EDP Sciences
Free access
Issue
A&A
Volume 387, Number 1, May III 2002
Page(s) 82 - 97
Section Galactic structure and dynamics
DOI http://dx.doi.org/10.1051/0004-6361:20020285


A&A 387, 82-97 (2002)
DOI: 10.1051/0004-6361:20020285

Towards a model of full-sky Galactic synchrotron intensity and linear polarisation: A re-analysis of the Parkes data

G. Giardino1, A. J. Banday2, K. M. Górski3, 4, K. Bennett1, J. L. Jonas5 and J. Tauber1

1  Research and Science Support Department of ESA, ESTEC, Postbus 299, 2200 AG Noordwijk, The Netherlands
2  Max-Planck Institut für Astrophysik, Garching bei München, 85741, Germany
3  ESO, Garching bei München, 85748, Germany
4  Warsaw University Observatory, Warsaw, Poland
5  Department of Physics & Electronics, Rhodes University, PO Box 94, Grahamstown 6140, South Africa

(Received 21 December 2001 / Accepted 22 February 2002 )

Abstract
We have analysed the angular power spectra of the Parkes radio continuum and polarisation survey of the Southern galactic plane at 2.4 GHz. We have found that in the multipole range l=40-250 the angular power spectrum of the polarised intensity is well described by a power-law spectrum with fitted spectral index $\alpha_{L} = 2.37 \pm 0.21$. In the same multipole range the angular power spectra of the E and B components of the polarised signal are significantly flatter, with fitted spectral indices respectively of $\alpha_{E} = 1.57 \pm 0.12$ and $\alpha_{B} = 1.45\pm
0.12$ . Temperature fluctuations in the E and B components are mostly determined by variations in polarisation angle. We have combined these results with other data from available radio surveys in order to produce a full-sky toy model of Galactic synchrotron intensity and linear polarisation at high frequencies ( $\nu \ga
10$  GHz). This can be used to study the feasibility of measuring the Cosmic Microwave Background polarisation with forthcoming experiments and satellite missions.


Key words: radio continuum: ISM -- surveys -- polarization -- cosmic microwave background

Offprint request: G. Giardino, ggiardin@rssd.esa.int

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