Modeling Secondary Neutral Helium in the Heliosphere

15th Annual International Astrophysics Conference: "The Science of Ed Stone: Celebrating his 80th Birthday"

物理学;天文学

Müller, Hans-Reinhard^1,2 ; Möbius, Eberhard^3 ; Wood, Brian E.^4

Department of Physics and Astronomy, Dartmouth College, Hanover

NH

03755, United States^1

Center for Space Plasma and Aeronomic Research, University of Alabama, Huntsville

AL

35805, United States^2

Space Science Center, Department of Physics, University of New Hampshire, Durham

NH

03824, United States^3

Naval Research Laboratory, Space Science Division, Washington

DC

20375, United States^4

关键词: Charge exchanges;    First principles;    Forward modeling;    In-situ observations;    Interstellar mediums;    Phase space densities;    Secondary components;    Secondary production;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/767/1/012019/pdf
DOI  :  10.1088/1742-6596/767/1/012019

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

An accurate, analytic heliospheric neutral test-particle code for helium atoms from the interstellar medium (ISM) is coupled to global heliospheric models dominated by hydrogen and protons from the solar wind and the ISM. This coupling enables the forward-calculation of secondary helium neutrals from first principles. Secondaries are produced predominantly in the outer heliosheath, upwind of the heliopause, by charge exchange of helium ions with neutral atoms. The forward model integrates the secondary production terms along neutral trajectories and calculates the combined neutral helium phase space density in the innermost heliosphere where it can be related to in-situ observations. The phase space density of the secondary component is lower than that of primary neutral helium, but its presence can change the analysis of primaries and the ISM, and can yield valuable insight into the characteristics of the plasma in the outer heliosheath.