Are symmetric radio spectra of some GPS/HFP sources related to a statistical acceleration mechanism?

We present the results of a new spectral analysis of a sample of HFPs. We took from literature simultaneous radio measurements at various epochs and studied the symmetry of flux distribution around the peak frequency by means of a log-parabolic fit. We found that a large fraction of spectra are symmetric and propose that this property may be a consequence of statistical acceleration. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei