Bibcode
Planck Collaboration; Aghanim, N.; Alves, M. I. R.; Arnaud, M.; Arzoumanian, D.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bracco, A.; Burigana, C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Chamballu, A.; Chiang, H. C.; Christensen, P. R.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Couchot, F.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Falgarone, E.; Ferrière, K.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Ghosh, T.; Giard, M.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gregorio, A.; Gruppuso, A.; Guillet, V.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Henrot-Versillé, S.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jewell, J.; Juvela, M.; Keskitalo, R.; Kisner, T. S.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Lasenby, A. et al.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 586, id.A137, 16 pp.
Fecha de publicación:
2
2016
Revista
Número de citas
28
Número de citas referidas
28
Descripción
Planck has mapped the polarized dust emission over the whole sky, making
it possible to trace the Galactic magnetic field structure that pervades
the interstellar medium (ISM). We combine polarization data from Planck
with rotation measure (RM) observations towards a massive star-forming
region, the Rosette Nebula in the Monoceros molecular cloud, to study
its magnetic field structure and the impact of an expanding H ii region
on the morphology of the field. We derive an analytical solution for the
magnetic field, assumed to evolve from an initially uniform
configuration following the expansion of ionized gas and the formation
of a shell of swept-up ISM. From the RM data we estimate a mean value of
the line-of-sight component of the magnetic field of about 3 μG
(towards the observer) in the Rosette Nebula, for a uniform electron
density of about 12 cm-3. The dust shell that surrounds the
Rosette H ii region is clearly observed in the Planck intensity map at
353 GHz, with a polarization signal significantly different from that of
the local background when considered asa whole. The Planck observations
constrain the plane-of-the-sky orientation of the magnetic field in the
Rosette's parent molecular cloud to be mostly aligned with the
large-scale field along the Galactic plane. The Planck data are compared
with the analytical model, which predicts the mean polarization
properties of a spherical and uniform dust shell for a given orientation
of the field. This comparison leads to an upper limit of about 45°
on the angle between the line of sight and the magnetic field in the
Rosette complex, for an assumed intrinsic dust polarization fraction of
4%. This field direction can reproduce the RM values detected in the
ionized region if the magnetic field strength in the Monoceros molecular
cloud is in the range 6.5-9 μG. The present analytical model is able
to reproduce the RM distribution across the ionized nebula, as well as
the mean dust polarization properties of the swept-up shell, and can be
directly applied to other similar objects.