The flow field in the sunspot canopy

Simple item page
dc.creatorRezaei, Reza
dc.creatorSchlichenmaier, R.
dc.creatorBeck, C. A. R.
dc.creatorRubio, L. R. Bellot
dc.date2006-04-13
dc.date.accessioned2026-07-07T07:04:39Z
dc.date.available2026-07-07T07:04:39Z
dc.descriptionWe investigate the flow field in the sunspot canopy using simultaneous Stokes vector spectropolarimetry of three sunspots ($θ$ = 27, 50, 75 deg) and their surroundings in visible (630.15 and 630.25 nm) and near infrared (1564.8 and 1565.2 nm) neutral iron lines.} {To calibrate the Doppler shifts, we compare an absolute velocity calibration using the telluric $O_2$-line at 630.20 nm and a relative velocity calibration using the Doppler shift of Stokes V profiles in the umbra under the assumption that the umbra is at rest. Both methods yield the same result within the calibration uncertainties (~150 m/s). We study the radial dependence of Stokes V profiles in the directions of disk center and limb side. Maps of Stokes V profile shifts, polarity, amplitude asymmetry, field strength and magnetic field azimuth provide strong evidence for the presence of a magnetic canopy and for the existence of a radial outflow in the canopy. Our findings indicate that the Evershed flow does not cease abruptly at the white-light spot boundary, but that at least a part of the penumbral Evershed flow continues into the magnetic canopy.
dc.description10 pages, accepted to A&A
dc.identifierhttps://arxiv.org/abs/astro-ph/0604301
dc.identifierhttp://arxiv.org/abs/astro-ph/0604301
dc.identifierAstron.Astrophys. 454 (2006) 975-982
dc.identifierdoi:10.1051/0004-6361:20065180
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/109396
dc.subjectAstrophysics
dc.titleThe flow field in the sunspot canopy
dc.typetext

Files

Collections

arXiv