Night-to-night variability of the emission lines in the spectrum of the Seyfert galaxy NGC 3227 nucleus

Abstract

This is a study of optical emission lines of the nucleus of the Seyfert galaxy NGC 3227. This work is based on53 spectrograms obtained with the 6-m telescope at the brightness maximum of this galactic nucleus on January 12-15, 1977. A set of profiles of the hydrogen H α , H β , and H γ lines and the equivalent widths ( λ EW ) of six emission lines and blends averaged over series of observations are presented. Broadening of the hydrogen line profiles was observed over the three days. At a level of 0.50 times the peak brightness the hydrogen line profiles were broadened by 12%, 35%, and 44%, respectively. The broadening of the H β line was accompanied by a reduction in its equivalent width ( β EW ). It is suggested that a flare was observed in the nucleus of the galaxy on a time scale of 3 days, possibly caused to a shock wave in long-lived flows from the galaxy nucleus.

Signs of gas flows in the variable Balmer line profiles of the Seyfert galaxy nuclei NGC 3227 and NGC 7469

“…12. The comparison of the profile widths of the H α , H β and H γ lines of the NGC 3227 nucleus on the levels 0.25 and 0.50 of peak intensity observed on January 12-15, 1977 (Metik et al 2006). the NGC 3227 nucleus brightness.…”