When Magnetized Winds Collide: The Role of Interstellar Magnetic Field in the Interaction of the Solar System and the Interstellar Medium

Merav Opher (George Mason University)

Magnetic effects are ubiquitous and known to be crucial in space physics and astrophysical media; Space physics is an excellent plasma laboratory and provide observational data that add crucial constraints to theoretical models. Voyager 1 crossed in Dec 2004, the termination shock and is now in the heliosheath. On August 30, 2007 Voyager 2 crossed the termination shock providing us for the first time with in-situ measurements of the subsonic solar wind in the heliosheath. Our recent results indicate that magnetic effects, in particular the interstellar magnetic field, are very important in the interaction between the solar system and the interstellar medium. Recently, combining radio emission and energetic particle streaming measurements from Voyager 1 and 2 with extensive state-of-the art 3D MHD modeling, we were able to constrain the direction of the local interstellar magnetic field. Although might take 7-12 years for Voyager 2 to leave the heliosheath and enter the pristine interstellar medium, the subsonic flows are immediately sensitive to the shape of the heliopause. I this talk I also show that the flows measured by Voyager 2 from days 277-320 indicate that the heliopause is being distorted by a local interstellar magnetic field ~ 60.