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46 results on '"ISM: cosmic rays"'

1. Neutral carbon in diffuse interstellar medium: abundance matching with H2 for damped Lyman alpha systems at high redshifts.

Author

Balashev, S A and Kosenko, D N

Subjects
*INTERSTELLAR medium, *COSMIC rays, *RADIATIVE transfer, *GEOMETRIC modeling, *REDSHIFT
Abstract

We present a study of C  i /H2 relative abundance in the diffuse cold neutral medium (CNM). Using the chemical and thermal balance model, we calculate the dependence of C  i /H2 on the main parameters of the medium: hydrogen number density, metallicity, strength of the UV field, and cosmic ray ionization rate (CRIR). We show that the observed relative C  i and H2 column densities in damped Lyman alpha systems (DLAs) at high redshifts can be reproduced within our model assuming the typically expected conditions in the diffuse CNM. Using additional observed information on metallicity, H  i column density, and excitation of C  i fine-structure levels, as well as temperature, we estimated for a wide range metallicities in the CNM at high redshifts that CRIRs are in the range from ∼10−16 to a |$\rm few \times 10^{-15}\, \rm s^{-1}$|⁠ , hydrogen number densities are in the range ∼10−103 cm−3, and the UV field is in the range from 10−2 to a |$\rm few \times 10^2$| of the Mathis field. We argue that because the observed quantities used in this work are quite homogeneous and much less affected by radiative transfer effects (in comparison with, for example, the dissociation of HD and UV pumping of H2 rotational levels), our estimates are quite robust against the assumption of the exact geometrical model of the cloud and local sources of the UV field. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Constraining cosmic ray transport with observations of the circumgalactic medium.

Author

Butsky, Iryna S, Nakum, Shreya, Ponnada, Sam B, Hummels, Cameron B, Ji, Suoqing, and Hopkins, Philip F

Subjects
*COSMIC rays, *INTERSTELLAR medium, *STAR formation, *GALACTIC evolution
Abstract

Recent theoretical studies predict that the circumgalactic medium (CGM) around low-redshift, ∼ L * galaxies could have substantial non-thermal pressure support in the form of cosmic rays. However, these predictions are sensitive to the specific model of cosmic ray transport employed, which is theoretically and observationally underconstrained. In this work, we propose a novel observational constraint for calculating the lower limit of the radially averaged, effective cosmic ray transport rate, |${\kappa _{\rm eff}^{\rm min}}$|⁠. Under a wide range of assumptions (so long as cosmic rays do not lose a significant fraction of their energy in the galactic disc, regardless of whether the cosmic ray pressure is important or not in the CGM), we demonstrate a well-defined relationship between |${\kappa _{\rm eff}^{\rm min}}$| and three observable galaxy properties: the total hydrogen column density, the average star formation rate, and the gas circular velocity. We use a suite of Feedback in Realistic Environments 2 galaxy simulations with a variety of cosmic ray transport physics to demonstrate that our analytical model of |${\kappa _{\rm eff}^{\rm min}}$| is a robust lower limit of the true cosmic ray transport rate. We then apply our new model to calculate |${\kappa _{\rm eff}^{\rm min}}$| for galaxies in the COS-Halos sample, and confirm this already reveals strong evidence for an effective transport rate that rises rapidly away from the interstellar medium to values |${\kappa _{\rm eff}^{\rm min}}\gtrsim 10^{30\!-\!31}\, {\rm cm}^2\, {\rm s}^{-1}$| (corresponding to anisotropic streaming velocities of |$v^{\rm stream}_{\rm eff} \gtrsim 1000\, {\rm km}\, {\rm s}^{-1}$|⁠) in the diffuse CGM, at impact parameters larger than 50–100 kpc. We discuss how future observations can provide qualitatively new constraints in our understanding of cosmic rays in the CGM and intergalactic medium. [ABSTRACT FROM AUTHOR]

Published
2023
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3. impact of cosmic rays on dynamical balance and disc–halo interaction in L⋆ disc galaxies.

Author

Chan, T K, Kereš, Dušan, Gurvich, Alexander B, Hopkins, Philip F, Trapp, Cameron, Ji, Suoqing, and Faucher-Giguère, Claude-André

Subjects
*DISK galaxies, *COSMIC rays, *INTERSTELLAR medium, *GAS dynamics, *GALACTIC redshift, *INTERFACE dynamics
Abstract

Cosmic rays (CRs) are an important component in the interstellar medium, but their effect on the dynamics of the disc–halo interface (<10 kpc from the disc) is still unclear. We study the influence of CRs on the gas above the disc with high-resolution FIRE-2 cosmological simulations of late-type L ⋆ galaxies at redshift z ∼ 0. We compare runs with and without CR feedback (with constant anisotropic diffusion κ∥ ∼ 3 × 1029 cm2 s−1 and streaming). Our simulations capture the relevant disc–halo interactions, including outflows, inflows, and galactic fountains. Extra-planar gas in all of the runs satisfies dynamical balance , where total pressure balances the weight of the overlying gas. While the kinetic pressure from non-uniform motion (≳1 kpc scale) dominates in the mid-plane, thermal and bulk pressures (or CR pressure if included) take over at large heights. We find that with CR feedback, (1) the warm (∼104 K) gas is slowly accelerated by CRs; (2) the hot (>5 × 105 K) gas scale height is suppressed; (3) the warm-hot (2 × 104–5 × 105 K) medium becomes the most volume-filling phase in the disc–halo interface. We develop a novel conceptual model of the near-disc gas dynamics in low-redshift L ⋆ galaxies: with CRs, the disc–halo interface is filled with CR-driven warm winds and hot superbubbles that are propagating into the circumgalactic medium with a small fraction falling back to the disc. Without CRs, most outflows from hot superbubbles are trapped by the existing hot halo and gravity, so typically they form galactic fountains. [ABSTRACT FROM AUTHOR]

Published
2022
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4. Diffuse galactic Gamma-rays from star clusters.

Author

Nath, Biman B and Eichler, David

Abstract

We demonstrate that young star clusters have a γ-ray surface brightness comparable to that of the diffuse Galactic emission (DGE), and estimate that their sky coverage in the direction of the inner Galaxy exceeds unity. We therefore suggest that they comprise a significant fraction of the DGE. [ABSTRACT FROM AUTHOR]

Published
2020
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5. Role of cosmic rays in the early stages of galactic outflows.

Author

Jana, Ranita, Gupta, Siddhartha, and Nath, Biman B

Subjects
*GAS distribution, *STAR formation, *STELLAR winds, *TEMPERATURE distribution, *COSMIC rays, *STABILITY constants
Abstract

Using an idealized set-up, we investigate the dynamical role of cosmic rays (CRs) in the early stages of galactic outflows for galaxies of halo masses 108, 1011, and 1012 M⊙. The outflow is launched from a central region in the galactic disc where we consider three different constant star formation rates (0.1, 1, and 10 |$\mathrm{M}_\odot \, \mathrm{yr}^{-1}$|⁠) over a dynamical time-scale of 50 Myr. We determine the temperature distribution of the gas and find that CRs can reduce the temperature of the shocked gas, which is consistent with previous results. However, we show that CRs do not have any noticeable effect on the mass loading by the outflow. We find that CRs can reduce the size of the outflow, which contradicts previous claims of efficient dynamical impact of CRs; however, it is consistent with earlier theoretical models of CR-driven blastwave as well as stellar wind. We discuss the dependence of our results on CR injection prescriptions and compare them with earlier studies. We conclude that in the early stages of galactic outflows the dynamical role of CRs is not important. [ABSTRACT FROM AUTHOR]

Published
2020
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6. High-energy cosmic rays from compact galactic star clusters: Particle fluxes and anisotropy.

Author

Bykov, A.M., Kalyashova, M.E., Ellison, D.C., and Osipov, S.M.

Subjects
*COMPACT objects (Astronomy), *OPEN clusters of stars, *CLUSTERING of particles, *GALACTIC magnetic fields, *STELLAR winds, *SUPERGIANT stars, *COSMIC rays, *STAR clusters
Abstract

It has been shown that supernova blast waves interacting with winds from massive stars in compact star clusters may be capable of producing cosmic-ray (CR) protons to above 10 17 eV. We give a brief description of the colliding-shock-flow mechanism and look at generalizations of the diffusion of ∼100 PeV CRs in the turbulent galactic magnetic field present in the galactic disk. We calculate the temporal evolution of the CR anisotropy from a possible distribution of young compact massive star clusters assuming the sources are intermittent on time scales of a few million years, i.e., comparable to their residence time in the Milky Way. Within the confines of our model, we determine the galactic/extra-galactic fraction of high-energy CRs resulting in anisotropies consistent with observed values. We find that galactic star clusters may contribute a substantial fraction of ∼100 PeV CRs without producing anisotropies above observed limits. [ABSTRACT FROM AUTHOR]

Published
2019
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7. On the origin of jet-like features in bow shock pulsar wind nebulae.

Author

Olmi, B and Bucciantini, N

Subjects
*SUPERNOVA remnants, *PARTICLE tracks (Nuclear physics), *NEBULAE, *MAGNETIC structure, *INTERSTELLAR medium, *PULSARS, *DARK energy
Abstract

Bow shock pulsar wind nebulae are a large class of non-thermal synchrotron sources associated to old pulsars that have emerged from their parent supernova remnant and are directly interacting with the interstellar medium. Within this class a few objects show extended X-ray features, generally referred as 'jets', that defies all the expectations from the canonical MHD models, being strongly misaligned respect to the pulsar direction of motion. It has been suggested that these jets might originate from high energy particles that escape from the system. Here we investigate this possibility, computing particle trajectories on top of a 3D relativistic MHD model of the flow and magnetic field structure, and we show not only that beamed escape is possible, but that it can easily be asymmetric and charge separated, which as we will discuss are important aspects to explain known objects. [ABSTRACT FROM AUTHOR]

Published
2019
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8. RISEPix—A Timepix‐based radiation monitor telescope onboard the RISESAT satellite.

Author

Filgas, Robert, Malich, Milan, Kuwahara, Toshinori, Broulím, Jan, Holík, Michael, Sakal, Morokot, Murata, Yu, Tomio, Hannah, Gohl, Stefan, and Pineda T., Johan M.

Subjects
*RADIATION dosimetry, *SCIENTIFIC apparatus & instruments, *ARTIFICIAL satellites, *TELESCOPES, *COSMIC rays, *SPACE environment, *DETECTORS
Abstract

Rapid International Scientific Experiment Satellite (RISESAT) is a small Japanese experimental Earth‐observing, science and technology demonstration satellite. One of the scientific instruments onboard is a miniature radiation monitor telescope RISEPix with two Timepix detectors, developed and built at the Institute of Experimental and Applied Physics, Czech Technical University in Prague. After its successful launch in January 2019, RISESAT joined two other still operational satellites with our Timepix‐based radiation monitors, SATRAM onboard the ESA satellite Proba‐V (launched in 2013) and the Czech VZLUSAT‐1 cubesat (launched 2017). In this work, we present general technical and scientific details about the RISESAT satellite mission and the RISEPix module, and a basic comparison of space weather monitoring from SATRAM and VZLUSAT‐1 radiation monitors. [ABSTRACT FROM AUTHOR]

Published
2019
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9. Probing the origin of the unidentified TeV γ-ray source HESS J1702–420 via the surrounding interstellar medium.

Author

Lau, J C, Rowell, G, Voisin, F, Blackwell, R, Burton, M G, Braiding, C, Wong, G F, Fukui, Y, and Casanova, S

Subjects
*INTERSTELLAR medium, *WAVELENGTHS, *STELLAR mass, *COSMIC rays, *LEPTONS (Nuclear physics)
Abstract

The unidentified TeV γ-ray source HESS J1702–420 has no firm associations with any counterparts at other wavelengths. We present an analysis of the interstellar medium using results from the Mopra Southern Galactic Plane CO survey and archival H  i data from the Southern Galactic Plane Survey. We find significant components of molecular and atomic gas overlapping the TeV γ-ray source at several velocities along the line of sight, with masses ∼102–104 M⊙ and densities up to ∼103 cm−3. Potentially interesting and favourable morphological correspondences between the ISM and the TeV γ-ray emission were found, and in a hadronic scenario, we find that cosmic ray (CR) enhancement values of ∼100 times the local solar values are required to produce the TeV γ-rays. We investigate the separate scenarios in which HESS J1702–420 is powered by the nearby SNR G344.7−0.1, PSRJ1702−4128, and an unknown accelerator. No evidence in the ISM was found to link the SNR with the TeV source. While the morphology of the gas located at the dispersion distance of PSRJ1702−4128 (5.2 kpc, |$v$| LSR ∼ −70 km s−1) did not discount the possibility of a leptonic origin, the required energetics and the broad and hard TeV spectrum would likely disfavour such a scenario. Given the presence of potentially favourable ISM overlapping HESS J1702–420, we additionally speculate on the plausibility of scenarios involving undetected CR accelerators. [ABSTRACT FROM AUTHOR]

Published
2019
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10. Escape of high-energy particles from bow-shock pulsar wind nebulae.

Author

Bucciantini, N

Subjects
*PULSARS, *NEBULAE, *SUPERNOVA remnants, *ACCRETION (Astrophysics), *STAR clusters
Abstract

The detection of bright X-ray features and large TeV haloes around old pulsars that have escaped their parent supernova remnants and are interacting directly with the ISM suggests that high-energy particles, more likely high-energy pairs, can escape from these systems, and that this escape if far more complex than a simple diffusive model can predict. Here, we present for the first time a detailed analysis of how high-energy particles escape from the head of the bow shock. In particular, we focus our attention on the role of the magnetic field geometry, and the inclination of the pulsar spin axis with respect to the direction of the pulsar kick velocity. We show that asymmetries in the escape pattern of charged particles are common, and they are strongly energy dependent. More interestingly, we show that the flow of particles from bow-shock pulsar wind nebulae is likely to be charge separated, which might have profound consequences on the way such a flow interacts with the ISM magnetic field, driving local turbulence. [ABSTRACT FROM AUTHOR]

Published
2018
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11. Evidence for GeV cosmic rays from white dwarfs in the local cosmic ray spectra and in the gamma-ray emissivity of the inner Galaxy.

Author

Tuneyoshi KAMAE, Shiu-Hang LEE, Kazuo MAKISHIMA, Shinpei SHIBATA, and Toshikazu SHIGEYAMA

Subjects
*COSMIC rays, *CATACLYSMIC variable stars, *WHITE dwarf stars, *SYNCHROTRON radiation sources, *PROTON spectra
Abstract

Recent observations found that electrons are accelerated to ~10 GeV and emit synchrotron hard X-rays in two magneticwhite dwarfs (WDs), also known as cataclysmic variables (CVs). In nova outbursts of WDs, multi-GeV gamma-rays were detected, implying that protons are accelerated to 100 GeV or higher. In recent optical surveys, the WD density is found to be higher near the Sun than in the Galactic disk by a factor ~2.5. The cosmic rays (CRs) produced by local CVs and novae will accumulate in the local bubble for 106-107 yr. On these findings, we search for CRs from historic CVs and novae in the observed CR spectra. We model the CR spectra at the heliopause as sums of Galactic and local components based on observational data as much as possible. The initial Galactic CR electron and proton spectra are deduced from the gamma-ray emissivity, the local electron spectrum from the hard X-ray spectra at the CVs, and the local proton spectrum from gamma-ray spectra at novae. These spectral shapes are then expressed in a simple set of polynomial functions of CR energy and regressively fitted until the highenergy (>100 GeV) CR spectra near Earth and the Voyager-1 spectra at the heliopause are reproduced. We then extend the modeling to nuclear CR spectra and find that one spectral shape fits all local nuclear CRs, and that the apparent hardening of the nuclear CR spectra is caused by the roll-down of local nuclear spectra around 100-200 GeV. All local CR spectra populate a limited energy band below 100-200 GeV and enhance gamma-ray emissivity below ~10 GeV. Such an enhancement is observed in the inner Galaxy, suggesting the CR fluxes from CVs and novae are substantially higher there. [ABSTRACT FROM AUTHOR]

Published
2018
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14. Cosmic-Ray Induced Diffusion in Interstellar Ices

Author

Kalvāns Juris

Subjects
astrochemistry, molecular processes, ism: clouds, ism: molecules, ism: cosmic rays, Astronomy, QB1-991
Abstract

Cosmic rays are able to heat interstellar dust grains. This may enhance molecule mobility in icy mantles that have accumulated on the grains in dark cloud cores. A three-phase astrochemical model was used to investigate the molecule mobility in interstellar ices. Specifically, diffusion through pores in ice between the subsurface mantle and outer surface, assisted by whole-grain heating, was considered. It was found that the pores can serve as an efficient transport route for light species. The diffusion of chemical radicals from the mantle to the outer surface are most effective. These species accumulate in the mantle because of photodissociation by the cosmic-ray induced photons. The faster diffusion of hydrogen within the warm ice enhances the hydrogenation of radicals on pore surfaces. The overall result of the whole grain heating-induced radial diffusion in ice are higher abundances of ice species, whose synthesis involve light radicals. Examples of stable species synthesized this way include complex organic molecules, OCS, H2O2 and cyanoplyynes.

Published
2014
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15. Turbulent magnetic field amplification driven by cosmic ray pressure gradients.

Author

Drury, L. O'C. and Downes, T. P.

Subjects
*NON-thermal plasmas, *SUPERNOVAE, *MAGNETIC fields, *COSMIC rays, *INTERSTELLAR medium
Abstract

ABSTRACT Observations of non-thermal emission from several supernova remnants suggest that magnetic fields close to the blast wave are much stronger than would be naively expected from simple shock compression of the field permeating the interstellar medium (ISM). We present a simple model which is capable of achieving sufficient magnetic field amplification to explain the observations. We propose that the cosmic ray pressure gradient acting on the inhomogeneous ISM upstream of the supernova blast wave induces strong turbulence upstream of the supernova blast wave. The turbulence is generated through the differential acceleration of the upstream ISM which occurs as a result of density inhomogeneities in the ISM. This turbulence then amplifies the pre-existing magnetic field. Numerical simulations are presented which demonstrate that amplification factors of 20 or more are easily achievable by this mechanism when reasonable parameters for the ISM and supernova blast wave are assumed. The length scale over which this amplification occurs is that of the diffusion length of the highest energy non-thermal particles. [ABSTRACT FROM AUTHOR]

Published
2012
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16. Interstellar and intergalactic dynamos.

Author

Hanasz, M., Woltanski, D., and Kowalik, K.

Abstract

We review recent developments of amplification models of galactic and intergalactic magnetic field. The most popular scenarios involve variety of physical mechanisms, including turbulence generation on a wide range of physical scales, effects of supernovae, buoyancy as well as the magnetorotational instability. Other models rely on galaxy interaction, which generate galactic and intergalactic magnetic fields during galaxy mergers. We present also global galactic-scale numerical models of the Cosmic Ray (CR) driven dynamo, which was originally proposed by Parker (1992). We conduct a series of direct CR+MHD numerical simulations of the dynamics of the interstellar medium (ISM), composed of gas, magnetic fields and CR components. We take into account CRs accelerated in randomly distributed supernova (SN) remnants, and assume that SNe deposit small-scale, randomly oriented, dipolar magnetic fields into the ISM. The amplification timescale of the large-scale magnetic field resulting from the CR-driven dynamo is comparable to the galactic rotation period. The process efficiently converts small-scale magnetic fields of SN-remnants into galactic-scale magnetic fields. The resulting magnetic field structure resembles the X-shaped magnetic fields observed in edge-on galaxies. [ABSTRACT FROM PUBLISHER]

Published
2012
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17. Explaining the cosmic-ray e +/(e − + e +) and ratios using a steady-state injection model

Author

Lee, S.-H., Kamae, T., Baldini, L., Giordano, F., Grondin, M.-H., Latronico, L., Lemoine-Goumard, M., Sgrò, C., Tanaka, T., and Uchiyama, Y.

Subjects
*COSMIC rays, *SUPERNOVA remnants, *MOLECULAR clouds, *NEBULAE, *TELESCOPES, *PARTICLES (Nuclear physics), *MATHEMATICAL models
Abstract

Abstract: We present a model of cosmic ray (CR) injection into the Galactic space based on recent γ-ray observations of supernova remnants (SNRs) and pulsar wind nebulae (PWNe) by the Fermi Large Area Telescope (Fermi) and imaging atmospheric Cherenkov telescopes (IACTs). Steady-state injection of nuclear particles and electrons (e −) from the Galactic ensemble of SNRs, and electrons and positrons (e +) from the Galactic ensemble of PWNe are assumed, with their injection spectra inferred under guidance of γ-ray observations and recent development of evolution and emission models. The ensembles of SNRs and PWNe are assumed to share the same spatial distributions. Assessment of possible secondary CR contribution from dense molecular clouds interacting with SNRs is also given. CR propagation in the interstellar space is handled by GALPROP. Different underlying source distribution models and Galaxy halo sizes are employed to estimate the systematic uncertainty of the model. We show that this observation-based model reproduces the positron fraction e +/(e − + e +) and antiproton-to-proton ratio reported by PAMELA and other previous missions reasonably well, without calling for any speculative sources. A discrepancy remains, however, between the total e − + e + spectrum measured by Fermi and our model below ∼20GeV, for which the potential causes are discussed. Important quantities for Galactic CRs including their energy injection, average lifetime in the Galaxy, and mean gas density along their typical propagation path are also estimated. [Copyright &y& Elsevier]

Published
2011
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18. 3D numerical simulations of magnetic field evolution in barred galaxies and in spiral galaxies under influence of tidal forces.

Author

Otmianowska-Mazur, Katarzyna, Kulpa-Dybeł, Katarzyna, Kulesza-Żydzik, Barbara, Siejkowski, Hubert, and Kowal, Grzegorz

Abstract

We present the results of the three-dimensional, fully non-linear MHD simulations of the large-scale magnetic field evolution in a barred galaxy with the back reaction of magnetic field to gas. We also include the process of the cosmic-ray driven dynamo. In addition, we check what physical processes are responsible for the magnetic field evolution in the tidally influenced spiral galaxies. We solve the MHD equations for the gas and magnetic field in a spiral galaxy with gravitationally prescribed bulge, disk and halo which travels along common orbit with the second body. In order to compare our modeling results with the observations we also construct the maps of high-frequency (Faraday rotation-free) polarized radio emission from the simulated magnetic fields. The model accounts for the effects of projection and limited resolution.We found that the obtained magnetic field configurations are highly similar to the observed maps of the polarized intensity of barred galaxies, because the modeled vectors form coherent structures along the bar and spiral arms. We also found a physical explanation of the problem of inconsistency between the velocity and magnetic fields character present in this type of galaxies. Due to the dynamical influence of the bar, the gas forms spiral waves which go radially outward. Each spiral arm forms the magnetic arm which stays much longer in the disk than the gaseous spiral structure. The modeled total energy of magnetic field and magnetic flux grows exponentially due to the action of the cosmic-ray driven dynamo. We also obtained the polarization maps of tidally influenced spiral galaxies which are similar to observations. [ABSTRACT FROM PUBLISHER]

Published
2010
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19. Cosmic-ray driven dynamo in galaxies.

Author

Hanasz, M., Wóltanski, D., Kowalik, K., and Kotarba, H.

Abstract

We present recent developments of global galactic-scale numerical models of the Cosmic Ray (CR) driven dynamo, which was originally proposed by Parker (1992). We conduct a series of direct CR+MHD numerical simulations of the dynamics of the interstellar medium (ISM), composed of gas, magnetic fields and CR components. We take into account CRs accelerated in randomly distributed supernova (SN) remnants, and assume that SNe deposit small-scale, randomly oriented, dipolar magnetic fields into the ISM. The amplification timescale of the large-scale magnetic field resulting from the CR-driven dynamo is comparable to the galactic rotation period. The process efficiently converts small-scale magnetic fields of SN-remnants into galactic-scale magnetic fields. The resulting magnetic field structure resembles the X-shaped magnetic fields observed in edge-on galaxies. [ABSTRACT FROM PUBLISHER]

Published
2010
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20. Predicted γ-ray image of SN 1006 due to inverse Compton emission.

Author

Petruk, O., Bocchino, F., Miceli, M., Dubner, G., Castelletti, G., Orlando, S., Iakubovskyi, D., and Telezhinsky, I.

Subjects
*SPECTRAL analysis (Phonetics), *ASTRONOMY, *COMPTON effect, *SUPERNOVAE, *GALACTIC X-ray sources
Abstract

We propose a method to synthesize the inverse Compton (IC) γ-ray image of a supernova remnant starting from the radio (or hard X-ray) map and using results of the spatially resolved X-ray spectral analysis. The method is successfully applied to SN 1006. We found that synthesized IC γ-ray images of SN 1006 show morphology in nice agreement with that reported by the High Energy Stereoscopic System (HESS) collaboration. The good correlation found between the observed very high energy γ-ray and X-ray/radio appearance can be considered as evidence of the fact that the γ-ray emission of SN 1006 observed by HESS is leptonic in origin, although a hadronic origin may not be excluded. [ABSTRACT FROM AUTHOR]

Published
2009
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21. Concluding remarks on solar and stellar activities and related planets.

Author

Turck-Chièze, Sylvaine

Abstract

The symposium has shown the dynamism of this rapidly evolving discipline. I shall concentrate here on some highlights and some complementary informations. I conclude on open questions with some perspectives on solar & stellar activity and related planets. [ABSTRACT FROM PUBLISHER]

Published
2009
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22. Influence of the Schwabe/Hale solar cycles on climate change during the Maunder Minimum.

Author

Miyahara, Hiroko, Yokoyama, Yusuke, and Yamaguchi, Yasuhiko T.

Abstract

We have examined the variation of carbon-14 content in annual tree rings, and investigated the transitions of the characteristics of the Schwabe/Hale (11-year/22-year) solar and cosmic-ray cycles during the last 1200 years, focusing mainly on the Maunder and Spoerer minima and the early Medieval Maximum Period. It has been revealed that the mean length of the Schwabe/Hale cycles changes associated with the centennial-scale variation of solar activity level. The mean length of Schwabe cycle had been ~14 years during the Maunder Minimum, while it was ~9 years during the early Medieval Maximum Period. We have also found that climate proxy record shows cyclic variations similar to stretching/shortening Schwabe/Hale solar cycles in time, suggesting that both Schwabe and Hale solar cycles are playing important role in climate change. In this paper, we review the nature of Schwabe and Hale cycles of solar activity and cosmic-ray flux during the Maunder Minimum and their possible influence on climate change. We suggest that the Hale cycle of cosmic rays are amplified during the grand solar minima and thus the influence of cosmic rays on climate change is prominently recognizable during such periods. [ABSTRACT FROM PUBLISHER]

Published
2009
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23. Simulations of galactic cosmic ray impacts on the Herschel/PACS bolometer arrays with Geant4 code.

Author

Bongardo, C., Andreani, P., Okumura, K., Horeau, B., Claret, A., Zotti, G., Giannitrapani, R., and Longo, F.

Subjects
*COSMIC rays, *ASTROPHYSICAL radiation, *ASTRONOMY, *METEOROLOGICAL instruments, *PHYSICS instruments, *SPACE environment
Abstract

The effects of the in-flight behaviour of the bolometer arrays of the Herschel/Photo-conductor Array Camera and Spectrometer (PACS) instrument under impacts of Galactic cosmic rays are explored. This instrument is part of the ESA-Herschel payload, which will be launched at the end of 2008 and will operate at the Lagrangian L2 point of the Sun-Earth system. We find that the components external to the detectors (the spacecraft, the cryostat, the PACS box, collectively referred to as the ‘shield’) are the major source of secondary events affecting the detector behaviour. The impacts deposit energy on the bolometer chips and influence the behaviour of nearby pixels. 25% of hits affect the adjacent pixels. The energy deposited raises the bolometer temperature by a factor ranging from 1 to 6 percent of the nominal value. We discuss the effects on the observations and compare simulations with laboratory tests. [ABSTRACT FROM AUTHOR]

Published
2008
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24. Diffusive shock acceleration in unmodified relativistic, oblique shocks

Author

Ellison, Donald C. and Double, Glen P.

Subjects
*COSMIC rays, *NUCLEAR physics, *SPACE environment, *MONTE Carlo method
Abstract

Abstract: We present results from a fully relativistic Monte Carlo simulation of diffusive shock acceleration (DSA) in unmodified shocks. The computer code uses a single algorithmic sequence to smoothly span the range from non-relativistic speeds to fully relativistic shocks of arbitrary obliquity, providing a powerful consistency check. While known results are obtained for non-relativistic and ultra-relativistic parallel shocks, new results are presented for the less explored trans-relativistic regime and for oblique, fully relativistic shocks. We find, for a wide trans-relativistic range extending to shock Lorentz factors >30, that the particle spectrum produced by DSA varies strongly from the canonical f(p)∝p−4.23 spectrum known to result in ultra-relativistic shocks. Trans-relativistic shocks may play an important role in γ-ray bursts and other sources and most relativistic shocks will be highly oblique. [Copyright &y& Elsevier]

Published
2004
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25. Radiation chemistry in astrochemical models: From the laboratory to the ISM.

Author

Shingledecker, Christopher N., Ivlev, Alexei, Kästner, Johannes, Herbst, Eric, Caselli, Paola, Salama, Farid, and Linnartz, Harold

Abstract

Most interstellar and planetary environments are suffused by a continuous flux of several types of ionizing radiation, including cosmic rays, stellar winds, x-rays, and gamma-rays from radionuclide decay. There is now a large body of experimental work showing that these kinds of radiation can trigger significant physicochemical changes in ices, including the dissociation of species (radiolysis), sputtering of surface species, and ice heating. Even so, modeling the chemical effects that result from interactions between ionizing radiation and interstellar dust grain ice mantles has proven challenging due to the complexity and variety of the underlying physical processes. To address this shortcoming, we have developed a method whereby such effects could easily be included in standard rate-equations-based astrochemical models. Here, we describe how such models, thus improved, can fruitfully be used to simulate experiments in order to better understand bulk chemistry at low temperatures. [ABSTRACT FROM AUTHOR]

Published
2019
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28. Two GeV-TeV Supernova Remnants without Associated Neutral and Molecular Clouds.

Author

Tian, W., Leahy, D., Zhu, H., and Su, H.

Abstract

TeV gamma ray emissions have been detected at the directions of supernova remnants (SNRs) W51C and Tycho SNR. We analyze the Hi absorption spectra towards W51C, Tycho SNR and their nearby compact sources. We conclude that W51C is at a distance of about 4.3 kpc and Tycho SNR has a distance of 2.5 ~ 3.0 kpc. Our study detects high-velocity Hi clouds which coincide with star formation region W51B, but finds that the clouds are behind W51B which argues against previous claims that W51C has shocked the high velocity Hi clouds. We argue that Tycho SNR is naked Ia SNR (lack of evidence of interacting with adjacent neutral and molecular cloud). This gives two examples that the very high gamma ray emission from SNRs does not likely originate from SNR-cloud interaction. [ABSTRACT FROM PUBLISHER]

Published
2013
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29. HESS J1741−302: a hidden accelerator in the Galactic plane

Author

Collaboration, H., Abdalla, H., Abramowski, A., Aharonian, F., Ait Benkhali, F., Angüner, E., Arakawa, M., Arrieta, M., Aubert, P., Backes, M., Balzer, A., Barnard, M., Becherini, Y., Becker Tjus, J., Berge, D., Bernhard, S., Bernloehr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas Coma, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Capasso, M., Carrigan, S., Caro, S., Carosi, A., Casanova, S., Cerruti, M., Chakraborty, N., Chaves, R., Chen, A., Chevalier, J., Colafrancesco, S., Condon, B., Conrad, J., Davids, I., Decock, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Domainko, W., Donath, A., Drury, L., Dutson, K., Dyks, J., Edwards, T., Egberts, K., Eger, P., Emery, G., Ernenwein, J., Eschbach, S., Farnier, C., Fegan, S., Fernandes, M., Fiasson, A., Fontaine, G., Förster, A., Funk, S., Füßling, M., Gabici, S., Gallant, Y., Garrigoux, T., Gast, H., Gaté, F., Giavitto, G., Giebels, B., Glawion, D., Glicenstein, J., Gottschall, D., Grondin, M., Hahn, J., Haupt, M., Hawkes, J., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J., Hofmann, W., Hoischen, C., Holch, T., Holler, M., Horns, D., Ivascenko, A., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jingo, M., Jouvin, L., Jung-Richardt, I., Kastendieck, M., Katarzynski, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., King, J., Klepser, S., Klochkov, D., Klúzniak, W., Komin, N., Kosack, K., Krakau, S., Kraus, M., Krüger, P., Lamanna, G., Lau, J., Lees, J., Lefaucheur, J., Lemière, A., Lemoine-Goumard, M., Lenain, J., Leser, E., Lohse, T., Lorentz, M., Liu, R., López-Coto, R., Lypova, I., Marandon, V., Malyshev, D., Marcowith, A., Mariaud, C., Marx, R., Maurin, G., Maxted, N., Mayer, M., Meintjes, P., Meyer, M., Mitchell, A., Moderski, R., Mohamed, M., Mohrmann, L., Morå, K., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O’Brien, P., Odaka, H., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R., Paz Arribas, M., Pekeur, N., Pelletier, G., Perennes, C., Petrucci, P., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Poon, H., Prokhorov, D., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Renaud, M., de los Reyes, R., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Rulten, C., Safi-Harb, S., Sahakian, V., Saito, S., Sanchez, D., Santangelo, A., Sasaki, M., Schandri, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Settimo, M., ert, A., Shafi, N., Shilon, I., Shiningayamwe, K., Simoni, R., Sol, H., Spanier, F., Spir-Jacob, M., Stawarz, Ł., Steenkamp, R., Stegmann, C., Steppa, C., Sushch, I., Takahashi, T., Tavernet, J., Tavernier, T., Taylor, A., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Voisin, F., Voelk, H., Vuillaume, T., Wadiasingh, Z., Wagner, S., Wagner, P., Wagner, R., White, R., Wierzcholska, A., Willmann, P., Wörnlein, A., Wouters, D., Yang, R., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A., Zech, A., Zefi, F., Ziegler, A., Zorn, J., Zywucka, N., Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), H.E.S.S., NANTEN, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire d'Annecy de Physique des Particules ( LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules ), Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université Savoie Mont Blanc ( USMB [Université de Savoie] [Université de Chambéry] ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Univers et Théories ( LUTH ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Physique Nucléaire et de Hautes Énergies ( LPNHE ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Univers et Particules de Montpellier ( LUPM ), Centre National de la Recherche Scientifique ( CNRS ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université Montpellier 2 - Sciences et Techniques ( UM2 ) -Université de Montpellier ( UM ), Centre d'Etudes Nucléaires de Bordeaux Gradignan ( CENBG ), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Laboratoire Leprince-Ringuet ( LLR ), Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -École polytechnique ( X ) -Centre National de la Recherche Scientifique ( CNRS ), AstroParticule et Cosmologie ( APC - UMR 7164 ), Centre National de la Recherche Scientifique ( CNRS ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Centre de Physique des Particules de Marseille ( CPPM ), Centre National de la Recherche Scientifique ( CNRS ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Aix Marseille Université ( AMU ), Institut de Planétologie et d'Astrophysique de Grenoble ( IPAG ), Observatoire des Sciences de l'Univers de Grenoble ( OSUG ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Centre National de la Recherche Scientifique ( CNRS ), High Energy Astrophys. & Astropart. Phys (API, FNWI), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), and Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
ISM: cosmic rays, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Hadron, Infrarot-Astrophysik - Abteilung Hofmann, binary, Astrophysics, power spectrum, 01 natural sciences, Pulsar wind nebula, ISM: clouds, gamma rays: individual objects: HESS J1741−302, particle: acceleration, Angular diameter, HESS, cloud, 010303 astronomy & astrophysics, HESS - Abteilung Hofmann, pulsar, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Spectral index, radio wave, model: hadronic, Particle acceleration, Astrophysics - High Energy Astrophysical Phenomena, clouds [ISM], signature, accelerator, Astrophysics::High Energy Astrophysical Phenomena, Hochenergie-Astrophysik Theorie - Abteilung Hofmann, Gamma rays: general, FOS: Physical sciences, X-ray, gamma rays: ISM, Pulsar, ISM [gamma rays], cosmic rays, 0103 physical sciences, ddc:530, 010308 nuclear & particles physics, Institut für Physik und Astronomie, Astronomy and Astrophysics, Galactic plane, flux, Crab Nebula, gamma ray: VHE, Space and Planetary Science, ddc:520, High Energy Physics::Experiment, galaxy, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], general [gamma rays], gamma rays: observations
Abstract

著者人数: H.E.S.S. Collaboration and NANTEN Collaboration 252名 (所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): 桂川, 美穂; 中島, 真也; 小高, 裕和; 高橋, 忠幸), Number of authors: H.E.S.S. Collaboration and NANTEN Collaboration 252 (Affiliation. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS): Katsuragawa, Miho; Nakashima, Shinya; Odaka, Hirokazu; Takahashi, Tadayuki), Accepted: 2017-10-24, 資料番号: SA1170363000

Published
2018
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30. Cosmic ray driven dynamo in barred and ringed galaxies.

Author

Kulpa-Dybeł, K., Otmianowska-Mazur, K., Kulesza-Żydzik, B., Kowal, G., Wóltański, D., Hanasz, M., and Kowalik, K.

Abstract

We study the global evolution of the magnetic field and interstellar medium (ISM) of the barred and ringed galaxies in the presence of non-axisymmetric components of the potential, i.e. the bar and/or the oval perturbations. The magnetohydrodynamical dynamo is driven by cosmic rays (CR), which are continuously supplied to the disk by supernova (SN) remnants. Additionally, weak, dipolar and randomly oriented magnetic field is injected to the galactic disk during SN explosions. To compare our results directly with the observed properties of galaxies we construct realistic maps of high-frequency polarized radio emission. The main result is that CR driven dynamo can amplify weak magnetic fields up to few μG within few Gyr in barred and ringed galaxies. What is more, the modelled magnetic field configuration resembles maps of the polarized intensity observed in barred and ringed galaxies. [ABSTRACT FROM PUBLISHER]

Published
2010
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31. Evolution of several space weather events connected with Forbush decreases.

Author

Dorotovič, I., Kudela, K., Lorenc, M., Pintér, T., and Rybanský, M.

Abstract

In our recent paper (Dorotovič et al. 2008a) we focused on a study of the Forbush decrease (FD) of January 17–18 and 21–22, 2005. It was shown that the corresponding recovery time can depend on the density of high-energy protons in the CME matter. In this paper we identified several additional events in the period between 1995 and 2007. We found that the majority of FDs studied is accompanied by an abrupt count increase in the proton channel P1 and by a simultaneous decrease in the channel P7 (GOES). However, the analysis of temporal evolution of all FDs did not confirm the hypothesis on different recovery time after FD as a function of the energy distribution of the particles penetrating into radiation belts of the Earth. [ABSTRACT FROM PUBLISHER]

Published
2008
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32. Galactic secondary positron flux at the Earth

Author

Roberto A. Lineros, Nicolao Fornengo, Timur Delahaye, Pierre Salati, Julien Lavalle, Richard Taillet, Fiorenza Donato, Laboratoire d'Annecy-le-Vieux de Physique Théorique (LAPTH), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Istituto Nazionale di Fisica Nucleare, Sezione di Torino (INFN, Sezione di Torino), Istituto Nazionale di Fisica Nucleare (INFN), Dipartimento di Fisica Teorica, Dipartimento di Fisica Università di Torino and INFN (DF_TORINO), and Dipartimento di Fisica infi & Università di Torino

Subjects
ISM: cosmic rays, [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Astrophysics::High Energy Astrophysical Phenomena, Dark matter, FOS: Physical sciences, Flux, Cosmic ray, Astrophysics, Electron, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], High Energy Physics - Phenomenology (hep-ph), Positron, astro-ph, 0103 physical sciences, 010303 astronomy & astrophysics, Physics, Annihilation, 010308 nuclear & particles physics, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Astrophysics (astro-ph), Astronomy and Astrophysics, hep-ph, Galaxy, High Energy Physics - Phenomenology, Amplitude, 13. Climate action, Space and Planetary Science, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph]
Abstract

Secondary positrons are produced by spallation of cosmic rays within the interstellar gas. Measurements have been typically expressed in terms of the positron fraction, which exhibits an increase above 10 GeV. Many scenarios have been proposed to explain this feature, among them some additional primary positrons originating from dark matter annihilation in the Galaxy. The PAMELA satellite has provided high quality data that has enabled high accuracy statistical analyses to be made, showing that the increase in the positron fraction extends up to about 100 GeV. It is therefore of paramount importance to constrain theoretically the expected secondary positron flux to interpret the observations in an accurate way. We find the secondary positron flux to be reproduced well by the available observations, and to have theoretical uncertainties that we quantify to be as large as about one order of magnitude. We also discuss the positron fraction issue and find that our predictions may be consistent with the data taken before PAMELA. For PAMELA data, we find that an excess is probably present after considering uncertainties in the positron flux, although its amplitude depends strongly on the assumptions made in relation to the electron flux. By fitting the current electron data, we show that when considering a soft electron spectrum, the amplitude of the excess might be far lower than usually claimed. We provide fresh insights that may help to explain the positron data with or without new physical model ingredients. PAMELA observations and the forthcoming AMS-02 mission will allow stronger constraints to be aplaced on the cosmic--ray transport parameters, and are likely to reduce drastically the theoretical uncertainties., 15 pages, 12 figures. The recent PAMELA data on the positron fraction (arXiv:0810.4995) have been included and the ensuing discussion has been extended. Accepted version in A&A

Published
2015
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33. Clumpiness of dark matter and the positron annihilation signal

Author

Richard Taillet, Pierre Salati, Julien Lavalle, Jonathan Pochon, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy-le-Vieux de Physique Théorique (LAPTH), and Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)

Subjects
ISM: cosmic rays, Physics, [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Annihilation, 010308 nuclear & particles physics, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Astrophysics::High Energy Astrophysical Phenomena, Dark matter, Gamma ray, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, cosmology: dark matter, Galaxy: halo, Galactic halo, Positron, Space and Planetary Science, Antiproton, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Halo, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Energy (signal processing)
Abstract

International audience; Context: The small-scale distribution of dark matter in galactic halos is poorly known. Several studies suggest that it could be very clumpy, which is of paramount importance when investigating the annihilation signal from exotic particles (e.g. supersymmetric or Kaluza-Klein). Aims: We focus on the annihilation signal in positrons. We estimate the associated uncertainty, that is due to the fact that we do not know exactly how the clumps are distributed in the Galactic halo. Methods: We perform a statistical study based on analytical computations, as well as numerical simulations. We study the average and variance of the annihilation signal over many Galactic halos having the same statistical properties. Results: We find that the so-called boost factor used by many authors should be used with caution, as i) it depends on energy and ii) it may be different for positrons, antiprotons and gamma rays, a fact which has not been discussed before. As an illustration, we use our results to discuss the positron spectrum measurements by the HEAT experiment.

Published
2006
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34. Cosmic-ray induced diffusion in interstellar ices

Author

Juris Kalvans

Subjects
ism: cosmic rays, Astrochemistry, Hydrogen, Astronomy, Radical, chemistry.chemical_element, FOS: Physical sciences, QB1-991, Cosmic ray, Mantle (geology), ism: clouds, Molecule, ism: molecules, Cosmic dust, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), astrochemistry, Photodissociation, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, molecular processes, chemistry, Space and Planetary Science, Chemical physics, Astrophysics of Galaxies (astro-ph.GA), Astrophysics - High Energy Astrophysical Phenomena
Abstract

Cosmic rays are able to heat interstellar dust grains. This may enhance molecule mobility in icy mantles that have accumulated on the grains in dark cloud cores. A three-phase astrochemical model was used to investigate the molecule mobility in interstellar ices. Specifically, diffusion through pores in ice between the subsurface mantle and outer surface, assisted by whole-grain heating, was considered. It was found that the pores can serve as an efficient transport route for light species. The diffusion of chemical radicals from the mantle to the outer surface are most effective. These species accumulate in the mantle because of photodissociation by the cosmic-ray induced photons. The faster diffusion of hydrogen within the warm ice enhances the hydrogenation of radicals on pore surfaces. The overall result of the whole grain heating-induced radial diffusion in ice are higher abundances of ice species, whose synthesis involve light radicals. Examples of stable species synthesized this way include complex organic molecules, OCS, H

Published
2014
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36. Modeling the gamma-ray emission produced by runaway cosmic rays in the environment of RX J1713.7-3946

Author

Hiroaki Yamamoto, Toshikazu Onishi, David I. Jones, Kazufumi Torii, Akiko Kawamura, Gavin Rowell, Felix Aharonian, Sabrina Casanova, Hidetoshi Sano, Yasuo Fukui, Stefano Gabici, Max-Planck-Institut für Kernphysik (MPIK), Max-Planck-Gesellschaft, Dublin Institute for Advanced Studies (DIAS), Department of Astrophysics [Nagoya], Nagoya University, APC - Astrophysique des Hautes Energies (APC - AHE), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), School of Chemistry and Physics, University of Adelaide, Dipartimento di Astronomia, Universita degli Studi di Bologna, Università di Bologna [Bologna] (UNIBO)-Università di Bologna [Bologna] (UNIBO)-AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Dipartimento di Astronomia, Universita degli Studi di Bologna, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO)-Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), and Gabici, Stefano

Subjects
ISM: cosmic rays, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, gamma rays: theory, ISM: clouds, 01 natural sciences, 7. Clean energy, [PHYS.HPHE] Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 13. Climate action, Space and Planetary Science, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ISM: supernova remnants
Abstract

Diffusive shock acceleration in supernova remnants is the most widely invoked paradigm to explain the Galactic cosmic ray spectrum. Cosmic rays escaping supernova remnants diffuse in the interstellar medium and collide with the ambient atomic and molecular gas. From such collisions gamma-rays are created, which can possibly provide the first evidence of a parent population of runaway cosmic rays. We present model predictions for the GeV to TeV gamma-ray emission produced by the collisions of runaway cosmic rays with the gas in the environment surrounding the shell-type supernova remnant RX J1713.7-3946. The spectral and spatial distributions of the emission, which depend upon the source age, the source injection history, the diffusion regime and the distribution of the ambient gas, as mapped by the LAB and NANTEN surveys, are studied in detail. In particular, we find for the region surrounding RX J1713-3946, that depending on the energy one is observing at, one may observe startlingly different spectra or may not detect any enhanced emission with respect to the diffuse emission contributed by background cosmic rays. This result has important implications for current and future gamma-ray experiments., Comment: version published on PASJ

Published
2010
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37. Study of the solar anisotropy of cosmic ray primaries of about 200 GeV energy with the L3+C muon detector

Author

Achard, P, Adriani, O, Aguilar-Benitez, M, van den Akker, M, Alcaraz, J, Alemanni, G, Allaby, J, Aloisio, A, Alviggi, M G, Anderhub, H, Andreev, Valery P, Anselmo, F, Arefev, A, Azemoon, T, Aziz, T, Bagnaia, P, Bajo, A, Baksay, G, Baksay, L, Bahr, J, Baldew, S V, Banerjee, S, Banerjee, Sw, Barczyk, A, Barillere, R, Bartalini, P, Basile, M, Batalova, N, Battiston, R, Bay, A, Becattini, F, Becker, U, Behner, F, Bellucci, L, Berbeco, R, Berdugo, J, Berges, P, Bertucci, B, Betev, B L, Biasini, M, Biglietti, M, Biland, A, Blaising, J J, Blyth, S C, Bobbink, G J, Bohm, A, Boldizsar, L, Borgia, B, Bottai, S, Bourilkov, D, Bourquin, M, Braccini, S, Branson, J G, Brochu, F, Burger, J D, Burger, W J, Cai, X D, Capell, M, Cara Romeo, G, Carlino, G, Cartacci, A, Casaus, J, Cavallari, F, Cavallo, N, Cecchi, C, Cerrada, M, Chamizo, M, Chiarusi, T, Chang, Y H, Chemarin, M, Chen, A, Chen, G, Chen, G M, Chen, H F, Chen, H S, Chiefari, G, Cifarelli, L, Cindolo, F, Clare, I, Clare, R, Coignet, G, Colino, N, Costantini, S, de la Cruz, B, Cucciarelli, S, van Dalen, J, de Asmundis, R, Deglon, P, Debreczeni, J, Degre, A, Dehmelt, K, Deiters, K, della Volpe, D, Delmeire, E, Denes, P, DeNotaristefani, F, De Salvo, A, Diemoz, M, Dierckxsens, M, Ding, L K, Dionisi, C, Dittmar, M, Doria, A, Dova, M T, Duchesneau, D, Duda, M, Duran, I, Echenard, B, Eline, A, El Hage, A, El Mamouni, H, Engler, A, Eppling, F J, Extermann, P, Faber, G, Falagan, M A, Falciano, S, Favara, A, Fay, J, Fedin, O, Felcini, M, Ferguson, T, Fesefeldt, H, Fiandrini, E, Field, J H, Filthaut, F, Fisher, W, Fisk, I, Forconi, G, Freudenreich, K, Furetta, C, Galaktionov, Iouri, Ganguli, S N, Garcia-Abia, Pablo, Gataullin, M, Gentile, S, Giagu, S, Gong, Z F, Grabosch, H J, Grenier, G, Grimm, O, Groenstege, H, Gruenewald, M W, Guida, M, Guo, Y N, Gupta, S, Gupta, V K, Gurtu, A, Gutay, L J, Haas, D, Haller, Ch, Hatzifotiadou, D, Hayashi, Y, He, Z X, Hebbeker, T, Herve, Alain, Hirschfelder, J, Hofer, H, Hohlmann, M, Holzner, G, Hou, 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Naumov, V, Natale, S, Napolitano, M, Nessi Tedaldi, F, Newman, H, Nisati, A, Novak, T, Nowak, H, Ofierzynski, R, Organtini, G, Pal, I, Palomares, C, Paolucci, P, Paramatti, R, Parriaud, J, Passaleva, G, Patricelli, S, Paul, T, Pauluzzi, M, Paus, C, Pauss, F, Pedace, M, Pensotti, S, Perret Gallix, D, Petersen, B, Piccolo, D, Pierella, F, Pieri, M, Pioppi, M, Piroué, P, Pistolesi, E, Plyaskin, V, Pohl, M, Pojidaev, V, Pothier, J, Prokofiev, D, Qing, C, Rahal Callot, G, Rahaman, M, Raics, P, Raja, N, Ramelli, R, Rancoita, P, Ranieri, R, Raspereza, A, Ravindran, K, Razis, P, Rembeczki, S, Ren, D, Rescigno, M, Reucroft, S, Rewiersma, P, Riemann, S, Riles, K, Roe, B, Rojkov, A, Romero, L, Rosca, A, Rosier Lees, S, Roth, S, Rubio, J, Ruggiero, G, Rykaczewski, H, Saidi, R, Sakharov, A, Saremi, S, Sarkar, S, Salicio, J, Sanchez, E, Schäfer, C, Schegelsky, V, Schmitt, V, Schoeneich, B, Schopper, H, Schotanus, D, Sciacca, C, Servoli, L, Shen, C, Shevchenko, S, Shivarov, N, Shoutko, V, Shumilov, 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de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), CMS, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), L3, P.ACHARD, O.ADRIANI, M.AGUILAR-BENITEZ, M.VAN DEN AKKER, J.ALCARAZ, G.ALEMANNI, J.ALLABY, A.ALOISIO, M.G.ALVIGGI, H.ANDERHUB, V.P.ANDREEV, F.ANSELMO, A.AREFIEV, T.AZEMOON, T.AZIZ, P.BAGNAIA, A.BAJO, G.BAKSAY, L.BAKSAY, J.BAHR, S.V.BALDEW, S.BANERJEE, SW.BANERJEE, A.BARCZYK, R.BARILLERE, P.BARTALINI, M.BASILE, N.BATALOVA, R.BATTISTON, A.BAY, F.BECATTINI, U.BECKER, F.BEHNER, L.BELLUCCI, R.BERBECO, J.BERDUGO, P.BERGES, B.BERTUCCI, B.L.BETEV, M.BIASINI, M.BIGLIETTI, A.BILAND, J.J.BLAISING, S.C.BLYTH, G.J.BOBBINK, A.BOHM, L.BOLDIZSAR, B.BORGIA, S.BOTTAI, D.BOURILKOV, M.BOURQUIN, S.BRACCINI, J.G.BRANSON, F.BROCHU, J.D.BURGER, W.J.BURGER, X.D.CAI, M.CAPELL, G.CARA ROMEO, G.CARLINO, A.CARTACCI, J.CASAUS, F.CAVALLARI, N.CAVALLO, C.CECCHI, M.CERRADA, M.CHAMIZO, Y.H.CHANG, M.CHEMARIN, A.CHEN, G.CHEN, G.M.CHEN, H.F.CHEN, H.S.CHEN, T.CHIARUSI, G.CHIEFARI, L.CIFARELLI, F.CINDOLO, I.CLARE, R.CLARE, G.COIGNET, N.COLINO, S.COSTANTINI, B.DE LA CRUZ, S.CUCCIARELLI, R.DE ASMUNDIS, P.DEGLON, J.DEBRECZENI, A.DEGRE, K.DEHMELT, K.DEITERS, D.DELLA VOLPE, E.DELMEIRE, P.DENES, F.DENOTARISTEFANI, A.DE SALVO, M.DIEMOZ, M.DIERCKXSENS, L.K.DING, C.DIONISI, M.DITTMAR, A.DORIA, M.T.DOVA, D.DUCHESNEAU, M.DUDA, I.DURAN, B.ECHENARD, A.ELINE, H.EL MAMOUNI, A.ENGLER, F.J.EPPLING, P.EXTERMANN, G.FABER, M.A.FALAGAN, S.FALCIANO, A.FAVARA, J.FAY, O.FEDIN, M.FELCINI, T.FERGUSON, E.FIANDRINI, J.H.FIELD, F.FILTHAUT, W.FISHER, G.FORCONI, K.FREUDENREICH, C.FURETTA, YU.GALAKTIONOV, S.N.GANGULI, P.GARCIA-ABIA, M.GATAULLIN, S.GENTILE, S.GIAGU, Z.F.GONG, H.J.GRABOSCH, G.GRENIER, O.GRIMM, H.GROENSTEGE, M.W.GRUENEWALD, Y.N.GUO, S.GUPTA, V.K.GUPTA, A.GURTU, L.J.GUTAY, D.HAAS, CH.HALLER, D.HATZIFOTIADOU, Y.HAYASHI, Z.X.HE, T.HEBBEKER, A.HERVE, J.HIRSCHFELDER, H.HOFER, H.HOFER JUN., M.HOHLMANN, G.HOLZNER, S.R.HOU, A.X.HUO, N.ITO, B.N.JIN, P.JINDAL, C.L.JING, L.W.JONES, P.DE JONG, I.JOSA-MUTUBERRIA, V.KANTSEROV, M.KAUR, S.KAWAKAMI, M.N.KIENZLE-FOCACCI, J.K.KIM, J.KIRKBY, W.KITTEL, A.KLIMENTOV, A.C.KOENIG, E.KOK, A.KORN, M.KOPAL, V.KOUTSENKO, M.KRABER, H.H.KUANG, R.W.KRAEMER, A.KRUGER, J.KUIJPERS, A.KUNIN, P.LADRON DE GUEVARA, I.LAKTINEH, G.LANDI, M.LEBEAU, A.LEBEDEV, P.LEBRUN, P.LECOMTE, P.LECOQ, P.LE COULTRE, J.M.LE GOFF, Y.LEI, H.LEICH, R.LEISTE, M.LEVTCHENKO, P.LEVTCHENKO, C.LI, L.LI, Z.C.LI, S.LIKHODED, C.H.LIN, W.T.LIN, F.L.LINDE, L.LISTA, Z.A.LIU, W.LOHMANN, E.LONGO, Y.S.LU, C.LUCI, L.LUMINARI, W.LUSTERMANN, W.G.MA, X.H.MA, Y.Q.MA, L.MALGERI, A.MALININ, C.MANA, J.MANS, J.P.MARTIN, F.MARZANO, K.MAZUMDAR, R.R.MCNEIL, S.MELE, X.W.MENG, L.MEROLA, M.MESCHINI, W.J.METZGER, A.MIHUL, A.VAN MIL, H.MILCENT, G.MIRABELLI, G.B.MOHANTY, B.MONTELEONI, G.S.MUANZA, A.J.M.MUIJS, M.MUSY, S.NAGY, R.NAHNHAUER, V.A.NAUMOV, S.NATALE, M.NAPOLITANO, F.NESSI-TEDALDI, H.NEWMAN, A.NISATI, T.NOVAK, H.NOWAK, R.OFIERZYNSKI, G.ORGANTINI, I.PAL, C.PALOMARES, P.PAOLUCCI, R.PARAMATTI, J.-F.PARRIAUD, G.PASSALEVA, S.PATRICELLI, T.PAUL, M.PAULUZZI, C.PAUS, F.PAUSS, M.PEDACE, S.PENSOTTI, D.PERRET-GALLIX, B.PETERSEN, D.PICCOLO, F.PIERELLA, M.PIERI, M.PIOPPI, P.A.PIROUE, E.PISTOLESI, V.PLYASKIN, M.POHL, V.POJIDAEV, J.POTHIER, D.PROKOFIEV, C.R.QING, G.RAHAL-CALLOT, M.A.RAHAMAN, P.RAICS, N.RAJA, R.RAMELLI, P.G.RANCOITA, R.RANIERI, A.RASPEREZA, K.C.RAVINDRAN, P.RAZIS, S.REMBECZKI, D.REN, M.RESCIGNO, S.REUCROFT, P.REWIERSMA, S.RIEMANN, K.RILES, B.P.ROE, A.ROJKOV, L.ROMERO, A.ROSCA, S.ROSIER-LEES, S.ROTH, J.A.RUBIO, G.RUGGIERO, H.RYKACZEWSKI, R.SAIDI, A.SAKHAROV, S.SAREMI, S.SARKAR, J.SALICIO, E.SANCHEZ, C.SCHAFER, V.SCHEGELSKY, V.SCHMITT, B.SCHOENEICH, H.SCHOPPER, D.J.SCHOTANUS, C.SCIACCA, L.SERVOLI, C.Q.SHEN, S.SHEVCHENKO, N.SHIVAROV, V.SHOUTKO, E.SHUMILOV, A.SHVOROB, D.SON, C.SOUGA, P.SPILLANTINI, M.STEUER, D.P.STICKLAND, B.STOYANOV, A.STRAESSNER, K.SUDHAKAR, H.SULANKE, G.SULTANOV, L.Z.SUN, H.SUTER, J.D.SWAIN, Z.SZILLASI, X.W.TANG, P.TARJAN, L.TAUSCHER, L.TAYLOR, B.TELLILI, D.TEYSSIER, C.TIMMERMANS, SAMUEL C.C.TING, S.M.TING, S.C.TONWAR, J.TOTH, G.TROWITZSCH, C.TULLY, K.L.TUNG, J.ULBRICHT, M.UNGER, E.VALENTE, H.VERKOOIJEN, R.T.VAN DE WALLE, R.VASQUEZ, G.VESZTERGOMBI, I.VETLITSKY, G.VIERTEL, M.VIVARGENT, S.VLACHOS, I.VODOPIANOV, H.VOGEL, H.VOGT, I.VOROBIEV, A.A.VOROBYOV, M.WADHWA, R.G.WANG, Q.WANG X.L.WANG, X.W.WANG, Z.M.WANG, M.WEBER, R.VAN WIJK, T.A.M.WIJNEN, H.WILKENS, S.WYNHOFF, L.XIA, Y.P.XU, J.S.XU, Z.Z.XU, J.YAMAMOTO, B.Z.YANG, C.G.YANG, H.J.YANG, M.YANG, X.F.YANG, Z.G.YAO, S.C.YEH, Z.Q.YU, AN.ZALITE, YU.ZALITE, C.ZHANG, F.ZHANG, J.ZHANG, S.ZHANG, Z.P.ZHANG, J.ZHAO, S.J.ZHOU, G.Y.ZHU, R.Y.ZHU, Q.Q.ZHU, H.L.ZHUANG, A.ZICHICHI, B.ZIMMERMANN, M.ZOELLER, A.N.M.ZWART., P., Achard, Aloisio, Alberto, Alviggi, Mariagrazia, Chiefari, Giovanni, DELLA VOLPE, Domenico, Merola, Leonardo, Napolitano, Marco, Patricelli, Sergio, Sciacca, Crisostomo, Achard, Pablo, Bourquin, Maurice, Braccini, Saverio, Chamizo Llatas, Maria, Deglon, Patrick, Delmeire, Evelyne, Echenard, Bertrand, Extermann, Pierre, Field, John, Kienzle, Maria-Novella, Natale, Sonia, Pohl, Martin, and Straessner, Arno

Subjects
ISM: cosmic rays, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, L3+C, Cosmic Rays, Cosmic ray, Context (language use), Astrophysics, ddc:500.2, Sun: solar wind, 01 natural sciences, 7. Clean energy, law.invention, FIS/05 - ASTRONOMIA E ASTROFISICA, plasmas, sun : magnetic fields, Sun : solar wind, interplanetary, medium, ISM : cosmic rays, Astronomy & Astrophysics, law, Solar wind(sun), Magnetic fields(sun), 0103 physical sciences, cosmic rays [ISM], [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], 010306 general physics, Anisotropy, Collider, 010303 astronomy & astrophysics, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Sun: magnetic fields, Ciencias Exactas, Physics, Large Hadron Collider, Muon, Isotropy, Astronomy and Astrophysics, solar wind [Sun], magnetic fields [Sun], Space and Planetary Science, Sidereal time, Plasmas, Experimental High Energy Physics, ddc:520, High Energy Physics::Experiment, Particle Physics - Experiment, FIS/04 - FISICA NUCLEARE E SUBNUCLEARE, Interplanetary medium
Abstract

Context. Primary cosmic rays experience multiple deflections in the non-uniform galactic and heliospheric magnetic fields which may generate anisotropies. Aims. A study of anisotropies in the energy range between 100 and 500 GeV is performed. This energy range is not yet well explored. Methods. The L3 detector at the CERN electron-positron collider, LEP, is used for a study of the angular distribution of atmospheric muons with energies above 20 GeV. This distribution is used to investigate the isotropy of the time-dependent intensity of the primary cosmic-ray flux with a Fourier analysis. Results. A small deviation from isotropy at energies around 200 GeV is observed for the second harmonics at the solar frequency. No sidereal anisotropy is found at a level above 10-4 . The measurements were performed in the years 1999 and 2000., La lista completa de autores que integran el documento puede consultarse en el archivo., Facultad de Ciencias Exactas

Published
2008
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38. Clumpiness of Dark Matter and Positron Annihilation Signal: Computing the odds of the Galactic Lottery

Author

Lavalle, Julien, Pochon, Jonathan, Salati, Pierre, Taillet, Richard, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy-le-Vieux de Physique Théorique (LAPTH), and Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)

Subjects
ISM: cosmic rays, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Cosmology: dark matter, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics, Galaxy: halo
Abstract

The small-scale distribution of dark matter in Galactic halos is poorly known. Several studies suggest that it could be very clumpy, which turns out to be of paramount importance when investigating the annihilation signal from exotic particles (e.g. supersymmetric or Kaluza-Klein). In this paper we focus on the annihilation signal in positrons. We estimate the associated uncertainty, due to the fact that we do not know exactly how the clumps are distributed in the Galactic halo. To this aim, we perform a statistical study based on analytical computations, as well as numerical simulations. In particular, we study the average and variance of the annihilation signal over many Galactic halos having the same statistical properties. We find that the so-called boost factor used by many authors should be handled with care, as i) it depends on energy and ii) it may be different for positrons, antiprotons and gamma rays, a fact which has not received any attention before. As an illustration, we use our results to discuss the positron spectrum measurements by the HEAT experiment., Comment: 31 pages, 12 figures, accepted in A&A

Published
2007
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39. Observation of VHE Gamma Radiation from HESS J1834-087/W41 with the MAGIC Telescope

Author

Albert, J, Aliu, E, Anderhub, H, Antoranz, P, Armada, A, Asensio, M, Baixeras, C, Barrio, Ja, Bartelt, M, Bartko, H, Bastieri, D, Bavikadi, Sr, Bednarek, W, Berger, K, Bigongiari, C, Biland, A, Bisesi, E, Bock, Rk, Bordas, P, Bosch Ramon, V, Bretz, T, Britvitch, I, Camara, M, Carmona, E, Chilingarian, A, Ciprini, S, Coarasa, Ja, Commichau, S, Contreras, Jl, Cortina, J, Curtef, V, Dame, Tm, Danielyan, V, Dazzi, F, DE ANGELIS, Alessandro, Reyes, Rdl, DE LOTTO, Barbara, Domingo Santamari, E, Dorner, D, Doro, M, Errando, M, Fagiolini, M, Ferenc, D, Fernandez, E, Firpo, R, Flix, J, Fonseca, Mv, Font, L, Fuchs, M, Galante, N, Garczarczyk, M, Gaug, M, Giller, M, Goebel, F, Hakobyan, D, Hayashida, M, Hengstebeck, T, Hohne, D, Hose, J, Hsu, Cc, Isar, Pg, Jacon, P, Kalekin, O, Kasyra, R, Kranich, D, Laatiaoui, M, Laille, A, Lenisa, T, Liebing, P, Lindfors, E, Lombardi, S, Longo, F, Lopez, J, Lopez, M, Lorenz, E, Lucarelli, F, Majumdar, P, Maneva, G, Mannheim, K, Mansutti, O, Mariotti, M, Martinez, M, Mase, K, Mazin, D, Merck, C, Meucci, M, Meyer, M, Miranda, Jm, Mirzoyan, R, Mizobuchi, S, Moralejo, A, Nilsson, K, Ona Wilhelmi, E, Orduna, R, Otte, N, Oya, I, Paneque, D, Paoletti, R, Paredes, Jm, Pasanen, M, Pascoli, D, Pauss, F, Pavel, N, Pegna, R, Persic, M, Peruzzo, L, Piccioli, A, Poller, M, Prandini, E, Raymers, A, Rico, J, Rhode, W, Ribo, M, Riegel, B, Rissi, M, Robert, A, Rugamer, S, Saggion, A, Sanchez, A, Sartori, P, Scalzotto, V, Scapin, V, Schmitt, R, Schweizer, T, Shayduk, M, Shinozaki, K, Shore, Sn, Sidro, N, Sillanpaa, A, Sobczynska, D, Stamerra, A, Stark, Ls, Takalo, L, Temnikov, P, Tescaro, D, Teshima, M, Tonello, N, Torres, A, Torres, Df, Turini, N, Vankov, H, Vitale, V, Wagner, Rm, Wibig, T, Wittek, W, Zanin, R, Zapatero, J., J., Albert, E., Aliu, H., Anderhub, P., Antoranz, A., Armada, M., Asensio, C., Baixera, J. A., Barrio, M., Bartelt, H., Bartko, D., Bastieri, S. R., Bavikadi, W., Bednarek, K., Berger, C., Bigongiari, A., Biland, E., Bisesi, R. K., Bock, P., Borda, V., Bosch Ramon, T., Bretz, I., Britvitch, M., Camara, E., Carmona, A., Chilingarian, S., Ciprini, J. A., Coarasa, S., Commichau, J. L., Contrera, J., Cortina, V., Curtef, T. M., Dame, V., Danielyan, F., Dazzi, Angelis, A., Los, R., Lotto, B., E., Domingo Santamar\i, D., Dorner, M., Doro, M., Errando, M., Fagiolini, D., Ferenc, E., Fernandez, R., Firpo, J., Flix, M. V., Fonseca, L., Font, M., Fuch, N., Galante, M., Garczarczyk, M., Gaug, M., Giller, F., Goebel, D., Hakobyan, M., Hayashida, T., Hengstebeck, D., H\ohne, J., Hose, C. C., Hsu, P. G., Isar, P., Jacon, O., Kalekin, R., Kasyra, D., Kranich, M., Laatiaoui, A., Laille, T., Lenisa, P., Liebing, E., Lindfor, S., Lombardi, Longo, Francesco, J., Lopez, M., Lopez, E., Lorenz, F., Lucarelli, P., Majumdar, G., Maneva, K., Mannheim, O., Mansutti, M., Mariotti, M., Mart\inez, K., Mase, D., Mazin, C., Merck, M., Meucci, M., Meyer, J. M., Miranda, R., Mirzoyan, S., Mizobuchi, A., Moralejo, K., Nilsson, E., O\~na Wilhelmi, R., Ordu\~na, N., Otte, I., Oya, D., Paneque, R., Paoletti, J. M., Parede, M., Pasanen, D., Pascoli, F., Pau, N., Pavel, R., Pegna, M., Persic, L., Peruzzo, A., Piccioli, M., Poller, E., Prandini, A., Raymer, J., Rico, W., Rhode, M., Ribo, B., Riegel, M., Rissi, A., Robert, S., R\ugamer, A., Saggion, A., Sanchez, P., Sartori, V., Scalzotto, V., Scapin, R., Schmitt, T., Schweizer, M., Shayduk, K., Shinozaki, S. N., Shore, N., Sidro, A., Sillanp\a\a, D., Sobczynska, A., Stamerra, L. S., Stark, L., Takalo, P., Temnikov, D., Tescaro, M., Teshima, N., Tonello, A., Torre, D. F., Torre, N., Turini, H., Vankov, V., Vitale, R. M., Wagner, T., Wibig, W., Wittek, R., Zanin, and J., Zapatero

Subjects
ISM: cosmic rays, Observation [Gamma Rays], Astrophysics::High Energy Astrophysical Phenomena, Flux, FOS: Physical sciences, Gamma Rays: Observations, ISM: Supernova Remnants, Astrophysics, Radiation, Power law, Supernova Remnants [ISM], Superposition principle, Raigs gamma, Coincident, MAGIC (telescope), Astrophysics::Galaxy Astrophysics, supernova remnants, Physics, Molecular cloud, Gamma rays, Astrophysics (astro-ph), observations [gamma rays], Astronomy and Astrophysics, Galactic plane, Space and Planetary Science, Electrónica, Física nuclear, Electricidad
Abstract

Recently, the HESS array has reported the detection of gamma-ray emission above a few hundred GeV from eight new sources located close to the Galactic Plane. The source HESS J1834-087 is spatially coincident with SNR G23.3-0.3 (W41). Here we present MAGIC observations of this source, resulting in the detection of a differential gamma-ray flux consistent with a power law, described as dN/(dA dt dE) = (3.7 +/- 0.6)*10^(-12) (E/TeV)^(-2.5 +/- 0.2) \ cm^(-2)s^(-1)TeV^(-1). We confirm the extended character of this flux. We briefly discuss the observational technique used, the procedure implemented for the data analysis, and put this detection in the perspective of the molecular environment found in the region of W41. We present 13CO and 12CO emission maps showing the existence of a massive molecular cloud in spatial superposition with the MAGIC detection., Comment: Accepted by ApJ Letters

Published
2006
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40. Origin of Thermal and Non-Thermal Hard X-Ray Emissionfrom the Galactic Center

Author

Dogiel, Vladimir A., Chernyshov, Dmitry, Yuasa, Takayuki, Prokhorov, Dmitry, Cheng, Kwong-Sang, Bamba, Aya, Inoue, Hajime, Ko, Chung-Ming, Kokubun, Motohide, Maeda, Yoshitomo, Mitsuda, Kazuhisa, Nakazawa, Kazuhiro, Yamasaki, Noriko, Dogiel, Vladimir A., Chernyshov, Dmitry, Yuasa, Takayuki, Prokhorov, Dmitry, Cheng, Kwong-Sang, Bamba, Aya, Inoue, Hajime, Ko, Chung-Ming, Kokubun, Motohide, Maeda, Yoshitomo, Mitsuda, Kazuhisa, Nakazawa, Kazuhiro, and Yamasaki, Noriko

Abstract

We analyse new results of Chandra and Suzaku Observatories which found a flux of hard X-ray emission from the compact region around Sgr A∗ (r ∼ 100 pc). We suppose that this emission is generated by accretion processes onto the central supermassive blackhole when an unbound part of captured stars obtains an additional momentum. As a result a flux of subrelativistic protons is generated near the galactic center which heats the background plasma up to temperatures about 6–10 keV and produces by inverse bremsstrahlung a flux of non-thermal X-ray emission in the energy range above 10 keV.

Published
2009
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41. Morphology of synchrotron emission in young supernova remnants

Author

Anne Decourchelle, Jean Ballet, Gamil Cassam-Chenai, Donald C. Ellison, Department of Physics, North Carolina State University [Raleigh] (NC State), University of North Carolina System (UNC)-University of North Carolina System (UNC), Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
ISM: cosmic rays, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Electron, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 0103 physical sciences, Radiative transfer, 010306 general physics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, acceleration of particles, ISM: supernova remnants, Physics, Shock (fluid dynamics), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics (astro-ph), Astronomy and Astrophysics, X-rays: ISM, Magnetic field, Synchrotron emission, Supernova, Discontinuity (linguistics), Space and Planetary Science
Abstract

In the framework of test-particle and cosmic-ray modified hydrodynamics, we calculate synchrotron emission radial profiles in young ejecta-dominated supernova remnants (SNRs) evolving in an ambient medium which is uniform in density and magnetic field. We find that, even without any magnetic field amplification by Raleigh-Taylor instabilities, the radio synchrotron emission peaks at the contact discontinuity because the magnetic field is compressed and is larger there than at the forward shock. The X-ray synchrotron emission sharply drops behind the forward shock as the highest energy electrons suffer severe radiative losses., 8 pages, 6 figures, Accepted for publication in A&A

Published
2005

42. G337.2+0.1: a new X-ray supernova remnant?

Author

Paula Benaglia, Mutsumi Sugizaki, Jorge Ariel Combi, and Gustavo E. Romero

Subjects
ISM: cosmic rays, Ciencias Astronómicas, Supernova remnants, Ciencias Físicas, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, purl.org/becyt/ford/1 [https], cosmic rays [ISM], AX J1635.9-4719 (estronomía), Radio continuum: ISM, ISM [X-rays], Radiative mechanisms, Supernova remnant, individuals: AX J1635.9-4719 [X-ray], Cosmic rays, Astrophysics::Galaxy Astrophysics, ISM: supernova remnants, Physics, Non thermal mechanisms, Line-of-sight, Spiral galaxy, X rays, supernova remnants [ISM], Astrophysics (astro-ph), X-ray, Astronomy and Astrophysics, purl.org/becyt/ford/1.3 [https], G337.2+0.1 (astronomía), Radiación cósmica, Radiative mechanism: non-thermal, ISM [Radio continuum], X-rays: ISM, Astronomía, Radio continuum, Space and Planetary Science, X-ray: individuals: AX J1635.9-4719, non-thermal [Radiative mechanism], CIENCIAS NATURALES Y EXACTAS
Abstract

We present evidence supporting a SNR origin for the radio source G337.2+0.1, which was discovered along the line of sight to the Norma spiral arm in the MOST 843-MHz radio survey. The radio source is spatially superposed to the unidentified ASCA source AX J1635.9-4719. An analysis of this latter source reveals that its X-ray spectrum, extended nature, and non-variable flux are consistent with what is expected for a SNR. In addition, we have used HI-line observations of the region to look for any effect of the presumed remnant on the ISM. We have found a well-defined minimum centered at the position of the radio source in the velocity range of ~ -25 to -19 km s-1. This feature appears as a sharp absorption dip in the spectrum that might be produced when the continuum emission from the SNR candidate is absorbed by foreground gas. Hence we have used it to constrain the distance to the source, which seems to be a young (age ~ a few 103 yr) and distant (d ~ 14 kpc) SNR. G337.2+0.1 and AX J1635.9-4719 would be the radio/X-ray manifestations of this remnant., Facultad de Ciencias Astronómicas y Geofísicas, Instituto Argentino de Radioastronomía

Published
2005

43. Supernova remnant evolution in uniform and non-uniform media

Author

10713158 - Ferreira, Stephanus Esaias Salomon, 10065857 - De Jager, Ocker Cornelis, Ferreira, S.E.S., De Jager, O.C., 10713158 - Ferreira, Stephanus Esaias Salomon, 10065857 - De Jager, Ocker Cornelis, Ferreira, S.E.S., and De Jager, O.C.

Published
2008

44. The lithium isotope ratio in the metal-poor halo star G271-162 from VLT/UVES observations

Author

Nissen, P.E, Asplund, Martin, Hill, V, D'Odorico, S, Nissen, P.E, Asplund, Martin, Hill, V, and D'Odorico, S

Abstract

A high resolution (lambda /Delta lambda =~ 110 000), very high S/N (>~ 600) spectrum of the metal-poor turnoff star G 271-162 has been obtained in connection with the commissioning of UVES at VLT/Kueyen. Using both 1D hydrostatic and 3D hydrodynamical model atmospheres, the lithium isotope ratio has been estimated from the \ion{Li}{i},670.8 nm line by means of spectral synthesis. The necessary stellar line broadening (1D: macroturbulence + rotation, 3D: rotation) has been determined from unblended \ion{K}{i}, \ion{Ca}{i} and \ion{Fe}{i} lines. The 3D line profiles agree very well with the observed profiles, including the characteristic line asymmetries. Both the 1D and 3D analyses reveal a possible detection of \element[][6]{Li} in G 271-162, element [][6]{Li}/element [][7]{Li} = 0.02+/-0.01 (1sigma ). It is discussed if the smaller amount of \element[][6]{Li} in G 271-162 than in the similar halo star HD 84937 could be due to differences in stellar mass and/or metallicity or whether it may reflect an intrinsic scatter of \element[][6]{Li}/\element[][7]{Li} in the ISM at a given metallicity. Based on public data released from the UVES commissioning at the VLT/Kueyen telescope, ESO, Paranal, Chile.

Published
2000

45. Measurement of the positron to electron ratio in the cosmic rays above 5 GeV RID G-6769-2011

Author

Golden, R, Stochaj, S, Stephens, S, Aversa, F, Barbiellini, G, Boezio, M, Bravar, U, Colavita, A, Fratnik, F, Schiavon, P, Vacchi, A, Zampa, N, Mitchell, J, Ormes, J, Streitmatter, R, Bellotti, R, Cafagna, F, Castellano, M, Circella, M, Decataldo, G, Demarzo, C, Giglietto, N, Marangelli, B, Raino, A, Spinelli, P, Bocciolini, M, Finetti, N, Papini, P, Perego, A, Piccardi, S, Spillantini, P, Basini, G, Brancaccio, F, Ricci, M, Codino, A, Grimani, C, Menichelli, M, Bidoli, V, Candusso, M, Casolino, M, Depascale, M, Morselli, A, Picozza, P, Sparvoli, R, Hof, M, Menn, W, and Simon, M

Subjects
ELEMENTARY PARTICLES, ISM: COSMIC RAYS, ISM: COSMIC RAYS, ELEMENTARY PARTICLES, Settore FIS/04 - Fisica Nucleare e Subnucleare
Published
1996

46. Broad view on hard X-ray background emission of the Galaxy.

Author

Krivonos, Roman, Revnivtsev, Mikhail, Tsygankov, Sergey, Churazov, Eugene, and Sunyaev, Rashid

Abstract

The nature of the Galactic Ridge X-Ray Emission (GRXE) has been under scientific debate since its discovery more than 30 years ago. It is observed as extended emission along the Galactic disk. The question was: is GRXE truly diffuse or is it composed from a large number of unresolved point sources? Using near-infrared Galaxy maps measured with the DIRBE experiment and data from the INTEGRAL observatory, we show that the galactic background in the energy range 20-60 keV originates from the stellar population of the Galaxy, which is in contrast to the diffuse nature believed before (Krivonos et al., 2007). Here we show preliminary results of studying the transition region from hard X-rays to gamma diffuse background of the Galaxy, revealing the broad band picture of Galactic Background emission. [ABSTRACT FROM PUBLISHER]

Published
2009
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