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تسجيل مستخدم جديدSpectral Variability of QSOs in the Optical Band
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A new analysis of the variability of the spectral slope of PG QSOs has been performed, on the basis of recent literature data in the B and R photometric bands. Preliminary results confirm our previous findings concerning the increase of variability with the rest-frame observing frequency. We also find a correlation of the spectral slope with luminosity, consistent with temperature changes of an emitting black body.
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In previous studies we have shown that the optical variability of quasars increases, on average, with redshift. We explained this dependance in terms of a hardening of the spectrum during bright phases, coupled with the increase of the rest-frame fre
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During the last decade, M87s jet has been the site of an extraordinary variability event, with one knot (HST-1) increasing by over a factor 100 in brightness. Variability was also seen on timescales of months in the nuclear flux. Here we discuss the
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