Plasma Properties of Pseudostreamers and Associated Solar Wind Streams

We study pseudostreamers (i.e., open-field extensions of plasma from unipolar footpoints in the corona; distinct from classical helmet streamers that have opposite-polarity footpoints) that are believed to be sources of slow to intermediate speed wind streams. We make use of multi-spacecraft and ground-based observations that extend from the solar corona to the solar wind at 1 AU. We compare the physical properties of selected pseudostreamers and helmet streamers to characterize how the differences in magnetic topology affect the plasma properties of the coronal structures and their wind. Due to the large number of pseudostreamers and their long persistence over multiple solar rotations, their contribution to the solar wind is likely to be substantial. In order to investigate solar wind heating and acceleration, we also compare our measurements with predictions from pseudostreamer and streamer theoretical models. This work is supported by NASA grant NNX10AQ58G to the Smithsonian Astrophysical Observatory.