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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Measuring the continuum polarization with ESPaDOnS

Full text
Author(s):
Pereyra, A. [1, 2] ; Rodrigues, C. V. [1] ; Martioli, E. [3]
Total Authors: 3
Affiliation:
[1] Inst Nacl Pesquisas Espaciais MCT, BR-12227010 Sao Jose Dos Campos, SP - Brazil
[2] Inst Geofis Peru, Area Astron, Lima - Peru
[3] Lab Nacl Astrofis LNA MCTI, Itajuba, MG - Brazil
Total Affiliations: 3
Document type: Journal article
Source: Astronomy & Astrophysics; v. 573, JAN 2015.
Web of Science Citations: 2
Abstract

Aims. Our goal is to test the feasibility of obtaining accurate measurements of the continuum polarization from high-resolution spectra using the spectropolarimetric mode of ESPaDOnS. Methods. We used the new pipeline OPERA to reduce recent and archived ESPaDOnS data. Several polarization standard stars and science objects were tested for the linear mode. In addition, the circular mode was tested using several objects from the archive with expected null polarization. Synthetic broad-band polarization was computed from the ESPaDOnS continuum polarization spectra and compared with published values (when available) to quantify the accuracy of the instrument. Results. The continuum linear polarization measured by ESPaDOnS is consistent with broad-band polarimetry measurements available in the literature. The accuracy in the degree of linear polarization is around 0.2-0.3% considering the full sample. The accuracy in polarization position angle using the most polarized objects is better than 5 degrees. Consistent with this, the instrumental polarization computed for the circular continuum polarization is also between 0.2-0.3%. Our results suggest that measurements of the continuum polarization using ESPaDOnS are viable and can be used to study many astrophysical objects. (AU)

FAPESP's process: 13/11473-7 - Young stellar objects polarimetry & SPARC4 pipeline
Grantee:Cláudia Vilega Rodrigues
Support type: Research Grants - Visiting Researcher Grant - International
FAPESP's process: 10/01584-8 - SPARC4: simultaneous polarimeter and rapid camera in four bands
Grantee:Cláudia Vilega Rodrigues
Support type: Regular Research Grants