Fermi Gamma-ray Space Telescope

Future mission CAMELOT for localisation of gamma-ray transients by fleet of cubesats

Jakub Ripa
(Norbert Werner, Andras Pal, Masanori Ohno, Norbert Tarcai, Kento Torigoe, Koji Tanaka, Nagomi Uchida, Laszlo Meszaros, Gabor Galgoczi, Yasushi Fukazawa, Tsunefumi Mizuno, Hitomitsu Takahashi, Kazuhiro Nakazawa, Zsolt Varhegyi, Teruaki Enoto, Hirokazu Odaka, Yuto Ichinohe, Zsolt Frei, Laszo Kiss)


The recent detection of the electromagnetic counterpart to the gravitational-wave source is the milestone of the multi-messenger astronomy. The need of a gamma-ray instrument with all-sky coverage and precise localization capability is eminent. Cubesats Applied for MEasuring and LOcalising Transients (CAMELOT) is a proposed fleet of nanosatellites for the all-sky monitoring and timing based localisation of gamma-ray transients which can fulfill this need. The fleet of at least nine 3U cubesats with large and thin CsI(Tl) scintillators on board with the sensitivity in soft gamma-ray range of about 10-300 keV is planned. The detectors are proposed to be read out by multi-pixel photon counters (MPPC) which have small size and low electricity consumption. Our feasibility study has shown that by cross-correlating the light curves of bright short gamma-ray bursts (GRBs), the fleet should be able to determine the source position with an accuracy of about 10 arcminutes. This will be achieved by precise time synchronization and accurate time stamping of the detected gamma-ray photons by using on-board GPS receivers. This overview summarizes the mission concept, preferred orbits, the sky coverage, the detector design, the localisation accuracy, and the expected background at low-earth orbit. Concerning the all-sky coverage, the proposed fleet will outperform all past and current GRB missions.