Searching for Intermediate Mass Black Holes in the Milky Way's galactic halo

TL;DR

This study searches for intermediate mass black holes in the Milky Way's halo by analyzing microlensing events from extensive Magellanic Cloud observations, developing a pipeline to identify potential candidates and variable stars.

Contribution

The paper introduces a novel data analysis pipeline for detecting microlensing events caused by IMBHs using Magellanic Cloud observations from the DECAM instrument.

Findings

Identified several variable objects, some potentially due to microlensing.

Developed a pipeline capable of distinguishing known and unknown variable sources.

Initial candidates show light curves similar to microlensing events, requiring further confirmation.

Abstract

Intermediate Mass Black Holes (IMBHs) are a class of black holes with masses in the range $10^2 \div 10^5$ $M_\odot$, which can not directly derive from stellar evolution. Looking for these objects and estimating their abundance is important not only for a deeper understanding of their origin but also for unveiling the nature and distribution of the dark matter in the galactic halo. Since February 2018 to January 2020, the Large and Small Magellanic Cloud have been intensively monitored by the DECAM instrument, installed on the 4m V. Blanco Telescope (CTIO, Chile) with the main objective to discover microlensing events possibly due to IMBHs. Here we outline the developed data analysis pipeline. We have tested it versus known variable sources finding many not previously known variables objects. A few sources show a light curve similar to that expected for a microlensing event, but further analysis is required to confirm the microlensing nature of these events. For these sources, and in particular for the uncatalogued variable stars, we try to determine if they are periodic or not via a periodogram analysis.