Globally Distributed Energetic Neutral Atom Maps for the “Croissant” Heliosphere

Kornbleuth, Marc; Opher, M.; Michael, Adam; Drake, J. F.

doi:10.3847/1538-4357/aadbac

Cited by 19 publications

(30 citation statements)

References 53 publications

(106 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We also note, that in the case of 𝛼 = 𝛽, the bi-Maxwellian boundary condition (11) transforms into a single Maxwellian distribution function with number density 𝑛 pui and temperature 𝑇 pui . Even though the assumption of thermal equilibrium of the populations is not justified, the attempts to model the pickup ion velocity distribution using the superposition of Maxwell distributions are made by some authors (see, e.g., Zank et al 2010;Zirnstein et al 2017;Kornbleuth et al 2018).…”

Section: «Bi-maxwellian» Scenariomentioning

confidence: 99%

“…Additionally, we note that the partition of PUIs into two Maxwellian populations is performed only immediately after (downstream) the TS, and in the IHS, the solution (1) of the kinetic equation is used. This method compares favorably with other existing approaches since it does not imply the assumption of fixed temperature fraction in the whole inner heliosheath (like it was done in Zirnstein et al 2017;Kornbleuth et al 2018), which is not justified. As can be seen from Figure 1, the power-law «tail» in the PUI distribution forms the proper slope of the spectrum and makes the fluxes higher at energies 2 keV.…”

Section: «Bi-maxwellian» Scenariomentioning

confidence: 99%

See 1 more Smart Citation

Energetic pickup proton population downstream of the termination shock as revealed by the IBEX-Hi data

Baliukin,

Izmodenov,

Alexashov

2021

Preprint

View full text Add to dashboard Cite

The pickup protons originate as a result of the ionization of hydrogen atoms in the supersonic solar wind, forming the suprathermal component of protons in the heliosphere. While picked by the heliospheric magnetic field and convected into the heliosheath, the pickup protons may suffer the stochastic acceleration by the solar wind turbulence in the region from the Sun up to the heliospheric termination shock, where they can also experience the shock-drift acceleration or the reflection from the cross-shock potential. These processes create a high-energy «tail» in the pickup ion energy distribution. The properties of this energetic pickup proton population are still not well-defined, despite they are vital for the models to simulate energetic neutral atom fluxes. We have considered two scenarios for pickup proton velocity distribution downstream of the heliospheric termination shock (filled shell with energetic power-law «tail» and bi-Maxwellian). Based on the numerical kinetic model and observations of the energetic neutral atom fluxes from the inner heliosheath by the IBEX-Hi instrument, we have characterized the pickup proton distribution and provided estimations on the properties of the energetic pickup proton population downstream of the termination shock.

show abstract

Section: «Bi-maxwellian» Scenariomentioning

confidence: 99%

Section: «Bi-maxwellian» Scenariomentioning

confidence: 99%

Energetic pickup proton population downstream of the termination shock as revealed by the IBEX-Hi data

Baliukin,

Izmodenov,

Alexashov

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…The ENA Flux model is the same as used in Kornbleuth et al (2020), which is an update to the model used in Kornbleuth et al (2018). We interpolate our Cartesian grid to a spherical grid of 2 AU × 6 • × 6 • .…”

Section: Ena Modelmentioning

confidence: 99%

“…Measured ENA intensities represent the line-of-sight integral of local proton intensities times the neutral H density, which means modeling is required to interpret the observations. To model ENAs in the heliosphere, global heliospheric solutions can be used to simulate ENA fluxes directly (Heerikhuisen et al 2008) or can be used in post-processing to simulate ENA fluxes from the plasma and neutral distributions (Prested et al 2008;Zirnstein et al 2013;Kornbleuth et al 2018;Baliukin et al 2020).…”

Section: Introductionmentioning

confidence: 99%

Signature of a heliotail organized by the solar magnetic field and the role of non-ideal processes in modeled IBEX ENA maps: a comparison of the BU and Moscow MHD models

Kornbleuth,

Opher,

Baliukin

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Energetic neutral atom (ENA) models typically require post-processing routines to convert the distributions of plasma and H atoms into ENA maps. Here we investigate how two different kinetic-MHD models of the heliosphere (the BU and Moscow models) manifest in modeled ENA maps using the same prescription and how they compare with Interstellar Boundary Explorer (IBEX) observations. Both MHD models treat the solar wind as a single-ion plasma for protons, which include thermal solar wind ions, pickup ions (PUIs), and electrons. Our ENA prescription partitions the plasma into three distinct ion populations (thermal solar wind, PUIs transmitted and ones energized at the termination shock) and models the populations with Maxwellian distributions. Both kinetic-MHD heliospheric models produce a heliotail with heliosheath plasma organized by the solar magnetic field into two distinct north and south columns that become lobes of high mass flux flowing down the heliotail, though in the BU model the ISM flows between the two lobes at distances in the heliotail larger than 300 AU. While our prescription produces similar ENA maps for the two different plasma and H atom solutions at the IBEX-Hi energy range (0.5 -6 keV), the modeled ENA maps require a scaling factor of ∼2 to be in agreement with the data. This problem is present in other ENA models with the Maxwellian approximation of multiple ion species and indicates that a higher neutral density or some acceleration of PUIs in the heliosheath is required.

show abstract

“…Zirnstein et al (2016Zirnstein et al ( , 2017, using a time dependent simulation with solar cycle variations of the solar wind, reproduced the spectral dependence and heliotail ENA maps as shown by IBEX with a model of the heliotail resembling a long comet-like tail. Kornbleuth et al (2018) investigated the ENA maps from the "croissant" heliosphere (Opher et al 2015) with a uniform solar wind. The collimation of the heliosheath plasma by the solar magnetic field created high latitude lobes despite the lack of fast solar wind at the poles.…”

Section: Introductionmentioning

confidence: 99%

The Confinement of the Heliosheath Plasma by the Solar Magnetic Field as Revealed by Energetic Neutral Atom Simulations

Kornbleuth,

Opher,

Michael

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Traditionally, the solar magnetic field has been considered to have a negligible effect in the outer regions of the heliosphere. Recent works have shown that the solar magnetic field may play a crucial role in collimating the plasma in the heliosheath. Interstellar Boundary Explorer (IBEX ) observations of the heliotail indicated a latitudinal structure varying with energy in the energetic neutral atom (ENA) fluxes. At energies ∼1 keV, the ENA fluxes show an enhancement at low latitudes and a deficit of ENAs near the poles. At energies >2.7 keV, ENA fluxes had a deficit within low latitudes, and lobes of higher ENA flux near the poles. This ENA structure was initially interpreted to be a result of the latitudinal profile of the solar wind during solar minimum. We extend the work of Kornbleuth et al. ( 2018) by using solar minimum-like conditions and the recently developed SHIELD model. The SHIELD model couples the magnetohydrodynamic (MHD) plasma solution with a kinetic description of neutral hydrogen. We show that while the latitudinal profile of the solar wind during solar minimum contributes to the lobes in ENA maps, the collimation by the solar magnetic field is important in creating and shaping the two high latitude lobes of enhanced ENA flux observed by IBEX. This is the first work to explore the effect of the changing solar magnetic field strength on ENA maps. Our findings suggest that IBEX is providing the first observational evidence of the collimation of the heliosheath plasma by the solar magnetic field.

show abstract

Globally Distributed Energetic Neutral Atom Maps for the “Croissant” Heliosphere

Cited by 19 publications

References 53 publications

Energetic pickup proton population downstream of the termination shock as revealed by the IBEX-Hi data

Energetic pickup proton population downstream of the termination shock as revealed by the IBEX-Hi data

Signature of a heliotail organized by the solar magnetic field and the role of non-ideal processes in modeled IBEX ENA maps: a comparison of the BU and Moscow MHD models

The Confinement of the Heliosheath Plasma by the Solar Magnetic Field as Revealed by Energetic Neutral Atom Simulations

Contact Info

Product

Resources

About