Forum Springer Astron. Astrophys.
Forum Whats New Search Orders

Astron. Astrophys. 338, 1-7 (1998)

Next Section Table of Contents

Galactic H[FORMULA] emission and the cosmic microwave background

M. Marcelin 1, P. Amram 1, J.G. Bartlett 2, D. Valls-Gabaud 2 and A. Blanchard 2

1 IGRAP, Observatoire de Marseille, 2 Place Le Verrier, F-13248 Marseille Cedex 04, France
2 Observatoire de Strasbourg, 11 rue de l'Université, F-67000 Strasbourg, France

Received 15 May 1998 / Accepted 24 June 1998


We present observations of Galactic [FORMULA] emission along two declination bands where the South Pole cosmic microwave background experiment reports temperature fluctuations. The high spectral resolution of our Fabry-Perot system allows us to separate the Galactic signal from the much larger local sources of [FORMULA] emission, such as the Earth's geocorona. For the two bands (at [FORMULA] and [FORMULA]), we find a total mean emission of [FORMULA] R with variations of [FORMULA] R. The variations are within the estimated uncertainty of our total intensity determinations. For an ionized gas at [FORMULA] K, this corresponds to a maximum free-free brightness temperature of less than 10 µK at 30 GHz (K-band). Thus, unless there is a hot gas component with [FORMULA] K, our results imply that there is essentially no free-free contamination of the SP91 (Schuster et al. 1993) and SP94 (Gunderson et al. 1995) data sets.

Key words: cosmic microwave background – diffuse radiation – Galaxy: halo – ISM: general

Send offprint requests to: M. Marcelin

This article contains no SIMBAD objects.


Next Section Table of Contents

© European Southern Observatory (ESO) 1998

Online publication: September 8, 1998