Two-dimensional distribution of oscillations in a quiescent solar prominence^*

¹ Departament de Física, Universitat de les Illes Balears, 07071 Palma de Mallorca, Spain e-mail: jaume@hubble.uib.es,ramon.oliver@uib.es,dfsjlb0@uib.es
² C/ Rocafort 93, 5, 1a, 08015 Barcelona, Spain e-mail: roberto_molowny_horas@yahoo.es
³ Universitäts-Sternwarte, Geismarlandstrasse 11, 37083 Göttingen, Germany e-mail: ewiehr@uni-sw.gwdg.de
⁴ Astrophysikalisches Institut Potsdam, Sonnenobservatorium Einsteinturm, Telegrafenberg, 14473 Potsdam, Germany e-mail: hbalthasar@aip.de

Corresponding author: J. Terradas, jaume@hubble.uib.es

Received: 20 March 2002
Accepted: 27 June 2002

Abstract

Using time series of two-dimensional Dopplergrams, a temporal and spatial analysis of oscillations in a quiescent prominence has been performed. The presence of an outstanding oscillatory signal in the acquired data has allowed us to study the two-dimensional distribution of wave motions and, in particular, to detect the location of wave generation and the anisotropic propagation of perturbations from that place. Moreover, a strong damping of oscillations has been observed, with damping times between two and three times the wave period. The direction of propagation, wavelength and phase speed, together with the damping time and wave period, have been quantified and their spatial arrangement has been analysed. Thanks to the goodness of the observational data, the image alignment procedure applied during the data reduction stage and the analysis tools employed, it has been possible to carry out a novel and far-reaching observational study of prominence oscillations.