Black Hole Hunters: A Future Microlensing Search for Quiescent Black Holes With LSST?


Adam McMaster

As the end stage of the evolution of massive stars, there should be tens of millions of stellar-mass black holes in the Galaxy. However, very few stellar-mass black holes have been detected to date, mostly as X-ray binaries. That leaves a substantial population of black holes which are still to be discovered, with quiescent black holes vastly outnumbering accreting black holes. Despite their number, such quiescent black holes are extremely challenging to detect. Only a handful of quiescent stellar-mass black holes have been detected to date.

We have conducted a search of the photometry archive of the SuperWASP all-sky survey, looking for microlensing magnifications that might indicate the presence of an unseen black hole in a binary orbit with a stellar companion. A confirmed detection would be the first detection of a so-called “self-lensing” event, where both the source and the lens are part of the same system.

To carry out the search, we enlisted the help of volunteers via the Zooniverse citizen science platform to visually inspect each light curve. The first results from the project are now being analysed, and we are beginning planning for follow up projects using data from ZTF and TESS.

In this talk, I will summarise the results from the SuperWASP project and discuss our plans for ZTF and TESS. I will then discuss the prospects for finding such self-lensing systems with next-generation surveys such as LSST.


This talk will be given in the Rubin Science Medley session.


Career Stage: 
Grad Student