Detection of type-2 quasars in the radio galaxies B3 0731+438 and 3C 257
Abstract
We present XMM-Newton observations and spectral fitting of two highly redshift, [OIII]-luminous, narrow-line radio galaxies, B3 0731+438 and 3C 257. Their X-ray continua are well fitted by a partial covering model with intrinsically unabsorbed and absorbed powerlaw components. The spectral models indicate that both objects harbour highly obscured nuclei, with NH ~ 0.5 - 2 x 1023 cm-2. Correcting for this absorption we find large intrinsic luminosities in the range LX ~ 0.2 - 1 x 1045 erg/s. Thus, both sources are type-2 quasars.
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