Alicia Aarnio, Joe Llama, Moira Jardine, Scott G. Gregory
The most extended, closed magnetic loops inferred on T Tauri stars confine
hot, X-ray emitting plasma at distances from the stellar surface beyond the the
X-ray bright corona and closed large-scale field, distances comparable to the
corotation radius. Mechanical equilibrium models have shown that dense
condensations, or "slingshot prominences", can rise to great heights due to
their density and temperatures cooler than their environs. On T Tauri stars,
however, we detect plasma at temperatures hotter than the ambient coronal
temperature. By previous model results, these loops should not reach the
inferred heights of tens of stellar radii where they likely no longer have the
support of the external field against magnetic tension. In this work, we
consider the effects of a stellar wind and show that indeed, hot loops that are
negatively buoyant can attain a mechanical equilibrium at heights above the
typical extent of the closed corona and the corotation radius.
View original:
http://arxiv.org/abs/1112.5356
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