Energetic Particles: From Sun to Heliosphere – and vice versa Robert Wimmer-Schweingruber1, Javier Rodriguez-Pacheco2, Sebastian Boden1, Stephan Böttcher1, Ignacio Cernuda2, Nina Dresing1, Christian Drews1, Wolfgang Dröge4, Francisco Espinosa Lara2, Raul Gomez-Herrero2, Bernd Heber1, George Ho3, Andreas Klassen1, Shrinivasrao Kulkarni1, Gottfried Mann5, Cesar Martin1, Glenn Mason3, Lauri Panitzsch1, Manuel Prieto2, Sebastian Sanchez2, Jan Steinhagen1, Jan Tammen1, Christoph Terasa1, Jia Yu1, Rami Vainio6 1Christian-Albrechts University Kiel, Germany, 2University of Alcala, Spain, 3Applied Physics Laboratory, MD, USA, 4University of Würzburg, Germany, 5Astrophysical Institute Potsdam, Germany, 6University of Turku, Finland 2017-12-12 rfws, ieap, cau 1 1

Red: Ulysses (see above) Blue: 1AU Red: Ulysses (see above) How does the Sun fill the heliosphere with energetic particles? Note how the decay phases are all very similar. This indicates that a large 'reservoir' of energetic particles that fills the heliosphere is being depleted at the same rate everywhere. How is it filled? Why does it empty in lockstep? Measurements close to Sun! (McKibben et al., 2003) 2017-12-12 rfws, ieap, cau

Radiation Transport in the Heliosphere Electrically charged ions and electrons IP Magnetic field controls propagation For a 1 MeV proton, rc is nearly 30,000 km at 1 AU 2017-12-12 rfws, ieap, cau

Charged energetic particles are tied to magnetic field... Large-scale interplanetary magnetic field organized along Parker spiral SOHO Charged energetic particles are tied to magnetic field... SOHO, STEREO, Messenger widely separated M STA STB 2017-12-12 rfws, ieap, cau

Connection Sun-Heliosphere for November 2011 Active region & flare Add PFSS model here STEREO B footpoint Nov. 3, 2011 SOHO footpoint Nov. 3, 2011 STEREO A footpoint Nov. 3, 2011 Messenger footpoint Nov. 3, 2011 (Gomez-Herrero et al., 2015) You don't really expect all spacecraft to see the event, do you? 2017-12-12 rfws, ieap, cau

How does the Sun connect to the heliosphere? We need to better understand the connection! SOHO Wide spread events seen in - ions, - electrons, - and 3He This is sobering... (can we connect S-H?) … but also at 1 AU! STEREO B STEREO A Messenger (Gomez-Herrero et al., 2015) (Richardson et al., 2014) 2017-12-12 rfws, ieap, cau

The Problem From the Solar Orbiter Red Book: How do solar eruptions produce energetic particle radiation that fills the heliosphere? 1) How and where are energetic particles accelerated at the Sun? 2) How are energetic particles released from their sources and distributed in space and time? 3) What are the seed populations for energetic particles? 2017-12-12 rfws, ieap, cau

To be an energetic particle, you need to be: - injected - accelerated - transported From the Solar Orbiter Red Book: How do solar eruptions produce energetic particle radiation that fills the heliosphere? 3) What are the seed populations for energetic particles? 1) How and where are energetic particles accelerated at the Sun? 2) How are energetic particles released from their sources and distributed in space and time? 2017-12-12 rfws, ieap, cau

To be an energetic particle, you need to be: - injected - accelerated - transported Suprathermal seed particles Origin not understood Flares, shocks, and compression Increasing role of turbulence Charged particles tied to B Perpendicular diffusion not understood 2017-12-12 rfws, ieap, cau

Have you seen this lately? Why does IMP8 at 1 AU only see such a smeared-out event? Can we infer solar onset times from particle data? (Kallenrode & Wibberenz, 1991) 2017-12-12 rfws, ieap, cau

How does the Sun connect to the heliosphere? Injection, Acceleration, and Transport Scatter-free transport in initial (onset) phase of event Outward moving particles Inward moving mirrored particles (Roelof, 2008) Agueda & Lario (2016) performed careful analysis of the Helios events and determined using this method. 2017-12-12 rfws, ieap, cau

Inversion method (not discussed) (previous slide) Inversion method (not discussed) (Kallenrode & Wibberenz, 1991) Reconstruction works remarkably well! (Agueda & Lario, 2016) 2017-12-12 rfws, ieap, cau

1) Different magnetic connection? Model predictions for IMP 8 assuming: a) same temporal release profile, b) same transport parameters from Helios to IMP 8 (Agueda & Lario, 2016) (Kallenrode & Wibberenz, 1991) 1) Different magnetic connection? 2) Different spatio-temporal evolution? 3) Transport effects? 2017-12-12 rfws, ieap, cau

STA/PLASTIC H+ measurements at SIRs Only little change Substantial flux downstream But also upstream (Yu et al, in prep.) 2017-12-12 rfws, ieap, cau

Power law like spectrum upstream (Yu et al, in prep.) Power law spectrum downstream Power law like spectrum upstream 2017-12-12 rfws, ieap, cau

Upstream VDFs are not always power laws (Yu et al, in prep.) ??? law ??? law Power law Should look for wave activity in these regions! 2017-12-12 rfws, ieap, cau

He+ at 1AU CIRs: Messengers from Elsewhere ACE/SWICS SOHO/CELIAS/ STOF (Yu et al., 2016) As observer moves away from reverse shock, magnetic connection moves farther out into heliosphere. If there is more He+ „out there“, we don‘t see it here. 2017-12-12 rfws, ieap, cau

Jovian Electrons (Pyle & Simpson, 1977) Jupiter‘s magnetosphere can be considered a point source at scale of heliosphere. 2017-12-12 rfws, ieap, cau

Jovian Electrons (Chenette et al., 1977) Measurements at 1 AU show 13-month periodicity (at quiet times) which is due to magnetic connection between Earth and Jupiter. 2017-12-12 rfws, ieap, cau

Jovian Electrons Access only by perp. diffusion (Kühl et al., 2013) Access only by perp. diffusion Measurements at 1 AU have potential to determine the efficiency of perpendicular diffusion. 2017-12-12 rfws, ieap, cau

Jovian Electrons „are all over the place“ Jupiter is a point source for relativistic and highly relativistic electrons Strong radial dependence from source (length along Parker spiral) Jovian electrons seen by Mariner 10 at 0.5 AU Jovian electrons also seen at up to 16° heliographic latitude and likely up to 84.5°. Inner heliosphere (r<1AU): Solar Orbiter and PSP „High“ latitudes: Solar Orbiter Can Solar Orbiter/EPD/HET and PSP/EPI-High measure Jovian electrons? 2017-12-12 rfws, ieap, cau

EPD/STEP EPD/SIS EPD/EPT-HET1 2017-12-12 rfws, ieap, cau

Summary & Conclusions EPD suite of 4 sensors part of Solar Orbiter Injection: suprathermal particles (STEP, EPT, SIS, SWA/HIS/PAS/EAS) Acceleration: plasma properties & turbulence (EPD, MAG, SWA, RPW, METIS, SPICE) Transport: plasma properties & turbulence, source (EPD, MAG, SWA, RPW, STIX, EUI) Connectivity: anisotropy, dispersion, source (EPD, MAG, RPW, SWA, STIX, EUI, SPICE, etc.) Combination with other instruments is crucial. Payload is meant to be used together, as a suite. Combination with PSP, Earth, & other assets. 2017-12-12 rfws, ieap, cau