The Missing Black Hole in the Large Magellanic Cloud: A Dynamical Prediction for Its Present-Day Location

Abstract

There are indications that the Large Magellanic Cloud (LMC) hosts a central supermassive black hole (SMBH), yet no direct detection exists: one reason is that its present-day location need not necessarily coincide with the photometric or kinematic centers. Here we frame a dynamical targeting problem and predict the present-day sky location of the LMC SMBH. We model the recent LMC-Small Magellanic Cloud (SMC) interaction, which induces a bar-disk offset, and integrate SMBH orbits within a realistic, time-dependent LMC-SMC-Milky Way (MW) potential. We show that the MW tidal field at present epoch exceeds that of the SMC by at least an order of magnitude, setting a preferred direction for coherent, vertical low-amplitude displacements, while the disk asymmetry drives in-plane offsets. Projecting onto the observed LMC frame, the mean of our predicted SMBH probability distribution is located at $(\alpha ,\delta )=(80.23^{\circ },-69.55^{\circ })$, with a $1\sigma$ confidence ellipse having semi-major and semi-minor axes of $(a,b)=(1.34^{\circ },0.56^{\circ })$, respectively. This mean is $\sim 6$ arcminutes north of the adopted dynamical center, while the mode coincides with the dynamical center and lies well within the $1\sigma$ confidence region. Furthermore, all literature estimates of the LMC center considered here fall within the $2\sigma$ confidence region. This provides a concrete, testable target for ongoing and upcoming spectroscopic surveys, transforming the search for the LMC SMBH from an unconstrained problem into a focused observational strategy.

10 pages, 2 figures, submitted to ApJ