V. Cracco

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

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

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

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

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

X-RAY GRATING OBSERVATIONS OF RECURRENT NOVA T PYXIDIS DURING THE 2011 OUTBURST

\sim 0.01

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

to

Compact steep-spectrum sources as the parent population of flat-spectrum radio-loud narrow-line Seyfert 1 galaxies

\sim 0.49

The origin of gas in extended narrow-line regions of nearby Seyfert galaxies – I. NGC 7212

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

[O III] line properties in two samples of radio-emitting narrow-line Seyfert 1 galaxies

\sim 10^{42.6}

Kiloparsec-scale emission in the narrow-line Seyfert 1 galaxy Mrk 783

to

Distribution of the heavy elements throughout the extended narrow-line region of the Seyfert galaxy NGC 7212

\sim 10^{45.6}