New evidence for charge-sign dependent modulation during the solar minimum of 2006 to 2009
arXiv:1608.01301 · doi:10.3847/1538-4357/834/1/89
Abstract
The PAMELA space experiment, in orbit since 2006, has measured cosmic rays through the most recent A < 0 solar minimum activity period. During this entire time, galactic electrons and protons have been detected down to 70 MV and 400 MV, respectively, and their differential intensity variation in time has been monitored with unprecedented accuracy. These observations are used to show how differently electrons and protons responded to the quiet modulation conditions that prevailed from 2006 to 2009. It is well known that particle drifts, as one of four major mechanisms for the solar modulation of cosmic rays, cause charge-sign dependent solar modulation. Solar minimum activity periods provide optimal conditions to study these drift effects. The observed behaviour is compared to the solutions of a three-dimensional model for cosmic rays in the heliosphere, including drifts. The numerical results confirm that the difference in the evolution of electron and proton spectra during the last prolonged solar minimum is attributed to a large extent to particle drifts. We therefore present new evidence of charge-sign dependent solar modulation, with perspective on its peculiarities for the observed period from 2006 to 2009.
arXiv comment11 pages, 7 figures Submitted to ApJ
References in corpus (19)
- Observation of an anomalous positron abundance in the cosmic radiation
- PAMELA Measurements of Cosmic-ray Proton and Helium Spectra
- Results from a Search for Light-Mass Dark Matter with a P-type Point Contact Germanium Detector
- Solar Modulation of Cosmic Rays
- PAMELA - A Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics
- The cosmic-ray electron flux measured by the PAMELA experiment between 1 and 625 GeV
- The cosmic-ray positron energy spectrum measured by PAMELA
- Time dependence of the proton flux measured by PAMELA during the July 2006 - December 2009 solar minimum
- Modulation of galactic protons in the heliosphere during the unusual solar minimum of 2006 to 2009
- Observations of annual modulation in direct detection of relic particles and light neutralinos
- Time dependence of the e^- flux measured by PAMELA during the July 2006 - December 2009 solar minimum
- A Predictive Analytic Model for the Solar Modulation of Cosmic Rays
- What Does The PAMELA Antiproton Spectrum Tell Us About Dark Matter?
- Low energy cosmic ray positron fraction explained by charge-sign dependent solar modulation
- Time dependence of the electron and positron components of the cosmic radiation measured by the PAMELA experiment between July 2006 and December 2015
- Very local interstellar spectra for galactic electrons, protons and helium
- Phenomenology of light neutralinos in view of recent results at the CERN Large Hadron Collider
- Global gradients for cosmic-ray protons in the heliosphere during the solar minimum of cycle 23/24
- Cosmic-ray antiproton constraints on light singlino-like dark matter candidates
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- Proton fluxes measured by the PAMELA experiment from the minimum to the maximum solar activity for the 24th solar cycle
- Cosmic-ray Antinuclei as Messengers of New Physics: Status and Outlook for the New Decade
- Modulation of Galactic Cosmic Rays in the Inner Heliosphere, Comparing with PAMELA Measurements
- Modeling of Heliospheric Modulation of Cosmic-ray Positrons in a Very Quiet Heliosphere
- Evidence of energy and charge sign dependence of the recovery time for the December 2006 Forbush event measured by the PAMELA experiment
- Time dependence of the flux of helium nuclei in cosmic rays measured by the PAMELA experiment between July 2006 and December 2009
- Time and Charge-Sign Dependence of the Heliospheric Modulation of Cosmic Rays
- Unfolding Drift Effects for Cosmic Rays over the Period of the Sun's Magnetic Field Reversal
- Late decaying 2-component dark matter scenario as an explanation of the AMS-02 positron excess
- Modulation of cosmic ray anti-protons in the heliosphere: simulations for a solar cycle
- An alternative Explanation for the Fermi GeV Gamma-Ray Excess
- Probing solar modulation of AMS-02 time-dependent D, He and He fluxes with modified force field approximation
- Solar modulation of cosmic ray positrons in a very quiet heliosphere