Proc. IAU volume 13, issue S336, P96-98 2017 DOI: 10.1017/s1743921317010614 View full text
Francesca Panessa, Paola Castangia, Andrea Tarchi, Loredana Bassani, Angela Malizia, Angela Bazzano, Pietro Ubertini

Abstract: Context. Water megamaser emission at 22 GHz has proven to be a powerful tool for astrophysical studies of active galactic nuclei (AGN) because it allows an accurate determination of the mass of the central black hole and of the accretion disc geometry and dynamics. However, after searches among thousands of galaxies, only about 200 of them have shown such spectroscopic features, most of them of uncertain classification. In addition, the physical and geometrical conditions under which a maser activates are stil…

expand abstract