CALET Search for Electromagnetic Counterparts of Gravitational Waves during the LIGO/Virgo O3 Run

Adriani, O.; Akaike, Y.; Asano, K.; Asaoka, Y.; Berti, E.; Bigongiari, G.; Binns, W. R.; Bongi, M.; Brogi, P.; Bruno, A.; Buckley, J. H.; Cannady, N.; Castellini, G.; Checchia, C.; Cherry, M. L.; Collazuol, G.; Ebisawa, K.; Ficklin, A. W.; Fuke, H.; Gonzi, S.; Guzik, T. G.; Hams, T.; Hibino, K.; Ichimura, M.; Ioka, K.; Ishizaki, W.; Israel, M. H.; Kasahara, K.; Kataoka, J.; Kataoka, R.; Katayose, Y.; Kato, C.; Kawanaka, N.; Kawakubo, Y.; Kobayashi, K.; Kohri, K.; Krawczynski, H. S.; Krizmanic, J. F.; Maestro, P.; Marrocchesi, P. S.; Messineo, A. M.; Mitchell, J. W.; Miyake, S.; Moiseev, A. A.; Mori, M.; Mori, N.; Motz, H. M.; Munakata, K.; Nakahira, S.; Nishimura, J.; Nolfo, G. A. D.; Okuno, S.; Ormes, J. F.; Ospina, N.; Ozawa, S.; Pacini, L.; Papini, P.; Rauch, B. F.; Ricciarini, S. B.; Sakai, K.; Sakamoto, T.; Sasaki, M.; Shimizu, Y.; Shiomi, A.; Spillantini, P.; Stolzi, F.; Sugita, S.; Sulaj, A.; Takita, M.; Tamura, T.; Terasawa, T.; Torii, S.; Tsunesada, Y.; Uchihori, Y.; Vannuccini, E.; Wefel, J. P.; Yamaoka, K.; Yanagita, S.; Yoshida, A.; Yoshida, K.; Zober, W. V.

doi:10.3847/1538-4357/ac6f53

The CALorimetric Electron Telescope (CALET) on the International Space Station consists of a high-energy cosmic-ray CALorimeter (CAL) and a lower-energy CALET Gamma-ray Burst Monitor (CGBM). CAL is sensitive to electrons up to 20 TeV, cosmic-ray nuclei from Z = 1 through Z ∼ 40, and gamma rays over the range 1 GeV-10 TeV. CGBM observes gamma rays from 7 keV to 20 MeV. The combined CAL-CGBM instrument has conducted a search for gamma-ray bursts (GRBs) since 2015 October. We report here on the results of a search for X-ray/gamma-ray counterparts to gravitational-wave events reported during the LIGO/Virgo observing run O3. No events have been detected that pass all acceptance criteria. We describe the components, performance, and triggering algorithms of the CGBM—the two Hard X-ray Monitors consisting of LaBr 3(Ce) scintillators sensitive to 7 keV-1 MeV gamma rays and a Soft Gamma-ray Monitor BGO scintillator sensitive to 40 keV-20 MeV—and the high-energy CAL consisting of a charge detection module, imaging calorimeter, and the fully active total absorption calorimeter. The analysis procedure is described and upper limits to the time-averaged fluxes are presented.

CALET Search for Electromagnetic Counterparts of Gravitational Waves during the LIGO/Virgo O3 Run / Adriani O.; Akaike Y.; Asano K.; Asaoka Y.; Berti E.; Bigongiari G.; Binns W.R.; Bongi M.; Brogi P.; Bruno A.; Buckley J.H.; Cannady N.; Castellini G.; Checchia C.; Cherry M.L.; Collazuol G.; Ebisawa K.; Ficklin A.W.; Fuke H.; Gonzi S.; Guzik T.G.; Hams T.; Hibino K.; Ichimura M.; Ioka K.; Ishizaki W.; Israel M.H.; Kasahara K.; Kataoka J.; Kataoka R.; Katayose Y.; Kato C.; Kawanaka N.; Kawakubo Y.; Kobayashi K.; Kohri K.; Krawczynski H.S.; Krizmanic J.F.; Maestro P.; Marrocchesi P.S.; Messineo A.M.; Mitchell J.W.; Miyake S.; Moiseev A.A.; Mori M.; Mori N.; Motz H.M.; Munakata K.; Nakahira S.; Nishimura J.; Nolfo G.A.D.; Okuno S.; Ormes J.F.; Ospina N.; Ozawa S.; Pacini L.; Papini P.; Rauch B.F.; Ricciarini S.B.; Sakai K.; Sakamoto T.; Sasaki M.; Shimizu Y.; Shiomi A.; Spillantini P.; Stolzi F.; Sugita S.; Sulaj A.; Takita M.; Tamura T.; Terasawa T.; Torii S.; Tsunesada Y.; Uchihori Y.; Vannuccini E.; Wefel J.P.; Yamaoka K.; Yanagita S.; Yoshida A.; Yoshida K.; Zober W.V.. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 1538-4357. - ELETTRONICO. - 933:(2022), pp. 85-1-85-16. [10.3847/1538-4357/ac6f53]