Infrared lines as probes of solar magnetic features. XV. Evershed flow in cool, weak penumbral fields


Observations of Ti I lines at 2.2 micrometer show that the Evershed flow takes place in cool, almost horizontal channels with a low magnetic field strength (~500-900 G) that does not appear to change significantly across the penumbra. This property might allow an outward directed siphon flow to exist along such cool flux tubes.

Astronomy & Astrophysics