Polarimetry toward the iras vela shell. ii. extinction and magnetic fields
Study of the polarized decametric radio emission measured by riometers
Analysis of the uncertainties in the determination of the Stokes parameters employ...
| Full text | |
| Author(s): |
Poidevin, Frederick
[1]
;
Falceta-Goncalves, Diego
[2, 3]
;
Kowal, Grzegorz
[2]
;
Dal Pino, Elisabete de Gouveia
[4]
;
Magalhaes, Antonio Mario
[4]
Total Authors: 5
|
| Affiliation: | [1] UCL, Dept Phys & Astron, London WC1E 6BT - England
[2] Univ Sao Paulo, Escola Artes Ciencias & Humanidades, BR-03828000 Sao Paulo - Brazil
[3] Univ St Andrews, Sch Phys & Astron, SUPA, St Andrews KY16 9SS, Fife - Scotland
[4] Univ Sao Paulo, Inst Astron Geofis & Ciencas Atmosfer, BR-05508900 Sao Paulo - Brazil
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | ASTROPHYSICAL JOURNAL; v. 777, n. 2 NOV 10 2013. |
| Web of Science Citations: | 11 |
| Abstract | |
We present an extensive analysis of the 850 mu m polarization maps of the SCUBA Polarimeter Legacy (SCUPOL) Catalogue produced by Matthews et al., focusing exclusively on the molecular clouds and star-forming regions. For the sufficiently sampled regions, we characterize the depolarization properties and the turbulent-to-mean magnetic field ratio of each region. Similar sets of parameters are calculated from two-dimensional synthetic maps of dust-emission polarization produced with three-dimensional magnetohydrodynamics (MHD) numerical simulations scaled to the S106, OMC-2/3, W49, and DR21 molecular cloud polarization maps. For these specific regions, the turbulent MHD regimes retrieved from the simulations, as described by the turbulent Alfven and Sonic Mach numbers, are consistent within a factor one to two with the values of the same turbulent regimes estimated from the analysis of Zeeman measurements data provided by Crutcher. Constraints on the values of the inclination angle a of the mean magnetic field with respect to the line of sight are also given. The values obtained from the comparison of the simulations with the SCUPOL data are consistent with the estimates made by using two observational methods provided by other authors. Our main conclusion is that simple, ideal, isothermal, and non-self-gravitating MHD simulations are sufficient in order to describe the large-scale observed physical properties of the envelopes of this set of regions. (AU) | |
| FAPESP's process: | 06/50654-3 - Investigation of high energy and plasma astrophysics phenomena: theory, observation, and numerical simulations |
| Grantee: | Elisabete Maria de Gouveia Dal Pino |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 11/12909-8 - Magnetic fields, turbulence and plasma effects in the intergalactic medium |
| Grantee: | Diego Antonio Falceta Gonçalves |
| Support Opportunities: | Regular Research Grants |