Microlensing Events with X-Ray Counterparts

For the past two decades, microlensing has been a promising phenomenon for a variety of astronomy fields. Detecting small amplification of distant objects’ flux has provided evidence of planetary star systems and faint, otherwise undetectable MACHOs, such as neutron stars and black holes. Identifying the locations of these previously unrecorded objects can provide more accurate details about the distribution of dark matter in the Milky Way’s Galactic Bulge and dark Halo. Two broad scale sky surveys, The Optical Gravitational Lensing Experiment (OGLE) and Microlensing Observation in Astrophysics (MOA), record the luminosity of objects that appear to be involved in microlensing events and post a light curve of the desired event: the magnitude of the source object plotted vs. the approximate event duration in Julian days. Frank Primini, a coworker of Rosanne DiStefano and member a team of astronomers researching microlensing events, has developed a program to monitor the MOA and OGLE events and find possible catalogued object matches near the recorded position of each announced event. The events are matched with objects registered in a variety of catalogues, two of which include X-Ray source objects - the Chandra Source Catalogue (CSC) and the XMM-Newton Serendipitous Source Catalogue (3XMM-DR4). I present a general discussion and classification of the 38 matches between X-Ray objects and microlensing events recorded in the past decade, searching specifically for indications of Black Holes or Neutron Stars. I offer a visual representation of these events including the type of X-Ray radiation (soft--hard), separation between event and matched object, closeness of lens fit, literature references, and potential error in flux observations due to gas emitted from dust (Schlatly & Finkbeiner 1992). From the original 38 microlensing events, I noted eleven events having amplifications that poorly represent a microlensing light curve and nine events with limited observational data. The remaining eighteen events deserve further observation and analysis before any other conclusions about their physical properties can be confirmed.