DOI

https://doi.org/10.48717/5afw-tt50

Project

ET038

Title

H2O megamaser VLBI: a powerful tool to study ejection and accretion

Abstract

Candidate extragalactic water masers associated with accretion disks around AGN are typically identified by a triple-peak profile of the maser spectra. However, a large number of maser sources show single-broad lines or groups of lines clustered in a narrow velocity range. In this proposal, we propose for a study of two galaxies, classified as Seyfert or LINER, hosting bright water masers and showing evidences of ejection/accretion nuclear activity. Our main goals are that of detecting the maser emission at VLBI scales, determining its location and distribution with respect to the main nuclear centers of activity, and derive the nature of the emission. These sources will potentially constitute new case studies for the scarcely-populated class of confirmed jet/outflow masers or very first examples of the exotic, recently-invoked class of 'inclined water maser disks'. Furthermore, the proposed measurements will set the basis for a number of follow-up (VLBI) studies aim at a better understanding of the physics and disk/jet geometry in Seyferts and LINERs.