Gravitational Wave Astrophysics and Cosmology with Large Galaxy Surveys
Abstract: On the occasion of the exciting discovery of the electromagnetic counterpart of the GW170817 gravitational wave event, the Dark Energy Survey (DES) collaboration produced a series of studies covering different aspects of the event. In particular, these studies showed that observations of the GW170817 host galaxy can provide information about the formation of the binary neutron star that merged, producing the gravitational wave signal. The synergy between gravitational wave data and large galaxy surveys such as DES can be further extended to binary black hole events. In fact, the first measurement of the Hubble constant using a binary-black-hole gravitational-wave detection was made possible by using the LIGO/Virgo GW170814 event and the DES galaxy catalog. To use GW170814 as a standard siren in the absence of a host galaxy redshift, we applied a statistical method that takes into account all the potential host galaxies observed with DES. Anticipating a multifold increase in the LIGO/Virgo event detection rate in the coming years, this method will allow precision cosmology studies using large galaxy surveys in the very near future.