Peaked sources and narrow?line Seyfert 1s: A love story

The Narrow-line Region of Seyfert Galaxies: Narrow-line Seyfert 1s versus Broad-line Seyfert 1s

It is known that the spectral energy distribution (SED) of the nuclear radiation of narrow-line Seyfert 1 galaxies (NLS1s) has different shapes with respect to that of ordinary broad-line Seyfert 1 galaxies (BLS1s), particularly in wavelengths of X-ray. This may cause some differences in the ionization degree and the temperature of gas in narrow-line regions (NLRs) between NLS1s and BLS1s. This...

Narrow-Line Seyfert 1s: 15 Years Later

The spectroscopic properties of the objects that came to be called Narrow-Line Seyfert 1s were first systematically described and named as such 15 years ago by Osterbrock & Pogge (1985). At the time, they were a relatively rare and peculiar subclass of Seyfert galaxies. Their discovery in large numbers in X-ray surveys, however, has elevated them to a role as important members of the AGN family...

Are Narrow-Line Seyfert 1s Really Strange?

Narrow-Line Seyfert 1s (NLS1s) are generally considered to be “strange” Active Galactic Nuclei (AGNs). Surprisingly, this makes them very useful for constraining models. I discuss what happens when one attempts to qualitatively fit the NLS1 phenomenon using the stellar wind model for AGN line emission (e.g., Kazanas 1989). The simplest way of narrowing profile bases of this model to the widths ...

Privacy and Markets: A Love Story

Humus and time: a love story

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