The ultraviolet variability of NGC 3783.

Abstract

The results of three years of monitoring the spectral variability of the type 1 Seyfert galaxy NGC 3783 with IUE spacecraft instrumentation are reported. Techniques for fitting power laws to the observed wavebands are described, noting the monitoring was carried out in the 1150-3150 A region. The continuum was found to vary by a factor of ten over several months time, and by 40% in two days. A positive correlation was determined between the continuum luminosity and the power law spectral index, indicating a synchrotron emission arising from nonthermal relativistic electrons heated by Fermi acceleration and cooled by relativistic bremmstrahlung emission. Similar variability was observed in the C III and C IV emission lines.