Astro JB-Host Galaxies

Epochs of low-metallicity star formation massively overproduce binary black holes. In any galaxy, most coalescing binary black holes often come from epochs of low-metallicity star formation, that occurred early in its lifetime. Low-mass galaxies, which are naturaly low-metallicity, will produce many more coalescing binary black holes per unit mass

The assembly history of galaxies can differ: galaxies with the same present-day properties will generally have different histories. I had guessed (incorrectly, it turns out) that this strong sensitivity meant that galaxies with similar present-day properties could host very differnt BBH properties. Using full galaxy assembly calculations, we found the opposite result: the star formation rate and metallicity vary in opposition, so the present-day BBH population is surprisingly stable to changes in the evolutionary trajectory.

For more information, see the links below, and prior posts

• Our paper O’Shaughnessy, Bellovary, et al, arxiv:1609.06715, in press at MNRAS