IRON LINE EMISSION AND 2-COMPONENT SPECTRAL BEHAVIOR IN THE ASCA OBSERVATION OF THE SEYFERT-1 GALAXY NGC-7469

The results of spectral-temporal analysis of an ASCA observation of the nearby Seyfert 1 galaxy NGC 7469 are presented providing an unprecedented combination of broadband coverage and energy resolution. A narrow fluorescence line (Gaussian dispersion sigma < 150 eV) of neutral iron was detected with equivalent width (EW) similar or equal to 120 eV. The iron line appears incompatible with emission from a relativistic accretion disk. The presence of a soft excess below 0.8 keV is confirmed by the ASCA data. Moreover, this component cannot be accounted for by a warm absorber model. A good agreement with the data is obtained by modeling the soft excess either via a thermal component or by reflection by a mildly ionized medium. Correlated luminosity and spectral variability was clearly detected in the observation, the spectrum getting steeper when the luminosity increases. A detailed analysis suggests that this behavior may be due to differing degrees of variability of the soft and hard components.