| Author(s): |
Carciofi, A. C.
;
Faes, D. M.
;
Townsend, R. H. D.
;
Carciofi, AC
;
Rivinius, T
Total Authors: 5
|
| Document type: | Journal article |
| Source: | CIRCUMSTELLAR DYNAMICS AT HIGH RESOLUTION; v. 464, p. 3-pg., 2012-01-01. |
| Abstract | |
Some massive stars possess strong magnetic fields that confine plasma in the circumstellar environment. These magnetospheres have been studied spectroscopically, photometrically and, more recently, interferometrically. Here we report on the first firm detection of a magnetosphere in continuum linear polarization, as a result of a monitoring of sigma Ori E done at the Pico dos Dias Observatory. A rotational modulation of the polarization was observed, with a period of half of the rotation period, which supports the theoretical prediction on the presence of two diametrally opposed, co-rotating blobs of gas. A phase lag of -0.08 was detected between the polarization minimum and the primary minimum of the light curve, suggestive of a complex shape of the plasma clouds. We present a preliminary analysis of the data with the Rigidly Rotating Magnetosphere model, which could not reproduce correctly the shape and the level of the polarization curve. A simple toy model consisting on two spherical co-rotating blobs proved more successful in explaining the polarization modulation. This result suggests that imaging polarimetry can provide a diagnostic of the geometry of clouds, which will serve as useful constraints for the Rigidly Rotating Magnetosphere model. (AU) | |
| FAPESP's process: | 10/19029-0 - 3D radiative transfer models: bridging theory and observations |
| Grantee: | Alex Cavaliéri Carciofi |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 10/19060-5 - An interferometric view on hot star disks |
| Grantee: | Daniel Moser Faes |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 09/54006-4 - A computer cluster for the Astronomy Department of the University of São Paulo Institute of Astronomy, Geophysics and Atmospheric Sciences and for the Cruzeiro do Sul University Astrophysics Center |
| Grantee: | Elisabete Maria de Gouveia Dal Pino |
| Support Opportunities: | Multi-user Equipment Program |