Dartmouth Events

Abstract: Interstellar neutral hydrogen (ISN H) is the dominant driver of the dynamics of our heliosphere, defined as the region within which the solar wind interacts with the part of the local interstellar medium (LISM) through which we travel. Explorer probes such as Interstellar Boundary Explorer (IBEX) and the recently launched Interstellar Mapping and Acceleration Probe (IMAP) measure the ISN H approaching Earth from regions far away, giving us a snapshot of what interstellar space around us is like. In my work, I use trajectory methods to solve the equations of motion for ISN H, tracing it back in time from locations corresponding to these near-Earth explorer probes to origins farther out within the heliosphere. The goals are understanding the particular dynamics of ISN H in a time-dependent stellar environment as their trajectories are impacted by the radiation pressure force caused by solar Lyman-α radiation, and making comparisons of simulation data with spacecraft data. I synthesize models of the radiation pressure force as well as loss drivers in the form of ionization, as well as factoring in Ly-α absorption, to create a fully realized model that allows us to simulate what an explorer probe should see based on model parameters. Finally, I present comparisons of simulation results with recently published IBEX data, demonstrating the power of the model and its use in analysis preceding the advent of IMAP data.

Graduate Student Advisor: Professor Hans Mueller 

Zoom Link: https://dartmouth.zoom.us/j/7490864617