We perform an analysis of the diffuse low-frequency Galactic components in the southern part of the Gould Belt system (130 degrees <= l <= 230 degrees and -50 degrees <= b <= -10 degrees). Strong ultra-violet flux coming from the Gould Belt super-association is responsible for bright diffuse foregrounds that we observe from our position inside the system and that can help us improve our knowledge of the Galactic emission. Free-free emission and anomalous microwave emission (AME) are the dominant components at low frequencies (nu < 40 GHz), while synchrotron emission is very smooth and faint. We separated diffuse free-free emission and AME from synchrotron emission and thermal dust emission by using Planck data, complemented by ancillary data, using the correlated component analysis (CCA) component-separation method and we compared our results with the results of cross-correlation of foreground templates with the frequency maps. We estimated the electron temperature T-e from Ha and free-free emission using two methods (temperature-temperature plot and cross-correlation) and obtained T-e ranging from 3100 to 5200 K for an effective fraction of absorbing dust along the line of sight of 30% (f(d) = 0.3). We estimated the frequency spectrum of the diffuse AME and recovered a peak frequency (in flux density units) of 25.5 +/- 1.5 GHz. We verified the reliability of this result with realistic simulations that include biases in the spectral model for the AME and in the free-free template. By combining physical models for vibrational and rotational dust emission and adding the constraints from the thermal dust spectrum from Planck and IRAS, we are able to present a good description of the AME frequency spectrum for plausible values of the local density and radiation field.

Ade, P., Aghanim, N., Alves, M., Arnaud, M., Ashdown, M., Atrio Barandela, F., et al. (2013). Planck intermediate results. XII: Diffuse Galactic components in the Gould Belt system. ASTRONOMY & ASTROPHYSICS, 557 [10.1051/0004-6361/201321160].

Planck intermediate results. XII: Diffuse Galactic components in the Gould Belt system

BALBI, AMEDEO;CABELLA, PAOLO;DE GASPERIS, GIANCARLO;MAZZOTTA, PASQUALE;VITTORIO, NICOLA;
2013-09-01

Abstract

We perform an analysis of the diffuse low-frequency Galactic components in the southern part of the Gould Belt system (130 degrees <= l <= 230 degrees and -50 degrees <= b <= -10 degrees). Strong ultra-violet flux coming from the Gould Belt super-association is responsible for bright diffuse foregrounds that we observe from our position inside the system and that can help us improve our knowledge of the Galactic emission. Free-free emission and anomalous microwave emission (AME) are the dominant components at low frequencies (nu < 40 GHz), while synchrotron emission is very smooth and faint. We separated diffuse free-free emission and AME from synchrotron emission and thermal dust emission by using Planck data, complemented by ancillary data, using the correlated component analysis (CCA) component-separation method and we compared our results with the results of cross-correlation of foreground templates with the frequency maps. We estimated the electron temperature T-e from Ha and free-free emission using two methods (temperature-temperature plot and cross-correlation) and obtained T-e ranging from 3100 to 5200 K for an effective fraction of absorbing dust along the line of sight of 30% (f(d) = 0.3). We estimated the frequency spectrum of the diffuse AME and recovered a peak frequency (in flux density units) of 25.5 +/- 1.5 GHz. We verified the reliability of this result with realistic simulations that include biases in the spectral model for the AME and in the free-free template. By combining physical models for vibrational and rotational dust emission and adding the constraints from the thermal dust spectrum from Planck and IRAS, we are able to present a good description of the AME frequency spectrum for plausible values of the local density and radiation field.
set-2013
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore FIS/05 - ASTRONOMIA E ASTROFISICA
English
Galaxy: general; radio continuum: ISM; radiation mechanisms: general
Ade, P., Aghanim, N., Alves, M., Arnaud, M., Ashdown, M., Atrio Barandela, F., et al. (2013). Planck intermediate results. XII: Diffuse Galactic components in the Gould Belt system. ASTRONOMY & ASTROPHYSICS, 557 [10.1051/0004-6361/201321160].
Ade, P; Aghanim, N; Alves, M; Arnaud, M; Ashdown, M; Atrio Barandela, F; Aumont, J; Baccigalupi, C; Balbi, A; Banday, A; Barreiro, R; Bartlett, J; Bat...espandi
Articolo su rivista
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/86836
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 3
  • ???jsp.display-item.citation.isi??? 9
social impact