A&A 490, 989-994 (2008)
Q2237+0305 in X-rays: spectra and variability with XMM-NewtonE. V. Fedorova1, V. I. Zhdanov1, C. Vignali2, and G. G. C. Palumbo2
1 Astronomical Observatory of Kyiv Shevchenko University, Observatorna St. 3, Kiev, UA- 04053, Ukraine
e-mail: firstname.lastname@example.org; email@example.com
2 Dipartimento di Astronomia, Università di Bologna, via Ranzani 1, 40127 Bologna, Italy
Received 25 September 2007 / Accepted 23 August 2008
Aims. X-ray observations of gravitationally lensed quasars may allow us to probe the inner structure of the central engine of a quasar. Observations of Q2237+0305 (Einstein Cross) in X-rays may be used to constrain the inner structure of the X-ray emitting source.
Methods. Here we analyze the XMM-Newton observation of the quasar in the gravitational lens system Q2237+0305 taken during 2002. Combined spectra of the four images of the quasar in this system were extracted and modelled with a power-law model. Statistical analysis was used to test the variability of the total flux.
Results. The total X-ray flux from all the images of this quadruple gravitational lens system is erg/(cm2 s) in the range 0.2–10 keV, showing no significant X-ray spectral variability during almost 42 ks of the observation time. Fitting of the cleaned source spectrum yields a photon power-law index of . The X-ray lightcurves obtained after background subtraction are compatible with the hypothesis of a stationary flux from the source.
Key words: gravitational lensing -- X-rays: general -- galaxies: quasars: general
© ESO 2008