Narrow-line Seyfert 1 galaxies: an amasing class of AGN

摘要: Context. Narrow-line Seyfert 1 (NLS1) galaxies are a class of active galactic nuclei (AGN) that have all the properties type but show peculiar characteristics, including narrowest Balmer lines, strongest Fe II emission, and extreme in X-rays. Line continuum radio observations provide an optimal tool to access (often) optically obscured innermost regions AGN reveal kinematics gas around their central engines. Aims. We investigate interplay between NLS1 maser phenomenon, help us understand nature emission some NLS1s where water has been detected. Methods. observed sample with Green Bank Telescope search for at 22 GHz. also reduced analysed archival Very Large Array data produced 22-GHz spectra five detected emission. In particular, we imaged nuclear NGC 5506 subarcsec scales Array. Results. discovered two galaxies: IGR J16385-2057, IRAS 03450+0055. addition three previously known detections Mrk 766, 4051, 5506, this yields detection rate ∼7% (5/71). This value rises significantly ∼21% (5/24) when considering only recessional velocities less than 10 000 km s −1 . For 4051 find is located within 5 12 pc, respectively, knots, which interpreted as core-jet structures. Conclusions. The surprisingly high, much higher obtained similar those 2 low-ionization emission-line region galaxies. masers associated AGN, either accretion disk, jet, or outflow. apparent lack high-velocity features evidence, recently reported, radiative outflows jets host seems favour interpretation jet A association seemingly true 03450+0055, although, these cases, without interferometric measurements cannot rule out off-nuclear origin