The behaviour of the H_α emission line in the spectrum of Seyfert galaxy NGC4151 from 1976-1999

摘要

Spectral observations of Seyfert galaxies have been carried out at Fessenkov Astro-physical Institute of Kazakhstan (AFI) since 1970. The first spectrograms of about 48 objects have been measured and the radial velocities and absolute magnitudes of the galaxies have been derived. Some years ago, when the strong variability of spectra of Seyfert galaxies became known, we began a regular spectral monitoring program of 50 objects in this class (Table 1). The number of spectrograms obtained are given in brackets. In total, 2651 spectrograms were obtained in the red region of the spectrum and 1517 spectrograms in the blue.