Gravitational-wave EM Counterpart Korean Observatory (GECKO)

Abstract

Identification of the electromagnetic-wave (EM) counterparts of gravitational-wave (GW) sources can significantly broaden the research scope of GW astronomy, by pinpointing the exact locations of GW events and their environments, and using GW sources as standard sirens for cosmology. Yet, only one GW event has been found to be associated with an EM counterpart so far. Here, we outline the challenges of identifying EM counterparts of GW events, and describe our global network of telescopes that has been used to uncover GW EM counterparts. We also introduce a new facility in construction, the 7-dimensional telescope (7DT). Our GECKO observations have demonstrated that we can cover 50 deg2 within one hour to find kilonovae at a few hundred Mpc away. Furthermore, 7DT will produce a low resolution spectral map of the GW localization area, facilitating the EM counterpart search.