  We present the results of new radio observations carried out with the Karl G.
Jansky Very Large Array C-configuration at 5.5 GHz for a sample of southern
narrow-line Seyfert 1 galaxies (NLS1s). This work increases the number of known
radio-detected NLS1s in the southern hemisphere, and confirms that the radio
emission of NLS1s is mainly concentrated in a central region at kpc-scale and
only a few sources show diffuse emission. In radio-quiet NLS1s, the radio
luminosity tends to be higher in steep-spectrum sources and be lower in
flat-spectrum sources, which is opposite to radio-loud NLS1s. This may be
because the radio emission of steep NLS1s is dominated by misaligned jets,
AGN-driven outflows, or star formation superposing on a compact core. Instead
the radio emission of flat NLS1s may be produced by a central core which has
not yet developed radio jets and outflows. We discover new NLS1s harboring
kpc-scale radio jets and confirm that a powerful jet does not require a
large-mass black hole to be generated. We also find sources dominated by star
formation. These NLS1s could be new candidates in investigating the radio
emission of different mechanisms.
