Determining the ionization rates of interstellar neutral species using direct-sampling observations of their direct and indirect beams
arXiv:2301.10793 · doi:10.3847/1538-4365/acb497
Abstract
A good understanding of the ionization rates of neutral species in the heliosphere is important for studies of the heliosphere and planetary atmospheres. So far, the intensities of the ionization reactions have been studied based on observations of the contributing phenomena, such as the solar spectral flux in the EUV band and the flux of the solar wind protons, alpha particles, and electrons. The results strongly depend on absolute calibration of these measurements, which, especially for the EUV measurements, is challenging. Here, we propose a novel method of determining the ionization rate of neutral species based on direct sampling of interstellar neutral gas from two locations in space distant to each other. In particular, we suggest performing observations from the vicinity of Earth's orbit and using ratios of fluxes of ISN He for the direct and indirect orbits of interstellar atoms. We identify the most favorable conditions and observations geometries, suitable for implementation on the forthcoming NASA mission Interstellar Mapping and Acceleration Probe.
arXiv commentAccepted for ApJS
References in corpus (16)
- Interstellar neutral helium in the heliosphere from IBEX observations. III. Mach number of the flow, velocity vector, and temperature from the first six years of measurements
- Survival probability and energy modification of hydrogen Energetic Neutral Atoms on their way from the termination shock to Earth orbit
- Modulation of neutral interstellar He, Ne, O in the heliosphere. Survival probabilities and abundances at IBEX
- The revised Brussels-Locarno Sunspot Number (1981-2015)
- Sun-Heliosphere Observation-based Ionization Rates Model
- Interstellar neutral helium in the heliosphere from IBEX observations. II. The Warsaw Test Particle Model (WTPM)
- Interstellar neutral helium in the heliosphere from IBEX observations. VI. The He density and the ionization state in the Very Local Interstellar Matter
- The helium Warm Breeze in IBEX observations as a result of charge exchange collisions in the outer heliosheath
- Interstellar neutral helium in the heliosphere from IBEX observations. V. Observations in IBEX-Lo ESA steps 1, 2, & 3
- Very Local Interstellar Medium Revealed by Complete Solar Cycle of Interstellar Neutral Helium Observations with IBEX
- The Interstellar Neutral He haze in the heliosphere: what can we learn?
- A new 3D solar wind speed and density model based on interplanetary scintillation
- Science Opportunities from Observations of the Interstellar Neutral Gas with Adjustable Boresight Direction
- Variation of Solar Microwave Spectrum in the Last Half Century
- WawHelioGlow: a model of the heliospheric backscatter glow. II. The helioglow buildup and the potential significance of the anisotropy in the solar EUV output
- Influence of Heliolatitudinal Anisotropy of Solar FUV/EUV Emissions on Lyman-alpha Helioglow: SOHO/SWAN Observations and WawHelioGlow Modeling