The Astrometric Microlensing of OB150211
Abstract
Definitive detection of the population of isolated black holes in our own Galaxy has yet to be successful, making it difficult to constrain the mass function and the relation between initial and final mass. Astrometric microlensing has been proposed as a method to find and measure the mass of black holes and neutron stars by tracking the image of a luminous background star as a remnant passes in front of it, lensing its starlight and allowing for an estimate of its mass. With the precision of the adaptive optics on the W. M. Keck II 10-meter telescope, we attempt to measure the source proper motion and astrometric shift and combine them with the properties derived from the OGLE photometric light curve, allowing us to break degeneracies in photometry-only microlensing models. We observed the microlensing event OGLE-2015-BLG-0211 (OB150211) for 13 epochs from 2015 to 2018. Its 132 day-long Einstein crossing time makes it a good candidate black hole for astrometric follow-up to the OGLE survey's photometry of the event. While our point-source-point-lens model yields a lens mass of 5.01 - 99.32 solar masses within a 99.7% confidence level, further fit to binary models and combined astrometry from the Spitzer survey are in progress.
- Publication:
-
American Astronomical Society Meeting Abstracts #233
- Pub Date:
- January 2019
- Bibcode:
- 2019AAS...23336902A