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Transport in Astrophysics: VI. Ultra-High Energy Cosmic Rays
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作者 Lorenzo Zaninetti 《International Journal of Astronomy and Astrophysics》 2024年第1期65-84,共20页
Two new solutions of the homogeneous diffusion equation in 1D are derived in the presence of losses and a trigonometric profile for a profile of density. A simulation for the ankle in the energy distribution of cosmic... Two new solutions of the homogeneous diffusion equation in 1D are derived in the presence of losses and a trigonometric profile for a profile of density. A simulation for the ankle in the energy distribution of cosmic rays (CRs) is provided in the framework of the fine tuning of the involved parameters. A theoretical image for the overall diffusion of CRs in galactic coordinates is provided. 展开更多
关键词 cosmic rays Particle Diffusion Random Walks
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The 111-Years-Old Cosmic Ray Puzzle Has Been Solved?
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作者 Shlomo Dado Arnon Dar 《Journal of Modern Physics》 2024年第1期125-131,共7页
We show that recently multi-messenger astronomy has provided compelling evidence that the bulk of high energy cosmic rays (CRs) are produced by highly relativistic narrow jets of plasmoids launched in core collapse of... We show that recently multi-messenger astronomy has provided compelling evidence that the bulk of high energy cosmic rays (CRs) are produced by highly relativistic narrow jets of plasmoids launched in core collapse of stripped-envelope massive stars to neutron stars and stellar mass black holes. Such events produce also a visible GRB if the jet happens to point in our direction. This has been long advocated by the cannon ball (CB) model of high energy CRs and GRBs, but the evidence has been provided only recently by what were widely believed to be unrelated discoveries. They include the very recent discovery of a knee around TeV in the energy spectrum of high energy CR electrons, the peak photon energy in the “brightest of all time” GRB221009A, and the failure of IceCube to detect high energy neutrinos from GRBs, including GRB221009A. They were all predicted by the cannonball (CB) model of high energy CRs and GRBs long before they were discovered in observations, despite a negligible probability to occur by chance. 展开更多
关键词 cosmic rays Gamma ray Bursts Neutrino Bursts
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Injection Spectra of Different Species of Cosmic Rays from AMS-02, ACE-CRIS and Voyager-1
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作者 Xu Pan Qiang Yuan 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第11期7-13,共7页
Precise measurements of energy spectra of different cosmic ray(CR) species have been obtained in recent years, by particularly the AMS-02 experiment on the International Space Station. It has been shown that apparent ... Precise measurements of energy spectra of different cosmic ray(CR) species have been obtained in recent years, by particularly the AMS-02 experiment on the International Space Station. It has been shown that apparent differences exist in different groups of the primary CRs. However, it is not straightforward to conclude that the source spectra of different particle groups are different since they will experience different propagation processes(e.g., energy losses and fragmentations) either. In this work, we study the injection spectra of different nuclear species using the measurements from Voyager-1 outside the solar system, and ACR-CRIS and AMS-02 on the top of atmosphere, in a physical framework of CR transportation. Two types of injection spectra are assumed, the broken power-law(BPL) form and the non-parametric spline interpolation form. The non-parametric form fits the data better than the BPL form, implying that potential structures beyond the constrained spectral shape of BPL may exist. For different nuclei the injection spectra are overall similar in shape but do show some differences among each other. For the non-parametric spectral form, the helium injection spectrum is the softest at low energies and the hardest at high energies. For both spectral shapes, the low-energy injection spectrum of neon is the hardest among all these species, and the carbon and oxygen spectra have more prominent bumps in 1–10 GV in the R2 d N dRpresentation.Such differences suggest the existence of differences in the sources or acceleration processes of various nuclei of CRs. 展开更多
关键词 (ISM:)cosmic rays acceleration of particles astroparticle physics
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The Role of Atmospheric Pressure, Temperature, and Humidity on Cosmic Ray Muons at a Low Latitude Station
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作者 Abdullrahman H. Maghrabi Safia A. Alzahrani Aied S. Alruhaili 《International Journal of Astronomy and Astrophysics》 2023年第3期236-258,共23页
This study aimed to investigate the relationship between atmospheric conditions and cosmic ray (CR) muons using daily and monthly CR data collected by the KAAU muon detector in Jeddah, Saudi Arabia between 2007 and 20... This study aimed to investigate the relationship between atmospheric conditions and cosmic ray (CR) muons using daily and monthly CR data collected by the KAAU muon detector in Jeddah, Saudi Arabia between 2007 and 2012. Specifically, the study examined the effects of atmospheric pressure, air temperature, and relative humidity on CR muons at different time scales (annual, seasonal, and monthly). The results of the analysis revealed that atmospheric pressure and air temperature had a negative impact on CR muons, while relative humidity had a positive impact. Although air temperature and relative humidity had small mean values across all time scales, their coefficients varied significantly from month to month and season to season. In addition, the study conducted multivariable correlation analyses for each day, which showed that pressure coefficients had consistently negative mean values, while the temperature and humidity coefficients had varying effects, ranging from positive to negative values. The reasons for the variations in the coefficients are not yet fully understood, but the study proposed several possible terrestrial and extraterrestrial explanations. These findings provide important insights into the complex interactions between the Earth’s atmosphere and cosmic rays, which can contribute to a better understanding of the potential impacts of cosmic rays on the Earth’s climate and environment. 展开更多
关键词 cosmic rays Jeddah Atmospheric Effect High Rigidity MUONS
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Testing the effect of solar wind parameters and geomagnetic storm indices on Galactic cosmic ray flux variation with automatically-selected Forbush decreases 被引量:1
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作者 Jibrin Adejoh Alhassan Ogbonnaya Okike Augustine Ejikeme Chukwude 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第9期207-216,共10页
Forbush decrease(FD),discovered by Scott E.Forbush about 80 years ago,is referred to as the non-repetitive short-term depression in Galactic cosmic ray(GCR)flux,presumed to be associated with large-scale perturbations... Forbush decrease(FD),discovered by Scott E.Forbush about 80 years ago,is referred to as the non-repetitive short-term depression in Galactic cosmic ray(GCR)flux,presumed to be associated with large-scale perturbations in solar wind and interplanetary magnetic field(IMF).It is the most spectacular variability in the GCR intensity which appears to be the compass for investigators seeking solar-terrestrial relationships.The method of selection and validation of FD events is very important to cosmic ray(CR)scientists.We have deployed new computer software to determine the amplitude and timing of FDs from daily-averaged CR data at Oulu Neutron Monitor station.The code selected 230 FDs between 1998 and 2002.In an attempt to validate the new FD automated catalog,the relationship between the amplitude of FDs,and IMF,solar wind speed(SWS)and geomagnetic storm indices(Dst,kp,ap)is tested here.A two-dimensional regression analysis indicates significant linear relationship between large FDs(CR(%)≤-3)and solar wind data and geomagnetic storm indices in the present sample.The implications of the relationship among these parameters are discussed. 展开更多
关键词 methods:data analysis methods:statistical Sun:coronal mass ejections(CMEs) (Sun:)solar-terrestrial relations (Sun:)solar wind (ISM:)cosmic rays
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First Observations of Cosmic Ray Neutrons by a Mini Neutron Monitor at Riyadh, Saudi Arabia 被引量:1
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作者 Maghrabi Abdullrahman Aldosari Abdulah Altilasi Mohammed 《International Journal of Astronomy and Astrophysics》 2020年第4期319-333,共15页
In April 2017, a mini neutron monitor (NM) was installed at King Abdulaziz City for Science and Technology (KACST) central Saudi Arabia (Riyadh;cut-off rigidity, Rc = 14.4 Gv) for continuous observation of the cosmic ... In April 2017, a mini neutron monitor (NM) was installed at King Abdulaziz City for Science and Technology (KACST) central Saudi Arabia (Riyadh;cut-off rigidity, Rc = 14.4 Gv) for continuous observation of the cosmic ray (CR) neutrons. The detector was built as a major aspect of the international scientific joint effort between the Centre of Space Research (North-West University, Potchefstroom, South Africa) and KACST. The recorded data correspond to low energy neutrons that primarily have energies lower than 20 GeV. In this paper, a brief description about the mini NM detector will be given. The influence of atmospheric pressure on the recorded CR neutrons was studied and the barometric coefficient was calculated and used to eliminate the pressure effects from the measured data. The obtained coefficient was consistent with those previously obtained by several investigators. The daily variation of the CR neutron was studied and characterized. Short-term CR periodicities, such as the 27-day period, and its two harmonics, were identified. The obtained periodicities are in agreement with those reported by different researchers. The obtained results from this detector have been compared to the existing 1 m<sup>2</sup> scintillator detector showing comparable results. Long-term data from this detector will be of incredible significance to the research community to investigate several types of CR variations resulting from solar activity at such high cut off rigidity site. 展开更多
关键词 Mini Neutron Monitor cosmic ray Saudi Arabia PERIODICITIES
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The Accurate Mass Formulas of Leptons, Quarks, Gauge Bosons, the Higgs Boson, and Cosmic Rays 被引量:2
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作者 Ding-Yu Chung 《Journal of Modern Physics》 2016年第12期1591-1606,共16页
One of the biggest unsolved problems in physics is the particle masses of all elementary particles which cannot be calculated accurately and predicted theoretically. In this paper, the unsolved problem of the particle... One of the biggest unsolved problems in physics is the particle masses of all elementary particles which cannot be calculated accurately and predicted theoretically. In this paper, the unsolved problem of the particle masses is solved by the accurate mass formulas which calculate accurately and predict theoretically the particle masses of all leptons, quarks, gauge bosons, the Higgs boson, and cosmic rays (the knees-ankles-toe) by using only five known constants: the number (seven) of the extra spatial dimensions in the eleven-dimensional membrane, the mass of electron, the masses of Z and W bosons, and the fine structure constant. The calculated masses are in excellent agreements with the observed masses. For examples, the calculated masses of muon, top quark, pion, neutron, and the Higgs boson are 105.55 MeV, 175.4 GeV, 139.54 MeV, 939.43 MeV, and 126 GeV, respectively, in excellent agreements with the observed 105.65 MeV, 173.3 GeV, 139.57 MeV, 939.27 MeV, and 126 GeV, respectively. The mass formulas also calculate accurately the masses of the new particle at 750 GeV from the LHC and the new light boson at 17 MeV. The theoretical base of the accurate mass formulas is the periodic table of elementary particles. As the periodic table of elements is derived from atomic orbitals, the periodic table of elementary particles is derived from the seven principal mass dimensional orbitals and seven auxiliary mass dimensional orbitals. All elementary particles including leptons, quarks, gauge bosons, the Higgs boson, and cosmic rays can be placed in the periodic table of elementary particles. The periodic table of elementary particles is based on the theory of everything as the computer simulation model of physical reality consisting of the mathematical computation, digital representation and selective retention components. The computer simulation model of physical reality provides the seven principal mass dimensional orbitals and seven auxiliary mass dimensional orbitals for the periodic table of elementary particles. 展开更多
关键词 Mass Formulas Particle Masses LEPTONS QUARKS Gauge Bosons Higgs Boson cosmic rays The Periodic Table of Elementary Particles Computer Simulation Knees-Ankles-Toe The Theory of Everything
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KELEA, Cosmic Rays, Cloud Formation and Electromagnetic Radiation: Electropollution as a Possible Explanation for Climate Change 被引量:1
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作者 W. John Martin 《Atmospheric and Climate Sciences》 2016年第2期174-179,共6页
The basic premise of this article is that human generated electromagnetic radiation is contributing to global warming. It may do so by diverting an energy force termed KELEA (kinetic energy limiting electrostatic attr... The basic premise of this article is that human generated electromagnetic radiation is contributing to global warming. It may do so by diverting an energy force termed KELEA (kinetic energy limiting electrostatic attraction) from its presumed association with cosmic rays. Cosmic ray delivered KELEA is viewed as normally participating in the formation of cloud condensation nuclei (CCN). It may do so by transforming electrostatically inert particles into electrostatic aerosols capable of acting as CCN. The resulting clouds act as a reflective barrier to some of the infrared radiation from the sun and, thereby, reduce the earth’s heat. This article proposes that increasing levels of electromagnetic radiation in the atmosphere is reducing the capacity of cosmic rays to deliver adequate KELEA to maintain climate stability through optimal cloud formation. Specifically, the fluctuating electrical fields accompanying electromagnetic radiation may do so by competitively withdrawing some of the KELEA from the incoming cosmic rays. Previously described studies by Dr. Wilhelm Reich attributed to an energy force termed orgone, are consistent with weather activity being inducible using a device that likely delivers KELEA to the atmosphere. In addition to the foregoing consideration, there are many agricultural and industrial applications of KELEA activated fluids that can reduce carbon emissions. It is important that the scope of climate science be broadened to include a detailed understanding of KELEA and of its many potential practical applications in addressing global warming. 展开更多
关键词 Climate Change CLOUD cosmic rays Electromagnetic Radiation KELEA Orgone WATER Cell Phone
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Simulation study on cosmic ray background at large zenith angle based on GRANDProto35 coincidence array experiment
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作者 Xiang-Li Qian Xu Wang +2 位作者 Hui-Ying Sun Zhen Wang Olivier Martineau-Huynh 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2021年第1期35-45,共11页
Neutrino detection in the 100 PeV energy region is the ultimate means of studying the origin of ultra-highenergy cosmic rays,in which the large radio detection array giant radio array for neutrino detection(GRAND)proj... Neutrino detection in the 100 PeV energy region is the ultimate means of studying the origin of ultra-highenergy cosmic rays,in which the large radio detection array giant radio array for neutrino detection(GRAND)project aims to use to decipher this century-old problem.The GRANDProto35 compact array is a microform of 35 radio prototype detectors for the GRAND experiment,which verifies the reliability of GRAND performance through operation,and data analysis of the prototype detectors.As radio detectors are a novel development in recent years,and their indexes need to be verified by traditional detectors,the GRAND Cooperation Group designed and constructed the GRANDProto35 coincidence array composed of radio detectors and scintillation detectors.This study simulated the changes in detection efficiency,effective area,and event rate of cosmic rays with zenith angle based on this coincidence array.The study found that the 1017 eV energy region is sensitive to GRANDProto35 detection.When the energy exceeded 1017 eV,the array detection efficiency could reach more than 95%and the effective area was up to*29106 m2.A simulation study on cosmic ray events with large zenith angles showed that the event rate detected by the array decreased significantly with increasing zenith angle,and the event rate of cosmic rays was approximately 0.1 per day for a zenith angle of 75.This serves as the background pollution rate for neutrino observation caused by largeangle cosmic-ray events,providing an important reference for further experiments.The study results will be verified after the joint operation of the coincidence array. 展开更多
关键词 GRANDProto35 GEANT4 Scintillation detector cosmic ray
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Simulation of the Galactic Cosmic Ray Shadow of the Sun
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作者 Mohsin Saeed 查敏 曹臻 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第12期79-83,共5页
The cosmic-ray particles of TeV-regime, outside the solar system are blocked in their way to the Earth, a deficit of particles is observed corresponding to the location of the Sun known as the Sun shadow. The center o... The cosmic-ray particles of TeV-regime, outside the solar system are blocked in their way to the Earth, a deficit of particles is observed corresponding to the location of the Sun known as the Sun shadow. The center of the Sun shadow is shifted from its nominal position due to the presence of magnetic fields in interplanetary space,and this shift is used indirectly as a probe to study the solar magnetic field that is difficult to measure otherwise.A detailed Monte Carlo simulation of galactic cosmic-ray propagation in the Earth-Sun system is carried out to disentangle the cumulative effects of solar, interplanetary and geomagnetic fields. The shadowing effects and the displacements results of the Sun shadow in different solar activities are reproduced and discussed. 展开更多
关键词 Simulation of the Galactic cosmic ray Shadow of the Sun LHAASO IMF
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Investigation of the relation between space-weather parameters and Forbush decreases automatically selected from Moscow and Apatity cosmic ray stations during solar cycle 23
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作者 Jibrin Adejoh Alhassan Ogbonnaya Okike Augustine Ejikeme Chukwude 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第11期28-34,共7页
We present the results of an investigation of the relation between space-weather parameters and cosmic ray(CR)intensity modulation using algorithm-selected Forbush decreases(FDs)from Moscow(MOSC)and Apatity(APTY)neutr... We present the results of an investigation of the relation between space-weather parameters and cosmic ray(CR)intensity modulation using algorithm-selected Forbush decreases(FDs)from Moscow(MOSC)and Apatity(APTY)neutron monitor(NM)stations during solar cycle 23.Our FD location program detected 408 and 383 FDs from MOSC and APTY NM stations respectively.A coincident computer code employed in this work detected 229 FDs that were observed at the same Universal Time(UT)at the two stations.Out of the 229 simultaneous FDs,we formed a subset of 139 large FDs(%)≤-4 at the MOSC station.We performed a two-dimensional regression analysis between the FD magnitudes and the space-weather data on the two samples.We find that there were significant space-weather disturbances at the time of the CR flux depressions.The correlation between the space-weather parameters and decreases in galactic cosmic ray(GCR)intensity at the two NM stations is statistically significant.The implications of the present space-weather data on CR intensity depressions are highlighted. 展开更多
关键词 methods:data analysis methods:statistical Sun:coronal mass ejections(CMEs) (Sun:)solar terrestrial relations (Sun:)solar wind (ISM:)cosmic rays
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A machine learning method to separate cosmic ray electrons from protons from 10 to 100 GeV using DAMPE data
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作者 Hao Zhao Wen-Xi Peng +4 位作者 Huan-Yu Wang Rui Qiao Dong-Ya Guo Hong Xiao Zhao-Min Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2018年第6期99-108,共10页
DArk Matter Particle Explorer(DAMPE) is a general purpose high energy cosmic ray and gamma ray observatory, aiming to detect high energy electrons and gammas in the energy range 5 Ge V to 10 Te V and hundreds of Te V ... DArk Matter Particle Explorer(DAMPE) is a general purpose high energy cosmic ray and gamma ray observatory, aiming to detect high energy electrons and gammas in the energy range 5 Ge V to 10 Te V and hundreds of Te V for nuclei. This paper provides a method using machine learning to identify electrons and separate them from gammas, protons, helium and heavy nuclei with the DAMPE data acquired from 2016 January 1 to 2017 June 30, in the energy range from 10 to 100 Ge V. 展开更多
关键词 astroparticle physics methods: data analysis cosmic rays
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Testing the Empirical Relationship between Forbush Decreases and Cosmic Ray Diurnal Anisotropy
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作者 Jibrin Adejoh Alhassan Ogbonnaya Okike Augustine Ejikeme Chukwude 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2022年第5期129-135,共7页
The abrupt aperiodic modulation of cosmic ray(CR)flux intensity,often referred to as Forbush decrease(FD),plays a significant role in our understanding of the Sun-Earth electrodynamics.Accurate and precise determinati... The abrupt aperiodic modulation of cosmic ray(CR)flux intensity,often referred to as Forbush decrease(FD),plays a significant role in our understanding of the Sun-Earth electrodynamics.Accurate and precise determinations of FD magnitude and timing are among the intractable problems in FD-based analysis.FD identification is complicated by CR diurnal anisotropy.CR anisotropy can increase or reduce the number and amplitude of FDs.It is therefore important to remove its contributions from CR raw data before FD identification.Recently,an attempt was made,using a combination of the Fourier transform technique and FD-location machine,to address this.Thus,two FD catalogs and amplitude diurnal variation(ADV)were calculated from filtered(FD1 and ADV)and raw(FD2)CR data.In the current work,we test the empirical relationship between FD1,FD2,ADV and solar-geophysical characteristics.Our analysis shows that two types of magnetic fields-interplanetary and geomagnetic(Dst)-govern the evolution of CR flux intensity reductions. 展开更多
关键词 METHODS data analysis-methods statistical-catalogs-Sun coronal mass ejections (CMEs)-(Sun:) solar wind-(Sun:)solar-terrestrial relations-(ISM:)cosmic rays
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THE INFLUENCE OF THE COSMIC RAY FORBUSH DECREASE ON THE LOW IONOSPHERE IN THE POLAR REGION
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作者 宗秋刚 叶宗海 +1 位作者 薛丙森 叶晓蔚 《Chinese Journal of Polar Science》 1993年第1期1-11,共11页
Used the ionization theory of the cosmic ray charged particles in the polar ionosphere, the influence of the cosmic ray Forbush decrease on the low ionosphere in the polar region is studied in this paper. The relation... Used the ionization theory of the cosmic ray charged particles in the polar ionosphere, the influence of the cosmic ray Forbush decrease on the low ionosphere in the polar region is studied in this paper. The relationship between the Forbush decrease and the cosmic noise absorption during the polar night is analysed based on the data recorded by a Riometer at Antarctic Zhongshan Station (69° 22'24'S, 76°22'40'E). The relation of between the cosmic ray Forbush decrease and the cosmic noise absorption is well interpreted by means of the ionizaiotn theory. 展开更多
关键词 cosmic ray Forbush decrease precipitation particles polar ionosphere cosmic noise absorption
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New Probability Distributions in Astrophysics: VII. The Truncated Gamma-Pareto Distribution Applied to Cosmic Rays 被引量:1
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作者 Lorenzo Zaninetti 《International Journal of Astronomy and Astrophysics》 2022年第1期132-146,共15页
Many astrophysical phenomena are modeled by an inverse power law distribution at high values of the random variable but often at low values of the random variable we have a departure from an inverse power law. In orde... Many astrophysical phenomena are modeled by an inverse power law distribution at high values of the random variable but often at low values of the random variable we have a departure from an inverse power law. In order to insert a continuous transition from low to high values of the random variable we analyse the truncated gamma-Pareto distribution in two versions by deriving the most important statistical parameters. The application of the results to the distribution in energy of cosmic rays allows deriving an analytical expression for the average energy, which is 2.6 GeV. 展开更多
关键词 cosmic rays
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Constraining Galactic pγ Interactions with Cosmic Ray Electron and Positron Spectra
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作者 Nayantara Gupta 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2008年第2期153-158,共6页
High energy protons produced by various sources of cosmic rays, e.g., supernova remnants, pulsar wind nebulae, active galactic nuclei and gamma-ray bursts, participate in pγ and pp interactions. Although pp interacti... High energy protons produced by various sources of cosmic rays, e.g., supernova remnants, pulsar wind nebulae, active galactic nuclei and gamma-ray bursts, participate in pγ and pp interactions. Although pp interactions may be the dominant mechanism in our Galaxy, it is unclear how important Pγ process is. We show that the upper bound on the fraction of total number of protons participating in pγ interactions inside all Galactic astrophysical sources of cosmic rays is 10%. 展开更多
关键词 cosmic rays protons electrons positrons
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Noble gases,nitrogen and cosmic ray exposure age of the Sulagiri chondrite
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作者 Ramakant R.Mahajan 《Geoscience Frontiers》 SCIE CAS CSCD 2017年第1期205-210,共6页
The Sulagiri meteorite fell in India on 12 September 2008,LL6 chondrite class is the largest among all the Indian meteorites.Isotopic compositions of noble gases(He,Ne,Ar,Kr and Xe) and nitrogen in the Sulagiri mete... The Sulagiri meteorite fell in India on 12 September 2008,LL6 chondrite class is the largest among all the Indian meteorites.Isotopic compositions of noble gases(He,Ne,Ar,Kr and Xe) and nitrogen in the Sulagiri meteorite and cosmic ray exposure history are discussed.Low cosmogenic(22Ne/21Ne)c ratio is consistent with irradiation in a large body.Cosmogenic noble gases indicate that Sulagiri has a 4πcosmic-ray exposure(CRE) age of 27.9 ± 3.4 Ma and is a member of the peak of CRE age distribution of IX chondrites.Radiogenic 4He and 40Ar concentrations in Sulagiri yields the radiogenic ages as 2.29 and4.56 Ca,indicating the loss of He from the meteorite.Xenon and krypton are mixture of Q and spallogenic components. 展开更多
关键词 Noble gases Nitrogen cosmic ray exposure age Meteorite Trapped gases
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Progenitor model of cosmic ray knee
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作者 biplab bijay arunava bhadra 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2016年第1期51-58,共8页
The primary energy spectrum of cosmic rays exhibits a knee at about 3 PeV where a change in the spectral index occurs. Despite many efforts, the origin of such a feature in the spectrum is not satisfactorily solved ye... The primary energy spectrum of cosmic rays exhibits a knee at about 3 PeV where a change in the spectral index occurs. Despite many efforts, the origin of such a feature in the spectrum is not satisfactorily solved yet. Here it is proposed that the steepening of the spectrum beyond the knee may be a consequence of the mass distribution of the progenitor of the cosmic ray source. The proposed speculative model can account for all the major observed features of cosmic rays without invoking any fine tuning to match flux or spectra at any energy point. The prediction of the proposed model regarding the primary composition scenario beyond the knee is quite different from most of the prevailing models of the knee, and thereby can be discriminated from precise experimental measurement of the primary composition. 展开更多
关键词 cosmic rays -- acceleration of particles -- black hole physics
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Ionization of protoplanetary disks by galactic cosmic rays,solar protons,and supernova remnants
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作者 Ryuho Kataoka Tatsuhiko Sato 《Geoscience Frontiers》 SCIE CAS CSCD 2017年第2期247-252,共6页
Galactic cosmic rays and solar protons ionize the present terrestrial atmosphere,and the air showers are simulated by well-tested Monte-Carlo simulations,such as PHITS code.We use the latest version of PHITS to evalua... Galactic cosmic rays and solar protons ionize the present terrestrial atmosphere,and the air showers are simulated by well-tested Monte-Carlo simulations,such as PHITS code.We use the latest version of PHITS to evaluate the possible ionization of protoplanetary disks by galactic cosmic rays(GCRs),solar protons,and by supernova remnants.The attenuation length of GCR ionization is updated as 118 g cm^-2,which is approximately 20% larger than the popular value.Hard and soft possible spectra of solar protons give comparable and 20% smaller attenuation lengths compared with those from standard GCR spectra,respectively,while the attenuation length is approximately 10% larger for supernova remnants.Further,all of the attenuation lengths become 10% larger in the compound gas of cosmic abundance,e.g.128 g cm^-2 for GCRs,which can affect the minimum estimate of the size of dead zones in protoplanetary disks when the incident flux is unusually high. 展开更多
关键词 Galactic cosmic rays Solar protons Supernova remnants Young Sun Protoplanetary disk T Tauri stars
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Absence of the Impact of the Flux of Cosmic Rays and the Cloud Cover on the Energy Balance of the Earth
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作者 H.I.Abdussamatov 《Journal of Atmospheric Science Research》 2020年第3期1-7,共7页
The energy of solar radiation absorbed by the Earth,as well as the thermal radiation of the Earth’s surface,which is released to the space through the atmospheric transparency window,depends on variations of the area... The energy of solar radiation absorbed by the Earth,as well as the thermal radiation of the Earth’s surface,which is released to the space through the atmospheric transparency window,depends on variations of the area of the cloud cover.Svensmark et al.suggest that the increase in the area of the cloud cover in the lower atmosphere,presumably caused by an increase in the flux of galactic cosmic rays during the quasi-bicentennial minimum of solar activity,results only in an increase in the fraction of the solar radiation reflected back to the space and weakens the flux of the solar radiation that reached the Earth surface.It is suggested,without any corresponding calculations of the variations of the average annual energy balance of the EarthЕ,that the consequences will include only a deficit of the solar energy absorbed by the Earth and a cooling of the climate up to the onset of the Little Ice Age.These suggestions ignore simultaneous impact of the opposite aspects of the increase in the area of the cloud cover on the climate warming.The latter will result from a decrease in the power of thermal radiation of the Earth’s surface released to the space,and also in the power of the solar radiation reflected from the Earth’s surface,due to the increase in their absorption and reflection back to the surface.A substantial strengthening in the greenhouse effect and the narrowing of the atmospheric transparency window will also occur.Here,we estimate the impact of all aspects of possible long-term 2%growth of the cloud cover area in the lower atmosphere byЕ.We found that an increase in the cloud cover area in the lower atmosphere will result simultaneously both in the decrease and in the increase in the temperature,which will virtually compensate each other,while the energy balance of the Earth E before and after the increase in the cloud cover area by 2%will stay essentially the same:E1-E0≈0. 展开更多
关键词 CLIMATE cosmic rays Cloud Cover Energy Balance Little Ice Age Solar Irradiance Greenhouse Effect Atmospheric Transparency Window
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