GBT24B-050

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

Abstract

Recent VLBA observations from our group has 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 HSA (VLBA+VLA+GBT) observations, observed in Nov 2023 (and just correlated), will allow us to 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 to extend and conclude the sensitive regular 1-year monitoring campaign with the GBT (that will start on Feb. 2024) with 4 epochs (from Oct. 2024 to Jan. 2025) 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
Elisabetta Ladu *	Istituto Nazionale di Astrofisica; Cagliari, Università degli Studi di
Andrea Tarchi	Istituto Nazionale di Astrofisica
Paola Castangia	Istituto Nazionale di Astrofisica
Gabriele Surcis	Istituto Nazionale di Astrofisica
Dominic Pesce	Virginia, University of; Smithsonian Astrophysical Observatory
Jim Braatz	National Radio Astronomy Observatory

* indicates the PI