Document Type
Article
Publication Date
9-20-2016
Abstract
We present upper limits in the hard X-ray and gamma-ray bands at the time of the Laser Interferometer Gravitational-wave Observatory (LIGO) gravitational-wave event GW151226 derived from the CALorimetric Electron Telescope (CALET) observation. The main instrument of CALET, CALorimeter (CAL), observes gamma-rays from ∼1 GeV up to 10 TeV with a field of view of ∼2 sr. The CALET gamma-ray burst monitor (CGBM) views ∼3 sr and ∼2π sr of the sky in the 7 keV-1 MeV and the 40 keV-20 MeV bands, respectively, by using two different scintillator-based instruments. The CGBM covered 32.5% and 49.1% of the GW151226 sky localization probability in the 7 keV-1 MeV and 40 keV-20 MeV bands respectively. We place a 90% upper limit of 2 ×10-7 erg cm-2 s-1 in the 1-100 GeV band where CAL reaches 15% of the integrated LIGO probability (∼1.1 sr). The CGBM 7σ upper limits are 1.0 ×10-6 erg cm-2 s-1 (7-500 keV) and 1.8 ×10-6 erg cm-2 s-1 (50-1000 keV) for a 1 s exposure. Those upper limits correspond to the luminosity of 3-5 ×1049 erg s-1, which is significantly lower than typical short GRBs.
Publication Source (Journal or Book title)
Astrophysical Journal Letters
Recommended Citation
Adriani, O., Akaike, Y., Asano, K., Asaoka, Y., Bagliesi, M., Bigongiari, G., Binns, W., Bonechi, S., Bongi, M., Brogi, P., Buckley, J., Cannady, N., Castellini, G., Checchia, C., Cherry, M., Collazuol, G., Felice, V., Ebisawa, K., Fuke, H., Guzik, T., Hams, T., Hareyama, M., Hasebe, N., Hibino, K., Ichimura, M., Ioka, K., Ishizaki, W., Israel, M., Javaid, A., Kasahara, K., Kataoka, J., Kataoka, R., & Katayose, Y. (2016). CALET UPPER LIMITS on X-RAY and GAMMA-RAY COUNTERPARTS of GW151226. Astrophysical Journal Letters, 829 (1) https://doi.org/10.3847/2041-8205/829/1/L20