# The Emission Structure of Formaldehyde MegaMasers

## TL;DR

This study maps and analyzes formaldehyde MegaMaser emissions in three galaxies, revealing their structure, extent, and masering mechanism driven by infrared-pumped molecular gas in starburst regions.

## Contribution

It provides detailed spatial mapping of formaldehyde MegaMaser emissions in three galaxies and interprets their masering mechanism in starburst environments.

## Key findings

- Elongated emission components at galaxy centers (30-100 pc)
- Brightness temperatures confirm masering nature
- Emission due to amplification of radio continuum by infrared-pumped molecular gas

## Abstract

The formaldehyde MegaMaser emission has been mapped for the three host galaxies IC\,860. IRAS\,15107$+$0724, and Arp\,220. Elongated emission components are found at the nuclear centres of all galaxies with an extent ranging between 30 to 100 pc. These components are superposed on the peaks of the nuclear continuum. Additional isolated emission components are found superposed in the outskirts of the radio continuum structure. The brightness temperatures of the detected features ranges from 0.6 to 13.4 $\times 10^{4}$ K, which confirms their masering nature. The masering scenario is interpreted as amplification of the radio continuum by foreground molecular gas that is pumped by far-infrared radiation fields in these starburst environments of the host galaxies.