Astronomy and Astrophysics – Astrophysics
Scientific paper
Dec 2011
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011agufmsh23b1965j&link_type=abstract
American Geophysical Union, Fall Meeting 2011, abstract #SH23B-1965
Astronomy and Astrophysics
Astrophysics
[2126] Interplanetary Physics / Heliosphere/Interstellar Medium Interactions, [2144] Interplanetary Physics / Interstellar Gas, [7524] Solar Physics, Astrophysics, And Astronomy / Magnetic Fields
Scientific paper
The crossing of the solar wind termination shock (TS) by Voyager 1 (V1) & Voyager 2 (V2) spacecrafts respectively at ~94 AU and ~84 AU revealed a rather strong asymmetry in the heliosphere that was immediately associated with the imprint of the unknown local interstellar medium magnetic field (LIMF). The observed asymmetry in the TS shape and further in situ measurements made by the Voyager plasma and magnetic field instruments deep in the heliosheath were interpreted as being a result of the unusually strong LIMF level that stands in stark contrast with commonly accepted values 1.8-2.5 μG derived from ground-based observations. In addition, the derived orientation was different from average orientation observed on the ~100 parsecs scale, requiring a distortion of the far field lines in order to adjust to the solar vicinity region. The Lyman-α emission originating from the neutral hydrogen component was reported to show a distortion in the heliosphere, however, and this distortion should also be used to constrain the LIMF strength and its two orientation angles. In addition, Interstellar Boundary Explorer (IBEX) reported a ribbon-like structure in the spatial distribution of energetic neutrals of heliospheric origin, a structure that may be explained by the presence of an oblique LIMF. Here we show that the asymmetries observed in respectively the Lyman-α emission deep in the heliosphere-in the TS position as measured by V1 and V2-and the Ibex ribbon could be explained with a rather weak 1.8-2.5 μG strength of LIMF and orientation well below the galactic plane. We also show that the magnetohydrodynamic (MHD) modelling of V1 and V2 plasma observations does not lead to unique values of the LIMF strength and orientation as previously claimed. The LIMF derived here is oriented almost orthogonal to the spiral arm that hosts our solar system, which is consistent with previous findings from pulsar rotation, diffuse radio emission, and polarization of starlight observations.
Ben-Jaffel Lotfi
Ratkiewicz Roma
No associations
LandOfFree
The Local Interstellar Medium Magnetic Field: Back to the Old Times! does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Local Interstellar Medium Magnetic Field: Back to the Old Times!, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Local Interstellar Medium Magnetic Field: Back to the Old Times! will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-878168