Gamma-ray narrow-line Seyfert galaxies: first long-term optical, UV, and X-ray monitoring

Gamma-ray narrow-line Seyfert 1 galaxies (-NLS1) are a well-established sub-class of jetted active galactic nuclei. Their number increased systematically since their discovery in 2009, but they were usually observed as a response to flares in the gamma-ray energy band. We performed, therefore, once-a-week, year-based Swift monitoring campaigns on four prominent -NLS1 which include the best candidates for detection by the Cherenkov Telescope Array Observatory, namely SBS 0846+513, PMN J0948+0022, PKS 1502+036, and FBQS J1644. 9+2619, in order to investigate the long-term behaviour of such kind of sources. The novelty of these campaigns is that they are unbiased with respect to possible target-of-opportunity observations, which makes our study the first on -NLS1 objects based on this systematic approach, and it allows us to investigate their intrinsic variability properties. We present the long-term monitoring light-curves of our objects obtained following our unbiased data acquisition strategy. We also present the recent results on the radio loud -NLS1 SDSS J164100. 10+345452. 7 that we monitored for two years with Swift and which we caught in flare.