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The 11-year and 22-year modulation of galactic cosmic rays (GCRs) in the inner heliosphere are studied using a numerical model developed by Qin and Shen in 2017. Based on the numerical solutions of Parker's transport equations, the model…

Space Physics · Physics 2018-02-28 Z. -N. Shen , G. Qin

Galactic cosmic rays (GCRs) inside the heliosphere are affected by magnetic turbulence and Solar wind disturbances which result in the so-called solar modulation effect. To investigate this phenomenon, we have performed a data-driven…

High Energy Astrophysical Phenomena · Physics 2022-10-13 Nicola Tomassetti , Bruna Bertucci , Federico Donnini , Emanuele Fiandrini , Maura Graziani , Behrouz Khiali , Alejandro Reina Conde

A precision measurement of the proton flux in primary cosmic rays with rigidity from 1 GV to 1.8 TV is presented based on 300 million events. The results show that the proton flux is smooth and exhibits no sharp structures with rigidity.…

High Energy Astrophysical Phenomena · Physics 2016-12-28 Cristina Consolandi

The intensity and energy spectrum of energetic charged radiation in the heliosphere are significantly influenced by solar activity. This phenomenon is known as solar modulation of galactic cosmic rays. As interplanetary travel becomes a…

High Energy Astrophysical Phenomena · Physics 2025-09-16 Miguel Orcinha , Fernando Barão , Bruna Bertucci , Emanuele Fiandrini , David Pelosi , Nicola Tomassetti

We present an analysis of the time-dependent modulation of galactic cosmic rays near Earth, with a focus on the cosmic proton flux and polar field. Using data from the Alpha Magnetic Spectrometer (AMS) and the Wilcox Solar Observatory, we…

Solar and Stellar Astrophysics · Physics 2025-04-30 Shaokun Gong , Linjing Duan , Jiawei Zhao , Xueyu Wei , Jie Feng , Zhibing Li

Transport equation of the galactic cosmic ray (GCR) is numerically solved for qA>0 and qA<0 based on the stochastic differential equation (SDE) method. We have developed a fully time-dependent and three-dimensional code adapted for the wavy…

Astrophysics · Physics 2007-05-23 Shoko Miyake , Shohei Yanagita

Recently, cosmic ray (CR) feedback has been identified as a critical process in galaxy formation but most previous simulations have integrated out the energy-dependence of the CR distribution, despite its large extent over more than twelve…

Astrophysics of Galaxies · Physics 2023-03-15 Philipp Girichidis , Christoph Pfrommer , Rüdiger Pakmor , Volker Springel

We study the high latitude (|b|>10) diffuse gamma-ray emission in the Galaxy in light of the recently published data from the Fermi collaboration at energies between 100 MeV and 100 GeV. The unprecedented accuracy in these measurements…

High Energy Astrophysical Phenomena · Physics 2013-04-16 I. Cholis , M. Tavakoli , C. Evoli , L. Maccione , P. Ullio

Recent data from CREAM seem to confirm early suggestions that primary cosmic ray (CR) spectra at few TeV/nucleon are harder than in the 10-100 GeV range. Also, helium and heavier nuclei spectra appear systematically harder than the proton…

High Energy Astrophysical Phenomena · Physics 2011-02-01 Fiorenza Donato , Pasquale D. Serpico

We study changes of the galactic cosmic ray (GCR) intensity for the ending period of the solar cycle 23 and the beginning of the solar cycle 24 using neutron monitors experimental data. We show that an increase of the GCR intensity in 2009…

Solar and Stellar Astrophysics · Physics 2015-04-06 M. V. Alania , R. Modzelewska , A. Wawrzynczak

Direct measurements of cosmic ray (CR) species combined with observations of their associated gamma-ray emissions can be used to constrain models of CR propagation, trace the structure of the Galaxy, and search for signatures of new…

High Energy Astrophysical Phenomena · Physics 2018-04-11 Gudlaugur Johannesson , Troy A. Porter , Igor V. Moskalenko

The time-dependent modulation of galactic cosmic rays in the heliosphere is studied by computing intensities using a time-dependent modulation model. By introducing recent theoretical advances in the transport coefficients in the model,…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Rex Manuel , Stefan Ferreira , Marius Potgieter

Galactic cosmic rays (GCRs), the highly energetic particles that may raise critical health issues for astronauts in space, are modulated by solar activity with their intensity lagging behind the sunspot number (SSN) variation by about one…

Solar and Stellar Astrophysics · Physics 2022-04-07 Yuming Wang , Jingnan Guo , Gang Li , Elias Roussos , Junwei Zhao

The existence of the spectral break around $\sim 3 \times 10^{15}$ eV in the cosmic ray spectrum (referred to as the `knee') is one of the biggest questions in cosmic ray astrophysics. At the same time, the origin of cosmic rays above the…

Astrophysics · Physics 2009-11-10 Hiroshi Muraishi , Shohei Yanagita , Tatsuo Yoshida

The search for cosmic ray anisotropy has been performed using particles collected by the Alpha Magnetic Spectrometer after the first five years of operation. The positron to electron ratio is consistent with isotropy at all energies and…

High Energy Astrophysical Phenomena · Physics 2016-12-30 G. La Vacca , AMS-02 Collaboration

We develop a numerical model to study the time-dependent modulation of galactic cosmic rays (GCRs) in the inner heliosphere. In the model a time-delayed modified Parker heliospheric magnetic field (HMF) and a new diffusion coefficient…

Space Physics · Physics 2017-09-26 Gang Qin , Zhenning Shen

Cosmic rays (CRs) are dynamically important for the formation and evolution of galaxies by regulating star formation and by powering galactic outflows. However, to what extent CRs regulate galaxy formation depends on the coupling strength…

Astrophysics of Galaxies · Physics 2023-12-27 Philipp Girichidis , Maria Werhahn , Christoph Pfrommer , Rüdiger Pakmor , Volker Springel

A two-dimensional, time-dependent numerical model is used to calculate the modulation of cosmic rays in the heliosphere. Computations are compared to spacecraft observations in the inner and outer heliosphere. It is shown that the model…

High Energy Astrophysical Phenomena · Physics 2013-10-22 Rex Manuel , Stefan Ferreira , Marius Potgieter

Global gradients for cosmic-ray (CR) protons in the heliosphere are computed with a comprehensive modulation model for the recent prolonged solar minimum of Cycle 23/24. Fortunately, the PAMELA (Payload for Antimatter Matter Exploration and…

Space Physics · Physics 2016-08-17 E. E. Vos , M. S. Potgieter

Galactic Cosmic Rays (GCRs) have to travel through the heliosphere before they interact with the Earth's atmosphere. During this, they are deflected by the Sun's magnetic field, causing variations in this field to imprint on the flux,…