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Brandt PC, Provornikova E, Bale SD, Cocoros A, DeMajistre R, Dialynas K, Elliott HA, Eriksson S, Fields B, Galli A, Hill ME, Horanyi M, Horbury T, Hunziker S, Kollmann P, Kinnison J, Fountain G, Krimigis SM, Kurth WS, Linsky J, Lisse CM, Mandt KE, Magnes W, McNutt RL, Miller J, Moebius E, Mostafavi P, Opher M, Paxton L, Plaschke F, Poppe AR, Roelof EC, Runyon K, Redfield S, Schwadron N, Sterken V, Swaczyna P, Szalay J, Turner D, Vannier H, Wimmer-Schweingruber R, Wurz P, Zirnstein EJ. Future Exploration of the Outer Heliosphere and Very Local Interstellar Medium by Interstellar Probe. SPACE SCIENCE REVIEWS 2023; 219:18. [PMID: 36874191 PMCID: PMC9974711 DOI: 10.1007/s11214-022-00943-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 12/07/2022] [Indexed: 06/18/2023]
Abstract
A detailed overview of the knowledge gaps in our understanding of the heliospheric interaction with the largely unexplored Very Local Interstellar Medium (VLISM) are provided along with predictions of with the scientific discoveries that await. The new measurements required to make progress in this expanding frontier of space physics are discussed and include in-situ plasma and pick-up ion measurements throughout the heliosheath, direct sampling of the VLISM properties such as elemental and isotopic composition, densities, flows, and temperatures of neutral gas, dust and plasma, and remote energetic neutral atom (ENA) and Lyman-alpha (LYA) imaging from vantage points that can uniquely discern the heliospheric shape and bring new information on the interaction with interstellar hydrogen. The implementation of a pragmatic Interstellar Probe mission with a nominal design life to reach 375 Astronomical Units (au) with likely operation out to 550 au are reported as a result of a 4-year NASA funded mission study.
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Affiliation(s)
- P. C. Brandt
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - E. Provornikova
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - S. D. Bale
- University of California Berkeley, Berkeley, CA USA
| | - A. Cocoros
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - R. DeMajistre
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - K. Dialynas
- Office of Space Research and Technology, Academy of Athens, Athens, 10679 Greece
| | | | - S. Eriksson
- Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, Boulder, CO USA
| | - B. Fields
- University of Illinois Urbana-Champaign, Urbana, IL USA
| | - A. Galli
- University of Bern, Bern, Switzerland
| | - M. E. Hill
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - M. Horanyi
- Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, Boulder, CO USA
| | | | | | - P. Kollmann
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - J. Kinnison
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - G. Fountain
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - S. M. Krimigis
- Office of Space Research and Technology, Academy of Athens, Athens, 10679 Greece
| | | | - J. Linsky
- University of Colorado Boulder, Boulder, CO USA
| | - C. M. Lisse
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - K. E. Mandt
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - W. Magnes
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - R. L. McNutt
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | | | - E. Moebius
- University of New Hampshire, Durham, NH USA
| | - P. Mostafavi
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - M. Opher
- Boston University, Boston, MA USA
| | - L. Paxton
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - F. Plaschke
- Technical University Braunschweig, Braunschweig, Germany
| | - A. R. Poppe
- University of California Berkeley, Berkeley, CA USA
| | - E. C. Roelof
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - K. Runyon
- Planetary Science Institute, Tucson, AZ USA
| | | | | | | | | | - J. Szalay
- Princeton University, Princeton, NJ USA
| | - D. Turner
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | | | | | - P. Wurz
- University of Bern, Bern, Switzerland
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2
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Kleimann J, Dialynas K, Fraternale F, Galli A, Heerikhuisen J, Izmodenov V, Kornbleuth M, Opher M, Pogorelov N. The Structure of the Large-Scale Heliosphere as Seen by Current Models. SPACE SCIENCE REVIEWS 2022; 218:36. [PMID: 35664863 PMCID: PMC9156516 DOI: 10.1007/s11214-022-00902-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/06/2022] [Indexed: 05/23/2023]
Abstract
This review summarizes the current state of research aiming at a description of the global heliosphere using both analytical and numerical modeling efforts, particularly in view of the overall plasma/neutral flow and magnetic field structure, and its relation to energetic neutral atoms. Being part of a larger volume on current heliospheric research, it also lays out a number of key concepts and describes several classic, though still relevant early works on the topic. Regarding numerical simulations, emphasis is put on magnetohydrodynamic (MHD), multi-fluid, kinetic-MHD, and hybrid modeling frameworks. Finally, open issues relating to the physical relevance of so-called "croissant" models of the heliosphere, as well as the general (dis)agreement of model predictions with observations are highlighted and critically discussed.
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Affiliation(s)
- Jens Kleimann
- Theoretische Physik IV, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | | | - Federico Fraternale
- Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL 35899 USA
| | | | - Jacob Heerikhuisen
- Department of Mathematics and Statistics, University of Waikato, Hamilton, 3240 New Zealand
| | - Vladislav Izmodenov
- Moscow Center of Fundamental and Applied Mathematics, Lomonosov Moscow State University, Moscow, Russia
- Space Research Institute (IKI) of Russian Academy of Sciences, Moscow, Russia
| | - Marc Kornbleuth
- Astronomy Department, Boston University, Boston, MA 02215 USA
| | - Merav Opher
- Astronomy Department, Boston University, Boston, MA 02215 USA
- Radcliffe Institute for Advanced Study at Harvard University, Cambridge, MA USA
| | - Nikolai Pogorelov
- Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL 35899 USA
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3
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Giacalone J, Fahr H, Fichtner H, Florinski V, Heber B, Hill ME, Kóta J, Leske RA, Potgieter MS, Rankin JS. Anomalous Cosmic Rays and Heliospheric Energetic Particles. SPACE SCIENCE REVIEWS 2022; 218:22. [PMID: 35502362 PMCID: PMC9046724 DOI: 10.1007/s11214-022-00890-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/04/2022] [Indexed: 05/08/2023]
Abstract
We present a review of Anomalous Cosmic Rays (ACRs), including the history of their discovery and recent insights into their acceleration and transport in the heliosphere. We focus on a few selected topics including a discussion of mechanisms of their acceleration, escape from the heliosphere, their effects on the dynamics of the heliosheath, transport in the inner heliosphere, and their solar cycle dependence. A discussion concerning their name is also presented towards the end of the review. We note that much is known about ACRs and perhaps the term Anomalous Cosmic Ray is not particularly descriptive to a non specialist. We suggest that the more-general term: "Heliospheric Energetic Particles", which is more descriptive, for which ACRs and other energetic particle species of heliospheric origin are subsets, might be more appropriate.
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Affiliation(s)
- J. Giacalone
- Lunar & Planetary Laboratory, University of Arizona, Tucson, AZ 85721 USA
| | - H. Fahr
- Argelander-Institute of Astronomy, University of Bonn, Bonn, Germany
| | - H. Fichtner
- Institut für Theoretische Physik, Ruhr-Universität, Bochum, Germany
| | - V. Florinski
- Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35805 USA
| | - B. Heber
- Institute for Experimental and Applied Physics, Christian-Albrechts University in Kiel, 24188 Kiel, Germany
| | - M. E. Hill
- Applied Physics Laboratory, Laurel, MD 20723 USA
| | - J. Kóta
- Lunar & Planetary Laboratory, University of Arizona, Tucson, AZ 85721 USA
| | - R. A. Leske
- California Institute of Technology, Pasadena, CA 91125 USA
| | - M. S. Potgieter
- Institute for Experimental and Applied Physics, Christian-Albrechts University in Kiel, 24188 Kiel, Germany
| | - J. S. Rankin
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08540 USA
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4
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Boschini MJ, Torre SD, Gervasi M, Grandi D, Jóhannesson G, La Vacca G, Masi N, Moskalenko IV, Pensotti S, Porter TA, Quadrani L, Rancoita PG, Rozza D, Tacconi M. Inference of the Local Interstellar Spectra of Cosmic-Ray Nuclei Z ⩽ 28 with the GalProp-HelMod Framework. THE ASTROPHYSICAL JOURNAL. SUPPLEMENT SERIES 2020; 250:27. [PMID: 34711999 PMCID: PMC8549769 DOI: 10.3847/1538-4365/aba901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Composition and spectra of Galactic cosmic rays (CRs) are vital for studies of high-energy processes in a variety of environments and on different scales, for interpretation of γ-ray and microwave observations, for disentangling possible signatures of new phenomena, and for understanding of our local Galactic neighborhood. Since its launch, AMS-02 has delivered outstanding-quality measurements of the spectra of p ¯ , e ±, and nuclei: 1H-8O, 10Ne, 12Mg, 14Si. These measurements resulted in a number of breakthroughs; however, spectra of heavier nuclei and especially low-abundance nuclei are not expected until later in the mission. Meanwhile, a comparison of published AMS-02 results with earlier data from HEAO-3-C2 indicates that HEAO-3-C2 data may be affected by undocumented systematic errors. Utilizing such data to compensate for the lack of AMS-02 measurements could result in significant errors. In this paper we show that a fraction of HEAO-3-C2 data match available AMS-02 measurements quite well and can be used together with Voyager 1 and ACE-CRIS data to make predictions for the local interstellar spectra (LIS) of nuclei that are not yet released by AMS-02. We are also updating our already-published LIS to provide a complete set from 1H-28Ni in the energy range from 1 MeV nucleon-1 to ~100-500 TeV nucleon-1, thus covering 8-9 orders of magnitude in energy. Our calculations employ the GalProp-HelMod framework, which has proved to be a reliable tool in deriving the LIS of CR p ¯ , e -, and nuclei 1H-8O.
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Affiliation(s)
- M J Boschini
- INFN, Milano-Bicocca, Milano, Italy
- CINECA, Segrate, Milano, Italy
| | | | - M Gervasi
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
| | - D Grandi
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
| | - G Jóhannesson
- Science Institute, University of Iceland, Dunhaga 3, IS-107 Reykjavik, Iceland
- NORDITA, Roslagstullsbacken 23, 106 91 Stockholm, Sweden
| | - G La Vacca
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
| | - N Masi
- INFN, Bologna, Italy
- Physics Department, University of Bologna, Bologna, Italy
| | - I V Moskalenko
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305, USA
- Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA
| | - S Pensotti
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
| | - T A Porter
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305, USA
- Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA
| | - L Quadrani
- INFN, Bologna, Italy
- Physics Department, University of Bologna, Bologna, Italy
| | | | - D Rozza
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
| | - M Tacconi
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
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5
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Formation and evolution of a pair of collisionless shocks in counter-streaming flows. Sci Rep 2017; 7:42915. [PMID: 28266497 PMCID: PMC5339721 DOI: 10.1038/srep42915] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 01/17/2017] [Indexed: 11/11/2022] Open
Abstract
A pair of collisionless shocks that propagate in the opposite directions are firstly observed in the interactions of laser-produced counter-streaming flows. The flows are generated by irradiating a pair of opposing copper foils with eight laser beams at the Shenguang-II (SG-II) laser facility. The experimental results indicate that the excited shocks are collisionless and electrostatic, in good agreement with the theoretical model of electrostatic shock. The particle-in-cell (PIC) simulations verify that a strong electrostatic field growing from the interaction region contributes to the shocks formation. The evolution is driven by the thermal pressure gradient between the upstream and the downstream. Theoretical analysis indicates that the strength of the shocks is enhanced with the decreasing density ratio during both flows interpenetration. The positive feedback can offset the shock decay process. This is probable the main reason why the electrostatic shocks can keep stable for a longer time in our experiment.
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6
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Krimigis SM, Decker RB, Roelof EC, Hill ME, Armstrong TP, Gloeckler G, Hamilton DC, Lanzerotti LJ. Search for the Exit: Voyager 1 at Heliosphere’s Border with the Galaxy. Science 2013; 341:144-7. [PMID: 23811223 DOI: 10.1126/science.1235721] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- S. M. Krimigis
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Office for Space Research and Technology, Academy of Athens, 106 79 Athens, Greece
| | - R. B. Decker
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
| | - E. C. Roelof
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
| | - M. E. Hill
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
| | | | - G. Gloeckler
- University of Michigan, Ann Arbor, MI 48109, USA
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7
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Stockem A, Boella E, Fiuza F, Silva LO. Relativistic generalization of formation and ion-reflection conditions in electrostatic shocks. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 87:043116. [PMID: 23679538 DOI: 10.1103/physreve.87.043116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Indexed: 06/02/2023]
Abstract
The theoretical model by Sorasio et al. [Phys. Rev. Lett. 96, 045005 (2006)] for the steady state Mach number of electrostatic shocks formed in the interaction of two plasma slabs of arbitrary density and temperature is generalized for relativistic electron and nonrelativistic ion temperatures. We find that the relativistic correction leads to lower Mach numbers and as a consequence ions are reflected with lower energies. The steady state bulk velocity of the downstream population is introduced as an additional parameter to describe the transition between the minimum and maximum Mach numbers that is dependent on the initial density and temperature ratios. In order to transform the solitonlike solution in the upstream region into a shock, a population of reflected ions is considered and differences from a zero-ion temperature model are discussed.
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Affiliation(s)
- A Stockem
- Grupo de Lasers e Plasmas, Laboratório Associado, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, 1049-001 Lisboa, Portugal.
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8
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Krimigis SM, Roelof EC, Decker RB, Hill ME. Zero outward flow velocity for plasma in a heliosheath transition layer. Nature 2011; 474:359-61. [PMID: 21677754 DOI: 10.1038/nature10115] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 04/11/2011] [Indexed: 11/09/2022]
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9
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Mediation of the solar wind termination shock by non-thermal ions. Nature 2008; 454:67-70. [PMID: 18596801 DOI: 10.1038/nature07030] [Citation(s) in RCA: 191] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2008] [Accepted: 04/15/2008] [Indexed: 11/08/2022]
Abstract
Broad regions on both sides of the solar wind termination shock are populated by high intensities of non-thermal ions and electrons. The pre-shock particles in the solar wind have been measured by the spacecraft Voyager 1 (refs 1-5) and Voyager 2 (refs 3, 6). The post-shock particles in the heliosheath have also been measured by Voyager 1 (refs 3-5). It was not clear, however, what effect these particles might have on the physics of the shock transition until Voyager 2 crossed the shock on 31 August-1 September 2007 (refs 7-9). Unlike Voyager 1, Voyager 2 is making plasma measurements. Data from the plasma and magnetic field instruments on Voyager 2 indicate that non-thermal ion distributions probably have key roles in mediating dynamical processes at the termination shock and in the heliosheath. Here we report that intensities of low-energy ions measured by Voyager 2 produce non-thermal partial ion pressures in the heliosheath that are comparable to (or exceed) both the thermal plasma pressures and the scalar magnetic field pressures. We conclude that these ions are the >0.028 MeV portion of the non-thermal ion distribution that determines the termination shock structure and the acceleration of which extracts a large fraction of bulk-flow kinetic energy from the incident solar wind.
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10
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Voyager 2 probe leaves the neighbourhood. Nature 2007. [DOI: 10.1038/news.2007.365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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11
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Abstract
The orientation of the local interstellar magnetic field introduces asymmetries in the heliosphere that affect the location of heliospheric radio emissions and the streaming direction of ions from the termination shock of the solar wind. We combined observations of radio emissions and energetic particle streaming with extensive three-dimensional magnetohydrodynamic computer simulations of magnetic field draping over the heliopause to show that the plane of the local interstellar field is approximately 60 degrees to 90 degrees from the galactic plane. This finding suggests that the field orientation in the Local Interstellar Cloud differs from that of a larger-scale interstellar magnetic field thought to parallel the galactic plane.
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Affiliation(s)
- M Opher
- Department of Physics and Astronomy, George Mason University, 4400 University Drive, Fairfax, VA 22030, USA.
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12
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Sorasio G, Marti M, Fonseca R, Silva LO. Very high Mach-number electrostatic shocks in collisionless plasmas. PHYSICAL REVIEW LETTERS 2006; 96:045005. [PMID: 16486838 DOI: 10.1103/physrevlett.96.045005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Indexed: 05/06/2023]
Abstract
The kinetic theory of collisionless electrostatic shocks resulting from the collision of plasma slabs with different temperatures and densities is presented. The theoretical results are confirmed by self-consistent particle-in-cell simulations, revealing the formation and stable propagation of electrostatic shocks with very high Mach numbers (M>>10), well above the predictions of the classical theories for electrostatic shocks.
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Affiliation(s)
- G Sorasio
- GoLP/Centro de Física dos Plasmas, Instituto Superior Técnico, Avenida Rovisco Pais, 1049-001 Lisbon, Portugal.
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13
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Langner UW, Potgieter MS, Fichtner H, Borrmann T. Modulation of anomalous protons: Effects of different solar wind speed profiles in the heliosheath. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005ja011066] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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14
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Abstract
The Voyager 1 spacecraft has passed an important milestone. As is reported in papers in this issue, Voyager 1 has crossed the termination shock of the solar wind, where the wind abruptly decelerates to begin its merger into the local interstellar medium. The termination shock provided surprises; the region beyond is truly uncharted territory.
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Affiliation(s)
- Len A Fisk
- Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, MI 48109-2143, USA.
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15
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Stone EC, Cummings AC, McDonald FB, Heikkila BC, Lal N, Webber WR. Voyager 1 explores the termination shock region and the heliosheath beyond. Science 2005; 309:2017-20. [PMID: 16179468 DOI: 10.1126/science.1117684] [Citation(s) in RCA: 413] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Voyager 1 crossed the termination shock of the supersonic flow of the solar wind on 16 December 2004 at a distance of 94.01 astronomical units from the Sun, becoming the first spacecraft to begin exploring the heliosheath, the outermost layer of the heliosphere. The shock is a steady source of low-energy protons with an energy spectrum approximately E(-1.41 +/- 0.15) from 0.5 to approximately 3.5 megaelectron volts, consistent with a weak termination shock having a solar wind velocity jump ratio r=2.6(-0.2)(+0.4). However, in contradiction to many predictions, the intensity of anomalous cosmic ray (ACR) helium did not peak at the shock, indicating that the ACR source is not in the shock region local to Voyager 1. The intensities of approximately 10-megaelectron volt electrons, ACRs, and galactic cosmic rays have steadily increased since late 2004 as the effects of solar modulation have decreased.
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Affiliation(s)
- E C Stone
- California Institute of Technology, Pasadena, CA 91125, USA.
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16
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Intriligator DS, Sun W, Dryer M, Fry CD“G, Deehr C, Intriligator J. From the Sun to the outer heliosphere: Modeling and analyses of the interplanetary propagation of the October/November (Halloween) 2003 solar events. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2004ja010939] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Wei Sun
- Geophysical Institute; University of Alaska; Fairbanks Alaska USA
| | - Murray Dryer
- NOAA Space Environment Center; Boulder Colorado USA
- Exploration Physics International, Inc.; Huntsville Alabama USA
| | | | - Charles Deehr
- Geophysical Institute; University of Alaska; Fairbanks Alaska USA
| | - James Intriligator
- Carmel Research Center; Santa Monica California USA
- University of Wales, Bangor; Wales UK
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17
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Richardson JD, McDonald FB, Stone EC, Wang C, Ashmall J. Relation between the solar wind dynamic pressure at Voyager 2 and the energetic particle events at Voyager 1. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2005ja011156] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- J. D. Richardson
- Center for Space Research; Massachusetts Institute of Technology; Cambridge Massachusetts USA
- Center for Space Science and Applied Research; Chinese Academy of Sciences; Beijing China
| | - F. B. McDonald
- Institute for Physical Science and Technology; University of Maryland; College Park Maryland USA
| | - E. C. Stone
- Division of Physics, Mathematics, and Astronomy; California Institute of Technology; Pasadena California USA
| | - C. Wang
- Center for Space Research; Massachusetts Institute of Technology; Cambridge Massachusetts USA
- Center for Space Science and Applied Research; Chinese Academy of Sciences; Beijing China
| | - J. Ashmall
- Center for Space Research; Massachusetts Institute of Technology; Cambridge Massachusetts USA
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18
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Burlaga LF, Ness NF, Acuña MH, Lepping RP, Connerney JEP, Stone EC, McDonald FB. Crossing the Termination Shock into the Heliosheath: Magnetic Fields. Science 2005; 309:2027-9. [PMID: 16179471 DOI: 10.1126/science.1117542] [Citation(s) in RCA: 182] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Magnetic fields measured by Voyager 1 show that the spacecraft crossed or was crossed by the termination shock on about 16 December 2004 at 94.0 astronomical units. An estimate of the compression ratio of the magnetic field strength B (+/- standard error of the mean) across the shock is B2/B1 = 3.05 +/- 0.04, but ratios in the range from 2 to 4 are admissible. The average B in the heliosheath from day 1 through day 110 of 2005 was 0.136 +/- 0.035 nanoteslas, approximately 4.2 times that predicted by Parker's model for B. The magnetic field in the heliosheath from day 361 of 2004 through day 110 of 2005 was pointing away from the Sun along the Parker spiral. The probability distribution of hourly averages of B in the heliosheath is a Gaussian distribution. The cosmic ray intensity increased when B was relatively large in the heliosheath.
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Affiliation(s)
- L F Burlaga
- NASA-Goddard Space Flight Center, Greenbelt, MD 20771, USA.
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19
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Decker RB, Krimigis SM, Roelof EC, Hill ME, Armstrong TP, Gloeckler G, Hamilton DC, Lanzerotti LJ. Voyager 1 in the Foreshock, Termination Shock, and Heliosheath. Science 2005; 309:2020-4. [PMID: 16179469 DOI: 10.1126/science.1117569] [Citation(s) in RCA: 350] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Voyager 1 (V1) began measuring precursor energetic ions and electrons from the heliospheric termination shock (TS) in July 2002. During the ensuing 2.5 years, average particle intensities rose as V1 penetrated deeper into the energetic particle foreshock of the TS. Throughout 2004, V1 observed even larger, fluctuating intensities of ions from 40 kiloelectron volts (keV) to >/=50 megaelectron volts per nucleon and of electrons from >26 keV to >/=350 keV. On day 350 of 2004 (2004/350), V1 observed an intensity spike of ions and electrons that was followed by a sustained factor of 10 increase at the lowest energies and lesser increases at higher energies, larger than any intensities since V1 was at 15 astronomical units in 1982. The estimated solar wind radial flow speed was positive (outward) at approximately +100 kilometers per second (km s(-1)) from 2004/352 until 2005/018, when the radial flows became predominantly negative (sunward) and fluctuated between approximately -50 and 0 km s(-1) until about 2005/110; they then became more positive, with recent values (2005/179) of approximately +50 km s(-1). The energetic proton spectrum averaged over the postshock period is apparently dominated by strongly heated interstellar pickup ions. We interpret these observations as evidence that V1 was crossed by the TS on 2004/351 (during a tracking gap) at 94.0 astronomical units, evidently as the shock was moving radially inward in response to decreasing solar wind ram pressure, and that V1 has remained in the heliosheath until at least mid-2005.
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Affiliation(s)
- R B Decker
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA.
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Research highlights. Nature 2005. [DOI: 10.1038/437598a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Lallement R, Quémerais E, Bertaux JL, Ferron S, Koutroumpa D, Pellinen R. Deflection of the interstellar neutral hydrogen flow across the heliospheric interface. Science 2005; 307:1447-9. [PMID: 15746421 DOI: 10.1126/science.1107953] [Citation(s) in RCA: 252] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Using an absorption cell, we measured the Doppler shifts of the interstellar hydrogen resonance glow to show the direction of the neutral hydrogen flow as it enters the inner heliosphere. The neutral hydrogen flow is found to be deflected relative to the helium flow by about 4 degrees . The most likely explanation of this deflection is a distortion of the heliosphere under the action of an ambient interstellar magnetic field. In this case, the helium flow vector and the hydrogen flow vector constrain the direction of the magnetic field and act as an interstellar magnetic compass.
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Affiliation(s)
- R Lallement
- Service d'Aéronomie du Centre National de la Recherche Scientifique, Institut Pierre Simon Laplace, Boite Postale 3, 91371 Verrières-le-Buisson, France.
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Affiliation(s)
- J R Jokipii
- Department of Planetary Sciences, University of Arizona, Tucson, AZ 85721, USA.
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Abstract
Stellar analogs for the solar wind have proven to be frustratingly difficult to detect directly. However, these stellar winds can be studied indirectly by observing the interaction regions carved out by the collisions between these winds and the interstellar medium (ISM). These interaction regions are called "astrospheres", analogous to the "heliosphere" surrounding the Sun. The heliosphere and astrospheres contain a population of hydrogen heated by charge exchange processes that can produce enough H I Lyα absorption to be detectable in UV spectra of nearby stars from the Hubble Space Telescope (HST). The amount of astrospheric absorption is a diagnostic for the strength of the stellar wind, so these observations have provided the first measurements of solar-like stellar winds. Results from these stellar wind studies and their implications for our understanding of the solar wind are reviewed here. Of particular interest are results concerning the past history of the solar wind and its impact on planetary atmospheres.
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Affiliation(s)
- Brian E. Wood
- JILA, University of Colorado, 440 UCB, Boulder, CO 80309-0440 USA
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McDonald FB, Stone EC, Cummings AC, Heikkila B, Lal N, Webber WR. Enhancements of energetic particles near the heliospheric termination shock. Nature 2003; 426:48-51. [PMID: 14603312 DOI: 10.1038/nature02066] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2003] [Accepted: 09/14/2003] [Indexed: 11/09/2022]
Abstract
The spacecraft Voyager 1 is at a distance greater than 85 au from the Sun, in the vicinity of the termination shock that marks the abrupt slowing of the supersonic solar wind and the beginning of the extended and unexplored distant heliosphere. This shock is expected to accelerate 'anomalous cosmic rays', as well as to re-accelerate Galactic cosmic rays and low-energy particles from the inner Solar System. Here we report a significant increase in the numbers of energetic ions and electrons that persisted for seven months beginning in mid-2002. This increase differs from any previously observed in that there was a simultaneous increase in Galactic cosmic ray ions and electrons, anomalous cosmic rays and low-energy ions. The low-intensity level and spectral energy distribution of the anomalous cosmic rays, however, indicates that Voyager 1 still has not reached the termination shock. Rather, the observed increase is an expected precursor event. We argue that the radial anisotropy of the cosmic rays is expected to be small in the foreshock region, as is observed.
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Affiliation(s)
- Frank B McDonald
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA.
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Voyager reaches the final frontier. Nature 2003. [DOI: 10.1038/news031103-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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