We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5– requires at least three detectors of sensitivity within a factor of of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

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KAGRA is a second-generation interferometric gravitational-wave detector with 3 km arms constructed at Kamioka, Gifu, Japan. It is now in its final installation phase, which we call bKAGRA (baseline KAGRA), with scientific observations expected to begin in late 2019. One of the advantages of KAGRA is its underground location of at least 200 m below the ground surface, which reduces seismic motion at low frequencies and increases the stability of the detector. Another advantage is that it cools down the sapphire test mass mirrors to cryogenic temperatures to reduce thermal noise. In April-May 2018, we operated a 3 km Michelson interferometer with a cryogenic test mass for 10 d, which was the first time that km-scale interferometer was operated at cryogenic temperatures. In this article, we report the results of this 'bKAGRA Phase 1' operation. We have demonstrated the feasibility of 3 km interferometer alignment and control with cryogenic mirrors.

The total syntheses of (+)-schizandrin (1), (+)-gomisin A (2), and (+)-isoschizandrin (3) having natural configurations were accomplished. Optically pure butyrolactones ((-)-9, (-)-31) were transformed to a-benzylidenebutyrolactones ((+)-10, (+)-32, (+)-35). By a highly efficient iron(III) perchlorate-mediated oxidative coupling reaction of 10, 32, and 35, the key intermediates with biphenyl skeletons ((-)-ll, (-)-33) were constructed with high stereoselectivity. Several methods for the stereoselective introduction of the C6-hydroxyl group were examined. For the synthesis of schizandrin and gomisin A, the Mukaiyama hydration reaction of (-)-ll and (-)-33 provided the desired products with satisfactory selectivity. For the synthesis of isoschizandrin, the stereoselective epoxidation of allylic alcohol (+)-48 was successfully utilized taking advantage of its conformational features.