Bibcode
Planck Collaboration; Abergel, A.; Ade, P. A. R.; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Balbi, A.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Battaner, E.; Benabed, K.; Benoît, A.; Bernard, J.-P.; Bersanelli, M.; Bhatia, R.; Bock, J. J.; Bonaldi, A.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bucher, M.; Burigana, C.; Cabella, P.; Cardoso, J.-F.; Catalano, A.; Cayón, L.; Challinor, A.; Chamballu, A.; Chiang, L.-Y.; Chiang, C.; Christensen, P. R.; Colombi, S.; Couchot, F.; Coulais, A.; Crill, B. P.; Cuttaia, F.; Dame, T. M.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Gasperis, G.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dickinson, C.; Donzelli, S.; Doré, O.; Dörl, U.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Grenier, I. A.; Gruppuso, A.; Hansen, F. K.; Harrison, D.; Henrot-Versillé, S.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hovest, W.; Hoyland, R. J.; Huffenberger, K. M.; Jaffe, T. R.; Jaffe, A. H.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knox, L.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Laureijs, R. J. et al.
Bibliographical reference
Astronomy and Astrophysics, Volume 536, id.A21
Advertised on:
12
2011
Journal
Citations
127
Refereed citations
120
Description
Planck has observed the entire sky from 30 GHz to 857GHz. The observed
foreground emission contains contributions from different phases of the
interstellar medium (ISM). We have separated the observed Galactic
emission into the different gaseous components (atomic, molecular and
ionised) in each of a number of Galactocentric rings. This technique
provides the necessary information to study dust properties (emissivity,
temperature, etc.), as well as other emission mechanisms as a function
of Galactic radius. Templates are created for various Galactocentric
radii using velocity information from atomic (neutral hydrogen) and
molecular (12CO) observations. The ionised template is
assumed to be traced by free-free emission as observed by WMAP, while
408 MHz emission is used to trace the synchrotron component. Gas
emission not traced by the above templates, namely "dark gas", as
evidenced using Planck data, is included as an additional template, the
first time such a component has been used in this way. These templates
are then correlated with each of the Planck frequency bands, as well as
with higher frequency data from IRAS and DIRBE along with radio data at
1.4 GHz. The emission per column density of the gas templates allows us
to create distinct spectral energy distributions (SEDs) per
Galactocentric ring and in each of the gaseous tracers from 1.4 GHz to
25 THz (12μm). The resulting SEDs allow us to explore the
contribution of various emission mechanisms to the Planck signal. Apart
from the thermal dust and free-free emission, we have probed the Galaxy
for anomalous (e.g., spinning) dust as well as synchrotron emission. We
find the dust opacity in the solar neighbourhood, τ/NH =
0.92 ± 0.05 × 10-25 cm2 at 250 μm,
with no significant variation with Galactic radius, even though the dust
temperature is seen to vary from over 25 K to under 14 K. Furthermore,
we show that anomalous dust emission is present in the atomic, molecular
and dark gas phases throughout the Galactic disk. Anomalous emission is
not clearly detected in the ionised phase, as free-free emission is seen
to dominate. The derived dust propeties associated with the dark gas
phase are derived but do not allow us to reveal the nature of this
phase. For all environments, the anomalous emission is consistent with
rotation from polycyclic aromatic hydrocarbons (PAHs) and, according to
our simple model, accounts for (25 ± 5)% (statistical) of the
total emission at 30 GHz.
Corresponding author: D. J. Marshall, e-mail:
douglas.marshall [at] irap.omp.eu (douglas[dot]marshall[at]irap[dot]omp[dot]eu)
Related projects
Anisotropy of the Cosmic Microwave Background
The general goal of this project is to determine and characterize the spatial and spectral variations in the temperature and polarisation of the Cosmic Microwave Background in angular scales from several arcminutes to several degrees. The primordial matter density fluctuations which originated the structure in the matter distribution of the present
Rafael
Rebolo López