Global Asymmetries in the Heliosphere: Signature of the Interstellar Magnetic Field
Abstract
In recent years it become clear that magnetic field effects, plays an important role in the Heliosphere, from shaping it and possible being responsible for the asymmetries observed in the Voyager data (e.g., Opher et al. 2007, 2009). However, the strength and orientation of the field in the local interstellar medium near the heliosphere has been poorly constrained. Previous estimates of the field strength range from 1.8-2.5 G and the field was thought to be parallel to the Galactic plane or inclined by 38-60 (Lallement et al. 2005) or 60-90 (Opher et al. 2007) to this plane. These estimates relied either on indirect observational inferences or modeling in which the interstellar neutral hydrogen was not taken into account. We will discuss recent work that indicate that based on asymmetries detected by Voyager 1 and 2 and measurements of the deflection of the solar wind plasma flows in the heliosheath (Opher et al. 2009) indicate that the field strength in the local interstellar medium is strong, between 4-5 G (Other works such as Izmodenov 2009; Pogorelov et al. 2009; Ratkiewickz et al. 2009 found similar strength). The field is tilted 20-30 from the interstellar medium flow direction (resulting from the peculiar motion of the Sun in the Galaxy) and is at an angle of about 30 from the Galactic plane. We will discuss the effect of such magnetic field in the global asymmetries of the heliosphere. We further will comment on the effect on asymmetries of our recent model of Kinetic-MHD model treating the neutrals in kinetic fashion (Alouani-Bibi et al. 2010). We will relate our findings with the most recent results of IBEX that indicate that the interstellar magnetic field has a strong signature in the emission of energetic neutrals.
- Publication:
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38th COSPAR Scientific Assembly
- Pub Date:
- 2010
- Bibcode:
- 2010cosp...38.1604O