What we talk about when we talk about blazars?
arXiv:1705.10166
Abstract
After the discovery of powerful relativistic jets from Narrow-Line Seyfert 1 Galaxies, and the understanding of their similarity with those of blazars, a problem of terminology was born. The word blazar is today associated to BL Lac Objects and Flat-Spectrum Radio Quasars, which are somehow different from Narrow-Line Seyfert 1 Galaxies. Using the same word for all the three classes of AGN could drive either toward some misunderstanding, or to the oversight of some important characteristics. I review the main characteristics of these sources, and finally I propose a new scheme of classification.
21 pages, 4 figures. Proceedings of the Conference "Quasars at All Cosmic Epochs" (Padova, Italy, April 2-7, 2017). Submitted to Frontiers in Astronomy and Space Science (Special Issue)