# Measuring the Obscuring Column of a Disk Megamaser AGN in a Nearby Merger

## TL;DR

This study analyzes the X-ray spectrum of a disk megamaser AGN in a merger, revealing it is highly obscured and reflection-dominated, which helps infer intrinsic source properties like luminosity and accretion rate.

## Contribution

It provides the first broadband X-ray spectral analysis of NGC 5765B, combining Chandra and NuSTAR data to characterize its obscuration and intrinsic parameters.

## Key findings

- NGC 5765B is highly Compton-thick and reflection-dominated.
- The Eddington ratio is estimated between 2% and 14%.
- X-ray spectral analysis confirms the robustness of these measurements.

## Abstract

Active Galactic Nuclei (AGNs) hosting disk water megamasers are well known to be obscured by large amounts of gas, likely due to the presence along the line of sight of an almost edge-on disky structure orbiting the supermassive black hole. Correcting for the high obscuration is crucial to infer parameters intrinsic to the source, like its luminosity. We present a broadband X-ray spectral analysis of a water megamaser AGN in an early merger (NGC 5765B), combining Chandra and NuSTAR data. NGC 5765B is highly Compton-thick and reflection-dominated, following the general trend among disk megamasers. Combining the exquisite black hole mass from masers with our X-ray spectroscopy, the Eddington ratio of the megamaser is estimated to be in the $2-14\%$ range, and its robustness is confirmed through SED fitting.