First joint observation by the underground gravitational-wave detector, KAGRA, with GEO600

Understand

We report the results of the first joint observation of the KAGRA detector with GEO600.

• KAGRA is a cryogenic and underground gravitational-wave detector consisting of a laser interferometer with three-kilometer arms, and located in Kamioka, Gifu, Japan.
• GEO600 is a British--German laser interferometer with 600 m arms, and located near Hannover, Germany.
• GEO600 and KAGRA performed a joint observing run from April 7 to 20, 2020.