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Supersonic Continuation of the Evershed Flow Outside a Sunspot as Observed with Hinode

Bibcode
2009ApJ...701L..79M
DOI
10.1088/0004-637X/701/2/L79
Martínez Pillet, V.; Katsukawa, Y.; Puschmann, K. G.; Ruiz Cobo, B.
Bibliographical reference

The Astrophysical Journal Letters, Volume 701, Issue 2, pp. L79-L82 (2009).

Advertised on:
8
2009
Number of authors
4
IAC number of authors
3
Citations
15
Refereed citations
9
Description
We report on the discovery of mostly horizontal field channels just outside sunspot penumbrae (in the so-called "moat" region) that are seen to sustain supersonic flows (line-of-sight component of 6 km s-1). The spectral signature of these supersonic flows corresponds to circular polarization profiles with an additional, satellite, third lobe of the same sign as the parent sunspot' Stokes V blue lobe, for both downflows and upflows. This is consistent with an outward directed flow that we interpret as the continuation of the magnetized Evershed flow outside sunspots at supersonic speeds. In Stokes Q and U, a clear signature of a transverse field connecting the two flow streams is observed. Such an easily detectable spectral signature should allow for a clear identification of these horizontal field channels in other spectropolarimetric sunspot data. For the spot analyzed in this paper, a total of five channels with this spectral signature have been unambiguously found.
Related projects
Project Image
Solar and Stellar Magnetism

Magnetic fields are at the base of star formation and stellar structure and evolution. When stars are born, magnetic fields brake the rotation during the collapse of the mollecular cloud. In the end of the life of a star, magnetic fields can play a key role in the form of the strong winds that lead to the last stages of stellar evolution. During

Tobías
Felipe García
In progress
Type
Refereed
Magnetic fields
Sunspots
Solar Physics (FS)

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