Discovery of an unusual new radio source in the star-forming galaxy M82: Faint supernova, supermassive blackhole, or an extra-galactic microquasar?

TL;DR

A new faint radio source was discovered in galaxy M82, with uncertain origin, possibly a faint supernova, a black hole, or an extragalactic microquasar, based on nine months of radio observations.

Contribution

This study reports the discovery and nine-month monitoring of a new radio source in M82, exploring its potential nature as a supernova, black hole, or microquasar.

Findings

Detected a new radio source in M82's nucleus.

Monitored the source over nine months.

Discussed possible origins including supernova, black hole, or microquasar.

Abstract

A faint new radio source has been detected in the nuclear region of the starburst galaxy M82 using MERLIN radio observations designed to monitor the flux density evolution of the recent bright supernova SN2008iz. This new source was initially identified in observations made between 1-5th May 2009 but had not been present in observations made one week earlier, or in any previous observations of M82. In this paper we report the discovery of this new source and monitoring of its evolution over its first 9 months of existence. The true nature of this new source remains unclear, and we discuss whether this source may be an unusual and faint supernova, a supermassive blackhole associated with the nucleus of M82, or intriguingly the first detection of radio emission from an extragalactic microquasar.