J-GEM follow-up observations to search for an optical counterpart of the first gravitational wave source GW150914

Tomoki Morokuma, Masaomi Tanaka, Yuichiro Asakura, Fumio Abe, Paul J. Tristram, Yousuke Utsumi, Mamoru Doi, Kenta Fujisawa, Ryosuke Itoh, Yoichi Itoh, Koji S. Kawabata, Nobuyuki Kawai, Daisuke Kuroda, Kazuya Matsubayashi, Kentaro Motohara, Katsuhiro L. Murata, Takahiro Nagayama, Kouji Ohta, Yoshihiko Saito, Yoichi TamuraNozomu Tominaga, Makoto Uemura, Kenshi Yanagisawa, Yoichi Yatsu, Michitoshi Yoshida

Research output: Contribution to journalArticlepeer-review

25 Citations (Scopus)


We present our optical follow-up observations to search for an electromagnetic counterpart of the first gravitational wave source GW150914 in the framework of the Japanese collaboration for Gravitational wave ElectroMagnetic follow-up (J-GEM), which is an observing group utilizing optical and radio telescopes in Japan, as well as in New Zealand, China, South Africa, Chile, and Hawaii. We carried out a wide-field imaging survey with the Kiso Wide Field Camera (KWFC) on the 1.05m Kiso Schmidt telescope in Japan and a galaxy-targeted survey with Tripole5 on the B&C 61cm telescope in New Zealand. Approximately 24 deg2 regions in total were surveyed in i-band with KWFC and 18 nearby galaxies were observed with Tripole5 in g-, r-, and i-bands 4-12 days after the gravitational wave detection. Median 5 σ depths are i 18.9mag for the KWFC data and g 18.9mag, r 18.7mag, and i 18.3mag for the Tripole5 data. The probability for a counterpart to be in the observed area is 1.2% in the initial skymap and 0.1% in the final skymap. We do not find any transient source associated to an external galaxy with spatial offset from its center, which is consistent with the local supernova rate.

Original languageEnglish
Article numberL9
JournalPublications of the Astronomical Society of Japan
Issue number4
Publication statusPublished - 2016 Aug 1
Externally publishedYes


  • Binaries
  • Close-black hole physics-gravitational waves-methods
  • Observational-surveys

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'J-GEM follow-up observations to search for an optical counterpart of the first gravitational wave source GW150914'. Together they form a unique fingerprint.

Cite this