Plasma and Flows in the Heliosheath

[摘要] Voyager 2 (V2) is now 20 AU deep into the heliosheath; if the heliosheath width were similar to that in the Voyager 1 (V1) direction, then V2 is 2/3 of the way to the heliopause. We present recent V2 observations, compare with observations from V1, and compare with model predictions. The speed of the flows observed by V2 in the heliosheath are, on average, remarkably constant at 150 km/s. The flow angle has changed dramatically, however, and is now over 60° from radial, with more of the turning occurring in the RT than RN planes. These flows are very different than those at V1, where the speed was always below 100 km/s and decreased across the heliosheath. Models predict VR at V2 well, but the the flow angle predictions differ from the observations. The average density and temperature of the plasma decreased by a factor of two in 2008, recovered in 2011, and have not changed significantly since 2011.

[发布机构] Kavli Center for Astrophysics and Space Sciences, Massachusetts Institute of Technology, Cambridge; MA; 02139, United States^1;Applied Physics Laboratory, Johns Hopkins University, Laurel; MD, United States^2

[效力级别] 天文学 [学科分类] 天文学(综合)

[关键词] Flow angles;Heliopause;Heliosheath;Model prediction;Speed of the flow;Voyager 1