HR: 0830h
AN: SP11A-08    [Abstracts]
TI: Flow filaments linking bright and dark filaments in a sunspot penumbra
AU: * Tritschler, A
EM: ali@bbso.njit.edu
AF: Big Bear Solar Observatory/NJIT, 40386 North Shore Lane, Big Bear City, CA 92314 United States
AU: Schlichenmaier, R
EM: schliche@kis.uni-freiburg.de
AF: Kiepenheuer Institut fuer Sonnenphysik, Schoeneckstrasse 6, Freiburg, 79104 Germany
AU: Bellot Rubio, L R
EM: lbellot@iaa.es
AF: Instituto de Astrofisica de Andalucia (CSIC), C/Camino Bajo de Huetor, 50, Granada, 18008 Spain
AB: We present two-dimensional spectroscopic sunspot observations of high spatial (≈ 0.5 arcsec) and high spectral resolution (λ/Δλ = 250000). The observations were taken with the Telecentric Solar Spectrometer (TESOS) operated at the German Vacuum Tower Telescope on Tenerife. We examine a single scan taken in the popular non-magnetic neutral iron line at 557.6 nm and concentrate our analysis on the unsettled issue of the relation between the Evershed flow and the intensity structure in a sunspot penumbra. At the end of the 20th century, observers concluded that the highest flow velocities are connected to the dark filaments which harbour more horizontal magnetic fields than the bright filaments. Based on a correlation analysis we find that the correlation between flows and intensity varies from the inner to the outer penumbra, from the center-side to the limb-side penumbra, and depends on the length of the trace used to perform the correlation. The line-of-sight velocity maps reveal that the Evershed flow on the center-side penumbra appears highly organised in narrow flow filaments, while the flows in the red-shifted limb-side penumbra do not show a filamentary fine-structure. A high correlation between flow speed and intensity is only observed over small spatial scales, i.e. considering short traces cutting individual features. The correlation is positive in the inner centre and limb-side penumbra, and tends to be negative in the outer penumbra. Our results imply that the Evershed flow is present in bright and dark filaments. In individual cases we find that flow filaments connect bright and dark filaments supporting the moving tube model for the penumbral fine structure.
DE: 7500 SOLAR PHYSICS, ASTROPHYSICS, AND ASTRONOMY
DE: 7524 Magnetic fields
DE: 7529 Photosphere
DE: 7594 Instruments and techniques
DE: 7599 General or miscellaneous
SC: Solar Physics Division - AAS [SP]
MN: 2005 Joint Assembly