2004/08/04 by F. Vagnetti, Vagnetti, F., D. Trevese +1
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0408074
4 pages, proceedings of "AGN Variability from X-rays to Radio Waves", Eds. C. M. Gaskell, I. M. McHardy, B. M. Peterson, and S. G. Sergeev
arxiv created 2004/08/04 · arxiv updated 2009/12/01
We present a combined analysis of the optical spectral variability for two samples of QSOs, 42 objects at z<0.4 monitored at the Wise Observatory (Giveon et al 1999), plus 59 objects up to z∼ 3 in the field of the Magellanic Clouds, detected and/or monitored within the MACHO Project database (Geha et al 2003). Our analysis shows some increase of the observed spectral variability as a function of redshift, with a large scatter. These data are compared with a model based on the addition of flares of different temperatures to a stationary quasar SED, taking into account also the intrinsic scatter of the SEDs.