Relationship between X-ray and ultraviolet emission in 3C 273
Paltani, S.; Walter, R.; Courvoisier, T. J. -L.; Türler, M.
Switzerland
Abstract
In 3C 273, ultraviolet flux and X-ray flux measured by BATSE are not well correlated, contrarily to predictions of several models, unless the X-ray flux lags the UV emission by 1.75 yr. The absence of observed correlation at small lag cannot be due to spectral variability. A Comptonizing corona model is however compatible with all UV and X-ray observations covering the BATSE period.