Binary black hole ( BBH ) mergers found by the LIGO and Virgo detectors are of immense scientific interest to the astrophysics community , but are considered unlikely to be sources of electromagnetic emission .
To test whether they have rapidly fading optical counterparts , we used the Dark Energy Camera to perform an i -band search for the BBH merger GW 170814 , the first gravitational wave detected by three interferometers .
The 87-deg ^ { 2 } localization region ( at 90 % confidence ) centered in the Dark Energy Survey ( DES ) footprint enabled us to image 86 % of the probable sky area to a depth of i \sim 23 mag and provide the most comprehensive dataset to search for EM emission from BBH mergers .
To identify candidates , we perform difference imaging with our search images and with templates from pre-existing DES images .
The analysis strategy and selection requirements were designed to remove supernovae and to identify transients that decline in the first two epochs .
We find two candidates , each of which is spatially coincident with a star or a high-redshift galaxy in the DES catalogs , and they are thus unlikely to be associated with GW 170814 .
Our search finds no candidates associated with GW 170814 , disfavoring rapidly declining optical emission from BBH mergers brighter than i \sim 23 mag ( L _ { optical } \sim 5 \times 10 ^ { 41 } erg/s ) 1-2 days after coalescence .
In terms of GW sky map coverage , this is the most complete search for optical counterparts to BBH mergers to date .