%0 Generic
%A Seeburger, Luzian
%C Heidelberg
%D 2025
%F heidok:37263
%R 10.11588/heidok.00037263
%T Hunting for dormant Black Holes in the Milky Way
%U https://archiv.ub.uni-heidelberg.de/volltextserver/37263/
%X Stellar population models predict 107 stellar mass black holes (BHs) in the Milky Way, with an unknown fraction in mostly dormant binary systems. To date, less than a handful of dor- mant BH binaries have been identified, and post-interaction star-star systems masquerading as BH systems — so-called impostors — have greatly complicated this identification.  In this thesis, we develop a set of tools to identify and characterise these impostors using spectroscopy. We demonstrate the power of spectral disentangling using both simulated and real data. Applying the tools to multi-epoch spectra of a sample of impostor systems, we confirm their post-interaction nature and place constraints on their stellar parameters. Critically, we now ascertain their rotation rates and can make improved inferences on their mass transfer history.  We also develop single-epoch high-resolution spectra as a diagnostic tool for Galactic binaries identified by Gaia , showing the capabilities of such data to determine fundamental properties, in particular the flux ratio, of these systems. We have been able to add flux ratio measurements or constraints to 80,000 spectra of Gaia binaries, which are crucial for the interpretation of the Gaia data.  These toolsets will prove invaluable when analysing upcoming data releases, allowing us to constrain important processes in (binary) stellar evolution and BH formation.