EUVE Observations of the Seyfert Galaxy MRK 279

摘要

We report EUVE spectral and photometric data of the Seyfert 1 galaxy MRK 279. The photo-metric data show large amplitude variations over time scales less than 10,000 s. The spectrum is characterized by several features between 80 and 100 A. We compare the observed data with several models. We can rule out the possibility that the EUV emission is from a diffuse corona or intercloud medium. Models that assume the soft X-ray/EUV emission results from reprocessing in an optical BLR region are also inconsistent with the data. A collisional excitation model is consistent with the observations but requires a cloud density > 1011 cm-3.