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		| Paper: | 
		Search for z > 4 Radio QSOs | 
	 
	
		| Volume: | 
		249, The Central Kiloparsec of Starbursts and AGN: the La Palma Connection | 
	 
	
		| Page: | 
		310 | 
	 
	
		| Authors: | 
		Holt, Joanna; Benn, Chris | 
	 
	
	
		| Abstract: | 
		We obtained spectra of 55 FIRST radio sources (S1.4 GHz > 1 mJy) with faint (POSS-I E < 18.6), red (POSS-I O-E > 3) starlike optical counterparts. Ten of the candidates are QSOs with redshift 3.6 < z < 4.4, of which six were previously unknown. The remaining 45 candidates comprise: a z = 2.6 BAL QSO, three low-z galaxies with narrow emission lines, 18 probable radio galaxies and 23 M stars. The efficiency of discovery of high redshift QSOs with this technique is 1/2 for S1.4 GHz > 10 mJy and 1/9 for S1.4 GHz > 1 mJy. Our search area is 4030 deg2 giving a surface density of z > 4 QSOs of 0.0015 deg-2. | 
	 
	
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