Linsky / Izmodenov / Mobius From the Outer Heliosphere to the Local Bubble

Comparisons of New Observations with Theory
1. Auflage 2009
ISBN: 978-1-4419-0247-4
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, Band 31, 478 Seiten

Reihe: Space Sciences Series of ISSI

Knowledge about the outer heliosphere and the interstellar medium, which were long treated as two separate fields, has improved dramatically over the past 25 years as a consequence of recent developments: The discovery of interstellar pickup ions and neutral helium inside the heliosphere, the determination of the interstellar hydrogen distribution in the heliosphere obtained using backscattered solar Lyman-alpha radiation, the prediction and subsequent detection of the hydrogen wall just outside of the heliopause, the development of detailed global models for the interaction of solar wind plasma with the interstellar medium, and most recently, direct in-situ plasma and field measurements inside of the heliosheath. At the same time, our understanding of the nearby galactic environment, including the composition and dynamics of the warm gas clouds and hot gas in the local bubble, has benefited greatly from absorption-line spectroscopy using nearby stars as background sources and dynamic modeling. The present volume provides a synopsis of these developments organised into seven sections: Dominant physical processes in the termination shock and heliosheath, three-dimensional shape and structure of the dynamic heliosphere, relation of the plasmas and dust inside and outside of the heliosphere, origin and properties of the very local interstellar medium, energy and pressure equilibria in the local bubble, physical processes in the multiphase interstellar medium inside of the local bubble, and the roles that magnetic fields play in the outer heliosphere and the local bubble. The last theme is probably the most basic of all as magnetic fields play important roles in most of the phenomena discussed here. The volume concludes with four papers providing the 'big picture' by looking at the time evolution of both the heliosphere and the local bubble, looking beyond the local bubble, and finally addressing the challenges in modeling the interface between the two media.

Autoren/Hrsg.

Möbius, E.

Steiger, R.

Linsky, J. L.

Izmodenov, V. V.

Mobius, E.

Steiger, Rudolf Von

Inhaltsverzeichnis

1;Foreword;8
2;Dedication to Dr. George Gloeckler;11
3;The Solar Wind in the Outer Heliosphere;13
3.1;Introduction;13
3.2;Solar Wind Evolution;15
3.3;Effects of the Neutral CHISM on the Solar Wind;17
3.4;The Termination Shock;17
3.5;Anomalous Cosmic Rays;23
3.6;Summary;24
3.7;Acknowledgements;24
3.8;References;24
4;Constraints on the Structure of the Heliospheric Interface Based on Lyalpha Absorption Spectra;27
4.1;Introduction;27
4.2;The Heliospheric Absorption Detections;28
4.3;Absorption Dependence on the ISM Magnetic Field;30
4.4;Extended Tail Models;33
4.5;Acknowledgements;36
4.6;References;36
5;Influence of the Interstellar Magnetic Field and Neutrals on the Shape of the Outer Heliosphere;37
5.1;Introduction;38
5.2;Heliospheric Asymmetry Induced by the ISMF;39
5.3;Sources of the 2-3 kHz radio emission;45
5.4;Conclusions;46
5.5;Acknowledgements;47
5.6;References;47
6;Confronting Observations and Modeling: The Role of the Interstellar Magnetic Field in Voyager 1 and 2 Asymmetries;49
6.1;Introduction;50
6.2;Observational Evidences for Asymmetries;52
6.3;Interstellar Magnetic Field Direction;53
6.4;Model;54
6.5;Squashed Solar System: Global Asymmetries;54
6.6;Discussion and Conclusions;58
6.6.1;Neutral H Atoms;58
6.6.2;Solar Cycle;59
6.6.3;Energetic-Particle Mediated Shock;59
6.7;Acknowledgements;59
6.8;References;60
7;The Dynamic Heliosphere: Outstanding Issues;62
7.1;Introduction;63
7.2;On the Origin of Anomalous Cosmic Rays;64
7.2.1;Observations of ACRs Near the Termination Shock;64
7.2.2;Classic (Drift) Paradigm;66
7.2.3;Shock Geometry and Longitudinal Effects;67
7.2.4;Dynamical Effects;68
7.2.5;Acceleration in the Heliosheath;69
7.3;Variability of the Termination Shock Region and Heliosheath: Solar Cycle and Transient Effects;70
7.3.1;Propagation of a Solar Wind Velocity Pulse through the Heliosphere;71
7.3.2;Instability of the Heliopause;75
7.3.3;The Effects of the Solar Activity Cycle;75
7.4;Connecting ENAs with Lyalpha Absorption Measurements;77
7.5;A Comparison between the Heliosheath and Other Sheaths in Space;80
7.5.1;Ion Distributions;81
7.5.2;Sheath Size and Structure;82
7.5.3;Waves;82
7.6;Outlook: Heliosheath Thickness and Processes at the Heliopause;83
7.6.1;Estimating the Thickness of the Heliosheath;83
7.6.2;Energetic Particles at the Heliopause;84
7.7;Conclusions;85
7.8;Acknowledgements;85
7.9;References;85
8;The Heliospheric Magnetic Field and Its Extension to the Inner Heliosheath;89
8.1;The Global Heliospheric Magnetic Field: the Parker Formulation;90
8.2;Deviations from the Parker Model of the Heliospheric Magnetic Field;91
8.3;Structures in the Heliospheric Magnetic Field: Solar Cycle Effects;93
8.3.1;The Solar Corona, the Heliospheric Magnetic Field and the Heliospheric Current Sheet;94
8.3.2;Corotating Interaction Regions;98
8.3.3;``Interplanetary'' Coronal Mass Ejections through the Heliosphere;102
8.4;The Magnetic Field in the Heliosheath;105
8.4.1;The Magnetic-Field Sector Structure in the Heliosheath;106
8.4.2;Application to Observations;108
8.4.3;Magnetic Fluctuations in the Heliosheath;109
8.5;Summary;110
8.6;Acknowledgements;111
8.7;References;111
9;Pickup Ion Acceleration at the Termination Shock and in the Heliosheath;115
9.1;Introduction;115
9.2;Modeling Anisotropic Distributions: Focused Transport;117
9.3;Distribution Functions of Energetic Particles Near a Quasi-Perpendicular Shock;119
9.4;Pitch-Angle Distributions;122
9.5;The Heliosheath;124
9.6;Conclusions;126
9.7;Acknowledgements;127
9.8;References;127
10;ENA Imaging of the Inner Heliosheath-Preparing for the Interstellar Boundary Explorer (IBEX);129
10.1;Introduction;129
10.2;Early Efforts to Observe ENAs from the Heliosheath;130
10.3;The Interstellar Boundary Explorer;132
10.4;Discussion;138
10.5;Acknowledgements;139
10.6;References;141
11;Local Interstellar Parameters as They Are Inferred from Analysis of Observations Inside the Heliosphere;143
11.1;Introduction;143
11.2;Observations from Inside the Heliosphere;145
11.3;Multi-Component Models of the Global Heliosphere;147
11.4;CHISM Parameters Inferred from Data and Theory;148
11.5;Conclusions and Perspectives;152
11.6;Acknowledgements;153
11.7;References;153
12;Interplanetary Lyman alpha Observations: Intensities from Voyagers and Line Profiles from HST/STIS;155
12.1;Introduction;155
12.2;Intensities in the Outer Heliosphere;156
12.2.1;Heliosphere Scans with Voyager-UVS;156
12.2.2;Radial Variation of the Upwind Intensity;159
12.3;Line Profiles in the Inner Heliosphere;162
12.4;Conclusion and Discussion;163
12.5;References;165
13;Composition of Interstellar Neutrals and the Origin of Anomalous Cosmic Rays;167
13.1;Introduction;168
13.2;Interstellar Neutral Densities at 90-100 AU;169
13.2.1;Abundance of Interstellar Neutrals at the TS from Pickup Ions;169
13.2.2;Tails and ACRs in the Inner Heliosheath;172
13.2.3;ACRs in the Outer Heliosheath;175
13.2.4;Abundance of Interstellar Neutrals from Tails and ACRs;175
13.3;Discussion and Summary;177
13.4;Acknowledgements;178
13.5;References;178
14;Neutral H Density at the Termination Shock: A Consolidation of Recent Results;180
14.1;Introduction;180
14.2;Neutral Gas Density from Pickup Ion Observations;181
14.2.1;Past Attempts to Derive the Density at the Termination Shock;181
14.2.2;Modeling Uncertainties in Pickup Ion Interpretations;182
14.2.3;Robust Method to Determine the Density at the Termination Shock;184
14.2.3.1;Simplified analytic derivation;185
14.2.3.2;Simulations of the H PUI Production Rate at Ulysses;186
14.3;Determination of Hydrogen Density at the Termination Shock;188
14.4;Consolidation of the Interstellar H Density;188
14.4.1;Density of H at the Termination Shock;188
14.4.2;Extrapolating the Termination Shock Density to the CHISM;189
14.5;Conclusions;191
14.6;Acknowledgements;191
14.7;References;191
15;Is the Sun Embedded in a Typical Interstellar Cloud?;194
15.1;Introduction;194
15.2;Galactic Environment of the Sun;195
15.3;Heliospheric ISM;195
15.4;Kinematics and Temperatures of Very Local ISM versus Warm Interstellar Gas;197
15.5;Partially Ionized Gas and the Interstellar Radiation Field;200
15.6;Chemical Composition of the ISM at the Sun ;202
15.7;Interstellar Magnetic Field at the Solar Location ;203
15.8;Conclusions;204
15.9;Acknowledgements;205
15.10;References;206
16;Pressure and Ionization Balances in the Circum-Heliospheric Interstellar Medium and the Local Bubble;208
16.1;Introduction: The Pressure Problem;208
16.2;Development of the Conventional View of the Local Bubble (LB);209
16.3;The Circum-Heliospheric Interstellar Medium (CHISM);210
16.4;Attempted Solutions that Seem to Fail;210
16.4.1;An imbalance is acceptable;210
16.4.2;Magnetic support;210
16.4.3;Turbulent support;211
16.5;Early Indications of Trouble with the X-ray Background Measurements;211
16.6;How Else to Measure the Pressure in the LB?;212
16.6.1;The Fine-Structure Excitation of Neutral Carbon;212
16.6.2;EUV Diffuse Background;213
16.6.3;Cloud Lifetimes;213
16.7;Pressure Balance Between the LB and Galactic Disk;214
16.8;Ionization State of the CHISM;214
16.8.1;Initial Findings;214
16.8.2;Incomplete Recombination?;215
16.8.3;Diffuse Hard Photoionization Flux;215
16.9;Acknowledgements;217
16.10;References;217
17;The Solar Wind Charge-eXchange Contribution to the Local Soft X-ray Background;220
17.1;Introduction;221
17.2;SWCX Model Description;222
17.3;SWCX in the 3/4 keV Band;223
17.3.1;Stationary Model Maps;223
17.3.2;Dynamic Simulations;225
17.3.2.1;The Case of the MBM 12 Suzaku Observation of February 2006;225
17.3.3;Summary of Shadowing Observations;227
17.4;SWCX in the 1/4 keV Band;228
17.4.1;Simulations;229
17.4.2;Model-Data Comparison;229
17.4.2.1;Wisconsin Sounding Rocket Survey;230
17.4.2.2;The ROSAT Survey;231
17.5;Discussion;232
17.6;Acknowledgements;233
17.7;References;233
18;Revising the Local Bubble Model due to Solar Wind Charge Exchange X-ray Emission;234
18.1;Introduction;234
18.2;The Historical Local Bubble Model;235
18.3;Charge Exchange in the Solar System;236
18.3.1;Solar Wind Charge Exchange X-rays;236
18.3.2;Solar Wind Charge Exchange O VI;237
18.4;Is There a Hot Local Bubble After All?;238
18.5;Revising the Local Bubble;240
18.6;How We Can Make Progress;241
18.7;Acknowledgements;241
18.8;References;241
19;Warm and Hot Gas in the Local ISM;243
19.1;Introduction;243
19.2;Local Warm Gas;245
19.2.1;Density and Temperature;245
19.2.2;Local Ionization;245
19.2.3;Velocity Structure;246
19.2.4;Element Abundances;248
19.3;The Detectability of Hot Gas in the Local Cavity;248
19.3.1;Local C IV and Si IV Absorption;248
19.3.2;Local O VI Absorption;249
19.4;The Local Chimney Connection;252
19.5;Future Observations;253
19.6;Acknowledgements;253
19.7;References;253
20;What Can Be Learned from X-ray Spectroscopy Concerning Hot Gas in the Local Bubble and Charge Exchange Processes?;255
20.1;Introduction;255
20.2;A Little History-Instrumentation;256
20.3;Spectrum Röntgen Gamma;258
20.4;What Can Be Learned?;259
20.5;Random Thoughts;261
20.6;Summary;262
20.7;Acknowledgements;264
20.8;References;264
21;What Physical Processes Drive the Interstellar Medium in the Local Bubble?;265
21.1;Introduction;266
21.2;Modeling the ISM and the Local Bubble;266
21.2.1;A Supernova Driven ISM Model;267
21.2.2;Results on the General ISM;268
21.2.3;Modeling the Local Bubble;271
21.2.4;Results on the Local Bubble;273
21.3;Comparison with Observations;275
21.4;Summary and Conclusions;277
21.5;Acknowledgements;277
21.6;References;277
22;Plasma Turbulence in the Local Bubble;279
22.1;Introduction;280
22.2;Radio Astronomy and Diagnostics of Interstellar Plasmas;280
22.3;Why the Hot Phase of the Interstellar Medium is of Interest;282
22.4;Probing the Local Bubble: The Case of Pulsar B0950+08;283
22.5;Relevant Recent Progress in Pulsar Astronomy;284
22.6;A New Set of Pulsars to Probe the Local Bubble;284
22.7;Results on Plasma and Plasma Turbulence in the Local Bubble;285
22.8;Estimates of Other Media Along Pulsar Lines of Sight;287
22.9;New Diagnostic Measurements for Local Interstellar Plasmas;289
22.10;Summary and Conclusions;291
22.11;Acknowledgements;291
22.12;References;291
23;Exotic Clouds in the Local Interstellar Medium;293
23.1;Introduction;293
23.2;Tiny Scale Atomic Structure (TSAS);294
23.3;Tiny Scale Ionized Structure (TSIS);295
23.4;Low Column Density Clouds;296
23.5;Cold Clouds Inside the Local Bubble;297
23.6;Comparison with the Cluster of Local Interstellar Clouds;299
23.7;Formation and Survival of Cold Clouds;300
23.8;Conclusions;301
23.9;Acknowledgements;302
23.10;References;302
24;The Local Bubble Debate;304
24.1;Introduction;304
24.2;Solar Wind Charge Exchange (SWCX);305
24.3;After We Consider the Effects of SWCX, Is There Reason to Believe that the LB Actually Exists?-the Local Bubble vs. Solar Wind Charge Exchange Debate;305
24.3.1;What Measurements Are Needed to Determine How Much Hot Gas May Exist in the Local Bubble? ;307
24.4;Pressure and Energy Balances in the Local Bubble;308
24.4.1;Pressure Balance;308
24.4.2;Energy Balance;309
24.5;Small Scale Structure in the LB ;309
24.6;Other Important Physical Processes?;309
24.7;Acknowledgements;310
24.8;References;310
25;The Origins and Physical Properties of the Complex of Local Interstellar Clouds;311
25.1;Introduction;311
25.2;The Physical Characteristics of the Complex of Local Interstellar Clouds;312
25.2.1;Primary Observational Evidence;312
25.2.2;Electron Density and Temperature of the LIC;313
25.2.3;Radiative Transfer Models;314
25.3;Dust and Elemental Abundances in the LIC;316
25.4;LIC Ionization and Thermal Balance;317
25.5;The Origin the Complex of Local Interstellar Clouds;320
25.6;Summary;321
25.7;Acknowledgements;321
25.8;References;321
26;Physical Properties of the Local Interstellar Medium;323
26.1;Introduction;323
26.2;LISM Observational Database;324
26.3;Physical Properties of Individual Structures in the LISM;325
26.3.1;Dynamics;325
26.3.2;Solar Location Relative to LISM Clouds;327
26.3.3;Turbulence and Depletion;327
26.3.4;Inter-cloud Variation of Physical Properties;327
26.3.5;Dynamical Cloud Interactions;328
26.3.5.1;Cold Clouds;328
26.3.5.2;Interstellar Radio Scintillation;329
26.4;Conclusions and Future Work;329
26.5;Acknowledgements;330
26.6;References;330
27;Perspectives on Interstellar Dust Inside and Outside of the Heliosphere;332
27.1; Introduction;332
27.2; Dust in the Diffuse Interstellar Medium;333
27.3; Models for Interstellar Dust: Extinction vs. Elemental Abundances;335
27.4; Contribution of Massive Grains to Extinction;338
27.5; Could the Dust in the Local ISM Be Atypical?;338
27.5.1;Turbulent Mixing in the ISM;339
27.5.2;Enrichment by Supernova Explosions?;339
27.5.3;Wake of an Evolved Star?;340
27.5.4; Dynamical Concentration of Massive Grains?;340
27.6; Structure of the Very Local ISM;342
27.7; Summary;342
27.8;Acknowledgements;343
27.9;References;343
28;Interstellar Dust Inside and Outside the Heliosphere;345
28.1;Introduction;346
28.2;Interstellar Dust Inside the Heliosphere;347
28.3;Interstellar Dust in the Local Interstellar Cloud;350
28.4;Outlook;352
28.5;Acknowledgements;352
28.6;References;352
29;Obtaining Spectra of Turbulent Velocity from Observations;355
29.1;Introduction;355
29.2;Ways to Analyze Position-Position-Velocity Data Cubes;358
29.3;Basics of the Formalism;360
29.4;Illustration of VCS and VCA Techniques for Power-Law Velocities and Densities;364
29.4.1;Velocity Channel Analysis;364
29.4.2;Velocity Coordinate Spectrum;364
29.4.3;Effects of Self-Absorption;366
29.5;Studies of Turbulence with Absorption Lines;366
29.6;Comparison of VCA and VCS;368
29.7;Numerical Testing;370
29.8;Extending VCA and VCS;371
29.8.1;Studying Non-power-Law Turbulence;371
29.8.2;Studies of Nearby Gas;372
29.8.3;Studies of Emission Lines with Emissivity rho2;372
29.9;Observational Studies;372
29.9.1;Applying VCA;372
29.9.2;Applying VCS;374
29.9.3;Expected Developments;376
29.10;Alternative Approaches;376
29.10.1;Velocity Centroids;376
29.10.2;Wavelets and Principal Component Analysis;376
29.10.3;Spectral Correlation Function;377
29.10.4;Identifying Objects in PPV Space;378
29.11;Synergy and Future Work;378
29.11.1;Synergetic Statistical Studies;378
29.11.2;Prospects of Quantiative Studies of PPV Data;379
29.11.3;Outlook onto Big Picture;380
29.12;Acknowledgements;381
29.13;References;381
30;Properties and Selected Implications of Magnetic Turbulence for Interstellar Medium, Local Bubble and Solar Wind;384
30.1;Introduction;385
30.2;Spectrum of Turbulence and Its Anisotropy;386
30.2.1;Anisotropic MHD Turbulence;386
30.2.2;Imbalanced Turbulence;391
30.2.3;Viscous Turbulence;394
30.3;Intermittency: Small Volumes with Extreme Conditions;395
30.4;Modification of Turbulence by Cosmic Rays;397
30.5;Selected Implications of Magnetic Turbulence;399
30.5.1;Cosmic Ray Scattering by Fast Modes of MHD Turbulence;399
30.5.2;Turbulent Reconnection and Cosmic Ray Acceleration;400
30.5.3;Perpendicular Diffusion and Subdiffusion;403
30.6;Studying Magnetic Turbulence in Interplanetary Medium Using Comets;405
30.7;Discussion and Summary;406
30.8;Acknowledgements;407
30.9;References;407
31;The Heliosphere in Time;411
31.1;Introduction;412
31.2;Basic Model Results;412
31.2.1;Contemporary ISM (LIC);413
31.2.2;Hot Local Bubble;414
31.2.3;Dense Neutral ISM;415
31.2.4;High Velocity ISM;416
31.3;Supernova Remnant Encounters with the Heliosphere;416
31.4;Sensitivity of the Heliosphere to ISM Conditions;417
31.5;Paleo-Heliosphere;419
31.6;Conclusions;420
31.7;Acknowledgements;421
31.8;References;421
32;Some Observations Related to the Origin and Evolution of the Local Bubble/Local ISM;422
32.1;Introduction;423
32.2;The Local ISM Deuterium Abundance Variability and its Link with the Local Bubble/Gould Belt Structure;423
32.2.1;The Deuterium Abundance within 500 pc;423
32.2.2;End of the Debate about Dust Release of Deuterium?;424
32.2.3;The Gould Belt;425
32.2.4;A Link between the LC, the Gould Belt and the D/H Pattern?;426
32.3;Highly Charged Ions;427
32.4;Charge eXchange (CX) X-Ray Emission;427
32.4.1;The Heliospheric CX Emission and its Impact on LC and Halo Hot Gas;427
32.4.2;Non-Solar Charge Transfer X-Ray Emission? The North Polar Spur?;428
32.5;Data Need for a Better Global Picture of the LISM;430
32.6;References;430
33;Origin of the Local Bubble;432
33.1;Introduction;432
33.2;Search for Nearby OB Associations;433
33.3;Results and Discussion;437
33.3.1;The Search for the ``Smoking Gun'';437
33.3.2;How Many Supernovae and Were They Enough to Create the LB?;440
33.4;Conclusions;442
33.5;Acknowledgements;443
33.6;References;443
34;Kinetic-Fluid Perspective on Modeling the Heliospheric/Interstellar Medium Interface;444
34.1;Introduction;444
34.2;Development of the Kinetic-Fluid Model;448
34.2.1;Extent of the Heliosphere in the Tail Region;448
34.2.2;Effect of the 11-Year Solar Activity Cycle;449
34.2.3;Effect of Cosmic Rays;450
34.2.4;Effect of Nonequilibrium of the Pickup and Solar Wind Protons;451
34.2.5;Interstellar Magnetic Field Effect;451
34.3;Some Critical Remarks;453
34.4;To the Problem of the Heliopause Properties;454
34.4.1;To the Problem of the Heliopause Instability;455
34.4.2;What Is the Role of the Magnetic Field?;456
34.5;Whether the MHD Outer Heliosheath Is Bounded;457
34.6;Acknowledgements;458
34.7;References;458
35;From the Heliosphere to the Local Bubble-What Have We Learned?;460
35.1;Purpose and Philosophy of Summary;460
35.2;Outer Heliosphere and Its Boundary Regions;461
35.3;Inferring the CHISM from within;462
35.4;Structure and Pressure Balance in the Local Bubble;464
35.5;Small Scale Structure and Turbulence;466
35.6;Future Perspectives;466
35.7;Acknowledgements;467
35.8;References;467