What is New in the Outer Heliosphere?: Voyager and IBEX

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1 What is New in the Outer Heliosphere?: Voyager and IBEX Marty Lee Durham, New Hampshire USA 1

2 Our Local Interstellar Environment From E. Möbius

3 Pogorelov et al., 2008

4 Plasma & Neutral Parameters R = 1 AU R = 100 AU LISM n p 5 cm -3 V sw 400 km/s B G V A 40 km/s n He cm 3 n p cm 3 V sw 300 km/s B G V A 20 km/s n H 0.1cm -3 n He cm 3 n p 0.05 cm -3 V ISM 23(?) km/s B (?)G V A 22(?) km/s n H 0.2 cm -3 n He cm 3 4

5 Voyagers 1&2: Still Exploring! 5

6 Voyager Trajectories Fig. by J. Richardson 15-Apr-13 AIAC12 6

7 IBEX Spacecraft Simple sun-pointed spinner (4 rpm) Two huge aperture single pixel ENA cameras: IBEX-Lo (~10 ev to 2 kev) IBEX-Hi (~300 ev to 6 kev) E. Möbius, UNH SSC, for the IBEX Team Colloquium Wesleyan University,

8 Termination Shock is Special plasma pickup ion neutral CR 8

9 Adventures in the Outer Heliosphere Where is the Shock and ACRs? ISM Gas Parameters No Heliospheric Bow Shock First Measurement of Primary ISM H Hydrogen Deflection Plane (Lallement) The IBEX Ribbon Heliosheath V r ~ 0 The Heliocliff First Measurement of Low-Energy GCRs

10 Voyager 1 Ions Decker et al., 2005

11 Stone et al., 2008

12 Termination Shock Plasma Data At Voyager 2 Richardson et al., 2008

13 Pickup Ion Distribution in SW v y 0 V sw v x

14 Voyager 1 Downstream Spectra Stone et al., 2005

15 Stone et al.,

16 Current Sheets & Reconnection Pogorelov et al.,

17 Particle acceleration Pumping Mechanism Island merging & contraction Fisk & Gloeckler 2010 Particles are accelerated by a series of adiabatic compressions and expansions, in which the particles can escape from a compression region. Fermo, Drake, Swisdak, 2010 Particles are accelerated by merging and Contracting islands.

18 Ideas of Particle Acceleration (cont.) Credit: NASA

19 Diffusive Shock Acceleration

20 The Blunt Termination Shock McComas and Schwadron, 2006

21 Blunt Shock: 2D Simulation for ACR energies TS is offset circe, small cross field diffusion: η=0.02 ACR flux increases into the Heliosheath V-2 V-1 Spectrum gradually unfolds Kota, 2010

22 (New) Puzzles and Controversies Where is the Shock and ACRs? ISM Gas Parameters No Heliospheric Bow Shock First Measurement of Primary ISM H Hydrogen Deflection Plane (Lallement) The IBEX Ribbon Heliosheath V r ~ 0 The Heliocliff First Measurement of Low-Energy GCRs

23 IBEX Observes He and H 23

24 Flow Latitude Distribution 24

25 Flow Longitude Distribution 25

26

27

28 Basic Equations (μ<1 and μ>1) 3 f (v,, )(V E / n) ( t) 3/2 exp t 1 v 2 2r 1 2 (1 ) v ISM 2v ISM [v 2 2r 1 (1 )] 1/2 cos cos cos sin [cos cos sin sin sin ] exp r(vsin ) 1 cos 1 (cos ) cos 2 1 rv 2 (1 ) 1 sin 2 r 2 v 3 (1 ) 2 v 2 2r 1 (1 ) 1/2 sin 2 cos rv 2 sin 2 rv2 sin cos (1 ) 1 2 [rv 2 (1 ) 1 1] 2 sin 2 cos 2 1/2 rv /2 rv 2 1 sin2 1 sin

29 Sun to Earth Frame V cos V 'cos ' V sin sin V 'sin 'sin ' V sin cos V 'sin 'cos ' V E

30 '/ Helium Integrated Intensity ' / 2 t 0.03 v ISM IBEX Frame /

31 Peak in Latitude 3 f (v,, )(V E / n) ( t) 3/2 exp t 1 v v ISM 2v ISM (v 2 2) 1/2 sin sin cos( ) 2lnv' v 1 cos 1 (v 2 1) 1 cos cos 0 sc v 0 (v 0 1) sin v 2 0 ( z cos 0 sc E sin 0 sc ) sin( (v 0 1)(v 2 0 2) 1/2 sin 0 ) Independent of Ionization Rate 1

32 Best ISM He Parameters ISM ISM ISM Witte, 2004 V ISM kms 1 T ISM K McComas et al.,

33 (New) Puzzles and Controversies Where is the Shock and ACRs? ISM Gas Parameters No Heliospheric Bow Shock First Measurement of Primary ISM H Hydrogen Deflection Plane (Lallement) The IBEX Ribbon Heliosheath V r ~ 0 The Heliocliff First Measurement of Low-Energy GCRs

34 No Bow Shock! McComas et al.,

35 (New) Puzzles and Controversies Where is the Shock and ACRs? ISM Gas Parameters No Heliospheric Bow Shock First Measurement of Primary ISM H Hydrogen Deflection Plane (Lallement) The IBEX Ribbon Heliosheath V r ~ 0 The Heliocliff First Measurement of Low-Energy GCRs

36 Interstellar Hydrogen Schwadron et al.,

37 Hydrogen Speed, Temperature and λ Schwadron et al.,

38 Radiation Pressure on H Schwadron et al.,

39 (New) Puzzles and Controversies Where is the Shock and ACRs? ISM Gas Parameters No Heliospheric Bow Shock First Measurement of Primary ISM H Hydrogen Deflection Plane (Lallement) The IBEX Ribbon Heliosheath V r ~ 0 The Heliocliff First Measurement of Low-Energy GCRs

40 Lyman-α Backscatter Lallement et al.,

41 Origin of Secondaries

42 Primary and Secondary H 42 Pogorelov et al., 2008

43 (New) Puzzles and Controversies Where is the Shock and ACRs? ISM Gas Parameters No Heliospheric Bow Shock First Measurement of Primary ISM H Hydrogen Deflection Plane (Lallement) The IBEX Ribbon Heliosheath V r ~ 0 The Heliocliff First Measurement of Low-Energy GCRs

44 IBEX Reveals the Ribbon

45

46 The View with IBEX SWRI/Adler Planetarium

47 Secondary ENAs as Source for the IBEX Ribbon Heerikhuisen et al., /29/2013 ASTRONUM 2012, Hawaii 47

48 (New) Puzzles and Controversies Where is the Shock and ACRs? ISM Gas Parameters No Heliospheric Bow Shock First Measurement of Primary ISM H Hydrogen Deflection Plane (Lallement) The IBEX Ribbon Heliosheath V r ~ 0 The Heliocliff First Measurement of Low-Energy GCRs

49 Voyager in the Transition Layer Zero radial outflow! Increase of tangential speed Krimigis et al., 2011

50 Time-Dependent Heliosheath Pogorelov et al.,

51 (New) Puzzles and Controversies Where is the Shock and ACRs? ISM Gas Parameters No Heliospheric Bow Shock First Measurement of Primary ISM H Hydrogen Deflection Plane (Lallement) The IBEX Ribbon Heliosheath V r ~ 0 The Heliocliff First Measurement of Low-Energy GCRs

52 Voyager at the Heliopause?

53 Voyager 1, 2012/ /98: Galactic cosmic rays enter the high-b regions, while low-energy heliosheath particles leave via magnetic connection to LISM 15-Apr-13 AIAC12 53

54 Voyager 1: Heliosheath particles escape, GCRs enter & B increases 15-Apr-13 AIAC12 54

55 Voyager 1: Angular distributions of protons MeV (1-d avg.) 2012/ Apr-13 AIAC12 55

56 Voyager in the Heliosheath Burlaga et al., 2013 Image credit: NASA/JPL- Caltech/GSFC/University of Delaware

57 Burlaga et al., 2013 Image credit: NASA/JPL- Caltech/GSFC/University of Delaware Magnetic Field Observations Conclusions: Increase of the magnetic field magnitude. NO change in the magnetic field orientation. Parker Spiral magnetic field

58 (New) Puzzles and Controversies Where is the Shock and ACRs? ISM Gas Parameters No Heliospheric Bow Shock First Measurement of Primary ISM H Hydrogen Deflection Plane (Lallement) The IBEX Ribbon Heliosheath V r ~ 0 The Heliocliff First Measurement of Low-Energy GCRs

59 The Current Picture of the Heliosphere McComas et al. 2012