We have analyzed the first XMM-Newton, Swift, and archival ROSAT PSPC observations of the quasar LBQS 0102-2713. The object was selected from the ROSAT archive as being notable due to the steep soft X-ray photon index and due to the UV brightness based on Hubble Space Telescope and optical spectroscopic observations. The first XMM-Newton observations carried out in 2009 December and the first Swift observations from 2010 have confirmed the steepness of the soft X-ray photon index, which ranges between 3.35 and 4.41 for the different XMM-Newton and ROSAT detectors, the UV brightness of the source, and the absence of significant absorption by neutral hydrogen. The new data allow a combined spectral fitting to the Swift Ultra-Violet/Optical Telescope and the XMM-Newton/ROSAT data which results in a huge luminosity of (6.2 ± 0.2) × 1047 erg s–1 and αox values ranging between (–1.87 ± 0.11) and (–2.11 ± 0.12). The nature of the soft X-ray emission can be explained as local Comptonized emission of the UV disk photons in the pseudo-Newtonian potential. The black hole mass is estimated from the Mg II line and translates into an Eddington ratio of L/L edd = 18+33 –12. For the dimensionless electron temperature of the plasma cloud θ = kT e/m ec2 we derive an upper limit of about 10 keV.
|Number of pages||4|
|Early online date||21 Mar 2011|
|Publication status||Published - 10 Apr 2011|
- galaxies: active, quasars: individual: LBQS 0102-2713, X-rays: galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics