Performance of the KAGRA detector during the first joint observation with GEO 600 (O3GK)

Understand

KAGRA, the kilometer-scale underground gravitational-wave detector, is located at Kamioka, Japan.

• In April 2020, an astrophysics observation was performed at the KAGRA detector in combination with the GEO 600 detector; this observation operation is called O3GK.
• The optical configuration in O3GK is based on a power recycled Fabry-P\'{e}rot Michelson interferometer; all the mirrors were set at room temperature.
• The duty factor of the operation was approximately 53%, and the strain sensitivity was $3\times10^{-22}~/\sqrt{\rm{Hz}}$ at 250 Hz.