Simulation of cometary jets in interaction with the solar wind

Wiehle, Stefan; Motschmann, U.; Gortsas, Nikolaos; Glaßmeier, K.‐H.; Müller, Jakob; Koenders, C.

doi:10.1016/j.asr.2011.05.024

Cited by 14 publications

(8 citation statements)

References 19 publications

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“…Neutral pressure measurements by the ROSINA/COPS instrument [ Balsiger et al , ] also observed this anisotropy attributed to the complicated shape and illumination pattern on the nucleus combined with the comet's rotation [ Bieler et al ., ]. Previous attempts have been made to simulate the effect of asymmetric neutral gas distributions and jets in the plasma environment of a comet [e.g., Jia et al , ; Wiehle et al ., ], and it has been established that the presence of neutral anisotropy around the comet affects the interaction of the solar wind with cometary plasma.…”

Section: The Neutral Coma Of Comet 67pmentioning

confidence: 99%

Suprathermal electrons near the nucleus of comet 67P/Churyumov‐Gerasimenko at 3 AU: Model comparisons with Rosetta data

et al. 2016

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Observations of the coma near the nucleus of comet 67P/Churyumov‐Gerasimenko (67P) made by the IES (Ion and Electron Sensor) instrument onboard the Rosetta Orbiter during late 2014 showed that electron fluxes greatly exceeded solar wind electron fluxes. The IES is part of the Rosetta Plasma Consortium. This paper reports on electron energy spectra measured by IES near the nucleus as well as approximate densities and average energies for the suprathermal electrons when the comet was at a heliocentric distance of about 3 AU. Comparisons are made with electron densities measured by other instruments. The high electron densities observed (e.g., ne ≈ 10–100 cm−3) must be associated with the cometary ion density enhancement created mainly by the photoionization of cometary gas by solar radiation; there are other processes that also contribute. Quasineutrality requires that the electron and ion densities be the same, and under certain conditions an ambipolar electric field is required to achieve quasi‐neutrality. We present the results of a test particle model of cometary ion pickup by the solar wind and a two‐stream electron transport code and use these results to interpret the IES data. We also estimate the effects on the electron spectrum of a compression of the electron fluid parcel. The electrons detected by IES can have energies as high as about 100–200 eV near the comet on some occasions, in which case the hot electrons can significantly enhance ionization rates of neutrals via impact ionization.

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Section: The Neutral Coma Of Comet 67pmentioning

confidence: 99%

Suprathermal electrons near the nucleus of comet 67P/Churyumov‐Gerasimenko at 3 AU: Model comparisons with Rosetta data

et al. 2016

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“…Modeling of the solar wind plasma interaction has been done extensively for weak comets [e.g., Bogdanov et al , ; Lipatov et al , ; Hansen et al , ; Gortsas et al , ; Wiehle et al , ; Behar et al , ], and in light of NASA's New Horizons mission, also for the dwarf planet Pluto[e.g., Delamere , ]. At these bodies, the pickup ion gyroradii are of the order of tens of thousands of kilometers.…”

Section: Introductionmentioning

confidence: 99%

Ceres interaction with the solar wind

Lindkvist

Holmström

Fatemi

et al. 2017

Geophysical Research Letters

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The solar wind interaction with Ceres is studied for a high water vapor release from its surface using a hybrid model including photoionization. We use a water vapor production rate of 6 kg/s, thought to be due to subsurface sublimation, corresponding to a detection on 6 March 2013 by the Herschel Space Observatory. We present the general morphology of the plasma interactions, both close to Ceres and on a larger scale. Mass loading of water ions causes a magnetic pileup region in front of Ceres, where the solar wind deflects up to 15° and slows down by 15%. The global plasma interaction with Ceres is not greatly affected by the source location of water vapor nor on gravity, only on the production rate of water vapor. On a global scale, Ceres has a comet‐like interaction with the solar wind with observable perturbations farther than 250 Ceres radii downstream of the body.

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“…25 This meant that even at large heliocentric distances the 26 weakly outgassing nucleus of 67P mass-loads the solar 27 wind plasma [5,6]. 28 29 Various ionization processes, such as electron-impact 30 ionization, photo-ionization, and charge exchange, 31 contribute to the shape of the near-cometary environ-32 ment [16][17][18]. Rosetta observed a radial dependence of Illustration of the solar wind interaction with a weakly outgassing comet representative of 67P/Churyumov-Gerasimenko at a heliocentric distance of 4.0 − 4.5 AU.…”

mentioning

confidence: 99%

Building a Weakly Outgassing Comet from a Generalized Ohm’s Law

et al. 2019

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When a weakly outgassing comet is sufficiently close to the Sun, the formation of an ionized coma results in solar wind mass loading and magnetic field draping around its nucleus. Using a 3D fully kinetic approach, we distill the components of a generalized Ohm's law and the effective electron equation of state directly from the self-consistently simulated electron dynamics and identify the driving physics in the various regions of the cometary plasma environment. Using the example of space plasmas, in particular multi-species cometary plasmas, we show how the description for the complex kinetic electron dynamics can be simplified through a simple effective closure, and identify where an isotropic single-electron fluid Ohm's law approximation can be used, and where it fails.Numerical models that seek to describe the evolution 1 of plasma without self-consistently including the electron 2 dynamics, such as (multi-)fluid and hybrid simulation 3 approaches [1], need to rely on a relation that prescribes 4 the behavior of the unresolved species. Typically a 5 generalized Ohm's law (GOL) is assumed [2], combined 6 with a closure relation such as a polytropic or a double 7 adiabatic evolution [3,4]. In this letter, we show how a 8 GOL can unravel the hidden mysteries of multi-species 9 plasma environments, such as the solar wind plasma 10 interaction with a weakly outgassing comet [5][6][7]. We 11 indicate where reduced plasma models can be applied, 12 e.g., to gain more direct access to the ongoing physics 13 and/or to decrease the needed amount of computational 14 resources, and show the consequences of this compromise. 15 * mailto: jandeca@gmail.com 16 The Rosetta spacecraft caught up with comet 17 67P/Churyumov-Gerasimenko (hereafter 67P) at a 18 heliocentric distance of 3.6 AU [8, 9]. At a few hundreds 19 of kilometers from the cometary nucleus, the Rosetta 20 plasma instruments, quite unexpectedly, picked up 21 the signatures of a plasma environment dominated 22 the plasma density with distance from the nucleus [19, 20] 34 or, in other words, there exists a continuously changing 35 ratio between the cometary and the upstream solar wind 36 plasma density throughout 67P's plasma environment, 37 both along the Sun-comet direction as well as in the 38 meridian plane [21-23]. To first order, for a weakly 39 outgassing comet, the dynamical interaction that de-40 termines the general structure of the cometary plasma 41 environment is representative of a four-fluid coupled 42 system (illustrated in Fig. 1), where the solar wind 43 electrons move to neutralize the cometary ions and the 44 cometary electrons organize themselves to neutralize the 45 solar wind ions [7]. 46 47 In addition to a detailed understanding of the kinetic 48 dynamics that governs the solar wind interaction with 49 a weakly outgassing comet, in this letter we provide 50 feedback to (multi-)fluid [24-29] and hybrid [16, 30-37] 51 models where the electrons dynamics is prescribed 52 through a GOL combined with an electron closure 53 relation. Using a f...

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Simulation of cometary jets in interaction with the solar wind

Cited by 14 publications

References 19 publications

Suprathermal electrons near the nucleus of comet 67P/Churyumov‐Gerasimenko at 3 AU: Model comparisons with Rosetta data

Suprathermal electrons near the nucleus of comet 67P/Churyumov‐Gerasimenko at 3 AU: Model comparisons with Rosetta data

Ceres interaction with the solar wind

Building a Weakly Outgassing Comet from a Generalized Ohm’s Law

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