11/08/2022
By Lynne Schaufenbil
Please join us on Thursday, Nov. 17 from 11 a.m. to noon for the virtual talk by Yifan Huang: "A Numerical Model for Understanding Pickup-Ion Dynamics in the Outer Heliosphere and IBEX Observations of the ENA Ribbon"
Yifan Huang, LANL, USA
Fan Guo, LANL, USA
Eric Zirnstein, Princeton University, USA
Hui Li, LANL, USA
Dan Reisenfeld, LANL, USA
Jacob Heerikhuisen, University of Waikato, New Zealand
We present a new numerical model for understanding the narrow and ribbon-like enhancement in the emission of energetic neutral atoms (ENA) coming from the outer heliosphere first discovered by the IBEX mission. We begin with a global MHD model which provides global magnetic field, plasma density and temperature, and neutral distributions in the heliosphere and local interstellar medium. The dynamics of the pickup ions is modeled by numerically solving the focused transport equation with prescribed diffusion coefficients, which includes the particle drifts and transport effects due to large-scale turbulence and micro-instabilities, such as field-line wandering and pitch-angle scattering. We determine the coefficients with test-particle simulations in magnetic field fluctuations similar to Voyager observations in the local interstellar medium. The ENA emission flux and image seen at 1 AU are calculated to enable comparisons between the simulation results and IBEX observations.
Yifan is a postdoc at Los Alamos National Laboratory, working on modelling the Interstellar Boundary Explorer (IBEX) ribbon and studying the heliosphere science. He was a Ph.D. student at UMass Lowell in 2015-2021, studying plasma physics and space physics. His thesis advisor is Dr. Paul Song.
If you wish to participate, please contact Lynne_Schaufenbil@uml.edu for the Zoom link.