MULTI-SCALE ANALYSIS OF MAGNETIC FIELDS IN FILAMENTARY MOLECULAR CLOUDS IN ORION A

Autor(es)

Poidevin, Frederick ^[1] ; Bastien, P. ^{[2, 3]} ; Jones, T. J. ^[4]

Afiliação do(s) autor(es)

^[1] UCL, Dept Phys & Astron, London WC1E 6BT - England

^[2] Univ Montreal, Dept Phys, Montreal, PQ H3C 3J7 - Canada

^[3] Univ Montreal, Observ Mont Megant, Ctr Ville, Montreal, PQ H3C 3J7 - Canada

^[4] Univ Minnesota, Dept Astron, Minneapolis, MN 55455 - USA

• Tipo de documento: Artigo Científico
• Fonte: ASTROPHYSICAL JOURNAL; v. 741, n. 2 NOV 10 2011.
• Citações Web of Science: 7

Resumo

New visible and K-band polarization measurements of stars surrounding molecular clouds in Orion A and stars in the Becklin-Neugebauer (BN) vicinity are presented. Our results confirm that magnetic fields located inside the Orion A molecular clouds and in their close neighborhood are spatially connected. On and around the BN object, we measured the angular offsets between the K-band polarization data and available submillimeter (submm) data. We find high values of the polarization degree, P(K), and of the optical depth, tau(K), close to an angular offset position of 90 degrees whereas lower values of P(K) and tau(K) are observed for smaller angular offsets. We interpret these results as evidence for the presence of various magnetic field components toward lines of sight in the vicinity of BN. On a larger scale, we measured the distribution of angular offsets between available H-band polarization data and the same submm data set. Here we find an increase of < P(H)> with angular offset, which we interpret as a rotation of the magnetic field by less than or similar to 60 degrees. This trend generalizes previous results on small scales toward and around lines of sight to BN and is consistent with a twist of the magnetic field on a larger scale toward OMC-1. A comparison of our results with several other studies suggests that a two-component magnetic field, perhaps helical, could be wrapping the OMC-1 filament. (AU)

• Processo FAPESP: 07/56302-4 - O campo magnético da galáxia
• Beneficiário: Frederic Nicolas David Poidevin
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado