The first six months of the Advanced LIGO's and Advanced Virgo's third observing run with GRANDMA
astro-ph.HE
/ Authors
S. Antier, S. Agayeva, V. Aivazyan, S. Alishov, E. Arbouch, A. Baransky, K. Barynova, J. M. Bai, S. Basa, S. Beradze
and 67 more authors
E. Bertin, J. Berthier, M. Blazek, M. Boer, O. Burkhonov, A. Burrell, A. Cailleau, B. Chabert, J. C. Chen, N. Christensen, A. Coleiro, B. Cordier, D. Corre, M. W. Coughlin, D. Coward, H. Crisp, C. Delattre, T. Dietrich, J. -G. Ducoin, P. -A. Duverne, G. Marchal-Duva, B. Gendre, L. Eymar, P. Fock-Hang
/ Abstract
We present the Global Rapid Advanced Network Devoted to the Multi-messenger Addicts (GRANDMA). The network consists of 21 telescopes with both photometric and spectroscopic facilities. They are connected together thanks to a dedicated infrastructure. The network aims at coordinating the observations of large sky position estimates of transient events to enhance their follow-up and reduce the delay between the initial detection and the optical confirmation. The GRANDMA program mainly focuses on follow-up of gravitational-wave alerts to find and characterise the electromagnetic counterpart during the third observational campaign of the Advanced LIGO and Advanced Virgo detectors. But it allows for any follow-up of transient alerts involving neutrinos or gamma-ray bursts, even with poor spatial localisation. We present the different facilities, tools, and methods we developed for this network, and show its efficiency using observations of LIGO/Virgo S190425z, a binary neutron star merger candidate. We furthermore report on all GRANDMA follow-up observations performed during the first six months of the LIGO-Virgo observational campaign, and we derive constraints on the kilonova properties assuming that the events' locations were imaged by our telescopes.