SH41E-2408
Exploring the Galactic Environment of the Sun with IMAP
Thursday, 17 December 2015
Poster Hall (Moscone South)
Priscilla C Frisch, University of Chicago, Chicago, IL, United States, Eberhard Moebius, University of New Hampshire, Institute for the Study of Earth, Oceans and Space, and Department of Physics, Durham, NH, United States, Herbert O Funsten, Los Alamos National Laboratory, Los Alamos, NM, United States, David J McComas, Southwest Research Institute, San Antonio, TX, United States, Nathan Schwadron, University of New Hampshire Main Campus, Space Science Center, Durham, NH, United States and Jonathan D Slavin, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, United States
Abstract:
The Interstellar Mapping and Acceleration Probe (IMAP) will be capable of providing detailed constraints on the physical conditions, ionization environment, and variability of the Local Interstellar Cloud (LIC) that surrounds the heliosphere. IBEX discovered an extended “ribbon” of energetic neutral atoms (ENAs) whose center is generally accepted to trace the interstellar magnetic field direction in the LIC. Models indicate that the ribbon configuration is a sensitive diagnostic of the LIC physical properties. The higher spatial resolution and sensitivity, and extended energy range, of the IMAP ENA detectors will provide deeper insight into the ribbon structure. Over time the ribbon data may allow sampling of spatial structure at the edge of the LIC. The long sampling interval of the combined IBEX and IMAP ribbon observations will also constrain temporal variations in the surrounding cloud over decades-long time scales. IBEX data on neutral atoms reveal that the LIC consists of warm, partially ionized gas. IMAP measurements of interstellar neutral atoms and pickup ions will provide an accurate basis for evaluating the LIC temperature and ionization state. These results have implications for the origin of the ultraviolet photons that maintain the LIC ionization, and for understanding the boundary regions of interstellar clouds in general. IMAP data on D/H, and 3He/4He will provide invaluable constraints on primordial nucleosynthesis. Different IMAP instruments will independently measure the relative abundances of the common dust grain constituent oxygen, and the noble gases He, Ne, and Ar that are not in the grains, and thus constrain interstellar grain composition in a unique way. IMAP ENA data on the heliosheath regions will add to the accuracy of the composition results by improving our understanding of the ionization processes of these neutrals once inside the heliosphere.
