Document type
ArticleVersion
Accepted versionPublication date
All rights reserved
Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/45365
VLA multifrequency observations of RSCVn binaries
Journal Title
Director/Tutor
Journal ISSN
Volume Title
Related resource
Abstract
We present multiepoch Very Large Array (VLA) observations at 1.4 GHz, 4.9 GHz, 8.5 GHz and 14.9 GHz for a sample of eight RS CVn binary systems. Circular polarization measurements of these systems are also reported. Most of the fluxes observed are consistent with incoherent emission from mildly relativistic electrons. Several systems show an increase of the degree of circular polarization with increasing frequency in the optically thin regime, in conflict with predictions by gyrosynchrotron models. We observed a reversal in the sense of circular polarization with increasing frequency in three non-eclipsing systems: EI Eri, DM Uma and HD 8358. We find clear evidence for coherent plasma emission at 1.4 GHz in the quiescent spectrum of HD 8358 during the helicity reversal. The degrees of polarization of the other two systems could also be accounted for by a coherent emission process. The observations of ER Vul revealed two U-shaped flux spectra at the highest frequencies. The U-shape of the spectra may be accounted for by an optically thin gyrosynchrotron source for the low frequency part whereas the high frequency part is dominated by a thermal emission component.
Subject (English)
Citation
Citation
GARCÍA-SÁNCHEZ, J., PAREDES I POY, Josep Maria and RIBÓ GOMIS, Marc. VLA multifrequency observations of RSCVn binaries. Astronomy and Astrophysics. 2003. Vol. 403, num. 613-624. ISSN 0004-6361. [consulted: 14 of June of 2026]. Available at: https://hdl.handle.net/2445/45365