G. La Mura

Properties of flat-spectrum radio-loud narrow-line Seyfert 1 galaxies

We have conducted a multiwavelength survey of 42 radio loud narrow-1ine Seyfert 1 galaxies (RLNLS1s), selected by searching among all the known sources of this type and omitting those with steep radio spectra. We analyse data from radio frequencies to X-rays, and supplement these with information available from online catalogs and the literature in order to cover the full electromagnetic spectrum. This is the largest known multiwavelength survey for this type of source. We detected 90% of the sources in X-rays and found 17% at gamma rays. Extreme variability at high energies was also found, down to timescales as short as hours. In some sources, dramatic spectral and flux changes suggest interplay between a relativistic jet and the accretion disk. The estimated masses of the central black holes are in the range

Contribution of a disc component to single-peaked broad lines of active galactic nuclei

\sim 10^{6-8}M_{\odot}

Detailed Analysis of Balmer Lines in a Sloan Digital Sky Survey Sample of 90 Broad-Line Active Galactic Nuclei

, smaller than those of blazars, while the accretion luminosities span a range from

Cosmic-ray electron-positron spectrum from 7 GeV to 2 TeV with the Fermi Large Area Telescope

\sim 0.01

Parent population of flat-spectrum radio-loud narrow-line Seyfert 1 galaxies

to

A spectroscopic analysis of a sample of narrow-line Seyfert 1 galaxies selected from the Sloan Digital Sky Survey

\sim 0.49

Balmer Emission Line Profiles and Complex Properties of Broad-Line Regions in Active Galactic Nuclei

times the Eddington limit, similar to those of quasars. The distribution of the calculated jet power spans a range from

Fermi-LAT Observations of High-energy Behind-the-limb Solar Flares

\sim 10^{42.6}

Spectral properties of the narrow-line region in Seyfert galaxies selected from the SDSS-DR7

to

Evidence for periodicity in 43-year-long monitoring of NGC 5548

\sim 10^{45.6}