Speaker
Ayse Ulubay-Siddiki
(Istanbul University)
Description
Warped megamaser discs in galactic nuclei provide a useful means of probing the close vicinity of the central black holes. The observations of some of the systems in nearby AGN, such as NGC1068 and Circinus, might be indicating the existence of a highly inclined, massive disc, prone to forming stars. We study for various surface density profiles, and disc radial extents, the long term evolution of warped discs incorporating the effects of self-gravity. We show that there is range in surface density profile indices for which the disc inclinations exhibit stable oscillations, enabling the modification of the warp by tens of degrees for certain parameters. Outside this range the discs dissolve. In either case, the discs break into separate pieces soon after the simulations start. We also perform a ray tracing through the model discs taking into account the beaming of maser radiation and construct maser maps and position-velocity diagrams to compare our results with recent observations.
Author
Ayse Ulubay-Siddiki
(Istanbul University)