Description
We have used the Australia Telescope Compact Array (ATCA) at 95GHz to carry out continuum observations of 130 extragalactic radio sources selected from the Australia Telescope 20GHz (AT20G) survey. We use a triple-correlation method to measure simultaneous 20- and 95-GHz flux densities for these objects, and over 90 per cent of our target sources are detected at 95GHz. We demonstrate that the ATCA can robustly measure 95-GHz flux densities with an accuracy of ~10 per cent in a few minutes for sources stronger than about 50mJy. We measure the distribution of radio spectral indices in a flux-limited sample of extragalactic sources, and show that the median 20-95GHz spectral index does not vary significantly with flux density for S_20_>150mJy . This finding allows us to estimate the extragalactic radio source counts at 95GHz by combining our observed 20-95GHz spectral-index distribution with the accurate 20-GHz source counts measured in the AT20G survey.
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