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Title: Simulating the Compton-Getting effect for hydrogen flux measurements: Implications for IBEX-Hi and -Lo observations

The Interstellar Boundary EXplorer (IBEX), launched in 2008 October, has improved our understanding of the solar wind-local interstellar medium interaction through its detection of neutral atoms, particularly that of hydrogen (H). IBEX is able to create full maps of the sky in six-month intervals as the Earth orbits the Sun, detecting H with energies between ∼0.01 and 6 keV. Due to the relative motion of IBEX to the solar inertial frame, measurements made in the spacecraft frame introduce a Compton-Getting (CG) effect, complicating measurements at the lowest energies. In this paper we provide results from a numerical simulation that calculates fluxes of H atoms at 1 AU in the inertial and spacecraft frames (both ram and anti-ram), at energies relevant to IBEX-Hi and -Lo. We show theory behind the numerical simulations, applying a simple frame transformation to derived flux equations that provides a straightforward way to simulate fluxes in the spacecraft frame. We then show results of H energetic neutral atom fluxes simulated at IBEX-Hi energy passbands 2-6 in all frames, comparing with IBEX-Hi data along selected directions, and also show results simulated at energies relevant to IBEX-Lo. Although simulations at IBEX-Hi energies agree reasonably well with the CG correctionmore » method used for IBEX-Hi data, we demonstrate the importance of properly modeling low energy H fluxes due to inherent complexities involved with measurements made in moving frames, as well as dynamic radiation pressure effects close to the Sun.« less
Authors:
;  [1] ;  [2] ;  [3]
  1. Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL 35805 (United States)
  2. Southwest Research Institute, San Antonio, TX 78228 (United States)
  3. Space Science Center, University of New Hampshire, Durham, NH 03824 (United States)
Publication Date:
OSTI Identifier:
22341953
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 778; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ATOMS; COMPARATIVE EVALUATIONS; COMPTON EFFECT; COMPUTERIZED SIMULATION; CORRECTIONS; DETECTION; EQUATIONS; HELIOSPHERE; HYDROGEN; INTERACTIONS; INTERSTELLAR SPACE; KEV RANGE; ORBITS; RADIATION PRESSURE; SKY; SOLAR WIND; SUN; TRANSFORMATIONS