The angular power spectrum of radio emission at 2.3 GHz

¹ Astrophysics Division -Space Science 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

Corresponding author: G. Giardino, ggiardin@astro.estec.esa.nl

Received: 24 November 2000
Accepted: 9 March 2001

Abstract

We have analysed the Rhodes/HartRAO survey at 2326 MHz and derived the global angular power spectrum of Galactic continuum emission. In order to measure the angular power spectrum of the diffuse component, point sources were removed from the map by median filtering. A least-square fit to the angular power spectrum of the entire survey with a power law spectrum , gives in the l range 2-100. The angular power spectrum of radio emission appears to steepen at high Galactic latitudes and for observed regions with , the fitted spectral index is . We have extrapolated this result to 30 GHz (the lowest frequency channel of Planck) and estimate that no significant contribution to the sky temperature fluctuation is likely to come from synchrotron at degree-angular scales.