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E. Möbius

E. Möbius with H. Kucharek, M. Bzowski, L. Saul, P. Wurz, S. Fuselier, V. Izmodenov, D. McComas, H.-R. Müller, D. B. Alexashov. DIAGNOSTICS OF THE LOCAL INTERSTELLAR MEDIUM AND ITS INTERACTION WITH THE HELIOSPHERE FROM WITHIN. Thanks to: IBEX Team and NASA SMEX Office ISSI He and H Team.

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E. Möbius

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  1. E. Möbius with H. Kucharek, M. Bzowski, L. Saul, P. Wurz, S. Fuselier, V. Izmodenov, D. McComas, H.-R. Müller, D. B. Alexashov DIAGNOSTICS OF THE LOCAL INTERSTELLAR MEDIUM AND ITS INTERACTION WITH THE HELIOSPHERE FROM WITHIN Thanks to: IBEX Team and NASA SMEX OfficeISSI He and H Team CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  2. Neutral LIC Flow Diagnosticswith IBEX • IntroductionInformation Imprinted on Interstellar Gas Flow, previous Observations & current Knowledge • New Observation Method- IBEX Mission Configuration and Simulations- IBEX Instrumentation and Sensitivity- IBEX Orbit Strategy- IBEX In-Flight Performance • Summary & Conclusions Overview CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  3. Interstellar Gas Penetrates the Barrier Rosetta Nebula 1967 ≈700 AU Fahr 1967 Showed that in-situ observationof the LIC is possible at 1 AU! “Strömgren Sphere” CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  4. Information in the Interstellar Gas Flow 3 In-Situ Methods - UV Backscattering - integral, - hard to calibrate + global info - Pickup Ions - lost velocity info + composition - Neutral Imaging + full distribution - hard to do few species mvB2/2 ≈ GmMs/Rat ≈ 1.3 AU Velocity Vector fromKinematics of Local Flow and Density Pattern Jmax/Jo: ISM Temperature VISM Opens With IBEX Jo: ISM Density CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  5. Pristine LIC State from He with 3 Methods(Efforts of an ISSI Team) He Parameters from Neutral Gas, Pickup & UV Scattering • VHe= 26.3 km/s; THe = 6300 K; nHe = 0.015 cm-3 Neutral Image(V, T, NHe) Let’s Turn to other Species! Neutral Gas Observations provide most accurate and detailed information CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  6. Plasma Interaction with the LIC Plasma Density Contours Blue & Green Solar Wind Bow Shock? He He Termination Shock ISM ≈ 26 km/s H & O Charge Exchange O, H slow & hot H+, O+ Heliopause ISM Orange - Pristine ISM Red - Decelerated ISM 3D MHD Model T. Linde, Thesis CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  7. LIC He State & H Density at TS (2 ISSI Teams) Combine He Parameters, TS Distance & H Density at the TS To infer H and H+ Densities in the LIC • SW Slowdown Richardson et al.: 0.09±0.02 cm-3Includes Uncertainties in Model & Parameters • UV Scattering Pryor et al.: 0.09±0.024 cm-3Modulation Damping; Incl. Observ. & Model Uncertainties • Pickup Ions Bzowski et al.: 0.087±0.022 cm-3Observation, Model, Ioniz. & Rad. Pressure Uncertainties Key Value: nH from SW Slowdown, UV Scattering & Pickup • Voyager Tails Gloeckler et al.: 0.055±0.021cm-3IncludesNHe & relative Uncertainties • Weighted Mean: 0.083±0.023 cm-3 There are still large Uncertainties Let us Expand the He Neutral Observations to H or O! And there is more to gain with Direct Flow Observations!! CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  8. Ly Alpha Observations Have RevealedDeflected Flow of H Asymmetric ISM Magnetic FieldDeflects the Decelerated FlowIzmodenov et al., 2005 H Latitude He Longitude Direct Neutral Observations & 2nd Species Highly Desirable Lallement et al. 2005 CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  9. Pattern of the Interstellar Gas Flow It Has Been Done for He, Revealing the Pristine Flow! Asymmetry Effect IBEX Oxygen will be Displaced, Revealing Deflection & Braking CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  10. Modeling of H & O Flow with ISM Magnetic Field BISM O Flow Deflected by ≈ 1orelative to He Izmodenov From Möbius et al., 2009 CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  11. Pattern of the Interstellar Gas Flow IBEX Oxygen Displaced, Revealing Deflection & Braking Simulated Observationin Longitude after Izmodenov et al., 1996 CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  12. Pattern of the Interstellar Gas Flow Oxygen Displaced, Revealing Deflection & Braking Fall Spring Simulated Flow Angle Difference Trajectory Computation Bzowski et al. CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  13. Neutral Gas Observation, How Does it Work?II. Oxygen + .. • Collimator CameraDirection DeterminationNeed large area: Collimator • Use Surface Conversion into Ions- Need Mass Spectrometer for Species Identification!- Negative Ions: For O, H, (C) Not for N! Is it for He?? • Technique doesn’t Provide E - Use the Sun as Gravitational Spectrometer- Determine Arrival Direction Also for Deflection by ISM Magnetic Field Oo O- CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  14. Imaging of Several Neutral Atom Species What Does it Take to Do this? IBEX-Lo Collimator Diamond-Like Carbon Analyzer Start 1 + Start 2 + Stop Hard DiskCoating e-Start 2 ion ion ion Stop Time-of-Flight foil1 foil2 MCP CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  15. He Represents the Pristine ISM Flow Can it be Observed Simultaneously? Yes, it Can! With Sputter Products Test with Neutral He at UoBern Spring Fall Meta-Stable He IBEX-Lo Wurz et al., 2008 CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  16. IBEX ISM O and He Observation Conditions • IBEX is a Sun-Pointed SpinnerIBEX-lo FoV at 90o to the Sun • Observation Periods:Fall and Spring • Fall: Large Angular Separation of Primary & Secondary O, but low Count RateBecause: Earth recedes from Flow • Spring: Small Angular Separation of Primary & Secondary O, but high Count RateBecause: RAM Direction • Observe O at 540 eV • Observe He at 135 eV (x1500 in Flux; High Sputtering Efficiency) CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  17. IBEX Keeps Orientation for One Full Orbit How Does that Affect the O Observation? • Overlapping Sweeps in Spring CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  18. Simulated O-Flow ObservationFor the Spring Flow Passage O Flow Spring CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  19. IBEX-Lo In-Flight Performance IBEX-Lo TOF Works Great! H & O Easily Identified e Filtered out! Excellent Tool to Tackle Background CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  20. IBEX-Lo In-Flight Performance Arbitrary Orbit 9 Sample No Selection or BackgroundSubtraction! Normalized toISM Flow Viewing Both ISM O & He will be well Visible! First Spring Period Starts Now! CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  21. Conclusions & Outlook • Neutral Atom Imaging is becoming a powerful new window for Local Astrophysics • ISM He Holds Unbiased LIC Account Neutral Gas Observations provide the most detailed and accurate LIC Parameters, in accordance with simultaneous Pickup Ion & UV Observations • ISM H & O - affected by the Heliospheric Interface - hold clues to the interaction with the LIC • IBEX-lo will determine the O Flow distribution in direct comparison with He and relative to star positions, thus providing slowdown, heating, and deflection of the Secondary O component • Flow Signal 2 orders of magnitude above average sample • First Observation Campaign starts now! CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  22. Thank You! CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  23. Neutral AtomsA New Window for Local Astrophysics • Neutral Atoms:Observed up to their Mean Free Pathlength:A few 100 AU in the Neighborhood of the Sun-> Ideal for charting the Heliosphere and its Boundaries-> No Interference from farther away, But Objects outside are also beyond the Neutral Atom Horizon • IBEX takes it up to its Horizon • Neutral Atom Imagingknits another connection between Space Physics & Astrophysics Point Source Diffuse Source CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  24. ISM Neutral Gas In Different ISM Cloud Environments • Hot Cloud like the Local Bubble:No Neutral Gas in the Bubble,Thus No In-Situ Observations • Cold and Dense ISM Clouds:- N ≥ 100 cm-3- He Remains most Important Species at 1 AU- Slowdown of SW inside 1 AU in Focusing Cone “He Comet”- Pickup Ions and Energetic He+ very important at 1 AU Möbius et al., 2006 CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  25. If We Could See Our Heliospherefrom Outside … ISM Gas Flow BZ Cam Spring AGU Mtg 2008 E. Möbius UNH/SSC

  26. Pattern of the Interstellar Gas FlowHe Provides Unbiased LIC Parameters Courtesy M. Witte CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  27. Three Step ApproachInto the Future • 1) Make Use of “S3C Great Observatory” with Coordinated ObservationsACE, SOHO, Wind, Ulysses, Voyagers • 2) Be Innovative at Our Front DoorstepModerately Improved Observation Techniques at 1 AU or up to ≈3 AU IBEX Improve Resolution and Collection Power • 3) Develop Seriously a Probe to the Frontier * Interstellar Probe *It definitely Needs Improved Technology!! Spring AGU Mtg 2008 E. Möbius UNH/SSC

  28. Combined He Cone PUI ObservationsAMPTE, ACE & NOZOMI Sliding 9-Day Averages Daily Averages Solar Minimum 30 – 40 Days Maximum Gloeckler et al., 2004

  29. Strong Variations in Pickup Ion Distributions • Pickup Ion Distributions are Highly Variable • Pickup Ions React to:- IMF Orientation (early Rollover)- IMF Strength (Compression and Rarefaction)- SW Density (Compression and Rarefaction)- Ionization rates &probably several unknown causes • For Deduction of LIC Parameters Mitigation Sought with:- Long Integration Times • Better: Attempt to Understand Causes- Also Provides Handle on Ion Transport and Acceleration • STEREO (also ACE) Provide Simultaneous Observations

  30. STEREO & ACE Now Allow Simultaneous Interstellar He Cone Observations This provides tools to separate spatial & temporal variations STEREO A ACE ≈40oin 2007 STEREO B Ongoing Analysis not discussed here

  31. Pristine LIC State from He with 3 Methods(Efforts of an ISSI Team) Sensitive to Ionization Cone Sensitive to V, T, Ionization J. Raymond G. Gloeckler Neutral Image(V, T, NHe) J. Vallerga SWICSPickup (NHe) Simulation:Courtesy J. Raymond UV Ionization, Solar Illuminationfrom SOHO SEM, EIT and SUMER IndependentCheck on V CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  32. Neutral Imaging Most Accurate & Detailed Spring AGU Mtg 2008 E. Möbius UNH/SSC

  33. Why Did we Start with Interstellar Helium?(and not Hydrogen) • Has the Highest Ionization Potential i.e. Reaches 1 AU • Second Most Abundant Species i.e. Is an Important Species in the LISM • Not Affected by the Heliospheric Interface i.e. Provides an Unbiased Account of the LISM • Could be Observed with 3 Methods First: Neutrals, Pickup, Scattering of Solar UV Spring AGU Mtg 2008 E. Möbius UNH/SSC

  34. IBEX ISM O Observation Conditions • IBEX is a Sun-Pointed SpinnerIBEX-lo FoV at 90o to the Sun • Observation Periods:Fall and Spring • Fall: Large Angular Separation of Primary & Secondary O, but low Count RateBecause: Earth recedes from Flow • Spring: Small Angular Separation of Primary & Secondary O, but high Count RateBecause: RAM Direction CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC

  35. IBEX-lo O Conversion EfficiencyFor ISM O Observations • O must be observed in Spring and FallSeparates Heliospheric from Gravitational Deflection • In Fall: O Flux down x4 (lower relative speed) & Efficiency down x20 • But Lo-Res Section can be usedIncreases collection x12 IBEX-Lo Energy Range Fall Spring x 20 Wurz et al., 2006 Spring AGU Mtg 2008 E. Möbius UNH/SSC

  36. Why Bother? Spring AGU Mtg 2008 E. Möbius UNH/SSC

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