LIMF direction inferred from the mechanism for IBEX ribbon generation based on SW-LIC interaction vs 2-3 kHz radio emission

After the discovery of the heliospheric ribbon of energetic neutral atoms (ENAs) by the first dedicated Energetic Neutral Atom spaceborn observatory IBEX, scientists have tried to explain the underlying physics of ribbon generation. Up to now two different mechanisms have been proposed: one based on the solar wind-local interstellar cloud (SW-LIC) interaction, the second on the LIC-LB (Local Bubble) interaction. An interpretation of the ribbon as coming up due to the production of the ENAs in locations in space ordered by the local interstellar magnetic field (LIMF) allows to constrain the spatial configuration (direction) of the LIMF near the Sun. However, the LIMF direction inferred from this mechanism (α ~ 45°) contradicts the result coming from the 2-3 kHz radio emission (α ~ 90°). The second mechanism based on the LIC-LB interaction does not involve directly the LIMF. Nevertheless it appears interesting to assume the LIMF direction as coming from the 2-3 kHz radio emission to investigate what is the relation of the LIMF to the ribbon structure in this case, and in particular, what is the angle between the interface layer LIC-LB and the LIMF direction. In this talk we also discuss implications of the B . r = 0 condition for the direction of the LIMF coming from a model of the interaction of an interplanetary shock with the heliopause (compare Gurnett et al., 2006).