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A survey for high-redshift radio-loud quasars: optical spectroscopy of S > 0.2 Jy, flat-spectrum radio sources

I. M. Hook·R. G. McMahon·M. J. Irwin·C. Hazard
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Abstract

We present optical spectroscopic data for a complete sample of 161 S_5GHz >= 0.2 Jy, flat-spectrum radio sources. The sources were observed as part of a survey for high redshift, radio-loud quasars, and were selected for spectroscopic follow-up based on criteria of red optical colour and unresolved optical counterpart, as measured from APM scans of POSS-I plates. 13 objects from the spectroscopic sample were found to be radio-loud quasars with z > 3, of which two were previously known. We give positions, E (red) magnitudes, O-E colours, 5GHz radio fluxes, radio spectral indices, optical spectra and redshifts where possible for the spectroscopic sample. We also give finding charts for the z > 3 QSOs. The highest redshift object found is a QSO with z = 4.30 (GB1508+5714, the subject of an earlier Letter). The sample also contains a z = 3.05 QSO, GB1759+7539, which is optically very luminous (E=16.1). In addition, spectra are given for 18 S_5GHz >= 0.2 Jy, flat-spectrum radio sources that do not form part of the complete sample.

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I. M. Hook, R. G. McMahon, M. J. Irwin, C. Hazard. 1996-08-20. A survey for high-redshift radio-loud quasars: optical spectroscopy of S > 0.2 Jy, flat-spectrum radio sources. https://doi.org/10.1093/mnras%2F282.4.1274

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