Building the Largest HLX Catalog: The Search for Intermediate-Mass Black Holes

We propose to construct the largest sample of hyperluminous X-ray sources (HLXs). This will be accomplished by combining our custom astrometric and registration pipeline with the excellent spatial resolution of Chandra, which will allow us to identify off-nuclear X-ray sources to smaller angular separations than previous catalogues. Based on our pilot study, this will increase the known number of HLXs by a factor of 10, and analysis of their environments will constrain their nature and origin. Emission from HLXs is often posited as originating from intermediate-mass black holes (IMBHs), and from the sample we will select the most compelling IMBH candidates. These will be targets of follow-up observations to obtain mass estimates and understand the conditions under which IMBHs grow.