GBT24A-278

Monitoring of the water megamaser in IC485: weighing the BH of a LINER galaxy

Abstract

Recent VLBA observations from our group has recently shown that the water megamaser in the LINER galaxy IC485 is seemingly associated with an accretion disk orbiting around the SMBH in the nucleus. New approved HSA (VLBA+VLA+GBT) observations, awaiting scheduling in Oct/Nov, will map all the three maser features in IC485 to confirm the hypothesis of a disk maser and derive the full distribution of the maser emission.
Here, we propose a sensitive regular 1-year monitoring campaign with the GBT (and the VLA for the epochs from May to Sept. 2024) of the water maser emission in IC485 to determine the accelerations of systemic maser features and thus provide a critical complement to the aforementioned HSA data, offering the chance to create, for the first time, a reliable model of an accretion disk in a LINER, ultimately, leading to a measure of the distance to the galaxy.

Investigators

Name	Institution
Paola Castangia	Istituto Nazionale di Astrofisica
Elisabetta Ladu *	Istituto Nazionale di Astrofisica; Cagliari, Università degli Studi di
Andrea Tarchi	Istituto Nazionale di Astrofisica
Jim Braatz	National Radio Astronomy Observatory
Gabriele Surcis	Istituto Nazionale di Astrofisica
Dominic Pesce	Virginia, University of; Smithsonian Astrophysical Observatory

* indicates the PI