keV gamma-rays using two germanium detectors inside a Nal(Tl) annulus. An upper limit of 2 x 10-8 was found for the beta(+) decay branch, corresponding to a lower limit of 13.7 for the log ft value.

The cosmic-ray shock structure problem for relativistic shocks

NASA Technical Reports Server (NTRS)

Webb, G. M.

1985-01-01

The time asymptotic behaviour of a relativistic (parallel) shock wave significantly modified by the diffusive acceleration of cosmic-rays is investigated by means of relativistic hydrodynamical equations for both the cosmic-rays and thermal gas. The form of the shock structure equation and the dispersion relation for both long and short wavelength waves in the system are obtained. The dependence of the shock acceleration efficiency on the upstream fluid spped, long wavelength Mach number and the ratio N = P sub co/cP sub co+P sub go)(Psub co and P sub go are the upstream cosmic-ray and thermal gas pressures respectively) are studied.

The Cosmic Ray Energy Spectrum and Related Measurements with the Pierre Auger Observatory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abraham, : J.; Abreu, P.; Aglietta, M.

2009-06-01

These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Measurement of the cosmic ray energy spectrum above 10{sup 18} eV with the Pierre Auger Observatory; (2) The cosmic ray flux observed at zenith angles larger than 60 degrees with the Pierre Auger Observatory; (3) Energy calibration of data recorded with the surface detectors of the Pierre Auger Observatory; (4) Exposure of the Hybrid Detector of The Pierre Auger Observatory; and (5) Energy scale derived from Fluorescence Telescopes using Cherenkov Light and Shower Universality.

Evaluating Galactic Cosmic Ray Environment Models Using RaD-X Flight Data

NASA Technical Reports Server (NTRS)

Norman, R. B.; Mertens, C. J.; Slaba, T. C.

2016-01-01

Galactic cosmic rays enter Earth's atmosphere after interacting with the geomagnetic field. The primary galactic cosmic rays spectrum is fundamentally changed as it interacts with Earth's atmosphere through nuclear and atomic interactions. At points deeper in the atmosphere, such as at airline altitudes, the radiation environment is a combination of the primary galactic cosmic rays and the secondary particles produced through nuclear interactions. The RaD-X balloon experiment measured the atmospheric radiation environment above 20 km during 2 days in September 2015. These experimental measurements were used to validate and quantify uncertainty in physics-based models used to calculate exposure levels for commercial aviation. In this paper, the Badhwar-O'Neill 2014, the International Organization for Standardization 15390, and the German Aerospace Company galactic cosmic ray environment models are used as input into the same radiation transport code to predict and compare dosimetric quantities to RaD-X measurements. In general, the various model results match the measured tissue equivalent dose well, with results generated by the German Aerospace Center galactic cosmic ray environment model providing the best comparison. For dose equivalent and dose measured in silicon, however, the models were compared less favorably to the measurements.

Heliospheric Modulation of Galactic Cosmic Rays; Diurnal Variability Abstract Details

NASA Astrophysics Data System (ADS)

Kalu, D. F.; Okpala, K. C.

2017-12-01

We have studied the variability of Cosmic rays flux during solar quiet days at mid and high latitudes in the Northern Hemisphere. By using the five (5) quietest days for each month and the five disturbed days for each month, the monthly mean diurnal variation of cosmic ray anisotropy have been derived for the period 1999-2015, which covers part of cycles 23, and cycle 24. This study seeks to understand the heliospheric contribution to the variation of these Cosmic rays on quietest days, three stations (Inuvik, Moscow, Rome) Neutron Monitors were employed. This study seeks to understand the important features of the high latitude and mid latitude diurnal wave, and how solar and geomagnetic activity may be influencing the wave characteristics. Cosmic ray wave characteristics were obtained by discrete Fourier transform (DFT). The mean, diurnal amplitude, phase and dispersion for each month's diurnal wave were calculated and profiled. There was clear indication that the terrestrial effect on the variability of the monthly mean was more associated with geomagnetic activity rather than rigidity of the cosmic rays. Correlation of the time series of these wave characteristic with solar and geomagnetic activity index showed better association with solar activity.

The Energetic Trans-Iron Cosmic-ray Experiment (ENTICE)

NASA Technical Reports Server (NTRS)

Binns, W. R.; Adams. J. H.; Barghouty, A. F.; Christian, E. R.; Cummings, A. C.; Hams, T.; Israel, M. H.; Labrador, A. W.; Leske, R. A.; Link, J. T.;

High-Energy Cosmic Rays from Supernovae

NASA Astrophysics Data System (ADS)

Morlino, Giovanni

Cosmic rays are charged relativistic particles that reach the Earth with extremely high energies, providing striking evidence of the existence of effective accelerators in the Universe. Below an energy around ˜ 1017 eV, cosmic rays are believed to be produced in the Milky Way, while above that energy, their origin is probably extragalactic. In the early 1930s, supernovae were already identified as possible sources for the galactic component of cosmic rays. After the 1970s this idea has gained more and more credibility, thanks to the development of the diffusive shock acceleration theory, which provides a robust theoretical framework for particle energization in astrophysical environments. Afterward, mostly in recent years, much observational evidence has been gathered in support of this framework, converting a speculative idea in a real paradigm. In this chapter the basic pillars of this paradigm will be illustrated. This includes the acceleration mechanism, the nonlinear effects produced by accelerated particles onto the shock dynamics needed to reach the highest energies, the escape process from the sources, and the transportation of cosmic rays through the Galaxy. The theoretical picture will be corroborated by discussing several observations which support the idea that supernova remnants are effective cosmic ray factories.

Th/U/Pu/Cm dating of galactic cosmic rays with the extremely heavy cosmic ray composition observer

NASA Astrophysics Data System (ADS)

Westphal, Andrew J.; Weaver, Benjamin A.; Tarlé, Gregory

The principal goal of ECCO, the Extremely-heavy Cosmic-ray Composition Observer, is the measurement of the age of heavy galactic cosmic-ray nuclei using the extremely rare actinides (Th, U, Pu, Cm) as clocks. ECCO is one of two cosmic-ray instruments comprising the Heavy Nuclei Explorer (HNX), which was recently selected as one of several missions for Phase A study under NASA's Small class Explorer (SMEX) program. ECCO is based on the flight heritage of Trek, an array of barium-phosphate glass tracketch detectors deployed on the Russian space station Mir from 1991-1995. Using Trek, we measured the abundances of elements with Z > 70 in the galactic cosmic rays (GCRs). Trek consisted of a 1 m 2 array of stacks of individually polished thin BP-1 glass detectors. ECCO will be a much larger instrument, but will achieve both excellent resolution and low cost through use of a novel detector configuration. Here we report the results of recent accelerator tests of the ECCO detectors that verify detector performance. We also show the expected charge and energy resolution of ECCO as a function of energy.

Cosmic Ray Interactions in Shielding Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Ankney, Austin S.

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-electronmore » 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.« less

Measurements of Cosmic-Ray Proton and Helium Spectra from the BESS-Polar Long-Duration Balloon Flights Over Antarctica

NASA Technical Reports Server (NTRS)

Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.; Kim, K. C.; Kumazawa, T.; Kusumoto, A.;

Comic ray flux anisotropies caused by astrospheres

NASA Astrophysics Data System (ADS)

Scherer, K.; Strauss, R. D.; Ferreira, S. E. S.; Fichtner, H.

2016-09-01

Huge astrospheres or stellar wind bubbles influence the propagation of cosmic rays at energies up to the TeV range and can act as small-scale sinks decreasing the cosmic ray flux. We model such a sink (in 2D) by a sphere of radius 10 pc embedded within a sphere of a radius of 1 kpc. The cosmic ray flux is calculated by means of backward stochastic differential equations from an observer, which is located at r0, to the outer boundary. It turns out that such small-scale sinks can influence the cosmic ray flux at the observer's location by a few permille (i.e. a few 0.1%), which is in the range of the observations by IceCube, Milagro and other large area telescopes.

Cosmic ray-modified stellar winds. I - Solution topologies and singularities

NASA Technical Reports Server (NTRS)

Ko, C. M.; Webb, G. M.

1987-01-01

In the present two-fluid hydrodynamical model for stellar wind flow modification due to its interaction with Galactic cosmic rays, these rays are coupled to the stellar wind by either hydromagnetic wave scattering or background flow irregularity propagation. The background flow is modified by the cosmic rays via their pressure gradient. The system of equations used possesses a line of singularities in (r, u, P sub c)-space, or a two-dimensional hypersurface of singularities in (r, u, P sub c, dP sub c/dr)-space, where r, u, and P sub c are respectively the radial distance from the star, the radial wind flow speed, and the cosmic ray pressure. The singular points may be nodes, foci, or saddle points.

The Tunka-Grande experiment

NASA Astrophysics Data System (ADS)

Monkhoev, R. D.; Budnev, N. M.; Chiavassa, A.; Dyachok, A. N.; Gafarov, A. R.; Gress, O. A.; Gress, T. I.; Grishin, O. G.; Ivanova, A. L.; Kalmykov, N. N.; Kazarina, Yu. A.; Korosteleva, E. E.; Kozhin, V. A.; Kuzmichev, L. A.; Lenok, V. V.; Lubsandorzhiev, B. K.; Lubsandorzhiev, N. B.; Mirgazov, R. R.; Mirzoyan, R.; Osipova, E. A.; Pakhorukov, A. L.; Panasyuk, M. I.; Pankov, L. V.; Poleschuk, V. A.; Popova, E. G.; Postnikov, E. B.; Prosin, V. V.; Ptuskin, V. S.; Pushnin, A. A.; Samoliga, V. S.; Semeney, Y. A.; Sveshnikova, L. G.; Silaev, A. A.; Silaev, A. A., Jr.; Skurikhin, A. V.; Sulakov, V. P.; Tabolenko, V. A.; Voronin, D. M.; Fedorov, O. L.; Spiering, C.; Zagorodnikov, A. V.; Zhurov, D. P.; Zurbanov, V. L.

2017-06-01

The investigation of energy spectrum and mass composition of primary cosmic rays in the energy range 1016-1018 eV and the search for diffuse cosmic gamma rays are of the great interest for understanding mechanisms and nature of high-energy particle sources, the problem of great importance in modern astrophysics. Tunka-Grande scintillator array is a part of the experimental complex TAIGA (Tunka Advanced Instrument for Cosmic Ray and Gamma Astronomy) which is located in the Tunka Valley, about 50 km from Lake Baikal. The purpose of this array is the study of diffuse gamma rays and cosmic rays of ultra-high energies by detecting extensive air showers. We describe the design, specifications of the read-out, data acquisition (DAQ) and control systems of the array.

A new population of very high energy gamma-ray sources in the Milky Way.

PubMed

Aharonian, F; Akhperjanian, A G; Aye, K-M; Bazer-Bachi, A R; Beilicke, M; Benbow, W; Berge, D; Berghaus, P; Bernlöhr, K; Boisson, C; Bolz, O; Borgmeier, C; Braun, I; Breitling, F; Brown, A M; Gordo, J Bussons; Chadwick, P M; Chounet, L-M; Cornils, R; Costamante, L; Degrange, B; Djannati-Ataï, A; Drury, L O'C; Dubus, G; Ergin, T; Espigat, P; Feinstein, F; Fleury, P; Fontaine, G; Funk, S; Gallant, Y A; Giebels, B; Gillessen, S; Goret, P; Hadjichristidis, C; Hauser, M; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hofmann, W; Holleran, M; Horns, D; de Jager, O C; Jung, I; Khélifi, B; Komin, Nu; Konopelko, A; Latham, I J; Le Gallou, R; Lemière, A; Lemoine, M; Leroy, N; Lohse, T; Marcowith, A; Masterson, C; McComb, T J L; de Naurois, M; Nolan, S J; Noutsos, A; Orford, K J; Osborne, J L; Ouchrif, M; Panter, M; Pelletier, G; Pita, S; Pühlhofer, G; Punch, M; Raubenheimer, B C; Raue, M; Raux, J; Rayner, S M; Redondo, I; Reimer, A; Reimer, O; Ripken, J; Rob, L; Rolland, L; Rowell, G; Sahakian, V; Saugé, L; Schlenker, S; Schlickeiser, R; Schuster, C; Schwanke, U; Siewert, M; Sol, H; Steenkamp, R; Stegmann, C; Tavernet, J-P; Terrier, R; Théoret, C G; Tluczykont, M; van der Walt, D J; Vasileiadis, G; Venter, C; Vincent, P; Visser, B; Völk, H J; Wagner, S J

2005-03-25

Very high energy gamma-rays probe the long-standing mystery of the origin of cosmic rays. Produced in the interactions of accelerated particles in astrophysical objects, they can be used to image cosmic particle accelerators. A first sensitive survey of the inner part of the Milky Way with the High Energy Stereoscopic System (HESS) reveals a population of eight previously unknown firmly detected sources of very high energy gamma-rays. At least two have no known radio or x-ray counterpart and may be representative of a new class of "dark" nucleonic cosmic ray sources.

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.

JUPITER AS A GIANT COSMIC RAY DETECTOR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rimmer, P. B.; Stark, C. R.; Helling, Ch., E-mail: pr33@st-andrews.ac.uk

We explore the feasibility of using the atmosphere of Jupiter to detect ultra-high-energy cosmic rays (UHECRs). The large surface area of Jupiter allows us to probe cosmic rays of higher energies than previously accessible. Cosmic ray extensive air showers in Jupiter's atmosphere could in principle be detected by the Large Area Telescope (LAT) on the Fermi observatory. In order to be observed, these air showers would need to be oriented toward the Earth, and would need to occur sufficiently high in the atmosphere that the gamma rays can penetrate. We demonstrate that, under these assumptions, Jupiter provides an effective cosmicmore » ray ''detector'' area of 3.3 × 10{sup 7} km{sup 2}. We predict that Fermi-LAT should be able to detect events of energy >10{sup 21} eV with fluence 10{sup –7} erg cm{sup –2} at a rate of about one per month. The observed number of air showers may provide an indirect measure of the flux of cosmic rays ≳ 10{sup 20} eV. Extensive air showers also produce a synchrotron signature that may be measurable by Atacama Large Millimeter/submillimeter Array (ALMA). Simultaneous observations of Jupiter with ALMA and Fermi-LAT could be used to provide broad constraints on the energies of the initiating cosmic rays.« less

Tunka Advanced Instrument for cosmic rays and Gamma Astronomy (TAIGA): Status, results and perspectives

NASA Astrophysics Data System (ADS)

Kuzmichev, L.; Astapov, I.; Bezyazeekov, P.; Boreyko, V.; Borodin, A.; Brückner, M.; Budnev, N.; Chiavassa, A.; Gress, O.; Gress, T.; Grishin, O.; Dyachok, A.; Epimakhov, S.; Fedorov, O.; Gafarov, A.; Grebenyuk, V.; Grinyuk, A.; Haungs, A.; Horns, D.; Huege, T.; Ivanova, A.; Jurov, D.; Kalmykov, N.; Kazarina, Y.; Kindin, V.; Kiryuhin, V.; Kokoulin, R.; Kompaniets, K.; Korosteleva, E.; Kostunin, D.; Kozhin, V.; Kravchenko, E.; Kunnas, M.; Lenok, V.; Lubsandorzhiev, B.; Lubsandorzhiev, N.; Mirgazov, R.; Mirzoyan, R.; Monkhoev, R.; Nachtigal, R.; Osipova, E.; Pakharukov, A.; Panasyuk, M.; Pankov, L.; Petrukhin, A.; Poleschuk, V.; Popesku, M.; Popova, E.; Porelli, A.; Postnikov, E.; Prosin, V.; Ptuskin, V.; Pushnin, A.; Rubtsov, G.; Ryabov, E.; Sagan, Y.; Samoliga, V.; Schröder, F. G.; Semeney, Yu.; Silaev, A.; Silaev, A.; Sidorenko, A.; Skurikhin, A.; Slunecka, V.; Sokolov, A.; Spiering, C.; Sveshnikova, L.; Sulakov, V.; Tabolenko, V.; Tarashansky, B.; Tkachenko, A.; Tkachev, L.; Tluczykont, M.; Wischnewski, R.; Zagorodnikov, A.; Zurbanov, V.; Yashin, I.

2017-06-01

We present the current status of high-energy cosmic-ray physics and gamma-ray astronomy at the Tunka Astrophysical Center (AC). This complex is located in the Tunka Valley, about 50 km from Lake Baikal. Present efforts are focused on the construction of the first stage of the gamma-ray observatory TAIGA - the TAIGA prototype. TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) is designed for the study of gamma rays and charged cosmic rays in the energy range 1013 eV-1018 eV. The array includes a network of wide angle timing Cherenkov stations (TAIGA-HiSCORE), each with a FOV = 0.6 sr, plus up to 16 IACTs (FOV - 10∘× 10∘). This part covers an area of 5 km2. Additional muon detectors (TAIGA-Muon), with a total coverage of 2000 m2, are distributed over an area of 1 km2.

Propagation of Cosmic Rays and Diffuse Galactic Gamma Rays

NASA Technical Reports Server (NTRS)

Moskalenko, Igor V.

2004-01-01

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.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Inoue, Yoshiyuki; Tanaka, Yasuyuki T., E-mail: yinoue@astro.isas.jaxa.jp

The Fermi gamma-ray space telescope has revolutionized our understanding of the cosmic gamma-ray background radiation in the GeV band. However, investigation on the cosmic TeV gamma-ray background radiation still remains sparse. Here, we report the lower bound on the cosmic TeV gamma-ray background spectrum placed by the cumulative flux of individual detected extragalactic TeV sources including blazars, radio galaxies, and starburst galaxies. The current limit on the cosmic TeV gamma-ray background above 0.1 TeV is obtained as 2.8 × 10{sup −8}(E/100 GeV){sup −0.55} exp(−E/2100GeV)[GeV cm{sup −2} s{sup −1} sr{sup −1}] < E{sup 2}dN/dE < 1.1 × 10{sup −7}(E/100 GeV){sup −0.49} [GeV cm{sup −2} s{sup −1} sr{sup −1}], wheremore » the upper bound is set by requirement that the cascade flux from the cosmic TeV gamma-ray background radiation can not exceed the measured cosmic GeV gamma-ray background spectrum. Two nearby blazars, Mrk 421 and Mrk 501, explain ∼70% of the cumulative background flux at 0.8–4 TeV, while extreme blazars start to dominate at higher energies. We also provide the cumulative background flux from each population, i.e., blazars, radio galaxies, and starburst galaxies which will be the minimum requirement for their contribution to the cosmic TeV gamma-ray background radiation.« less

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1970-01-01

This artist's concept depicts the third observatory, the High Energy Astronomy Observatory (HEAO)-3 in orbit. Designed and developed by TRW, Inc. under the direction of the Marshall Space Flight Center, the HEAO-3's mission was to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit.

Evaluation of the cosmic-ray induced background in coded aperture high energy gamma-ray telescopes

NASA Technical Reports Server (NTRS)

Owens, Alan; Barbier, Loius M.; Frye, Glenn M.; Jenkins, Thomas L.

1991-01-01

While the application of coded-aperture techniques to high-energy gamma-ray astronomy offers potential arc-second angular resolution, concerns were raised about the level of secondary radiation produced in a thick high-z mask. A series of Monte-Carlo calculations are conducted to evaluate and quantify the cosmic-ray induced neutral particle background produced in a coded-aperture mask. It is shown that this component may be neglected, being at least a factor of 50 lower in intensity than the cosmic diffuse gamma-rays.

Interpretation of various radiation backgrounds observed in the gamma-ray spectrometer experiments carried on the Apollo missions and implications for diffuse gamma-ray measurements

NASA Technical Reports Server (NTRS)

Dyer, C. S.; Trombka, J. I.; Metzger, A. E.; Seltzer, S. M.; Bielefeld, M. J.; Evans, L. G.

1975-01-01

Since the report of a preliminary analysis of cosmic gamma-ray measurements made during the Apollo 15 mission, an improved calculation of the spallation activation contribution has been made including the effects of short-lived spallation fragments, which can extend the correction to 15 MeV. In addition, a difference between Apollo 15 and 16 data enables an electron bremsstrahlung contribution to be calculated. A high level of activation observed in a crystal returned on Apollo 17 indicates a background contribution from secondary neutrons. These calculations and observations enable an improved extraction of spurious components and suggest important improvements for future detectors.

Neural network and wavelets in prediction of cosmic ray variability: The North Africa as study case

NASA Astrophysics Data System (ADS)

Zarrouk, Neïla; Bennaceur, Raouf

2010-04-01

Since the Earth is permanently bombarded with energetic cosmic rays particles, cosmic ray flux has been monitored by ground based neutron monitors for decades. In this work an attempt is made to investigate the decomposition and reconstructions provided by Morlet wavelet technique, using data series of cosmic rays variabilities, then to constitute from this wavelet analysis an input data base for the neural network system with which we can then predict decomposition coefficients and all related parameters for other points. Thus the latter are used for the recomposition step in which the plots and curves describing the relative cosmic rays intensities are obtained in any points on the earth in which we do not have any information about cosmic rays intensities. Although neural network associated with wavelets are not frequently used for cosmic rays time series, they seems very suitable and are a good choice to obtain these results. In fact we have succeeded to derive a very useful tool to obtain the decomposition coefficients, the main periods for each point on the Earth and on another hand we have now a kind of virtual NM for these locations like North Africa countries, Maroc, Algeria, Tunisia, Libya and Cairo. We have found the aspect of very known 11-years cycle: T1, we have also revealed the variation type of T2 and especially T3 cycles which seem to be induced by particular Earth's phenomena.

Cosmic Ray-Air Shower Measurement from Space

NASA Technical Reports Server (NTRS)

Takahashi, Yoshiyuki

1997-01-01

A feasibility study has been initiated to observe from space the highest energy cosmic rays above 1021 eV. A satellite observatory concept, the Maximum-energy Auger (Air)-Shower Satellite (MASS), is recently renamed as the Orbital Wide-angle Collector (OWL) by taking its unique feature of using a very wide field-of-view (FOV) optics. A huge array of imaging devices (about 10(exp 6) pixels) is required to detect and record fluorescent light profiles of cosmic ray cascades in the atmosphere. The FOV of MASS could extend to as large as about 60 in. diameter, which views (500 - 1000 km) of earth's surface and more than 300 - 1000 cosmic ray events per year could be observed above 1020 eV. From far above the atmosphere, the MASS/OWL satellite should be capable of observing events at all angles including near horizontal tracks, and would have considerable aperture for high energy photon and neutrino observation. With a large aperture and the spatial and temporal resolution, MASS could determine the energy spectrum, the mass composition, and arrival anisotropy of cosmic rays from 1020 eV to 1022 eV; a region hitherto not explored by ground-based detectors such as the Fly's Eye and air-shower arrays. MASS/OWL's ability to identify cosmic neutrinos and gamma rays may help providing evidence for the theory which attributes the above cut-off cosmic ray flux to the decay of topological defects. Very wide FOV optics system of MASS/OWL with a large array of imaging devices is applicable to observe other atmospheric phenomena including upper atmospheric lightning. The wide FOV MASS optics being developed can also improve ground-based gamma-ray observatories by allowing simultaneous observation of many gamma ray sources located at different constellations.

Proton flux and radiation dose from galactic cosmic rays in the lunar regolith and implications for organic synthesis at the poles of the Moon and Mercury

NASA Astrophysics Data System (ADS)

Crites, S. T.; Lucey, P. G.; Lawrence, D. J.

2013-11-01

Galactic cosmic rays are a potential energy source to stimulate organic synthesis from simple ices. The recent detection of organic molecules at the polar regions of the Moon by LCROSS (Colaprete, A. et al. [2010]. Science 330, 463-468, http://dx.doi.org/10.1126/science.1186986), and possibly at the poles of Mercury (Paige, D.A. et al. [2013]. Science 339, 300-303, http://dx.doi.org/10.1126/science.1231106), introduces the question of whether the organics were delivered by impact or formed in situ. Laboratory experiments show that high energy particles can cause organic production from simple ices. We use a Monte Carlo particle scattering code (MCNPX) to model and report the flux of GCR protons at the surface of the Moon and report radiation dose rates and absorbed doses at the Moon’s surface and with depth as a result of GCR protons and secondary particles, and apply scaling factors to account for contributions to dose from heavier ions. We compare our results with dose rate measurements by the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) experiment on Lunar Reconnaissance Orbiter (Schwadron, N.A. et al. [2012]. J. Geophys. Res. 117, E00H13, http://dx.doi.org/10.1029/2011JE003978) and find them in good agreement, indicating that MCNPX can be confidently applied to studies of radiation dose at and within the surface of the Moon. We use our dose rate calculations to conclude that organic synthesis is plausible well within the age of the lunar polar cold traps, and that organics detected at the poles of the Moon may have been produced in situ. Our dose rate calculations also indicate that galactic cosmic rays can induce organic synthesis within the estimated age of the dark deposits at the pole of Mercury that may contain organics.

Constraining heavy dark matter with cosmic-ray antiprotons

NASA Astrophysics Data System (ADS)

Cuoco, Alessandro; Heisig, Jan; Korsmeier, Michael; Krämer, Michael

2018-04-01

Cosmic-ray observations provide a powerful probe of dark matter annihilation in the Galaxy. In this paper we derive constraints on heavy dark matter from the recent precise AMS-02 antiproton data. We consider all possible annihilation channels into pairs of standard model particles. Furthermore, we interpret our results in the context of minimal dark matter, including higgsino, wino and quintuplet dark matter. We compare the cosmic-ray antiproton limits to limits from γ-ray observations of dwarf spheroidal galaxies and to limits from γ-ray and γ-line observations towards the Galactic center. While the latter limits are highly dependent on the dark matter density distribution and only exclude a thermal wino for cuspy profiles, the cosmic-ray limits are more robust, strongly disfavoring the thermal wino dark matter scenario even for a conservative estimate of systematic uncertainties.

Astrophysics at the Highest Energy Frontiers

NASA Technical Reports Server (NTRS)

Stecker, F. W.; White, Nicholas E. (Technical Monitor)

2002-01-01

I discuss recent advances being made in the physics and astrophysics of cosmic rays and cosmic gamma-rays at the highest observed energies as well as the related physics and astrophysics of very high energy cosmic neutrinos. I also discuss the connections between these topics.

A time-dependent diffusion convection model for the long term modulation of cosmic rays

NASA Technical Reports Server (NTRS)

Gallagher, J. J.

1974-01-01

A model is developed which incorporates to first order the direct effects of the time dependent diffusive propagation of interstellar cosmic rays in a slowly changing interplanetary medium. The model provides a physical explanation for observed rigidity-dependent phase lags in modulated spectra (cosmic ray hysteresis). The average distance to the modulating boundary during the last solar cycle is estimated.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Earl, James A.

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

Silicon to iron abundances in solar cosmic rays and in the sun

NASA Technical Reports Server (NTRS)

Vahia, M. N.; Biswas, S.; Durgaprasad, N.

1985-01-01

Differential spectra of even charged nuclei between Si and Fe in the August 4, 1972 event were made in the energy region of 10 to 40 MeV/n-1 using rocket borne plastic detectors. The resulting relative abundances of elements and low energy enhancements are obtained and compared with spectroscopically determined photospheric abundances. The implications of the relative abundances on the acceleration mechanisms is discussed.

Fun Times with Cosmic Rays

NASA Technical Reports Server (NTRS)

Wanjek, Christopher

2003-01-01

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

Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground-Based Computation and Control Systems, and Human Health and Safety

NASA Technical Reports Server (NTRS)

Atwell, William; Koontz, Steve; Normand, Eugene

2012-01-01

Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools needed to design, test, and verify the safety and reliability of modern complex technological systems. The effects of primary cosmic ray particles and secondary particle showers produced by nuclear reactions with the atmosphere, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth s surface, especially if the net target area of the sensitive electronic system components is large. Finally, accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO). In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as human health and the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in ground-based atmospheric flight, and space flight environments. Ground test methods applied to microelectronic components and systems are used in combinations with radiation transport and reaction codes to predict the performance of microelectronic systems in their operating environments. Similar radiation transport codes are used to evaluate possible human health effects of cosmic ray exposure, however, the health effects are based on worst-case analysis and extrapolation of a very limited human exposure data base combined with some limited experimental animal data. Finally, the limitations on human space operations beyond low-Earth orbit imposed by long term exposure to galactic cosmic rays are discussed.

Ashra Neutrino Telescope Array (NTA): Combined Imaging Observation of Astroparticles — For Clear Identification of Cosmic Accelerators and Fundamental Physics Using Cosmic Beams —

NASA Astrophysics Data System (ADS)

Sasaki, Makoto; Kifune, Tadashi

In VHEPA (very high energy particle astronomy) 2014 workshop, focused on the next generation explorers for the origin of cosmic rays, held in Kashiwa, Japan, reviewing and discussions were presented on the status of the observation of GeV-TeV photons, TeV-PeV neutrinos, EeV-ZeV hadrons, test of interaction models with Large Hadron Collider (LHC), and theoretical aspects of astrophysics. The acceleration sites of hadrons, i.e., sources of PeV-EeV cosmic rays, should exist in the universe within the GZK-horizon even in the remotest case. We also affirmed that the hadron acceleration mechanism correlates with cosmic ray composition so that it is important to investigate the acceleration mechanism in relevance to the composition survey at PeV-EeV energy. We regard that LHC and astrophysics theories are ready to be used to probe into hadron acceleration mechanism in the universe. Recently, IceCube has reported detection of three events of neutrinos with energies around 1 PeV and additional events at lower energies, which significantly deviate from the expected level of background events. It is necessary to observe GeV-TeV photon, EeV-ZeV hadron and TeV-PeV neutrino all together, in order to understand hadronic interactions of cosmic rays in the PeV-EeV energy region. It is required to make a step further toward exploring the PeV-EeV universe with high accuracy and high statistics observations for both neutrinos and gamma rays simultaneously, by using the instrument such as Ashra Neutrino Telescope Array (NTA). Wide and fine survey of gamma-rays and neutrinos with simultaneously detecting Cherenkov and fluorescence light with NTA will guide us to a new intriguing stage of recognizing astronomical objects and non-thermal phenomena in ultra-high energy region, in addition, new aspect about the fundamental concepts of physics beyond our presently limited understanding; the longstanding problem of cosmic ray origin, the radiation mechanism of gamma-rays, neutrino and cosmic rays from violent objects like blazars, interaction of gamma-rays and cosmic rays with microwave and infrared background photons, and PeV-EeV neutrinos originated from far places beyond the GZK-horizon.

Study of large Forbush decreases in cosmic-ray intensity observed during solar cycle 23 and 24

NASA Astrophysics Data System (ADS)

Kumar, Anand; Badruddin, B.

2016-07-01

Neutron monitors at different geomagnetic latitude and longitude of Earth measure the cosmic-ray intensity with high precision. Sudden decreases in cosmic-ray intensity within few hours and slow recovery to pre-decrease level within a few days (Forbush decreases) are observed in neutron monitor data. We identify large-amplitude Forbush decreases (FDs), using high counting rate neutron monitor data, that occurred during previous solar cycle 23 (1995-2009) and current solar cycle 24 (2010-2015). We then search for the solar sources and the interplanetary structures responsible for these decreases. We attempt to find the relative importance of various interplanetary plasma and field parameters and the physical mechanism(s) responsible for FDs of varying amplitudes. We analyze a number of interplanetary plasma and field parameters, during both the phases (main and recovery) of FDs. The interplanetary plasma and field data analyzed in this study are the solar-wind velocity, the interplanetary magnetic field, its fluctuations, interplanetary electric field and the time variation of interplanetary electric potential. For monitoring the changes in interplanetary plasma/field conditions during the development of FDs, we also utilize plasma density, temperature and plasma beta, dynamic pressure and Mach number during the passage of interplanetary structures responsible for FDs. In addition to their amplitude, we study the recovery of FDs in detail after determining the time constant during their recovery by exponential fit to the data. As the solar magnetic polarity reversed during the maximum phase of solar cycle 23 (in the year 2000), we study the differences in amplitude, time constant of recovery and plasma/field condition to search for the polarity dependent effects, if any, on the amplitude and recovery of FDs due to implication for the models suggested to explain the Forbush decrease phenomena. The implications of these results are discussed.

Cosmic-ray record in solar system matter

NASA Technical Reports Server (NTRS)

Reedy, R. C.; Arnold, J. R.; Lal, D.

1983-01-01

The interaction of galactic cosmic rays (GCR) and solar cosmic rays (SCR) with bodies in the solar system is discussed, and what the record of that interaction reveals about the history of the solar system is considered. The influence of the energy, charge, and mass of the particles on the interaction is addressed, showing long-term average fluxes of solar protons, predicted production rates for heavy-nuclei tracks and various radionuclides as a function of depth in lunar rock, and integral fluxes of protons emitted by solar flares. The variation of the earth's magnetic field, the gardening of the lunar surface, and the source of meteorites and cosmic dust are studied using the cosmic ray record. The time variation of GCR, SCR, and VH and VVH nuclei is discussed for both the short and the long term.

Development of the cosmic ray techniques

NASA Technical Reports Server (NTRS)

Rossi, B.

1982-01-01

It has been found that most advances of cosmic-ray physics have been directly related to the development of observational techniques. The history of observational techniques is discussed, taking into account ionization chambers, refinements applied to ionization chambers to make them suitable for an effective use in the study of cosmic radiation, the Wulf-type electrometer, the electrometer designed by Millikan and Neher, the Geiger-Mueller counter, the experiment of Bothe and Kolhoerster, the coincidence circuit, and a cosmic-ray 'telescope'. Attention is given to a magnetic lens for cosmic rays, a triangular arrangement of Geiger-Mueller counters used to demonstrate the production of a secondary radiation, a stereoscopic cloud-chamber photograph of showers, the cloud-chamber picture which provided the first evidence of the positive electron, and arrangements for studying photon components, mu-mesons, and air showers.

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.

The distribution of cosmic rays in the galaxy and their dynamics as deduced from recent gamma-ray observations. [X-ray intensity variations with galactocentric distance

NASA Technical Reports Server (NTRS)

Puget, J. L.; Stecker, F. W.

1974-01-01

Recent data from SAS-2 on the galactic gamma ray line flux as a function of longitude reveal a broad maximum in the gamma ray intensity in the region absolute value of l approximately smaller than 30 deg. These data imply that the low energy galactic cosmic ray flux varies with galactocentric distance and is about an order of magnitude higher than the local value in a toroidal region between 4 and 5 kpc from the galactic center. This enhancement can be plausibly accounted for by first order Fermi acceleration, compression and trapping of cosmic rays consistent with present ideas of galactic dynamics and galactic structure theory. Calculations indicate that cosmic rays in the 4 to 5 kpc region are trapped and accelerated over a mean time of the order of a few million years or about 2 to 4 times the assumed trapping time in the solar region of the galaxy.

Sudden Intensity Increases and Radial Gradient Changes of Cosmic Ray Mev Electrons and Protons Observed at Voyager 1 Beyond 111 AU in the Heliosheath

NASA Technical Reports Server (NTRS)

Webber, W. R.; Mcdonald, F. B.; Cummings, A. C.; Stone, E. C.; Heikkila, B.; Lal, N.

2012-01-01

Voyager 1 has entered regions of different propagation conditions for energetic cosmic rays in the outer heliosheathat a distance of about 111 AU from the Sun. The low energy 614 MeV galactic electron intensity increased by 20over a time period 10 days and the electron radial intensity gradient abruptly decreased from 19AU to 8AU at2009.7 at a radial distance of 111.2 AU. At about 2011.2 at a distance of 116.6 AU a second abrupt intensity increase of25 was observed for electrons. After the second sudden electron increase the radial intensity gradient increased to18AU. This large positive gradient and the 13 day periodic variations of 200 MeV particles observed near theend of 2011 indicate that V1 is still within the overall heliospheric modulating region. The implications of these resultsregarding the proximity of the heliopause are discussed.

A cocoon of freshly accelerated cosmic rays detected by Fermi in the Cygnus superbubble.

PubMed

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

2011-11-25

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.

Anisotropy in the Arrival Directions of Ultrahigh-Energy Cosmic Rays

NASA Astrophysics Data System (ADS)

Villaseñor, Luis

2017-06-01

In this article we illustrate, in an interactive way, the analysis and visualization of anisotropy properties in the arrival directions of ultrahigh-energy cosmic rays detected by the Telescope Array and the Pierre Auger experiments by using data released by both collaborations. We describe the use of several programs that we have written in Python and Julia languages for this purpose. We also discuss the potential sources and analyse the effect of correcting the arrival directions to take into account the deflections of the cosmic rays by the magnetic field of our galaxy for one specific model of the galactic magnetic field under several assumptions about the composition of the primary cosmic rays.

The structure of cosmic ray shocks

NASA Astrophysics Data System (ADS)

Axford, W. I.; Leer, E.; McKenzie, J. F.

1982-07-01

The acceleration of cosmic rays by steady shock waves has been discussed in brief reports by Leer et al. (1976) and Axford et al. (1977). This paper presents a more extended version of this work. The energy transfer and the structure of the shock wave is discussed in detail, and it is shown that even for moderately strong shock waves most of the upstream energy flux in the background gas is transferred to the cosmic rays. This holds also when the upstream cosmic ray pressure is very small. For an intermediate Mach-number regime the overall shock structure is shown to consist of a smooth transition followed by a gas shock (cf. Drury and Voelk, 1980).

Observation of Galactic and Solar Cosmic Rays from October 13, 1959 to February 17, 1961 with Explorer VII (Satellite 1959 Iota)

NASA Technical Reports Server (NTRS)

Lin, Wei Ching

1961-01-01

This paper gives a comprehensive summary of cosmic-ray intensity observations at high latitudes over North America and over Australia in the altitude range 550 to 1100 km by means of Geiger tubes in Explorer VII (Earth satellite 1959 Iota). The time period covered is October 13, 1959 to February 17, 1961. Of special interest are the observational data on some 20 solar cosmic-ray events including major events of early April 1960, early September 1960, and of mid-November 1960. Detailed study of the latitude dependence of solar cosmic ray intensity will be presented in a later companion paper.

SMALL-SCALE ANISOTROPIES OF COSMIC RAYS FROM RELATIVE DIFFUSION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahlers, Markus; Mertsch, Philipp

2015-12-10

The arrival directions of multi-TeV cosmic rays show significant anisotropies at small angular scales. It has been argued that this small-scale structure can naturally arise from cosmic ray scattering in local turbulent magnetic fields that distort a global dipole anisotropy set by diffusion. We study this effect in terms of the power spectrum of cosmic ray arrival directions and show that the strength of small-scale anisotropies is related to properties of relative diffusion. We provide a formalism for how these power spectra can be inferred from simulations and motivate a simple analytic extension of the ensemble-averaged diffusion equation that canmore » account for the effect.« less

Stochastic Acceleration of Galactic Cosmic Rays by Compressible Plasma Fluctuations in Supernova Shells

NASA Astrophysics Data System (ADS)

Zhang, Ming

2015-10-01

A theory of 2-stage acceleration of Galactic cosmic rays in supernova remnants is proposed. The first stage is accomplished by the supernova shock front, where a power-law spectrum is established up to a certain cutoff energy. It is followed by stochastic acceleration with compressible waves/turbulence in the downstream medium. With a broad \\propto {k}-2 spectrum for the compressible plasma fluctuations, the rate of stochastic acceleration is constant over a wide range of particle momentum. In this case, the stochastic acceleration process extends the power-law spectrum cutoff energy of Galactic cosmic rays to the knee without changing the spectral slope. This situation happens as long as the rate of stochastic acceleration is faster than 1/5 of the adiabatic cooling rate. A steeper spectrum of compressible plasma fluctuations that concentrate their power in long wavelengths will accelerate cosmic rays to the knee with a small bump before its cutoff in the comic-ray energy spectrum. This theory does not require a strong amplification of the magnetic field in the upstream interstellar medium in order to accelerate cosmic rays to the knee energy.

A New Approach in Coal Mine Exploration Using Cosmic Ray Muons

NASA Astrophysics Data System (ADS)

Darijani, Reza; Negarestani, Ali; Rezaie, Mohammad Reza; Fatemi, Syed Jalil; Akhond, Ahmad

2016-08-01

Muon radiography is a technique that uses cosmic ray muons to image the interior of large scale geological structures. The muon absorption in matter is the most important parameter in cosmic ray muon radiography. Cosmic ray muon radiography is similar to X-ray radiography. The main aim in this survey is the simulation of the muon radiography for exploration of mines. So, the production source, tracking, and detection of cosmic ray muons were simulated by MCNPX code. For this purpose, the input data of the source card in MCNPX code were extracted from the muon energy spectrum at sea level. In addition, the other input data such as average density and thickness of layers that were used in this code are the measured data from Pabdana (Kerman, Iran) coal mines. The average thickness and density of these layers in the coal mines are from 2 to 4 m and 1.3 gr/c3, respectively. To increase the spatial resolution, a detector was placed inside the mountain. The results indicated that using this approach, the layers with minimum thickness about 2.5 m can be identified.

High-Energy Cosmic Ray Self-Confinement Close to Extra-Galactic Sources.

PubMed

Blasi, Pasquale; Amato, Elena; D'Angelo, Marta

2015-09-18

The ultrahigh-energy cosmic rays observed on the Earth are most likely accelerated in extra-Galactic sources. For the typical luminosities invoked for such sources, the electric current associated to the flux of cosmic rays that leave them is large. The associated plasma instabilities create magnetic fluctuations that can efficiently scatter particles. We argue that this phenomenon forces cosmic rays to be self-confined in the source proximity for energies E

Search for Cosmic-Ray Antiproton Origins and for Cosmological Antimatter with BESS

NASA Technical Reports Server (NTRS)

Yamamoto, A.; Mitchell, J. W.; Yoshimura, K.; Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.;

Measurement of cosmic ray positron and negatron spectra between 50 and 800 MeV. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Daugherty, J. K.

1974-01-01

A balloon-borne magnetic spectrometer was used to measure the spectra of cosmic ray positrons and negatrons at energies between 50 and 800 MeV. Comparisons of the separate positron and negatron spectra observed near the earth with their expected intensities in interstellar space can be used to investigate the complex (and variable) interaction of galactic cosmic rays with the expanding solar wind. The present measurements, which have established finite values or upper limits for the positron and negatron spectral between 50 and 800 MeV, have confirmed earlier evidence for the existence of a dominant component of negatrons from primary sources in the galaxy. The present results are shown to be consistent with the hypothesis that the positron component is in fact mainly attributable to collisions between cosmic ray nuclei and the interstellar gas. The estimate of the absolute intensities confirm the indications from neutron monitors that in 1972 the interplanetary cosmic ray intensities were already recovering toward their high levels observed in 1965.

Cosmic-ray antiprotons, positrons, and gamma rays from halo dark matter annihilation

NASA Technical Reports Server (NTRS)

Rudaz, S.; Stecker, F. W.

1988-01-01

The subject of cosmic ray antiproton production is reexamined by considering other choices for the nature of the Majorana fermion chi other than the photino considered in a previous article. The calculations are extended to include cosmic-ray positrons and cosmic gamma rays as annihilation products. Taking chi to be a generic higgsino or simply a heavy Majorana neutrino with standard couplings to the Z-zero boson allows the previous interpretation of the cosmic antiproton data to be maintained. In this case also, the annihilation cross section can be calculated independently of unknown particle physics parameters. Whereas the relic density of photinos with the choice of parameters in the previous paper turned out to be only a few percent of the closure density, the corresponding value for Omega in the generic higgsino or Majorana case is about 0.2, in excellent agreement with the value associated with galaxies and one which is sufficient to give the halo mass.

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.

Measurement of secondary cosmic ray intensity at Regener-Pfotzer height using low-cost weather balloons and its correlation with solar activity

NASA Astrophysics Data System (ADS)

Sarkar, Ritabrata; Chakrabarti, Sandip K.; Pal, Partha Sarathi; Bhowmick, Debashis; Bhattacharya, Arnab

2017-09-01

Cosmic ray flux in our planetary system is primarily modulated by solar activity. Radiation effects of cosmic rays on the Earth strongly depend on latitude due to the variation of the geomagnetic field strength. To study these effects we carried out a series of measurements of the radiation characteristics in the atmosphere due to cosmic rays from various places (geomagnetic latitude: ∼14.50°N) in West Bengal, India, located near the Tropic of Cancer, for several years (2012-2016) particularly covering the solar maximum in the 24th solar cycle. We present low energy (15-140 keV) secondary radiation measurement results extending from the ground till the near space (∼40 km) using a scintillator detector on board rubber weather balloons. We also concentrate on the cosmic ray intensity at the Regener-Pfotzer maxima and find a strong anti-correlation between this intensity and the solar activity even at low geomagnetic latitudes.

Application of cosmic-ray shock theories to the Cygnus Loop - an alternative model

NASA Astrophysics Data System (ADS)

Boulares, Ahmed; Cox, Donald P.

1988-10-01

Steady state cosmic-ray shock models are investigated in light of observations of the Cygnus Loop supernova remnant. In this work the authors find that the model of Völk, Drury, and McKenzie, in which the plasma waves are generated by the streaming instability of the cosmic rays and are dissipated into the gas, can be made consistent with some observed characteristics of Cygnus Loop shocks. The waves heat the gas substantially in the cosmic-ray precursor, in addition to the usual heating in the (possibly weak) gas shock. The model is used to deduce upstream densities and shock velocities using known quantities for Cygnus Loop shocks. Compared to the usual pure gas shock interpretation, it is found that lower densities and approximately 3 times higher velocities are required. If the cosmic-ray models are valid, this could significantly alter our understanding of the Cygnus Loop's distance and age and of the energy released during the initial explosion.

Primary cosmic rays on the lunar surface

NASA Technical Reports Server (NTRS)

Vernov, S. N.; Lavrukhina, A. K.

1977-01-01

Results are reported for determination of the galactic cosmic ray flux during various time intervals in the 1965-1972 period, on the basis of data from the instruments of a spacecraft that made a soft landing on the lunar surface, and from the radioactivity of samples returned by the spacecraft. During minimum solar activity (the second half of 1965 and the beginning of 1966) I sub 0 (E greater than or equal to 30 percent MeV/nucleon) was determined to be 0.43 (plus or minus 10 percent). These values, within the error limits of the determinations, agree with the corresponding values of galactic cosmic ray intensities determined by stratospheric measurements. The mean flux of galactic cosmic rays over the past million years is equal to I (E greater or equal to 100 MeV/nucleon) + 0.28 (plus or minus 20 percent). This value agrees with the mean flux of modulated cosmic rays during the period of the nineteenth solar cycle. The mean flux of solar protons between 1965 and 1972 was 2.46.

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

NASA Technical Reports Server (NTRS)

Fichtel, C. E.

1982-01-01

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

The interstellar medium and star formation of galactic disks. I. Interstellar medium and giant molecular cloud properties with diffuse far-ultraviolet and cosmic-ray backgrounds

NASA Astrophysics Data System (ADS)

Li, Qi; Tan, Jonathan C.; Christie, Duncan; Bisbas, Thomas G.; Wu, Benjamin

2018-05-01

We present a series of adaptive mesh refinement hydrodynamic simulations of flat rotation curve galactic gas disks, with a detailed treatment of the interstellar medium (ISM) physics of the atomic to molecular phase transition under the influence of diffuse far-ultraviolet (FUV) radiation fields and cosmic-ray backgrounds. We explore the effects of different FUV intensities, including a model with a radial gradient designed to mimic the Milky Way. The effects of cosmic rays, including radial gradients in their heating and ionization rates, are also explored. The final simulations in this series achieve 4 pc resolution across the ˜20 kpc global disk diameter, with heating and cooling followed down to temperatures of ˜10 K. The disks are evolved for 300 Myr, which is enough time for the ISM to achieve a quasi-statistical equilibrium. In particular, the mass fraction of molecular gas is stabilized by ˜200 Myr. Additional global ISM properties are analyzed. Giant molecular clouds (GMCs) are also identified and the statistical properties of their populations are examined. GMCs are tracked as the disks evolve. GMC collisions, which may be a means of triggering star cluster formation, are counted and their rates are compared with analytic models. Relatively frequent GMC collision rates are seen in these simulations, and their implications for understanding GMC properties, including the driving of internal turbulence, are discussed.

The effect of cosmic rays on thunderstorm electricity

NASA Technical Reports Server (NTRS)

Bragin, Y. A.

1975-01-01

The inflow of charges of small ions, formed by cosmic rays, into thunderstorm cells is estimated on the basis of rocket measurements of ionic concentrations below 90 km. Out of the two processes that form the thunderstorm charge (generation and separation of charges), the former is supposed to be caused by cosmic rays, and the nature of separation is assumed to be the same as in other thunderstorm theories.

Observed antiprotons and energy dependent confinement of cosmic rays: A conflict?

NASA Technical Reports Server (NTRS)

Stephens, S. A.

1985-01-01

In the frame work of energy dependent confinement for cosmic rays, the energy spectrum inside the source is flatter than that observed. Antiproton observation suggests large amount of matter is being traversed by cosmic rays in some sources. As a result, secondary particles are produced in abundance. Their spectra was calculated and it is shown that the energy dependent confinement model is in conflict with some observations.

Exact solutions for sporadic acceleration of cosmic rays

NASA Technical Reports Server (NTRS)

Cowsik, R.

1985-01-01

The steady state spectra of cosmic rays which are subject to a sporadic acceleration process, wherein the gain in energy in each encounter is a finite fraction of the particle energy are discussed. They are derived from a mathematical model which includes the possibility of energy dependent leakage of cosmic rays from the galaxy. Comparison with observations allows limits to be placed on the frequency and efficiency of such encounters.

Plasmoid Impacts on Neutron Stars and Highest Energy Cosmic Rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Litwin, C.; Rosner, R.

Particle acceleration by electrostatic polarization fields that arise in plasmas streaming across magnetic fields is discussed as a possible acceleration mechanism of highest energy ({approx}>10{sup 20} eV) cosmic rays. Specifically, plasmoids arising in planetoid impacts onto neutron star magnetospheres are considered. We find that such impacts at plausible rates may account for the observed flux and energy spectrum of the highest energy cosmic rays.

Precise measurement of cosmic ray fluxes with the AMS-02 experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vecchi, Manuela, E-mail: manuela.vecchi@ifsc.usp.br

2015-12-17

The AMS-02 detector is a large acceptance magnetic spectrometer operating onboard the International Space Station since May 2011. The main goals of the detector are the search for antimatter and dark matter in space, as well as the measurement of cosmic ray composition and flux. In this document we present precise measurements of cosmic ray positrons, electrons and protons, collected during the first 30 months of operations.

Cosmic ray antimatter: Is it primary or secondary?

NASA Technical Reports Server (NTRS)

Stecker, F. W.; Protheroe, R. J.; Kazanas, D.

1981-01-01

The relative merits and difficulties of the primary and secondary origin hypotheses for the observed cosmic ray antiprotons, including the low energy measurement of Buffington, were examined. It is concluded that the cosmic ray antiproton data may be strong evidence for antimatter galaxies and baryon symmetric cosmology. The present antiproton data are consistent with a primary extragalactic component having antiproton/proton approximately equal to .0032 + or - 0.7.

New Solution of Diffusion-Advection Equation for Cosmic-Ray Transport Using Ultradistributions

NASA Astrophysics Data System (ADS)

Rocca, M. C.; Plastino, A. R.; Plastino, A.; Ferri, G. L.; de Paoli, A.

2015-11-01

In this paper we exactly solve the diffusion-advection equation (DAE) for cosmic-ray transport. For such a purpose we use the Theory of Ultradistributions of J. Sebastiao e Silva, to give a general solution for the DAE. From the ensuing solution, we obtain several approximations as limiting cases of various situations of physical and astrophysical interest. One of them involves Solar cosmic-rays' diffusion.

Diffuse flux of galactic neutrinos and gamma rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carceller, J.M.; Masip, M., E-mail: jmcarcell@correo.ugr.es, E-mail: masip@ugr.es

We calculate the fluxes of neutrinos and gamma rays from interactions of cosmic rays with interstellar matter in our galaxy. We use EPOS-LHC, SIBYLL and GHEISHA to parametrize the yield of these particles in proton, helium and iron collisions at kinetic energies between 1 and 10{sup 8} GeV, and we correlate the cosmic ray density with the mean magnetic field strength in the disk and the halo of our galaxy. We find that at E > 1 PeV the fluxes depend very strongly on the cosmic-ray composition, whereas at 1–5 GeV the main source of uncertainty is the cosmic-ray spectrummore » out of the heliosphere. We show that the diffuse flux of galactic neutrinos becomes larger than the conventional atmospheric one at E >1 PeV, but that at all IceCube energies it is 4 times smaller than the atmospheric flux from forward-charm decays.« less

Insights into the Galactic Cosmic-ray Source from the TIGER Experiment

NASA Technical Reports Server (NTRS)

Link, Jason T.; Barbier, L. M.; Binns, W. R.; Christian, E. R.; Cummings, J. R.; Geier, S.; Israel, M. H.; Lodders, K.; Mewaldt,R. A.; Mitchell, J. W.;

Diffusive Cosmic-Ray Acceleration at Shock Waves of Arbitrary Speed with Magnetostatic Turbulence. I. General Theory and Correct Nonrelativistic Speed Limit

NASA Astrophysics Data System (ADS)

Schlickeiser, R.; Oppotsch, J.

2017-12-01

The analytical theory of diffusive acceleration of cosmic rays at parallel stationary shock waves of arbitrary speed with magnetostatic turbulence is developed from first principles. The theory is based on the diffusion approximation to the gyrotropic cosmic-ray particle phase-space distribution functions in the respective rest frames of the up- and downstream medium. We derive the correct cosmic-ray jump conditions for the cosmic-ray current and density, and match the up- and downstream distribution functions at the position of the shock. It is essential to account for the different particle momentum coordinates in the up- and downstream media. Analytical expressions for the momentum spectra of shock-accelerated cosmic rays are calculated. These are valid for arbitrary shock speeds including relativistic shocks. The correctly taken limit for nonrelativistic shock speeds leads to a universal broken power-law momentum spectrum of accelerated particles with velocities well above the injection velocity threshold, where the universal power-law spectral index q≃ 2-{γ }1-4 is independent of the flow compression ratio r. For nonrelativistic shock speeds, we calculate for the first time the injection velocity threshold, settling the long-standing injection problem for nonrelativistic shock acceleration.

A Geant Study of the Scintillating Optical Fiber (SOFCAL) Cosmic Ray Detector

NASA Technical Reports Server (NTRS)

Munroe, Ray B., Jr.

1998-01-01

Recent energy measurements by balloon-borne passive emulsion chambers indicate that the flux ratios of protons to helium nuclei and of protons to all heavy nuclei decrease as the primary cosmic ray energy per nucleon increases above approx. 200 GeV/n, and suggest a "break" in the proton spectrum between 200 GeV and 5 TeV. However, these passive emulsion chambers are limited to a lower energy threshold of approx. 5 TeV/n, and cannot fully explore this energy regime. Because cosmic ray flux and composition details may be significant to acceleration models, a hybrid detector system called the Scintillating Optical Fiber Calorimeter (SOFCAL) has been designed and flown. SOFCAL incorporates both conventional passive emulsion chambers and an active calorimeter utilizing scintillating plastic fibers as detectors. These complementary types of detectors allow the balloon-borne SOFCAL experiment to measure the proton and helium spectra from approx. 400 GeV/n to approx. 20 TeV. The fundamental purpose of this study is to use the GEANT simulation package to model the hadronic and electromagnetic shower evolution of cosmic rays incident on the SOFCAL detector. This allows the interpretation of SOFCAL data in terms of charges and primary energies of cosmic rays, thus allowing the determinations of cosmic ray flux and composition as functions of primary energy.

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.

Global diffusion of cosmic rays in random magnetic fields

NASA Astrophysics Data System (ADS)

Snodin, A. P.; Shukurov, A.; Sarson, G. R.; Bushby, P. J.; Rodrigues, L. F. S.

2016-04-01

The propagation of charged particles, including cosmic rays, in a partially ordered magnetic field is characterized by a diffusion tensor whose components depend on the particle's Larmor radius RL and the degree of order in the magnetic field. Most studies of the particle diffusion presuppose a scale separation between the mean and random magnetic fields (e.g. there being a pronounced minimum in the magnetic power spectrum at intermediate scales). Scale separation is often a good approximation in laboratory plasmas, but not in most astrophysical environments such as the interstellar medium (ISM). Modern simulations of the ISM have numerical resolution of the order of 1 pc, so the Larmor radius of the cosmic rays that dominate in energy density is at least 106 times smaller than the resolved scales. Large-scale simulations of cosmic ray propagation in the ISM thus rely on oversimplified forms of the diffusion tensor. We take the first steps towards a more realistic description of cosmic ray diffusion for such simulations, obtaining direct estimates of the diffusion tensor from test particle simulations in random magnetic fields (with the Larmor radius scale being fully resolved), for a range of particle energies corresponding to 10-2 ≲ RL/lc ≲ 103, where lc is the magnetic correlation length. We obtain explicit expressions for the cosmic ray diffusion tensor for RL/lc ≪ 1, that might be used in a sub-grid model of cosmic ray diffusion. The diffusion coefficients obtained are closely connected with existing transport theories that include the random walk of magnetic lines.

MODELING THE GAMMA-RAY EMISSION IN THE GALACTIC CENTER WITH A FADING COSMIC-RAY ACCELERATOR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Ruo-Yu; Wang, Xiang-Yu; Prosekin, Anton

2016-12-20

Recent HESS observations of the ∼200 pc scale diffuse gamma-ray emission from the central molecular zone (CMZ) suggest the presence of a PeV cosmic-ray accelerator (PeVatron) located in the inner 10 pc region of the Galactic center. Interestingly, the gamma-ray spectrum of the point-like source (HESS J1745-290) in the Galactic center shows a cutoff at ∼10 TeV, implying a cutoff around 100 TeV in the cosmic-ray proton spectrum. Here we propose that the gamma-ray emission from the inner and the outer regions may be explained self-consistently by run-away protons from a single yet fading accelerator. In this model, gamma-rays frommore » the CMZ region are produced by protons injected in the past, while gamma-rays from the inner region are produced by protons injected more recently. We suggest that the blast wave formed in a tidal disruption event (TDE) caused by the supermassive black hole (Sgr A*) could serve as such a fading accelerator. With typical parameters of the TDE blast wave, gamma-ray spectra of both the CMZ region and HESS J1745-290 can be reproduced simultaneously. Meanwhile, we find that the cosmic-ray energy density profile in the CMZ region may also be reproduced in the fading accelerator model when appropriate combinations of the particle injection history and the diffusion coefficient of cosmic rays are adopted.« less

The imprint of Gould's belt on the local cosmic ray electron spectrum

NASA Astrophysics Data System (ADS)

Pohl, M.; Perrot, C.; Grenier, I.

2001-08-01

In a recent paper Pohl and Esposito (1998) demonstrated that if the sources of cosmic-rays are discrete, as are Supernova Remnants (SNR), then the spectra of cosmic-ray electrons largely vary with location and time and the locally measured electron spectrum may not be representative of the electron spectra elsewhere in the Galaxy, which could be substantially harder than the local one. They have shown that the observed excess of γ-ray emission above 1 GeV can in fact be partially explained as a correspondingly hard inverse Compton component, provided the bulk of cosmic-ray electrons is produced in SNR. As part of a program to model the Galactic γ-ray foreground we have continued the earlier studies by investigating the impact of the star forming region Gould's Belt on the local electron spectrum. If the electron sources in Gould's Belt were continous, the local electron spectrum would be slightly hardened. If the electron sources are discrete, which is the more probable case, the variation in the local electron spectrum found by Pohl & Esposito persists. 1 The local cosmic-ray electron spectrum The recent detections of non-thermal X-ray synchrotron radiation from the supernova remnants SN1006 (Koyama et al., 1995), RX J1713.7-3946 (Koyama et al., 1997), IC443 (Keohane et al., 1997; Slane et al., 1999), Cas A (Allen et al., 1997), and RCW86 (Borkowski et al., 2001) and the subsequent detections of SN1006 (Tanimori et al., 1998), RX J1713.7-3946 (Muraishi et al., 2000), and Cas A (Aharonian et al., 2001) at TeV energies support the hypothesis that at least Galactic cosmic-ray electrons are accelerated predominantly in SNR. The Galactic distribution and spectrum of cosmic-ray electrons are intimately linked to the distribution and nature of their sources. Supernovae and hence their remnants are tran-

Development of a national cosmic-ray dose monitoring system with Health Canada's Fixed Point Surveillance network.

PubMed

Liu, Chuanlei; Zhang, Weihua; Ungar, Kurt; Korpach, Ed; White, Brian; Benotto, Mike; Pellerin, Eric

2018-05-07

This work explores the application of Health Canada's Fixed Point Surveillance (FPS) network for cosmic ray monitoring and dose estimation purposes. This network is comprised of RS250 3 inch by 3 inch Sodium Iodide (NaI) spectroscopic dosimeters distributed throughout Canada. The RS250's high channel count rate responds to the electromagnetic and muonic components of cosmic ray shower. These count rates are used to infer cosmic ray doses throughout FPS locations. The derived dose was found to have an accuracy within 6.5% deviation relative to theoretical calculation. The solar cycle effect and meteorologically induced fluctuation can be realistically reflected in the estimated dose. This work may serve as a basis to enable the FPS network to monitor and report both terrestrial and cosmic radiation in quasi-real time. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Very high-energy gamma-ray signature of ultrahigh-energy cosmic-ray acceleration in Centaurus A

NASA Astrophysics Data System (ADS)

Joshi, Jagdish C.; Miranda, Luis Salvador; Razzaque, Soebur; Yang, Lili

2018-04-01

The association of at least a dozen ultrahigh-energy cosmic-ray (UHECR) events with energy ≳ 55 EeV detected by the Pierre Auger Observatory (PAO) from the direction of Centaurus-A, the nearest radio galaxy, supports the scenario of UHECR acceleration in the jets of radio galaxies. In this work, we model radio to very high energy (VHE,≳ 100 GeV) γ-ray emission from Cen A, including GeV hardness detected by Fermi-LAT and TeV emission detected by HESS. We consider two scenarios: (i) Two zone synchrotron self-Compton (SSC) and external-Compton (EC) models, (ii) Two zone SSC, EC and photo-hadronic emission from cosmic ray interactions. The GeV hardness observed by Fermi-LAT can be explained using these two scenarios, where zone 2 EC emission is very important. Hadronic emission in scenario (ii) can explain VHE data with the same spectral slope as obtained through fitting UHECRs from Cen A. The peak luminosity in cosmic ray proton at 1 TeV, to explain the VHE γ-ray data is ≈2.5 × 1046 erg/s. The bolometric luminosity in cosmic ray protons is consistent with the luminosity required to explain the origin of 13 UHECR signal events that are correlated with Cen A.

Very high-energy gamma-ray signature of ultrahigh-energy cosmic ray acceleration in Centaurus A

NASA Astrophysics Data System (ADS)

Joshi, Jagdish C.; Miranda, Luis Salvador; Razzaque, Soebur; Yang, Lili

2018-07-01

The association of at least a dozen ultrahigh-energy cosmic ray (UHECR) events with energy ≳ 55 EeV detected by the Pierre Auger Observatory from the direction of Centaurus-A, the nearest radio galaxy, supports the scenario of UHECR acceleration in the jets of radio galaxies. In this work, we model radio to very high energy (VHE,≳ 100 GeV) γ-ray emission from Cen A, including GeV hardness detected by Fermi-LAT and TeV emission detected by the High Energy Stereoscopic System (HESS). We consider two scenarios: (i) two-zone synchrotron self-Compton (SSC) and external-Compton (EC) models, (ii) two-zone SSC, EC, and photohadronic emission from cosmic ray interactions. The GeV hardness observed by Fermi-LAT can be explained using these two scenarios, where zone 2 EC emission is very important. Hadronic emission in scenario (ii) can explain VHE data with the same spectral slope as obtained through fitting UHECRs from Cen A. The peak luminosity in cosmic ray proton at 1 TeV, to explain the VHE γ-ray data is ≈2.5 × 1046 erg s-1. The bolometric luminosity in cosmic ray protons is consistent with the luminosity required to explain the origin of 13 UHECR signal events that are correlated with Cen A.

Correlated Measurements of the Disturbances of Geomagnetic Field and Changes of Secondary Particle Fluxes at Aragats-Space Environmental Center (ASEC)

DTIC Science & Technology

2010-02-01

Fluxes at Aragats-Space Environmental Center (ASEC) Ashot A. Chilingarian Alikhanyan Physics Institute Cosmic Ray Division 2 Alikhanian...GMS occurred during 23rd Solar activity cycle demonstrate that Cosmic Ray increase during GMS occurs coherently (or ~ 1 hour in advance) with abrupt...data on Solar bursts and secondary cosmic ray data. The magnetometer operates stable, noise level is low. 15. SUBJECT TERMS

DoD Space Radiation Concerns.

DTIC Science & Technology

1992-07-15

cosmic - ray transport. NASA TM X-2440, 1972:117-122. DoD Space Radiation Concerns 8 2. Atkins SG, Small JT, McFarland TH. Military Man-in Space (MMIS...136. 29. Silberberg R, Tsao CH, Adams JH Jr., Letaw JR. Radiation doses and LET distributions of cosmic rays . Rad. Res., 1984, 98:209-226. 30. Stauber...levels on mission success and completion. Natural Radiation Trapped Radiation Belts Galactic Cosmic Rays (GCR) Solar Particle Events (SPEs) Man-Made

MUFFSgenMC: An Open Source MUon Flexible Framework for Spectral GENeration for Monte Carlo Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chatzidakis, Stylianos; Greulich, Christopher

A cosmic ray Muon Flexible Framework for Spectral GENeration for Monte Carlo Applications (MUFFSgenMC) has been developed to support state-of-the-art cosmic ray muon tomographic applications. The flexible framework allows for easy and fast creation of source terms for popular Monte Carlo applications like GEANT4 and MCNP. This code framework simplifies the process of simulations used for cosmic ray muon tomography.

Live 129I-129Xe dating

NASA Technical Reports Server (NTRS)

Marti, K.

1986-01-01

A technique of cosmic ray exposure age dating using cosmic ray produced I-129 and Xe-129 components is discussed. The live I-129 - Xe-129 method provides an ideal monitor for cosmic ray flux variations on the 10(7)y - 10(8)y time-scale. It is based on low-energy neutron reactions on Te, and these data, when coupled to those from other methods, may facilitate the detection of complex exposure histories.

Neutron measurements of the OGO-VI Spacecraft

NASA Technical Reports Server (NTRS)

Lockwood, J. A.

1973-01-01

The neutron measurements with the OGO-6 spacecraft are reported. Topics discussed include: the design and calibration of a neutron monitor for measuring the cosmic ray neutron leakages from the earth's atmosphere, determination of latitude dependence of cosmic ray leakage flux, determination of the angular distribution of neutron leakage flux as deduced by measurements of the altitude dependence, and verification of the solar modulation of the cosmic ray source for the neutron leakage.

Observation of shadowing of ultrahigh-energy cosmic rays by the Moon and the Sun

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alexandreas, D.E.; Allen, R.C.; Berley, D.

1991-03-01

Data from an extensive air shower detector of ultrahigh-energy cosmic rays shows shadowing of the cosmic-ray flux by the Moon and the Sun with significance of 4.9 standard deviations. This is the first observation of such shadowing. The effect has been used to determine that the angular resolution of the detector is 0.75{degree} {sub {minus}0.90{degree}}{sup +0.13{degree}}.

Cosmic-ray streaming and anisotropies

NASA Technical Reports Server (NTRS)

Forman, M. A.; Gleeson, L. J.

1975-01-01

The paper is concerned with the differential current densities and anisotropies that exist in the interplanetary cosmic-ray gas, and in particular with a correct formulation and simple interpretation of the momentum equation that describes these on a local basis. Two examples of the use of this equation in the interpretation of previous data are given. It is demonstrated that in interplanetary space, the electric-field drifts and convective flow parallel to the magnetic field of cosmic-ray particles combine as a simple convective flow with the solar wind, and that there exist diffusive currents and transverse gradient drift currents. Thus direct reference to the interplanetary electric-field drifts is eliminated, and the study of steady-state and transient cosmic-ray anisotropies is both more systematic and simpler.

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.

Neutrino flux from cosmic ray accelerators in the Cygnus spiral arm of the Galaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anchordoqui, Luis; Halzen, Francis; O'Murchadha, Aongus

2007-09-15

Intriguing evidence has been accumulating for the production of cosmic rays in the Cygnus region of the galactic plane. We here show that the IceCube experiment can produce incontrovertible evidence for cosmic ray acceleration by observing the neutrinos from the decay of charged pions accompanying the TeV photon flux observed in the HEGRA, Whipple, Tibet, and Milagro experiments. Our assumption is that the TeV photons observed are the decay products of neutral pions produced by cosmic ray accelerators in the nearby spiral arm of the galaxy. Because of the proximity of the sources, IceCube will obtain evidence at the 5{sigma}more » level in 15 years of observation.« less

Interplanetary flow systems associated with cosmic ray modulation in 1977-1980

NASA Technical Reports Server (NTRS)

Burlaga, L. F.; Mcdonald, F. B.; Ness, N. F.; Schwenn, R.; Lazarus, A. J.; Mariani, F.

1984-01-01

The hydromagnetic flow configurations associated with the cosmic ray modulation in 1977-1980 were determined using solar wind plasma and magnetic field data from Voyager 1 and 2 and Helios 1. The modulation was related to two types of large-scale systems of flows: one containing a number of transients such as shocks and postshock flows, the other consisting primarily of a series of quasi-stationary flows following interaction regions containing a stream interface and often bounded by a forward-reverse shock pair. Each of three major episodes of cosmic ray modulation was associated with the passage of a system of transient flows. Plateaus in the cosmic ray intensity-time profile were associated with the passage of systems of corotating streams.

THE UNREASONABLE WEAKNESS OF R -PROCESS COSMIC RAYS IN THE NEUTRON-STAR-MERGER NUCLEOSYNTHESIS SCENARIO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kyutoku, Koutarou; Ioka, Kunihito, E-mail: koutarou.kyutoku@riken.jp

We reach the robust conclusion that, by combining the observed cosmic rays of r -process elements with the fact that the velocity of the neutron-star-merger ejecta is much higher than that of the supernova ejecta, either (1) the reverse shock in the neutron-star-merger ejecta is a very inefficient accelerator that converts less than 0.003% of the ejecta kinetic energy to the cosmic-ray energy or (2) the neutron star merger is not the origin of the Galactic r -process elements. We also find that the acceleration efficiency should be less than 0.1% for the reverse shock of the supernova ejecta withmore » observed cosmic rays lighter than the iron.« less

Detection of Ultrahigh-Energy Cosmic Rays with the Auger Engineering Radio Array

NASA Astrophysics Data System (ADS)

Krause, Raphael; Pierre Auger Collaboration

2017-02-01

Ultrahigh-energy cosmic rays interact with the Earth's atmosphere and produce great numbers of secondary particles forming an extensive air shower. These air showers emit radiation in the radio frequency range which delivers important information about the processes of radio emission in extensive air showers and properties of the primary cosmic rays, e.g. arrival direction, energy and mass with a duty cycle close to 100%. The radio extension of the world's largest cosmic-ray experiment, the Pierre Auger Observatory, is called the Auger Engineering Radio Array (AERA). In addition to the particle and fluorescence detectors of the Pierre Auger Observatory, AERA investigates the electromagnetic component of extensive air showers using 153 autonomous radio stations on an area of 17km2 .

[The evolutionary role of nitric oxide in circadian activity and defense of the organism from cosmic rays].

PubMed

Iamshanov, V A

2009-01-01

The cosmic rays are one of the constantly acting factors influencing on genetic apparatus and depending from sun activity, which have the circadian rhythm. The nature creates a number of mechanisms, which defend the organism from cosmic rays and free radicals as consequence. However, the malfunctions of these mechanisms damage the genetic apparatus, accelerate the aging and bring to a number of illnesses. It is supposed that to neutralise the free radicals as cosmic rays consequence the organism uses its own free radicals, which have the physiological functions, for example, the nitric oxide. To limit the nitric oxide production, the mechanism of melatonin formation is used, which has a circadian rhythm.

The diffuse gamma-ray background, light element abundances, and signatures of early massive star formation

NASA Technical Reports Server (NTRS)

Silk, Joseph; Schramm, David N.

1992-01-01

Attention is drawn to a potentially observable flux of diffuse extragalactic gamma rays produced by inelastic cosmic-ray interactions that is inevitably a by-product of spallation-synthesized Be. The epoch of cosmic ray-induced Population II light element nucleosynthesis is constrained to be at redshift greater than 0.5. A spectral feature in the diffuse extragalactic gamma-ray background with amplitude 0.1 above 10 MeV is predicted if the Be is synthesized at z less than 10. The possibility is discussed that the cosmic-ray flux responsible for Population II Be and B synthesis may be associated with a precursor hypothesized Population III.

On the Energy Spectra of GeV/TeV Cosmic Ray Leptons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stawarz, Lukasz; /KIPAC, Menlo Park /Jagiellonian U., Astron. Observ.; Petrosian, Vahe

2011-08-19

Recent observations of cosmic ray electrons from several instruments have revealed various degrees of deviation in the measured electron energy distribution from a simple power-law, in a form of an excess around 0.1 to 1 TeV energies. An even more prominent deviation and excess has been observed in the fraction of cosmic ray positrons around 10 and 100 GeV energies. These observations have received considerable attention and many theoretical models have been proposed to explain them. The models rely on either dark matter annihilation/decay or specific nearby astrophysical sources, and involve several additional assumptions regarding the dark matter distribution ormore » particle acceleration. In this paper we show that the observed excesses in the electron spectrum may be easily reproduced without invoking any unusual sources other than the general diffuse Galactic components of cosmic rays. The model presented here assumes a power-law injection of electrons (and protons) by supernova remnants, and evaluates their expected energy spectrum based on a simple kinetic equation describing the propagation of charged particles in the interstellar medium. The primary physical effect involved is the Klein-Nishina suppression of the electron cooling rate around TeV energies. With a very reasonable choice of the model parameters characterizing the local interstellar medium, we can reproduce the most recent observations by Fermi and HESS experiments. Interestingly, in our model the injection spectral index of cosmic ray electrons becomes comparable to, or even equal to that of cosmic ray protons. The Klein-Nishina effect may also affect the propagation of the secondary e{sup {+-}} pairs, and therefore modify the cosmic ray positron-to-electron ratio. We have explored this possibility by considering two mechanisms for production of e{sup {+-}} pairs within the Galaxy. The first is due to the decay of {pi}{sup {+-}}'s produced by interaction of cosmic ray nuclei with ambient protons. The second source discussed here is due to the annihilation of the diffuse Galactic {gamma}-rays on the stellar photon field. We find that high positron fraction increasing with energy, as claimed by the PAMELA experiment, cannot be explained in our model with the conservative set of the model parameters. We are able, however, to reproduce the PAMELA (as well as Fermi and HESS) results assuming high values of the starlight and interstellar gas densities, which would be more appropriate for vicinities of supernova remnants. A possible solution to this problem may be that cosmic rays undergo most of their interactions near their sources due to the efficient trapping in the far upstream of supernova shocks by self-generated, cosmic ray-driven turbulence.« less

Particle Physics at the Cosmic, Intensity, and Energy Frontiers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Essig, Rouven

Major efforts at the Intensity, Cosmic, and Energy frontiers of particle physics are rapidly furthering our understanding of the fundamental constituents of Nature and their interactions. The overall objectives of this research project are (1) to interpret and develop the theoretical implications of the data collected at these frontiers and (2) to provide the theoretical motivation, basis, and ideas for new experiments and for new analyses of experimental data. Within the Intensity Frontier, an experimental search for a new force mediated by a GeV-scale gauge boson will be carried out with the $A'$ Experiment (APEX) and the Heavy Photon Searchmore » (HPS), both at Jefferson Laboratory. Within the Cosmic Frontier, contributions are planned to the search for dark matter particles with the Fermi Gamma-ray Space Telescope and other instruments. A detailed exploration will also be performed of new direct detection strategies for dark matter particles with sub-GeV masses to facilitate the development of new experiments. In addition, the theoretical implications of existing and future dark matter-related anomalies will be examined. Within the Energy Frontier, the implications of the data from the Large Hadron Collider will be investigated. Novel search strategies will be developed to aid the search for new phenomena not described by the Standard Model of particle physics. By combining insights from all three particle physics frontiers, this research aims to increase our understanding of fundamental particle physics.« less

Observation of the large scale cosmic-ray anisotropy at TeV energies with the Milagro detector

NASA Astrophysics Data System (ADS)

Kolterman, Brian E.

Cosmic-rays with energies in the range of 1-100 TeV are nearly isotropic in their arrival directions due to interactions with randomly scattered inhomogeneities in the Galactic magnetic field. Observation of the large scale anisotropy in the arrival direction of these cosmic-rays is therefore a useful tool in constraining theoretical models of cosmic-ray propagation, probing the magnetic field structure in our interstellar neighborhood, as well as providing information about the distribution of sources. In this work results are presented of a harmonic analysis of the large scale cosmic-ray anisotropy as observed by the Milagro observatory. A two- dimensional display of the anisotropy projections in right ascension is generated by the fitting of three harmonics to 18 separate declination bands. Milagro is a water Cherenkov detector located at an elevation of 2630m in the Jemez mountains outside of Los Alamos, NM. With a live time > 90 and a large field-of-view (~2 sr), Milagro is an excellent instrument for measuring this anisotropy with high sensitivity at TeV energies. The analysis is conducted using a seven year data sample consisting of more than 95 billion events. A sidereal anisotropy is observed with a magnitude around 0.1% for cosmic-rays with a median energy of 6 TeV. The dominant feature in this data set is a deficit region of depth (-2.85±0.06 stat. ±0.08 syst.)×10 -3 in the direction of the Galactic North Pole with a range in declination of - 10 to 45 degrees and 150 to 225 degrees in right ascension. The anisotropy also shows evidence of a time dependence, with a steady increase in the magnitude of the signal in this region over the course of seven years. An analysis of the energy dependence of the anisotropy in this region is also presented showing possible deviation of the spectral index of the anisotropy signal from that of the nominal cosmic-ray background. The anisotropy of cosmic-rays in universal time is analyzed showing a dipole structure at the level of 3×10 -4 , consistent with the Compton-Getting effect expected due to the Earth's motion around the Sun through the cosmic-ray ether.

THE COSMIC RAY EQUATOR FROM DATA OF THE SECOND SOVIET EARTH SATELLITE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Savenko, I.A.; Shavrin, P.I.; Nesterov, V.Ye.

1962-11-01

Determination of the geographical position of the line of minimum intensity of primary cosmic radiation (cosmic ray equator) makes is possible to study the structure of the geomagnetic field and to check theoretical and empirical approximations to this field. The minima of cosmic radiation intensity were determined by the second Soviet spaceship for 22 latitude curves obtained from various crossings in the region of the geographical equator. (W.D.M.)

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.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1979-01-01

This photograph was taken during encapsulation of the High Energy Astronomy Observatory (HEAO)-3. Designed and developed by TRW, Inc. under the direction of the Marshall Space Flight Center, the objectives of the HEAO-3 were to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit. The Marshall Space Flight Center had the project management responsibilities for the HEAO missions.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1979-01-01

This photograph shows the High Energy Astronomy Observatory (HEAO)-3 being prepared for encapsulation. Designed and developed by TRW, Inc. under the direction of the Marshall Space Flight Center, the objectives of the HEAO-3 were to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit. The Marshall Space Flight Center had the project management responsibilities for the HEAO missions.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1979-01-01

This photograph shows the High Energy Astronomy Observatory (HEAO)-3 being assembled at TRW, Inc. Designed and developed by TRW, Inc. under the direction of the Marshall Space Flight Center, the objectives of the HEAO-3 were to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit. The Marshall Space Flight Center had the project management responsibilities for the HEAO missions.

Obtaining Parts

Science.gov Websites

The Cosmic Connection Computer Interface For each count, the detector sends out a signal that is room temperature on the upper plot and the cosmic ray count rate per minute on the lower scale. Please contact us for more details on this setup. Sample Data for Cosmic Ray Detector Last modified: April 27

The Heavy Nuclei eXplorer (HNX) Small Explorer Mission

NASA Astrophysics Data System (ADS)

Mitchell, John; Binns, W. Robert; Hams, Thomas; Israel, Martin; Krizmanic, John; Link, Jason; Rauch, Brian; Sakai, Kenichi; Sasaki, Makoto; Westphal, Andrew; Wiedenbeck, Mark; Heavy Nuclei eXplorer Collaboration

2015-04-01

The Heavy Nuclei eXplorer (HNX) will investigate the nature of the reservoirs of nuclei at the cosmic-ray sources, the mechanisms by which nuclei are removed from the reservoirs and injected into the cosmic accelerators, and the acceleration mechanism. HNX will use two large high-precision instruments, the Extremely-heavy Cosmic-ray Composition Observer (ECCO) and the Cosmic-ray Trans-Iron Galactic Element Recorder (CosmicTIGER), flying in the SpaceX DragonLab, to measure, for the first time, the abundance of every individual element in the periodic table from carbon through the actinides, providing the first measurement of many of these elements. HNX will measure several thousand ultra-heavy galactic cosmic ray (UHGCR) nuclei Z >= 30, including about 50 actinides, and will: determine whether GCRs are accelerated from new or old material, and find their age; measure the mix of nucleosynthesis processes responsible for the UHGCRs; determine how UHGCR elements are selected for acceleration, and measure the mean integrated pathlength traversed by UHGCRs before observation. The scientific motivation and instrument complement of HNX will be discussed.

Review of the Theoretical and Experimental Status of Dark Matter Identification with Cosmic-Ray Antideuterons

NASA Technical Reports Server (NTRS)

Aramaki, T.; Boggs, S.; Bufalino, S.; Dal, L.; von Doetinchem, P.; Donato, F.; Fornengo, N.; Fuke, H.; Grefe, M.; Hailey, C.;

Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground Based Computation and Control Systems and Human Health and Safety

NASA Technical Reports Server (NTRS)

Atwell, William; Koontz, Steve; Normand, Eugene

2012-01-01

In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as on human health and safety, as well as the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in earth surface, atmospheric flight, and space flight environments. Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools (e.g. ground based test methods as well as high energy particle transport and reaction codes) needed to design, test, and verify the safety and reliability of modern complex electronic systems as well as effects on human health and safety. The effects of primary cosmic ray particles, and secondary particle showers produced by nuclear reactions with spacecraft materials, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth's surface, especially if the net target area of the sensitive electronic system components is large. Accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO).

Alteration of the Carbon and Nitrogen Isotopic Composition in the Martian Surface Rocks Due to Cosmic Ray Exposure

NASA Technical Reports Server (NTRS)

Pavlov, A. A.; Pavlov, A. K.; Ostryakov, V. M.; Vasilyev, G. I.; Mahaffy, P.; Steele, A.

2014-01-01

C-13/C-12 and N-15/N-14 isotopic ratios are pivotal for our understanding of the Martian carbon cycle, history of the Martian atmospheric escape, and origin of the organic compounds on Mars. Here we demonstrate that the carbon and nitrogen isotopic composition of the surface rocks on Mars can be significantly altered by the continuous exposure of Martian surface to cosmic rays. Cosmic rays can effectively produce C-13 and N-15 isotopes via spallation nuclear reactions on oxygen atoms in various Martian rocks. We calculate that in the top meter of the Martian rocks, the rates of production of both C-13 and N-15 due to galactic cosmic rays (GCRs) exposure can vary within 1.5-6 atoms/cm3/s depending on rocks' depth and chemical composition. We also find that the average solar cosmic rays can produce carbon and nitrogen isotopes at a rate comparable to GCRs in the top 5-10 cm of the Martian rocks. We demonstrate that if the total carbon content in a surface Martian rock is <10 ppm, then the "light," potentially "biological" C-13/C-12 ratio would be effectively erased by cosmic rays over 3.5 billion years of exposure. We found that for the rocks with relatively short exposure ages (e.g., 100 million years), cosmogenic changes in N-15/N-14 ratio are still very significant. We also show that a short exposure to cosmic rays of Allan Hills 84001 while on Mars can explain its high-temperature heavy nitrogen isotopic composition (N-15/N-14). Applications to Martian meteorites and the current Mars Science Laboratory mission are discussed.

The Global Survey Method Applied to Ground-level Cosmic Ray Measurements

NASA Astrophysics Data System (ADS)

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

2018-04-01

The global survey method (GSM) technique unites simultaneous ground-level observations of cosmic rays in different locations and allows us to obtain the main characteristics of cosmic-ray variations outside of the atmosphere and magnetosphere of Earth. This technique has been developed and applied in numerous studies over many years by the Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation (IZMIRAN). We here describe the IZMIRAN version of the GSM in detail. With this technique, the hourly data of the world-wide neutron-monitor network from July 1957 until December 2016 were processed, and further processing is enabled upon the receipt of new data. The result is a database of homogeneous and continuous hourly characteristics of the density variations (an isotropic part of the intensity) and the 3D vector of the cosmic-ray anisotropy. It includes all of the effects that could be identified in galactic cosmic-ray variations that were caused by large-scale disturbances of the interplanetary medium in more than 50 years. These results in turn became the basis for a database on Forbush effects and interplanetary disturbances. This database allows correlating various space-environment parameters (the characteristics of the Sun, the solar wind, et cetera) with cosmic-ray parameters and studying their interrelations. We also present features of the coupling coefficients for different neutron monitors that enable us to make a connection from ground-level measurements to primary cosmic-ray variations outside the atmosphere and the magnetosphere. We discuss the strengths and weaknesses of the current version of the GSM as well as further possible developments and improvements. The method developed allows us to minimize the problems of the neutron-monitor network, which are typical for experimental physics, and to considerably enhance its advantages.

Influence of hadron and atmospheric models on computation of cosmic ray ionization in the atmosphere-Extension to heavy nuclei

NASA Astrophysics Data System (ADS)

Mishev, A. L.; Velinov, P. I. Y.

2014-12-01

In the last few years an essential progress in development of physical models for cosmic ray induced ionization in the atmosphere is achieved. The majority of these models are full target, i.e. based on Monte Carlo simulation of an electromagnetic-muon-nucleon cascade in the atmosphere. Basically, the contribution of proton nuclei is highlighted, i.e. the contribution of primary cosmic ray α-particles and heavy nuclei to the atmospheric ionization is neglected or scaled to protons. The development of cosmic ray induced atmospheric cascade is sensitive to the energy and mass of the primary cosmic ray particle. The largest uncertainties in Monte Carlo simulations of a cascade in the Earth atmosphere are due to assumed hadron interaction models, the so-called hadron generators. In the work presented here we compare the ionization yield functions Y for primary cosmic ray nuclei, such as α-particles, Oxygen and Iron nuclei, assuming different hadron interaction models. The computations are fulfilled with the CORSIKA 6.9 code using GHEISHA 2002, FLUKA 2011, UrQMD hadron generators for energy below 80 GeV/nucleon and QGSJET II for energy above 80 GeV/nucleon. The observed difference between hadron generators is widely discussed. The influence of different atmospheric parametrizations, namely US standard atmosphere, US standard atmosphere winter and summer profiles on ion production rate is studied. Assuming realistic primary cosmic ray mass composition, the ion production rate is obtained at several rigidity cut-offs - from 1 GV (high latitudes) to 15 GV (equatorial latitudes) using various hadron generators. The computations are compared with experimental data. A conclusion concerning the consistency of the hadron generators is stated.

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

DOE PAGES

Aramaki, T.; Boggs, S.; Bufalino, S.; ...

2016-01-27

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 γ-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 detectablemore » 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 propagation through the magnetic fields, plasma currents, and molecular material of our Galaxy, the solar system, the Earth’s geomagnetic field, and the atmosphere. Lastly, the three ongoing or planned experiments that are sensitive to cosmic-ray antideuterons, BESS, AMS-02, and GAPS, are detailed. As cosmic-ray antideuteron detection is a rare event search, multiple experiments with orthogonal techniques and backgrounds are essential. Furthermore, the combination of AMS-02 and GAPS antideuteron searches is highly desirable. Many theoretical and experimental groups have contributed to these studies over the last decade, this review aims to provide the first coherent discussion of the relevant dark matter theories that antideuterons probe, the challenges to predictions and interpretations of antideuteron signals, and the experimental efforts toward cosmic antideuteron detection.« less

Clinical cosmobiology: distribution of deaths during 180 months and cosmophysical activity. The Lithuanian study, 1990-2004. The role of cosmic rays.

PubMed

Stoupel, Elyiahu; Kalediene, Ramune; Petrauskiene, Jadvyga; Starkuviene, Skirmante; Abramson, Evgeny; Israelevich, Peter; Sulkes, Jaqueline

2007-01-01

The aim of this study is a next step of our previous, initial, publications--to explore the links between monthly death number (total, and for the major death causes and each gender) with levels of monthly cosmophysical activity in a long-term, big cohort observation. Death number during 180 consecutive months from the National Registry of Lithuania for years 1990-2004 were studied. A total of 630,205 deaths were analyzed (333,035 males). For comparison, monthly indices of solar activity, geomagnetic activity, and cosmic ray activity and year and month (1-12) of the study were used. The cosmophysical data were obtained from space research centers in the USA, Russia, and Finland. Statistics. Pearson correlation coefficients (r) and their probabilities (P) between compared parameters were calculated. A multivariate model of prediction was designed. It was a significant correlation between total monthly death number and indices of cosmic ray activity and, inverse, of solar activity; in men stronger than in women. Monthly geomagnetic activity was significantly correlated with traffic accidents, ischemic heart disease/stroke ratio, suicide victim number. Deaths from stroke, noncardiovascular causes, suicide, traffic accidents were related with cosmic ray activity and, inverse, with solar activity. Relationship of ischemic heart disease/stroke ratio to year of observation showed additional evidence for the growing role of stroke in cardiovascular mortality. Monthly death number is linked to cosmic ray activity, and inverse, to solar activity. Central place of stroke-related deaths in cardiovascular mortality is emerging. Geomagnetic activity, in monthly account, plays a relatively minor role. We presume that forces antagonistic to cosmic ray activity, like solar activity and geomagnetic activity, can prevent some negative biologic effects of cosmic ray.

New fermionic dark matters, extended Standard Model and cosmic rays

NASA Astrophysics Data System (ADS)

Hwang, Jae-Kwang

2017-08-01

Three generations of leptons and quarks correspond to the lepton charges (LCs) in this work. Then, the leptons have the electric charges (ECs) and LCs. The quarks have the ECs, LCs and color charges (CCs). Three heavy leptons and three heavy quarks are introduced to make the missing third flavor of EC. Then the three new particles which have the ECs are proposed as the bastons (dark matters) with the rest masses of 26.121 eV/c2, 42.7 GeV/c2 and 1.9 × 1015 eV/c2. These new particles are applied to explain the origins of the astrophysical observations like the ultra-high energy cosmic rays and supernova 1987A anti-neutrino data. It is concluded that the 3.5 keV X-ray peak observed from the cosmic X-ray background spectra is originated not from the pair annihilations of the dark matters but from the X-ray emission of the Q1 baryon atoms which are similar in the atomic structure to the hydrogen atom. The presence of the 3.5 keV cosmic X-ray supports the presence of the Q1 quark with the EC of -4/3. New particles can be indirectly seen from the astrophysical observations like the cosmic ray and cosmic gamma ray. In this work, the systematic quantized charges of EC, LC and CC for the elementary particles are used to consistently explain the decay and reaction schemes of the elementary particles. Also, the strong, weak and dark matter forces are consistently explained.

Cosmic-ray tracks in plastics: the apollo helmet dosimetry experiment.

PubMed

Comstock, G M; Fleischer, R L; Giard, W R; Hart, H R; Nichols, G E; Price, P B

1971-04-09

Counts of tracks from heavy cosmic-ray nuclei in helmets from Apollo missions 8 and 12 show variations caused by solar modulation of the galactic cosmic-ray flux. Specific estimates of the biological damage to certain nonreplaceable cells by track-forming particles during these space missions indicate that the fraction of deactivated cells could range from a lower limit of 3 x 10(-7) to an upper limit of 1.4 x 10(-4).

The WiZard Collaboration cosmic ray muon measurements in the atmosphere

NASA Astrophysics Data System (ADS)

Circella, M.; Ambriola, M. L.; Barbiellini, G.; Bartalucci, S.; Bellotti, R.; Bergström, D.; Bidoli, V.; Boezio, M.; Bravar, U.; Cafagna, F.; Carlson, P.; Casolino, M.; Ciacio, F.; Circella, M.; de Marzo, C. N.; de Pascale, M. P.; Finetti, N.; Francke, T.; Grinstein, S.; Hof, M.; Khalchukov, F.; Kremer, J.; Menn, W.; Mitchell, J. W.; Morselli, A.; Ormes, J. F.; Papini, P.; Piccardi, S.; Picozza, P.; Ricci, M.; Schiavon, P.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stephens, S. A.; Stochaj, S. J.; Streitmatter, R. E.; Suffert, M.; Vacchi, A.; Zampa, N.

Balloon-borne experiments allow cosmic ray measurements to be performed over large ranges of atmospheric depths. The WiZard Collaboration is involved in a long-range investigation of the cosmic ray muon fluxes in the atmosphere. In this paper, we will discuss the relevance of such measurements to the atmospheric neutrino calculations and will review the results reported by the Collaboration, with particular emphasis on those coming from the latest flight CAPRICE98

Synchrotron Radiation from Ultra-High Energy Protons and the Fermi Observations of GRB 080916C

DTIC Science & Technology

2010-01-01

compared with keV – MeV radiation. Here we show that synchrotron radiation from cosmic ray protons accelerated in GRBs, delayed by the proton synchrotron... cosmic rays from sources within 100 Mpc for nano-Gauss intergalactic magnetic fields. The total energy requirements in a proton synchrotron model are...component arising from cosmic - ray proton synchrotron radiation explains the delayed onset of the LAT emission. If GRBs accelerate UHECRs, then the

Low cloud properties influenced by cosmic rays

PubMed

Marsh; Svensmark

2000-12-04

The influence of solar variability on climate is currently uncertain. Recent observations have indicated a possible mechanism via the influence of solar modulated cosmic rays on global cloud cover. Surprisingly the influence of solar variability is strongest in low clouds (

Observing Short-wave Infrared Atmospheric Fluorescence Near Radioactive Sources: A Feasibility Study

DTIC Science & Technology

2014-03-17

Defense Threat Reduction Agency Ft. Belvoir, VA 22060 76-4184-32-5 MIPR HDTRA 124655 1NRC Postdoctoral Research Associate Contents 1 Introduction 1 2...a desire to measure cosmic ray effects. For example, the pioneering study of cosmic ray detection by fluorescence was by Bunner in 1967 wherein he...wavelengths, the ultra-high energy cosmic ray (UHECR) community has continued to pursue studies of the fluorescence yield from high energy particle impact on

Wind Observations of Anomalous Cosmic Rays from Solar Minimum to Maximum

NASA Technical Reports Server (NTRS)

Reames, D. V.; McDonald, F. B.

2003-01-01

We report the first observation near Earth of the time behavior of anomalous cosmic-ray N, O, and Ne ions through the period surrounding the maximum of the solar cycle. These observations were made by the Wind spacecraft during the 1995-2002 period spanning times from solar minimum through solar maximum. Comparison of anomalous and galactic cosmic rays provides a powerful tool for the study of the physics of solar modulation throughout the solar cycle.

Cosmic-Ray Energetics and Mass (CREAM) Processing - Bonding

NASA Image and Video Library

2017-06-20

In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, technicians and engineers inspect components for the Cosmic-Ray Energetics and Mass investigation, or CREAM, instrument. It is designed to measure the charges of cosmic rays to better understand what gives them such incredible energies, and how that effects the composition of the universe. The instrument will be launched to the space station on the SpaceX CRS-12 commercial resupply mission in August 2017.

Cosmic-Ray Energetics and Mass (CREAM) Processing - Bonding

NASA Image and Video Library

2017-06-20

In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, a technician remove a protective cover on the Cosmic-Ray Energetics and Mass investigation, or CREAM, instrument. It is designed to measure the charges of cosmic rays to better understand what gives them such incredible energies, and how that effects the composition of the universe. The instrument will be launched to the space station on the SpaceX CRS-12 commercial resupply mission in August 2017.

Cosmic-Ray Energetics and Mass (CREAM) Unbagging and Inspection

NASA Image and Video Library

2017-06-22

In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, technicians and engineers inspect the Cosmic-Ray Energetics and Mass investigation, or CREAM, instrument. It is designed to measure the charges of cosmic rays to better understand what gives them such incredible energies, and how that effects the composition of the universe. The instrument will be launched to the space station on the SpaceX CRS-12 commercial resupply mission in August 2017.

Analytical Model for Estimating Terrestrial Cosmic Ray Fluxes Nearly Anytime and Anywhere in the World: Extension of PARMA/EXPACS.

PubMed

Sato, Tatsuhiko

2015-01-01

By extending our previously established model, here we present a new model called "PHITS-based Analytical Radiation Model in the Atmosphere (PARMA) version 3.0," which can instantaneously estimate terrestrial cosmic ray fluxes of neutrons, protons, ions with charge up to 28 (Ni), muons, electrons, positrons, and photons nearly anytime and anywhere in the Earth's atmosphere. The model comprises numerous analytical functions with parameters whose numerical values were fitted to reproduce the results of the extensive air shower (EAS) simulation performed by Particle and Heavy Ion Transport code System (PHITS). The accuracy of the EAS simulation was well verified using various experimental data, while that of PARMA3.0 was confirmed by the high R2 values of the fit. The models to be used for estimating radiation doses due to cosmic ray exposure, cosmic ray induced ionization rates, and count rates of neutron monitors were validated by investigating their capability to reproduce those quantities measured under various conditions. PARMA3.0 is available freely and is easy to use, as implemented in an open-access software program EXcel-based Program for Calculating Atmospheric Cosmic ray Spectrum (EXPACS). Because of these features, the new version of PARMA/EXPACS can be an important tool in various research fields such as geosciences, cosmic ray physics, and radiation research.

Analytical Model for Estimating Terrestrial Cosmic Ray Fluxes Nearly Anytime and Anywhere in the World: Extension of PARMA/EXPACS

PubMed Central

Sato, Tatsuhiko

2015-01-01

By extending our previously established model, here we present a new model called “PHITS-based Analytical Radiation Model in the Atmosphere (PARMA) version 3.0,” which can instantaneously estimate terrestrial cosmic ray fluxes of neutrons, protons, ions with charge up to 28 (Ni), muons, electrons, positrons, and photons nearly anytime and anywhere in the Earth’s atmosphere. The model comprises numerous analytical functions with parameters whose numerical values were fitted to reproduce the results of the extensive air shower (EAS) simulation performed by Particle and Heavy Ion Transport code System (PHITS). The accuracy of the EAS simulation was well verified using various experimental data, while that of PARMA3.0 was confirmed by the high R 2 values of the fit. The models to be used for estimating radiation doses due to cosmic ray exposure, cosmic ray induced ionization rates, and count rates of neutron monitors were validated by investigating their capability to reproduce those quantities measured under various conditions. PARMA3.0 is available freely and is easy to use, as implemented in an open-access software program EXcel-based Program for Calculating Atmospheric Cosmic ray Spectrum (EXPACS). Because of these features, the new version of PARMA/EXPACS can be an important tool in various research fields such as geosciences, cosmic ray physics, and radiation research. PMID:26674183

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anthony, Stephen

The Sandia hyperspectral upper-bound spectrum algorithm (hyper-UBS) is a cosmic ray despiking algorithm for hyperspectral data sets. When naturally-occurring, high-energy (gigaelectronvolt) cosmic rays impact the earth’s atmosphere, they create an avalanche of secondary particles which will register as a large, positive spike on any spectroscopic detector they hit. Cosmic ray spikes are therefore an unavoidable spectroscopic contaminant which can interfere with subsequent analysis. A variety of cosmic ray despiking algorithms already exist and can potentially be applied to hyperspectral data matrices, most notably the upper-bound spectrum data matrices (UBS-DM) algorithm by Dongmao Zhang and Dor Ben-Amotz which served as themore » basis for the hyper-UBS algorithm. However, the existing algorithms either cannot be applied to hyperspectral data, require information that is not always available, introduce undesired spectral bias, or have otherwise limited effectiveness for some experimentally relevant conditions. Hyper-UBS is more effective at removing a wider variety of cosmic ray spikes from hyperspectral data without introducing undesired spectral bias. In addition to the core algorithm the Sandia hyper-UBS software package includes additional source code useful in evaluating the effectiveness of the hyper-UBS algorithm. The accompanying source code includes code to generate simulated hyperspectral data contaminated by cosmic ray spikes, several existing despiking algorithms, and code to evaluate the performance of the despiking algorithms on simulated data.« less

Temperature Effect in Secondary Cosmic Rays (MUONS) Observed at the Ground: Analysis of the Global MUON Detector Network Data

NASA Astrophysics Data System (ADS)

de Mendonça, R. R. S.; Braga, C. R.; Echer, E.; Dal Lago, A.; Munakata, K.; Kuwabara, T.; Kozai, M.; Kato, C.; Rockenbach, M.; Schuch, N. J.; Jassar, H. K. Al; Sharma, M. M.; Tokumaru, M.; Duldig, M. L.; Humble, J. E.; Evenson, P.; Sabbah, I.

2016-10-01

The analysis of cosmic ray intensity variation seen by muon detectors at Earth's surface can help us to understand astrophysical, solar, interplanetary and geomagnetic phenomena. However, before comparing cosmic ray intensity variations with extraterrestrial phenomena, it is necessary to take into account atmospheric effects such as the temperature effect. In this work, we analyzed this effect on the Global Muon Detector Network (GMDN), which is composed of four ground-based detectors, two in the northern hemisphere and two in the southern hemisphere. In general, we found a higher temperature influence on detectors located in the northern hemisphere. Besides that, we noticed that the seasonal temperature variation observed at the ground and at the altitude of maximum muon production are in antiphase for all GMDN locations (low-latitude regions). In this way, contrary to what is expected in high-latitude regions, the ground muon intensity decrease occurring during summertime would be related to both parts of the temperature effect (the negative and the positive). We analyzed several methods to describe the temperature effect on cosmic ray intensity. We found that the mass weighted method is the one that best reproduces the seasonal cosmic ray variation observed by the GMDN detectors and allows the highest correlation with long-term variation of the cosmic ray intensity seen by neutron monitors.

THE EFFECT OF INTERMITTENT GYRO-SCALE SLAB TURBULENCE ON PARALLEL AND PERPENDICULAR COSMIC-RAY TRANSPORT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Le Roux, J. A.

Earlier work based on nonlinear guiding center (NLGC) theory suggested that perpendicular cosmic-ray transport is diffusive when cosmic rays encounter random three-dimensional magnetohydrodynamic turbulence dominated by uniform two-dimensional (2D) turbulence with a minor uniform slab turbulence component. In this approach large-scale perpendicular cosmic-ray transport is due to cosmic rays microscopically diffusing along the meandering magnetic field dominated by 2D turbulence because of gyroresonant interactions with slab turbulence. However, turbulence in the solar wind is intermittent and it has been suggested that intermittent turbulence might be responsible for the observation of 'dropout' events in solar energetic particle fluxes on small scales.more » In a previous paper le Roux et al. suggested, using NLGC theory as a basis, that if gyro-scale slab turbulence is intermittent, large-scale perpendicular cosmic-ray transport in weak uniform 2D turbulence will be superdiffusive or subdiffusive depending on the statistical characteristics of the intermittent slab turbulence. In this paper we expand and refine our previous work further by investigating how both parallel and perpendicular transport are affected by intermittent slab turbulence for weak as well as strong uniform 2D turbulence. The main new finding is that both parallel and perpendicular transport are the net effect of an interplay between diffusive and nondiffusive (superdiffusive or subdiffusive) transport effects as a consequence of this intermittency.« less

Cosmic ray signatures of a 2-3 Myr old local supernova

NASA Astrophysics Data System (ADS)

Kachelrieß, M.; Neronov, A.; Semikoz, D. V.

2018-03-01

The supernova explosion which deposited Fe 60 isotopes on Earth 2-3 million years ago should have also produced cosmic rays which contribute to the locally observed cosmic ray flux. We show that the contribution of this "local source" causes the "anomalies" observed in the positron and antiproton fluxes and explains why their spectral shapes agree with that of the proton flux. At the same time, this local source component accounts for the difference in the slopes of the spectra of cosmic ray nuclei as the result of the slightly varying relative importance of the "local" and the average component for distinct CR nuclei. Such a "local supernova" model for the spectra of nuclei can be tested via a combined measurement of the energy dependence of the boron-to-carbon (primary-to-secondary cosmic rays) ratio and of the antiproton spectrum: while the antiproton spectrum is predicted to extend approximately as a power law into the TeV range without any softening break, the B/C ratio is expected to show a "plateau" at a level fixed by the observed positron excess in the 30-300 GeV range. We discuss the observability of such a plateau with dedicated experiments for the measurement of the cosmic ray composition in the 10 TeV energy range (NUCLEON, ISS-CREAM).

Cosmic Rays and Clouds, 1. Formation of Lead Mesoatoms In Neutron Monitor By Soft Negative Muons and Expected Atmospheric Electric Field Effect In The Cosmic Ray Neutron Component

NASA Astrophysics Data System (ADS)

Dorman, L. I.; Dorman, I. V.

We extend our model (Dorman and Dorman, 1995) of cosmic ray atmospheric electric field effect on the case of neutron monitor. We take into account that about 0.07 of neu- tron monitor counting rate caused by negative soft muons captured by lead nucleons and formed mesoatoms with generation of several MeV energy neutrons from lead. In this case the neutron monitor or neutron supermonitor works as analyzer which de- tects muons of only one, negative sign. It is very important because the atmospheric electric field effect have opposite signs for positive and negative muons that main part of this effect in the muon telescope or in ionization chamber is compensated and we can observe only small part of total effect of one sign muons. On the basis of our gen- eral theory of cosmic ray meteorological effects with taking into account of negative soft muon acceleration and deceleration in the Earth atmosphere (in dependence of di- rection and intensity of electric field) we discuss the possibility of existing this effect in cosmic ray neutron component and made some rough estimations. REFERENCES: Dorman L.I. and Dorman I.V., 1995. "Cosmic-ray atmospheric electric field effects". Canadian J. of Physics, Vol. 73, pp. 440-443.

The Status and Recent Results of the Telescope Array Experiment

NASA Astrophysics Data System (ADS)

Yamazaki, Katsuya

The Telescope Array (TA) is a cosmic ray observatory of the largest aperture in the northern hemisphere, located in a desert in the western part of Utah, U.S.A., to explore the origin of ultrahigh energy cosmic rays, photons, and neutrinos. The TA employs two types of detectors to observe air showers generated by cosmic rays in the atmosphere: the first is a "surface detector (SD)" of scintillation counters to measure shower particles on the ground, and the second is a "fluorescence detector (FD)" of telescopes installed in three stations to observe fluorescence light, caused by air shower particles, from the atmosphere above the SD array. The TA detectors have been in routine operation since May 2008. We measured the energy spectrum of cosmic rays with energy greater than 1018 eV from our first 4-year data. We found a clear suppression of comic ray intensity above 5 × 1019 eV. This feature is consistent with a theoretical prediction that cosmic rays lose energies due to interaction with cosmic microwave background photons during propagation in the intergalactic space. In this talk, We will present the status of the TA experiment and the recent results, including the energy spectrum, study of the primary mass composition, and searches for anisotropies in the arrival directions. We also briefly describe plans for further extensions.

THE TEMPERATURE EFFECT IN SECONDARY COSMIC RAYS (MUONS) OBSERVED AT THE GROUND: ANALYSIS OF THE GLOBAL MUON DETECTOR NETWORK DATA

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Mendonça, R. R. S.; Braga, C. R.; Echer, E.

2016-10-20

The analysis of cosmic ray intensity variation seen by muon detectors at Earth's surface can help us to understand astrophysical, solar, interplanetary and geomagnetic phenomena. However, before comparing cosmic ray intensity variations with extraterrestrial phenomena, it is necessary to take into account atmospheric effects such as the temperature effect. In this work, we analyzed this effect on the Global Muon Detector Network (GMDN), which is composed of four ground-based detectors, two in the northern hemisphere and two in the southern hemisphere. In general, we found a higher temperature influence on detectors located in the northern hemisphere. Besides that, we noticedmore » that the seasonal temperature variation observed at the ground and at the altitude of maximum muon production are in antiphase for all GMDN locations (low-latitude regions). In this way, contrary to what is expected in high-latitude regions, the ground muon intensity decrease occurring during summertime would be related to both parts of the temperature effect (the negative and the positive). We analyzed several methods to describe the temperature effect on cosmic ray intensity. We found that the mass weighted method is the one that best reproduces the seasonal cosmic ray variation observed by the GMDN detectors and allows the highest correlation with long-term variation of the cosmic ray intensity seen by neutron monitors.« less

Cosmic PeV neutrinos and the sources of ultrahigh energy protons

NASA Astrophysics Data System (ADS)

Kistler, Matthew D.; Stanev, Todor; Yüksel, Hasan

2014-12-01

The IceCube experiment recently detected the first flux of high-energy neutrinos in excess of atmospheric backgrounds. We examine whether these neutrinos originate from within the same extragalactic sources as ultrahigh energy cosmic rays. Starting from rather general assumptions about spectra and flavors, we find that producing a neutrino flux at the requisite level through pion photoproduction leads to a flux of protons well below the cosmic-ray data at ˜1 018 eV , where the composition is light, unless pions/muons cool before decaying. This suggests a dominant class of accelerator that allows for cosmic rays to escape without significant neutrino yields.

Cosmic ray injection spectrum at the galactic sources

NASA Astrophysics Data System (ADS)

Lagutin, Anatoly; Tyumentsev, Alexander; Volkov, Nikolay

The spectra of cosmic rays measured at Earth are different from their source spectra. A key to understanding this difference, being crucial for solving the problem of cosmic-ray origin, is the determination of how cosmic-ray (CR) particles propagate through the turbulent interstellar medium (ISM). If the medium is a quasi-homogeneous the propagation process can be described by a normal diffusion model. However, during a last few decades many evidences, both from theory and observations, of the existence of multiscale structures in the Galaxy have been found. Filaments, shells, clouds are entities widely spread in the ISM. In such a highly non-homogeneous (fractal-like) ISM the normal diffusion model certainly is not kept valid. Generalization of this model leads to what is known as "anomalous diffusion". The main goal of the report is to retrieve the cosmic ray injection spectrum at the galactic sources in the framework of the anomalous diffusion (AD) model. The anomaly in this model results from large free paths ("Levy flights") of particles between galactic inhomogeneities. In order to evaluate the CR spectrum at the sources, we carried out new calculation of the CR spectra at Earth. AD equation in terms of fractional derivatives have been used to describe CR propagation from the nearby (r≤1 kpc) young (t≤ 1 Myr) and multiple old distant (r > 1 kpc) sources. The assessment of the key model parameters have been based on the results of the particles diffusion in the cosmic and laboratory plasma. We show that in the framework of the anomalous diffusion model the locally observed basic features of the cosmic rays (difference between spectral exponents of proton, He and other nuclei, "knee" problem, positron to electron ratio) can be explained if the injection spectrum at the main galactic sources of cosmic rays has spectral exponent p˜ 2.85. The authors acknowledge support from The Russian Foundation for Basic Research grant No. 14-02-31524.

Observation of cosmic-ray anisotropy in the decade below 1 PeV with a pentagon array

NASA Astrophysics Data System (ADS)

Moghaddam, S. Mortazavi; Bahmanabadi, M.

2018-03-01

The study of the anisotropy of the arrival directions is an essential tool to investigate the origin and propagation of cosmic rays primaries. A pentagon array has been designed to collect data around the knee region of cosmic ray spectrum. The experimental results of this array obtained from October 2016 to October 2017. During this period, more than 5.3 ×105 extensive air shower events at energies in the decade below 1 PeV has been accumulated by this array at Sharif University of Technology in Tehran (3 5 ° 4 3'N , 5 1 ° 2 0'E , 1200m a .s .l =890 g cm-2 ). In analyzing the data set, we have used appropriate techniques of analysis and considered environmental effects. We report the analysis of the sidereal anisotropy of Galactic cosmic rays (GCRs). In this analysis, in addition to the Compton- Getting effect due to the motion of the earth in the Galaxy, an anisotropy has been observed which is due to a unidirectional anisotropy of cosmic ray flow along the Galactic arms.

Questions and Answers in Extreme Energy Cosmic Rays - a guide to explore the data set of the Pierre Auger Observatory

NASA Astrophysics Data System (ADS)

Abreu, P.; Andringa, S.; Diogo, F.; Espírito Santo, M. C.; Pierre Auger Collaboration

2016-04-01

The Pierre Auger Observatory is the largest extensive air shower detector, covering 3000 km2 in Argentina. The Observatory makes available, for educational and outreach purposes, 1% of its cosmic ray data set, corresponding after 10 years of running to more than 35 000 cosmic ray events. Several different proposals of educational activities have been developed within the collaboration and are available. We will focus on the activity guide we developed with the aim of exploring the rich education and outreach potential of cosmic rays with Portuguese high school students. In this guide we use the Auger public data set as a starting point to introduce open questions on the origin, nature and spectrum of high energy cosmic rays. To address them, the students learn about the air-shower cascade development, data reconstruction and its statistical analysis. The guide has been used both in the context of student summer internships at research labs and directly in schools, under the supervision of trained teachers and in close collaboration with Auger researchers. It is now available in Portuguese, English and Spanish.

Measurement of the Anisotropy of Cosmic-ray Arrival Directions with IceCube

NASA Astrophysics Data System (ADS)

Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Adams, J.; Aguilar, J. A.; Ahlers, M.; 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.; Benabderrahmane, M. L.; BenZvi, S.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bissok, M.; Blaufuss, E.; Boersma, D. J.; Bohm, C.; Böser, S.; Botner, O.; Bradley, L.; Braun, J.; Buitink, S.; Carson, M.; Chirkin, D.; Christy, B.; Clem, J.; Clevermann, F.; Cohen, S.; Colnard, C.; Cowen, D. F.; D'Agostino, M. V.; Danninger, M.; Davis, J. C.; De Clercq, C.; Demirörs, L.; Depaepe, O.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; DeYoung, T.; Díaz-Vélez, J. C.; Dierckxsens, M.; Dreyer, J.; Dumm, J. P.; Duvoort, M. R.; Ehrlich, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Feusels, T.; Filimonov, K.; Finley, C.; Foerster, M. M.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Geisler, M.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Goodman, J. A.; Grant, D.; Griesel, T.; Groß, A.; Grullon, S.; Gurtner, M.; Ha, C.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Helbing, K.; Herquet, P.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Homeier, A.; Hoshina, K.; Hubert, D.; Huelsnitz, W.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Joseph, J. M.; Kampert, K.-H.; Karg, T.; Karle, A.; Kelley, J. L.; Kemming, N.; Kenny, P.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Knops, S.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Koskinen, D. J.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Krings, T.; Kroll, G.; Kuehn, K.; Kuwabara, T.; Labare, M.; Lafebre, S.; Laihem, K.; Landsman, H.; Lauer, R.; Lehmann, R.; Lennarz, D.; Lünemann, J.; Madsen, J.; Majumdar, P.; Marotta, A.; Maruyama, R.; Mase, K.; Matis, H. S.; Matusik, M.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Middell, E.; Milke, N.; Miller, J.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Nam, J. W.; Naumann, U.; Nießen, P.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; O'Murchadha, A.; Ono, M.; Panknin, S.; Paul, L.; Pérez de los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Porrata, R.; Posselt, J.; Price, P. B.; Prikockis, M.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Rizzo, A.; Rodrigues, J. P.; Roth, P.; Rothmaier, F.; Rott, C.; Roucelle, C.; Ruhe, T.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Sander, H.-G.; Santander, M.; Sarkar, S.; Schatto, K.; Schlenstedt, S.; Schmidt, T.; Schukraft, A.; Schultes, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Slipak, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stephens, G.; Stezelberger, T.; Stokstad, R. G.; Stoyanov, S.; Strahler, E. A.; Straszheim, T.; Sullivan, G. W.; Swillens, Q.; Taavola, H.; Taboada, I.; Tamburro, A.; Tarasova, O.; Tepe, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Toscano, S.; Tosi, D.; Turčan, D.; van Eijndhoven, N.; Vandenbroucke, J.; Van Overloop, A.; van Santen, J.; Voge, M.; Voigt, B.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Weaver, Ch.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Wikström, G.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Wolf, M.; Woschnagg, K.; Xu, C.; Xu, X. W.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; IceCube Collaboration

2010-08-01

We report the first observation of an anisotropy in the arrival direction of cosmic rays with energies in the multi-TeV region in the Southern sky using data from the IceCube detector. Between 2007 June and 2008 March, the partially deployed IceCube detector was operated in a configuration with 1320 digital optical sensors distributed over 22 strings at depths between 1450 and 2450 m inside the Antarctic ice. IceCube is a neutrino detector, but the data are dominated by a large background of cosmic-ray muons. Therefore, the background data are suitable for high-statistics studies of cosmic rays in the southern sky. The data include 4.3 billion muons produced by downward-going cosmic-ray interactions in the atmosphere; these events were reconstructed with a median angular resolution of 3° and a median energy of ~20 TeV. Their arrival direction distribution exhibits an anisotropy in right ascension with a first-harmonic amplitude of (6.4 ± 0.2 stat. ± 0.8 syst.) × 10-4.

First cosmic-ray images of bone and soft tissue

NASA Astrophysics Data System (ADS)

Mrdja, Dusan; Bikit, Istvan; Bikit, Kristina; Slivka, Jaroslav; Hansman, Jan; Oláh, László; Varga, Dezső

2016-11-01

More than 120 years after Roentgen's first X-ray image, the first cosmic-ray muon images of bone and soft tissue are created. The pictures, shown in the present paper, represent the first radiographies of structures of organic origin ever recorded by cosmic rays. This result is achieved by a uniquely designed, simple and versatile cosmic-ray muon-imaging system, which consists of four plastic scintillation detectors and a muon tracker. This system does not use scattering or absorption of muons in order to deduct image information, but takes advantage of the production rate of secondaries in the target materials, detected in coincidence with muons. The 2D image slices of cow femur bone are obtained at several depths along the bone axis, together with the corresponding 3D image. Real organic soft tissue, polymethyl methacrylate and water, never seen before by any other muon imaging techniques, are also registered in the images. Thus, similar imaging systems, placed around structures of organic or inorganic origin, can be used for tomographic imaging using only the omnipresent cosmic radiation.

Recent Results of the Telescope Array Experiment

NASA Astrophysics Data System (ADS)

Ivanov, Dmitri

2015-04-01

The Telescope Array (TA) is the largest cosmic ray experiment in the northern hemisphere and covers 10 PeV to 100 EeV range. TA is a hybrid detector that uses air fluorescence detectors combined with a ground array. TA consists of 507 plastic scintillation counters on a 1.2km square grid, overlooked by 3 fluorescence detector stations, and measures cosmic rays above 1 EeV. TA has collected 6.5 years of data. Results from the TA low energy extension (TALE), which sees cosmic rays down to 10 PeV, will also be shown. This contribution will consist of three parts. First, we will present the cosmic ray energy spectrum measured over 4 decades in energy. Next, we will discuss the latest results of the measurements of cosmic ray mass composition by the TA fluorescence detectors. Finally, we will show the latest results of the TA anisotropy measurements at the highest energies, where we have seen a concentration of events, called the ``hotspot,'' centered in the Ursa Major. For the Telescope Array Collaboration. Done...processed 1261 records...10:46:59 Beginning APS data extraction...10:47:48

Galactic Cosmic-Ray Anistropy During the Forbush Decrease Starting 2013 April 13

NASA Astrophysics Data System (ADS)

Tortermpun, U.; Ruffolo, D.; Bieber, J. W.

2018-01-01

The flux of Galactic cosmic rays (GCRs) can undergo a Forbush decrease (FD) during the passage of a shock, sheath region, or magnetic flux rope associated with a coronal mass ejection (CME). Cosmic-ray observations during FDs can provide information complementary to in situ observations of the local plasma and magnetic field, because cosmic-ray distributions allow remote sensing of distant conditions. Here we develop techniques to determine the GCR anisotropy before and during an FD using data from the worldwide network of neutron monitors, for a case study of the FD starting on 2013 April 13. We find that at times with strong magnetic fluctuations and strong cosmic-ray scattering, there were spikes of high perpendicular anisotropy and weak parallel anisotropy. In contrast, within the CME flux rope there was a strong parallel anisotropy in the direction predicted from a theory of drift motions into one leg of the magnetic flux rope and out the other, confirming that the anisotropy can remotely sense a large-scale flow of GCRs through a magnetic flux structure.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abe, K.; Itazaki, A.; Kusumoto, A.

The BESS-Polar Collaboration measured the energy spectra of cosmic-ray protons and helium during two long-duration balloon flights over Antarctica in 2004 December and 2007 December at substantially different levels of solar modulation. Proton and helium spectra probe the origin and propagation history of cosmic rays in the galaxy, and are essential to calculations of the expected spectra of cosmic-ray antiprotons, positrons, and electrons from interactions of primary cosmic-ray nuclei with the interstellar gas, and to calculations of atmospheric muons and neutrinos. We report absolute spectra at the top of the atmosphere for cosmic-ray protons in the kinetic energy range 0.2–160more » GeV and helium nuclei in the range 0.15–80 GeV/nucleon. The corresponding magnetic-rigidity ranges are 0.6–160 GV for protons and 1.1–160 GV for helium. These spectra are compared to measurements from previous BESS flights and from ATIC-2, PAMELA, and AMS-02. We also report the ratio of the proton and helium fluxes from 1.1 to 160 GV and compare this to the ratios from PAMELA and AMS-02.« less

Cosmic Rays in the "Urusvati" Institute from Archives of Nicolas Roerich Centre-Museum (Moscow)

NASA Astrophysics Data System (ADS)

Miroshnichenko, L. I.; Sidorov, V. I.

2013-02-01

The history of cosmic ray study by means of ground-based methods in the 1930s contains some gaps. The press barely covered the study of cosmic rays at the "Urusvati» Himalayan Research Institute that functioned in the Indian Himalayas in 1928-1939. Archival materials of the "Urusvati" Institute now stored at the International Centre-Museum named after N.K. Roerich (Moscow), give evidence to the active participation of the Institute staff in the study of cosmic rays. By the initiative of A.H. Compton, in 1932 several expeditions on the studies of cosmic rays were organized in different parts of the world. One of these expeditions passed through the Himalayas in the region of the South-Eastern Ladakh. The report on this highland expedition which took place at the altitude of 19,500 feet above the sea level was published by J.M. Benade in the "Urusvati Journal" (was issued during 1931-1933). Cooperation between George Roerich, the Institute Director, and Prof. J.M. Benade in expedition to Ladakh has been documented.

Simulations of a Thin Sampling Calorimeter with GEANT/FLUKA

NASA Technical Reports Server (NTRS)

Lee, Jeongin; Watts, John; Howell, Leonard; Rose, M. Franklin (Technical Monitor)

2000-01-01

The Advanced Cosmic-ray Composition Experiment for the Space Station (ACCESS) will investigate the origin, composition and acceleration mechanism of cosmic rays by measuring the elemental composition of the cosmic rays up to 10(exp 15) eV. These measurements will be made with a thin ionization calorimeter and a transition radiation detector. This paper reports studies of a thin sampling calorimeter concept for the ACCESS thin ionization calorimeter. For the past year, a Monte Carlo simulation study of a Thin Sampling Calorimeter (TSC) design has been conducted to predict the detector performance and to design the system for achieving the ACCESS scientific objectives. Simulation results show that the detector energy resolution function resembles a Gaussian distribution and the energy resolution of TSC is about 40%. In addition, simulations of the detector's response to an assumed broken power law cosmic ray spectra in the region where the 'knee' of the cosmic ray spectrum occurs have been conducted and clearly show that a thin sampling calorimeter can provide sufficiently accurate estimates of the spectral parameters to meet the science requirements of ACCESS. n

Studies of the performance of the ATLAS detector using cosmic-ray muons

NASA Astrophysics Data System (ADS)

Aad, G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; Abramowicz, H.; Abreu, H.; Acharya, B. S.; Adams, D. L.; Addy, T. N.; Adelman, J.; Adomeit, S.; Adragna, P.; Adye, T.; Aefsky, S.; Aguilar-Saavedra, J. A.; Aharrouche, M.; Ahlen, S. P.; Ahles, F.; Ahmad, A.; Ahsan, M.; Aielli, G.; Akdogan, T.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Aktas, A.; Alam, M. S.; Alam, M. A.; Albrand, S.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alison, J.; Aliyev, M.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alviggi, M. G.; Amako, K.; Amelung, C.; Amorim, A.; Amorós, G.; Amram, N.; Anastopoulos, C.; Andeen, T.; Anders, C. F.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angerami, A.; Anghinolfi, F.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonelli, S.; Antos, J.; Antunovic, B.; Anulli, F.; Aoun, S.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Archambault, J. P.; Arfaoui, S.; Arguin, J.-F.; Argyropoulos, T.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnault, C.; Artamonov, A.; Arutinov, D.; Asai, M.; Asai, S.; Silva, J.; Asfandiyarov, R.; Ask, S.; Åsman, B.; Asner, D.; Asquith, L.; Assamagan, K.; Astvatsatourov, A.; Atoian, G.; Auerbach, B.; Augsten, K.; Aurousseau, M.; Austin, N.; Avolio, G.; Avramidou, R.; Ay, C.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Bach, A. M.; Bachacou, H.; Bachas, K.; Backes, M.; Badescu, E.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, M. D.; Baker, S.; Dos Santos Pedrosa, F. Baltasar; Banas, E.; Banerjee, P.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bansal, V.; Baranov, S. P.; Barashkou, A.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Bardin, D. 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I.; Tsulaia, V.; Tsung, J.-W.; Tsuno, S.; Tsybychev, D.; Tuggle, J. M.; Turecek, D.; Turk Cakir, I.; Turlay, E.; Tuts, P. M.; Twomey, M. S.; Tylmad, M.; Tyndel, M.; Uchida, K.; Ueda, I.; Ueno, R.; Ugland, M.; Uhlenbrock, M.; Uhrmacher, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Unno, Y.; Urbaniec, D.; Urkovsky, E.; Urquijo, P.; Urrejola, P.; Usai, G.; Uslenghi, M.; Vacavant, L.; Vacek, V.; Vachon, B.; Vahsen, S.; Valente, P.; Valentinetti, S.; Valkar, S.; Valladolid Gallego, E.; Vallecorsa, S.; Valls Ferrer, J. A.; van der Graaf, H.; van der Kraaij, E.; van der Poel, E.; van der Ster, D.; van Eldik, N.; van Gemmeren, P.; van Kesteren, Z.; van Vulpen, I.; Vandelli, W.; Vaniachine, A.; Vankov, P.; Vannucci, F.; Vari, R.; Varnes, E. W.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vassilakopoulos, V. I.; Vazeille, F.; Vellidis, C.; Veloso, F.; Veneziano, S.; Ventura, A.; Ventura, D.; Venturi, M.; Venturi, N.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. 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2011-03-01

Muons from cosmic-ray interactions in the atmosphere provide a high-statistics source of particles that can be used to study the performance and calibration of the ATLAS detector. Cosmic-ray muons can penetrate to the cavern and deposit energy in all detector subsystems. Such events have played an important role in the commissioning of the detector since the start of the installation phase in 2005 and were particularly important for understanding the detector performance in the time prior to the arrival of the first LHC beams. Global cosmic-ray runs were undertaken in both 2008 and 2009 and these data have been used through to the early phases of collision data-taking as a tool for calibration, alignment and detector monitoring. These large datasets have also been used for detector performance studies, including investigations that rely on the combined performance of different subsystems. This paper presents the results of performance studies related to combined tracking, lepton identification and the reconstruction of jets and missing transverse energy. Results are compared to expectations based on a cosmic-ray event generator and a full simulation of the detector response.

Overview of galactic cosmic ray solar modulation in the AMS-02 era

NASA Astrophysics Data System (ADS)

Bindi, V.; Corti, C.; Consolandi, C.; Hoffman, J.; Whitman, K.

2017-08-01

A new era in cosmic rays physics has started thanks to the precise and continuous observations from space experiments such as PAMELA and AMS-02. Invaluable results are coming out from these new data that are rewriting the theory of acceleration and propagation of cosmic rays. Both at high energies, where several new behaviors have been measured, challenging the accuracy of theoretical models, and also at low energies, in the region affected by the solar modulation. Precise measurements are increasing our knowledge of the effects of solar modulation on low energy cosmic rays, allowing a detailed study of propagation and composition as it has never been done before. These measurements will serve as a high-precision baseline for continued studies of GCR composition, GCR modulation over the solar cycle, space radiation hazards, and other topics. In this review paper, the status of the latest measurements of the cosmic rays in the context of solar modulation are presented together with the current open questions and the future prospects. How new measurements from the AMS-02 experiment will address these questions is also discussed.

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

NASA Astrophysics Data System (ADS)

Sedrati, R.; Attallah, R.

2014-04-01

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

Search for microquasar features in cosmic ray spectra with AMS-01

NASA Astrophysics Data System (ADS)

Monreal, Benjamin

2004-12-01

Accreting x-ray binaries are sometimes observed to emit compact, relativistic jets of cool plasma; these objects are called "microquasars". It is possible that these jets are responsible for a large flux of galactic cosmic ray protons and nuclei. The energy spectrum from these sources will be very different from the featureless power-law expected from ordinary cosmic-ray acceleration in supernova shocks. The AMS-01 instrument measured cosmic ray protons and helium during 10 days on the Space Shuttle Discovery in 1998; we analyze this data searching for spectral distortions due to nearby microquasar activity. We show that the microquasar contribution to the CR proton flux can be no more than ~2% in the range 2-50 GeV. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

An algorithm to resolve γ-rays from charged cosmic rays with DAMPE

NASA Astrophysics Data System (ADS)

Xu, Zun-Lei; Duan, Kai-Kai; Shen, Zhao-Qiang; Lei, Shi-Jun; Dong, Tie-Kuang; Gargano, Fabio; Garrappa, Simone; Guo, Dong-Ya; Jiang, Wei; Li, Xiang; Liang, Yun-Feng; Mazziotta, Mario Nicola; Munoz Salinas, Maria Fernanda; Su, Meng; Vagelli, Valerio; Yuan, Qiang; Yue, Chuan; Zang, Jing-Jing; Zhang, Ya-Peng; Zhang, Yun-Long; Zimmer, Stephan

2018-03-01

The DArk Matter Particle Explorer (DAMPE), also known as Wukong in China, which was launched on 2015 December 17, is a new high energy cosmic ray and γ-ray satellite-borne observatory. One of the main scientific goals of DAMPE is to observe GeV-TeV high energy γ-rays with accurate energy, angular and time resolution, to indirectly search for dark matter particles and for the study of high energy astrophysics. Due to the comparatively higher fluxes of charged cosmic rays with respect to γ-rays, it is challenging to identify γ-rays with sufficiently high efficiency, minimizing the amount of charged cosmic ray contamination. In this work we present a method to identify γ-rays in DAMPE data based on Monte Carlo simulations, using the powerful electromagnetic/hadronic shower discrimination provided by the calorimeter and the veto detection of charged particles provided by the plastic scintillation detector. Monte Carlo simulations show that after this selection the number of electrons and protons that contaminate the selected γ-ray events at ∼ 10GeV amounts to less than 1% of the selected sample. Finally, we use flight data to verify the effectiveness of the method by highlighting known γ-ray sources in the sky and by reconstructing preliminary light curves of the Geminga pulsar.

Cosmic ray topography

NASA Astrophysics Data System (ADS)

Bressler, Matthew; Goodwin, Lydia; Kryemadhi, Abaz

2017-11-01

Cosmic ray muons are produced when high energy particles interact with nuclei in Earth's atmosphere. Muons make up the majority of charged particles that reach sea level and are the only particles (apart from neutrinos) that can penetrate to significant depths underground. The muon flux underground decreases approximately exponentially as a function of depth. We use a cosmic ray detector developed by the QuarkNet Program at Fermi National Laboratory to map the topography of the mountain above an abandoned Pennsylvania Turnpike tunnel by analyzing muon flux at different rock overburdens. Cosmic ray muons have been used in this capacity before to search for hidden chambers in pyramids and for mapping volcanoes. This study provides a unique field experience to learn about particle physics and particle detectors, which could be of interest to students and teachers in physics.