The Evershed Effect Observed with 0.2″ Angular Resolution | Zendy

J. Sánchez Alméida | Zendy; I. Márquez | Zendy; José Bonet | Zendy; I. Domínguez Cerdeña | Zendy

AI Assistant Blog Pricing

Home ZAIA Blog

Open Access

The Evershed Effect Observed with 0.2″ Angular Resolution

Author(s) -

J. Sánchez Alméida,

I. Márquez,

José Bonet,

I. Domínguez Cerdeña

Publication year - 2007

Publication title -

the astrophysical journal

Language(s) - English

Resource type - Journals

SCImago Journal Rank - 2.376

H-Index - 489

eISSN - 1538-4357

pISSN - 0004-637X

DOI - 10.1086/511254

Subject(s) - penumbra , physics , spectrograph , doppler effect , sunspot , astrophysics , line (geometry) , resolution (logic) , spectral line , solar telescope , angular resolution (graph drawing) , temporal resolution , optics , telescope , magnetic field , astronomy , geometry , medicine , mathematics , ischemia , quantum mechanics , artificial intelligence , combinatorics , computer science , cardiology

We present an analysis of the Evershed effect observed with a resolution of0.2 arcsec. Using the new Swedish 1-m Solar Telescope and its Littrowspectrograph, we scan a significant part of a sunspot penumbra. Spectra of thenon-magnetic line Fe I 7090.4 A allows us to measure Doppler shifts withoutmagnetic contamination. The observed line profiles are asymmetric. The Dopplershift depends on the part of the line used for measuring, indicating that thevelocity structure of penumbrae remains unresolved even with our angularresolution. The observed line profiles are properly reproduced if twocomponents with velocities between zero and several km/s co-exist in theresolution elements. Using Doppler shifts at fixed line depths, we find a localcorrelation between upflows and bright structures, and downflows and darkstructures. This association is not specific of the outer penumbra but it alsooccurs in the inner penumbra. The existence of such correlation was originallyreported by Beckers & Schroter (1969), and it is suggestive of energy transportby convection in penumbrae.Comment: To appear in ApJ. 14 pages and 17 figure

The content you want is available to Zendy users.

Already have an account? Click here to sign in.

Having issues? You can contact us here

Accelerating Research