| Texto completo | |
| Autor(es): |
Angarita, Y.
;
Versteeg, M. J. F.
;
Haverkorn, M.
;
Rodrigues, C. V.
;
Magalhaes, A. M.
;
Santos-Lima, R.
;
Kawabata, Koji S.
Número total de Autores: 7
|
| Tipo de documento: | Artigo Científico |
| Fonte: | ASTRONOMICAL JOURNAL; v. 166, n. 1, p. 19-pg., 2023-07-01. |
| Resumo | |
Optical starlight can be partially polarized while propagating through the dusty, magnetized interstellar medium (ISM). The polarization efficiency describes the polarization intensity fraction per reddening unit, P-V/E(B - V), related to the interstellar dust grains and magnetic field properties. The maximum value observed, [P-V/E(B - V)](max), is thus achieved under optimal polarizing conditions of the ISM. Therefore, the analysis of polarization efficiency observations across the Galaxy contributes to the study of magnetic field topology, small-scale magnetic fluctuations, grain-alignment efficiency, and composition. Infrared observations from Planck satellite have set [P-V/E(B - V)](max) to 13% mag(-1). However, recent optical polarization observations in Planck's highly polarized regions showed polarization efficiency values between 13.6% mag(-1) and 18.2% mag(-1) (depending on the extinction map used), indicating that [P-V/E(B - V)] max is not well constrained yet. We used V-band polarimetry of the Interstellar Polarization Survey ( consisting of similar to 10,500 high-quality observations distributed in 34 fields of 0 degrees. 3 x 0 degrees. 3) to accurately estimate the polarization efficiency in the ISM. We estimated the upper limit of PV/E(B - V) with the weighted 99th percentile of the field. In five regions, the polarization efficiency upper limit is above 13% mag-1. Furthermore, we found [P-V/E(B - V)](max) = 15.8(-0.9)(+1.3) mag(-1) using diffuse intermediate-latitude (|b| > 7 degrees. 5) regions with apparently strong regular Galactic magnetic field in the plane-of-sky. We studied the variations of P-V/E(B - V) across the sky and tested toy models of polarization efficiency with Galactic longitude that showed some correspondence with a uniform spiral magnetic field. (AU) | |
| Processo FAPESP: | 10/19694-4 - SOUTH POL: descobrindo o céu Austral polarizado |
| Beneficiário: | Antônio Mário Magalhães |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |
| Processo FAPESP: | 01/12589-1 - Stars, the interstellar medium and their interrelationships |
| Beneficiário: | Antônio Mário Magalhães |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |