摘要
We compile the observed intensity ratios of the Balmer lines for low redshift quasars and Seyfert Ⅰ galaxies. In the framework of the Cerenkov line emission theory, we compare the theoretical intensity ratios with those of observations, and find that the observed intensity ratios for the radio-loud quasars and the Seyfert Ⅰ galaxies are nearer to the theoretical expectation than those for the radio-quiet sources. It seems that for the radio-loud AGNs, the characteristics of the Cerenkov line emission are more remarkable because of the existence of a great number of relativistic electrons. We also discuss the reddening by dust in quasars and the Seyfert galaxies. The fact that the reddening of the Seyfert galaxies is more serious than quasars shows that the Seyfert galaxies have more dust than quasars. This is in agreement with the present point of view.
We compile the observed intensity ratios of the Balmer lines for low redshift quasars and Seyfert Ⅰ galaxies. In the framework of the Cerenkov line emission theory, we compare the theoretical intensity ratios with those of observations, and find that the observed intensity ratios for the radio-loud quasars and the Seyfert Ⅰ galaxies are nearer to the theoretical expectation than those for the radio-quiet sources. It seems that for the radio-loud AGNs, the characteristics of the Cerenkov line emission are more remarkable because of the existence of a great number of relativistic electrons. We also discuss the reddening by dust in quasars and the Seyfert galaxies. The fact that the reddening of the Seyfert galaxies is more serious than quasars shows that the Seyfert galaxies have more dust than quasars. This is in agreement with the present point of view.
基金
Project supported by the National Natural Science Foundation of China.
