出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：In this contribution we show that the host galaxies of NLS1s differ dramatically from those of Broad-Line Seyfert 1s (BLS1s). This leads us to propose that NLS1s represent a class of AGN in which the black hole growth is, and has always been, dominated by secular evolution. Our line of argument is as follows. Firstly, by looking at the properties of NLS1 hosts in the literature, we show that the evolution of NLS1s is currently mainly driven by secular processes, in contrast to BLS1s. Secondly, we study the bulges of NLS1 and BLS1 galaxies, and we find that statistically NLS1s have lower Sérsic indices (< nb > 1:5) and less prominent bulges (bulge-to-total light ratio, < B=T > 0:2) than BLS1s (< nb > 2:5 and < B=T > 0:4). This result indicates that NLS1 host bulges are pseudo-bulges and distinct from BLS1 bulges. The direct consequence of this result is that internal secular evolution must have dominated the past evolution of NLS1 hosts, possibly explaining their particular AGN properties.
