We present the results from XMM-Newton observations of the highly optically polarized broad absorption line quasar ( BALQSO ) CSO 755 .
By analyzing its X-ray spectrum with a total of \sim 3000 photons we find that this source has an X-ray continuum of ‘ typical ’ radio-quiet quasars , with a photon index of \Gamma =1.83 ^ { +0.07 } _ { -0.06 } , and a rather flat ( X-ray bright ) intrinsic optical-to-X-ray spectral slope of \alpha _ { ox } = - 1.51 .
The source shows evidence for intrinsic absorption , and fitting the spectrum with a neutral-absorption model gives a column density of N _ { H } \sim 1.2 \times 10 ^ { 22 } cm ^ { -2 } ; this is among the lowest X-ray columns measured for BALQSOs .
We do not detect , with high significance , any other absorption features in the X-ray spectrum .
Upper limits we place on the rest-frame equivalent width of a neutral ( ionized ) Fe K \alpha line , \leq 180 eV ( \leq 120 eV ) , and on the Compton-reflection component parameter , R \leq 0.2 , suggest that most of the X-rays from the source are directly observed rather than being scattered or reflected ; this is also supported by the relatively flat intrinsic \alpha _ { ox } we measure .
The possibility that most of the X-ray flux is scattered due to the high level of UV–optical polarization is ruled out .
Considering data for 46 BALQSOs from the literature , including CSO 755 , we have found that the UV–optical continuum polarization level of BALQSOs is not correlated with any of their X-ray properties .
A lack of significant short- and long-term X-ray flux variations in the source may be attributed to a large black-hole mass in CSO 755 .
We note that another luminous BALQSO , PG 2112 + 059 , has both similar shallow C iv BALs and moderate X-ray absorption .