Diagnostics of the local interstellar medium and its interaction with the heliosphere from within
This presentation is the property of its rightful owner.
Sponsored Links
1 / 36

E. Möbius PowerPoint PPT Presentation


  • 151 Views
  • Uploaded on
  • Presentation posted in: General

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.

Download Presentation

E. Möbius

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


Simulated O-Flow ObservationFor the Spring Flow Passage

O Flow Spring

CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC


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


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


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


Thank You!

CSPAR Conf Voyagers in the Heliosheath Jan 2009 E. Möbius UNH/SSC


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


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


If We Could See Our Heliospherefrom Outside …

ISM Gas Flow

BZ Cam

Spring AGU Mtg 2008 E. Möbius UNH/SSC


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


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


Combined He Cone PUI ObservationsAMPTE, ACE & NOZOMI

Sliding 9-Day Averages

Daily Averages

Solar Minimum

30 – 40

Days

Maximum

Gloeckler et al., 2004


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


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


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


Neutral Imaging Most Accurate & Detailed

Spring AGU Mtg 2008 E. Möbius UNH/SSC


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


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


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


Why Bother?

Spring AGU Mtg 2008 E. Möbius UNH/SSC


  • Login