  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.
