First Detection of Radio Emission from the Intermediate Mass Black Hole in POX 52: Deep Multi-Band Observations with ATCA and VLA

TL;DR

This study reports the first detection of radio emission from the intermediate mass black hole in POX 52, using deep multi-band observations that reveal AGN activity, variability, and consistency with the fundamental plane of AGNs.

Contribution

First multi-band radio detection of POX 52's IMBH, confirming AGN activity and variability, and linking it to the low-mass extension of the AGN fundamental plane.

Findings

Detected compact radio emission confirming AGN activity.

Observed radio variability over two decades.

POX 52 aligns with the low-mass extension of the AGN fundamental plane.

Abstract

We present the first multi-band centimeter detection of POX 52, a nearby dwarf galaxy believed to habor a robust intermediate mass black hole (IMBH). We conducted the deep observations using the Australia Telescope Compact Array (ATCA), spanning frequencies from 4.5 to 10 GHz, as well as the sensitive observations from the Karl G. Jansky Very Large Array (VLA) operating in its most extended A-configuration at S band (2--4 GHz) and C band (4--8 GHz). In the ATCA observations, the source shows a compact morphology, with only one direction marginally resolved. The higher resolution of the VLA allowed us to slightly resolve the source, fitting it well with a two-dimensional Gaussian model. The detected radio emission confirms the presence of Active Galactic Nucleus (AGN) activity, indicating either a low-power jet or AGN-driven winds/outflows. Our dual-epoch observations with ATCA and VLA, together with previous non-detection flux density upper limits, reveal radio emission variability spanning two decades. In addition, we find that POX 52 aligns well with the low-mass extension of the fundamental plane for high-accretion, radio-quiet massive AGNs.