CAN IBEX IDENTIFY VARIATIONS IN THE GALACTIC ENVIRONMENT OF THE SUN USING ENERGETIC NEUTRAL ATOMS?

Journal Article · Fri Aug 20 04:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/719/2/1984· OSTI ID:21457050

Frisch, Priscilla C ^[1]; Heerikhuisen, Jacob; Pogorelov, Nikolai V

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1. Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)

The Interstellar Boundary Explorer (IBEX) spacecraft is providing the first all-sky maps of the energetic neutral atoms (ENAs) produced by charge exchange between interstellar neutral H{sup o} atoms and heliospheric solar wind and pickup ions in the heliosphere boundary regions. The 'edge' of the interstellar cloud presently surrounding the heliosphere extends less than 0.1 pc in the upwind direction, terminating at an unknown distance, indicating that the outer boundary conditions of the heliosphere could change during the lifetime of the IBEX satellite. Using reasonable values for future outer heliosphere boundary conditions, ENA fluxes are predicted for one possible source of ENAs coming from outside of the heliopause. The ENA-production simulations use three-dimensional MHD plasma models of the heliosphere that include a kinetic description of neutrals and a Lorentzian distribution for ions. Based on this ENA-production model, it is then shown that the sensitivities of the IBEX 1.1 keV skymaps are sufficient to detect the variations in ENA fluxes that are expected to accompany the solar transition into the next upwind cloud. Approximately 20% of the IBEX 1.1 keV pixels appear capable of detecting the predicted model differences at the 3{sigma} level, with these pixels concentrated in the Ribbon region. Regardless of the detailed ENA production model, the success of the modeled B {center_dot} R {approx} 0 directions in reproducing the Ribbon locus, together with our results, indicates that the Ribbon phenomenon traces the variations in the heliosphere distortion caused by the relative pressures of the interstellar magnetic and gaseous components.

• OSTI ID: 21457050
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 719; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
79 ASTRONOMY AND ASTROPHYSICS
ATMOSPHERES
BOUNDARY CONDITIONS
CHARGE EXCHANGE
FLUID MECHANICS
HELIOSPHERE
HYDRODYNAMICS
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MAIN SEQUENCE STARS
MECHANICS
PLASMA
SIMULATION
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR WIND
STARS
STELLAR ACTIVITY
STELLAR ATMOSPHERES
STELLAR WINDS
SUN
THREE-DIMENSIONAL CALCULATIONS