Volume 490, Number 3, November II 2008
|Page(s)||989 - 994|
|Published online||17 September 2008|
Q2237+0305 in X-rays: spectra and variability with XMM-Newton*
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 e-mail: [cristian.vignali;giorgio.palumbo]@unibo.it
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
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.