Direct Collapse Black Holes as LISA Sources

Direct-collapse black holes (DCBHs) are an important component of the massive black hole population of the early universe, and their formation and early mergers will be prominent in the data stream of the Laser Interferometer Space Antenna (LISA). However, the population and binary properties of these early black holes are poorly understood, with masses, mass ratios, spins, and orbital eccentricities strongly dependent on the details of their formation, and the properties of the remaining exterior material (baryonic and non-baryonic), which may be substantial to the point of merger.



We report on progress on our project to take collapsing cosmological halos from the Renaissance Simulations generated by the Enzo code, evolving them to the onset of the relativistic regime with the MESA stellar evolution code, and on to full collapse to intermediate-mass black holes using the Einstein Toolkit. The aims of this project are to assess the ability of LISA to detect and identify the collapse gravitational waveforms, and also to inform massive black hole populations available for later mergers in the LISA regime.