We report on an XMM-Newton observation of the z = 1.055 quasar and Giga-hertz Peaked Spectrum ( GPS ) source 3C 287 .
Our 62.3 ksec observation provides an exceptional X-ray view of a prominent member of this important subclass of active galactic nuclei ( AGN ) .
The X-ray spectra of 3C 287 are consistent with a simple absorbed power-law with a spectral index of \Gamma = 1.72 \pm 0.02 .
Our fits imply a bolometric luminosity of L = 5.8 \pm 0.2 \times 10 ^ { 45 } ~ { } { erg } ~ { } { s } ^ { -1 } over the 0.3–10.0 keV band ; this gives a mass lower limit of M _ { BHmin } \geq 4.6 \times 10 ^ { 7 } ~ { } { M _ { \odot } } assuming X-rays contribute 10 % of the bolometric luminosity and radiation at the Eddington limit .
Iron emission lines are common in the X-ray spectra of many AGN , but the observed spectra appear to rule-out strong emission lines in 3C 287 .
The simple power-law spectrum and absence of strong emission lines may support a picture where our line of sight intersects a relativistic jet .
Milliarcsecond radio imaging of 3C 287 appears to support this interpretation .
We discuss our results in the context of different AGN sub-classes and the possibility that GPS sources harbor newly-formed black hole jets .