NUCLEUS OF C16.16 - ANOTHER CASE OF A DOUBLE-PEAKED ACTIVE GALACTIC NUCLEUS

We study optical spectra in high and low activity states of the faint, distant Seyfert 1 galaxy C16.16. A strong stellar population contribu tion to the continuum is observed, even in the high-state spectrum. Th e low-ionization emission lines show large equivalent widths. Narrow-l ine ratios are used to parameterize and investigate the physical condi tions in the narrow-line region. Photoionization models with nitrogen depletion, ionization continuum typical of an active galactic nucleus (AGN), and an ionization parameter U = 10(-2.8) reproduce the observed narrow lines. The AGN continuum shows a strong variation, while the B almer lines vary moderately. The Balmer lines have a broad and asymmet ric component with double-peaked structure. Using the profiles of emis sion lines originated in a relativistic circular disk, we successfully fit the observed broad H alpha profile. This disk component shows no variation in the observations. A variable, intermediate-width (similar to 6000 km s(-1)) Balmer component is also found. These two component s seem to arise by different processes.