Modeling the host galaxies of binary compact object mergers across cosmic time
The first direct detection of a gravitational wave (GW) in 2015 opened a new era for gravitational-wave astrophysics. Since then, more than 70 events have been announced by the LIGO-Virgo-KAGRA collaboration including merging binary black holes (most of them), binary neutron stars, and black hole – neutron star binary systems. GW observations will allow us to address an impressive set of questions in cosmology and astrophysics, such as the nature of dark matter, the nature of gravity, the early Universe, and the different stellar evolution stages currently under debate.
In this talk, I will focus on the properties of the host galaxies where merging binary compact objects form and merge. Characterizing the properties of the host galaxies of binary compact object mergers provides essential clues to interpret current and future GW detections. I will discuss the probability that a galaxy hosts a compact binary coalescence according to its stellar mass and star formation rate. Finally, I will show that, at low redshift, early-type galaxies provide a significant contribution to the merger rate density, while late-type galaxies dominate at z>1. These results are crucial for low-latency searches of GW sources, reducing the number of viable host candidates.
Host: Idit Zehavi