摘要:

The historical development of our understanding of the heliosphere is outlined with emphasis placed on early ideas, dating from about 1600 to the launch of the Voyager spacecraft in 1970s. At the present time we seem to be on the verge of penetrating the solar wind termination shock making such a retrospective view timely and interesting as an example of the manner in which astrophysical concepts and ideas gradually evolve. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1809491

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Properties of the magnetic field near the termination shock and in the (inner) heliosheath are summarized. These ideas are based on Parker’s prediction of the spiral magnetic field and a simple analytic model of flow in the heliosheath. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1809492

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

This paper is a brief survey of theoretical expectations for the geometry of the heliospheric termination shock. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1809493

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

We studied the termination shock near the ecliptic, and near 35° latitude on the upwind side of the heliosphere. The shock location is solar cycle dependent; the shock moves outwards and inwards over timescales of a solar cycle in response to the variations in the average solar wind speed. The maximum distance occurs during the rising phase of the solar cycle, and the minimum distance during the declining phase; the amplitude increases with the latitude. Shock parameters are distinctly different when the shock moves outwards or inwards. If Voyager 1 did cross the termination shock in 2002.6, the spacecraft would likely cross the shock at least two more times before 2010. If Voyager 1 did not cross the termination shock in 2002, it might still do so very soon. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1809494

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The solar system moves through interstellar space populated by three principal particle species: plasma with magnetic field, neutral atoms, and galactic cosmic rays. Their interaction with the solar wind creates what is known as the heliospheric interface, containing two shocks and a tangential discontinuity. The 21st century view of the heliosphere is emerging as a highly dynamic, non‐stationary environment with plasma flows carrying imprints of the solar cycle variations. Instabilities produced by interactions between non‐equilibrium flows add to the complexity and may have important implications for charged particle transport near the heliopause. Proliferation of MHD models brought discoveries of new effects caused by the heliospheric magnetic field geometry and a realization of the importance of the magnitude and direction of the interstellar field on the properties of the bow shock. Finally, cosmic ray evolution in the global heliosphere was found to be a more complex process with a variety of modulation and acceleration sites, including the heliosheath and the heliotail. The role of cosmic rays as a dynamic variable in determining the global structure is now being reassessed. Here we will review the latest theoretical and modeling development and discuss future challenges awaiting the global heliospheric community. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1809495

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Three‐dimensional structure of the heliosphere is analyzed for the effects of coupling between the interstellar and interplanetary magnetic fields (ISMF and IMF). The case when the ISMF is orthogonal to the velocity of the local interstellar medium, and tilted 60° to the ecliptic plane, is specifically investigated in view of the recent suggestion that this is the most probable ISMF orientation. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1809496

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

In this paper we present results of a new time‐dependent kinetic model of the H atom penetration through the solar wind — interstellar medium interaction region. The kinetic 6D (time, two dimensions in space, and three dimensions in velocity‐space) equation for interstellar H atoms was solved self‐consistently with time‐dependent Euler equations for the solar wind and interstellar charged components. We study the response of the interaction region to the 11 year solar cycle variations of the solar wind. The termination shock location varies within ±7 AU, the heliopause variation is ∼2 AU, and the bow shock variation is negligible. At large heliocentric distances, the solar cycle induces 10–12 &percent; of fluctuations in the number density of both primary and secondary interstellar H atoms and atoms created in the inner heliosheath. Closer to the Sun the variation increases up to 30–35 &percent; at 5 AU due to the solar cycle variation of the charge exchange rate. Solar cycle variations of interstellar H atoms in the heliospheric interface and within the heliosphere may have a major importance for the interpretation of H atom observations inside the heliosphere. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1809497

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

We discuss measurements and models related to composition and dynamics of dust grains near and inside the heliosphere. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1809498

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

We include a latitudinally localized increase in ionization and subsequent mass loading in a 2.5‐dimensional magneto‐hydrodynamic case study to analyze its impact on the magnetic field, the flow field geometry, and the TS location. The localized additional mass loading leads to deflection of the flow and weakens the TS. We suggest the possibility that Voyager 1 may have been inside such a region during the recent ∼ 6 month period in 2002 when Voyager 1 observed energetic particle signatures consistent with a TS crossing, but only moderate changes in the magnetic field intensity and ACR spectrum. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1809499

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Energetic neutral atoms (ENA) are energetic ions neutralized by charge exchange with atoms in an ambient gas. The dynamics of charge exchange and the neutrality of ENA allow their sue to sample the mass and energy distributions of the ion population in regions of ENA production far away across magnetic fields. For ENA of energies > 30 keV/amu in the heliosphere, the energetic ions include anomalous cosmic rays in the heliosheath and pickup ions accelerated in interplanetary shocks; and the ambient gas is the neutral component of the local interstellar medium that permeates the heliosphere. ENA provide unique access to all regions of the heliosphere. We review some aspects of using ENA of energies > 30 keV/amu to study the heliosphere and suggest what can be done to fully utilize ENA in gaining a global view of the different particle populations linked by the acceleration and transport processes in the heliosphere. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1809500

出版商:AIP    

年代:1904

数据来源: AIP