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.
Planck intermediate results. XII: Diffuse Galactic components in the Gould Belt system / P. A. R., Ade; N., Aghanim; M. I. R., Alves; M., Arnaud; M., Ashdown; F., Atrio Barandela; J., Aumont; C., Baccigalupi; A., Balbi; A. J., Banday; R. B., Barreiro; J. G., Bartlett; E., Battaner; L., Bedini; K., Benabed; A., Benoit; J. P., Bernard; M., Bersanelli; A., Bonaldi; J. R., Bond; J., Borrill; F. R., Bouchet; F., Boulanger; C., Burigana; R. C., Butler; P., Cabella; J. F., Cardoso; X., Chen; L. Y., Chiang; P. R., Christensen; D. L., Clements; S., Colombi; L. P. L., Colombo; A., Coulais; F., Cuttaia; R. D., Davies; R. J., Davis; DE BERNARDIS, Paolo; G., De Gasperis; G., De Zotti; J., Delabrouille; C., Dickinson; J. M., Diego; G., Dobler; H., Dole; S., Donzelli; O., Dore; M., Douspis; X., Dupac; T. A., Ensslin; F., Finelli; O., Forni; M., Frailis; E., Franceschi; S., Galeotta; K., Ganga; R. T., Genova Santos; T., Ghosh; M., Giard; G., Giardino; Y., Giraud Heraud; J., Gonzalez Nuevo; K. M., Gorski; A., Gregorio; A., Gruppuso; F. K., Hansen; D., Harrison; C., Hernandez Monteagudo; S. R., Hildebrandt; E., Hivon; M., Hobson; W. A., Holmes; A., Hornstrup; W., Hovest; K. M., Huffenberger; T. R., Jaffe; A. H., Jaffe; M., Juvela; E., Keihanen; R., Keskitalo; T. S., Kisner; J., Knoche; M., Kunz; H., Kurki Suonio; G., Lagache; A., Lahteenmaki; J. M., Lamarre; A., Lasenby; C. R., Lawrence; S., Leach; R., Leonardi; P. B., Lilje; M., Linden Vørnle; M., Linden Vornle; P. M., Lubin; J. F., Macias Perez; B., Maffei; D., Maino; N., Mandolesi; M., Maris; D. J., Marshall; P. G., Martin; E., Martinez Gonzalez; Masi, Silvia; M., Massardi; S., Matarrese; P., Mazzotta; Melchiorri, Alessandro; A., Mennella; S., Mitra; M. A., Miville Deschenes; A., Moneti; L., Montier; G., Morgante; D., Mortlock; D., Munshi; J. A., Murphy; P., Naselsky; Nati, Federico; P., Natoli; H. U., Nørgaard Nielsen; H. U., Norgaard Nielsen; F., Noviello; D., Novikov; I., Novikov; S., Osborne; C. A., Oxborrow; F., Pajot; R., Paladini; D., Paoletti; M., Peel; L., Perotto; F., Perrotta; Piacentini, Francesco; M., Piat; E., Pierpaoli; D., Pietrobon; S., Plaszczynski; E., Pointecouteau; Polenta, Gianluca; L., Popa; T., Poutanen; G. W., Pratt; S., Prunet; J. L., Puget; J. P., Rachen; W. T., Reach; R., Rebolo; M., Reinecke; C., Renault; Ricciardi, Sara; I., Ristorcelli; G., Rocha; C., Rosset; J. A., Rubino Martin; B., Rusholme; E., Salerno; M., Sandri; Savini, Giorgio; D., Scott; L., Spencer; V., Stolyarov; R., Sudiwala; A. S., Suur Uski; J. F., Sygnet; J. A., Tauber; L., Terenzi; C. T., Tibbs; L., Toffolatti; M., Tomasi; M., Tristram; L., Valenziano; B., Van Tent; J., Varis; P., Vielva; F., Villa; N., Vittorio; L. A., Wade; B. D., Wandelt; N., Ysard; D., Yvon; A., Zacchei; A., Zonca. - In: ASTRONOMY & ASTROPHYSICS. - ISSN 0004-6361. - STAMPA. - 557:(2013), pp. A53--. [10.1051/0004-6361/201321160]
Planck intermediate results. XII: Diffuse Galactic components in the Gould Belt system
DE BERNARDIS, Paolo;G. De Gasperis;MASI, Silvia;MELCHIORRI, Alessandro;NATI, FEDERICO;PIACENTINI, Francesco;POLENTA, GIANLUCA;RICCIARDI, Sara;SAVINI, Giorgio;
2013
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
