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 +/- 0.02. Our fits imply a bolometric luminosity of L = 5.8 +/- 0.2 E+45 erg/s over the 0.3-10.0 keV band; this gives a mass lower limit of M > 4.6 E+7 Msun, 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.
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