A likely Micro-quasar in the Shadow of M82 X-1

TL;DR

This paper identifies a transient micro-quasar near M82 X-1 using high-resolution X-ray and radio observations, revealing a new candidate hidden in the vicinity of a prominent ULX.

Contribution

It reports the discovery of a likely micro-quasar near M82 X-1, distinguished by its X-ray outburst and radio flare, using sub-pixel analysis of Chandra data.

Findings

A secondary source separated by 1.1 arcseconds from M82 X-1.

The secondary source is associated with a radio flare and X-ray outburst.

The source S1 is likely a micro-quasar similar to one in M31.

Abstract

The ultra-luminous X-ray source (ULX) M82 X-1 is one of the most promising intermediate mass black hole candidates in the local universe based on its high X-ray luminosities ($10^{40}-10^{41} {\rm erg s^{-1}}$) and quasi-periodic oscillations, and is possibly associated with a radio flare source. In this work, applying the sub-pixel technique to the 120 ks Chandra observation (ID: 10543) of M82 X-1, we split M82 X-1 into two sources separated by 1.1$\arcsec$. The secondary source is not detected in other M82 observations. The radio flare source is found to associate not with M82 X-1, but with the nearby transient source S1 with an outburst luminosity of $\sim 10^{39} {\rm erg s^{-1}}$. With X-ray outburst and radio flare activities analogous to the recently discovered micro-quasar in M31, S1 is likely to be a micro-quasar hidden in the shadow of M82 X-1.