Magnetic fields in the Local ISM and the Local Bubble
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), but 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 μG 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 μG. 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 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. We will discuss the possible implications of a strong magnetic field for the environment in the Local ISM and the Local Bubble.
- Publication:
-
American Astronomical Society Meeting Abstracts #216
- Pub Date:
- May 2010
- Bibcode:
- 2010AAS...21620103O