Powerful relativistic jets in spiral galaxies

The discovery of high-energy (E>100 MeV) gamma rays from Narrow-Line Seyfert 1 Galaxies (gamma-NLS1s) has confirmed the presence of powerful relativistic jets in this class of active galactic nuclei (AGN). Although the jet emission is similar to that of blazars and radio galaxies, gamma-NLS1s have some striking differences: relatively small masses (10^6-10^8 M_sun), high accretion rates (0.1-1 times the Eddington limit) and are generally hosted by spiral galaxies. It is now possible to study a rather unexplored range of mass and accretion rates of AGN with relativistic jets. Specifically, in this work I present some results obtained by comparing a sample of blazars and gamma-NLS1s with another sample of Galactic binaries with relativistic jets (stellar mass black holes and neutron stars).