LIGO/Virgo G275404: AGILE MCAL observations

In response to the LIGO/Virgo GW event G275404 at T0 = 2017-02-25 18:30:21.374 UTC, a preliminary analysis of the AGILE-GW fast data processing procedure found no AGILE MiniCALorimeter (MCAL) event candidates within a time interval covering -/+ 40 sec from the LIGO T0. Two data acquisitions where collected about 45 sec before and 45 sec after the LIGO T0; they show no significant transient candidate event. A 3-sigma UL was computed for a 1 s integration time, on different celestial positions within the G275404 error box, and varies from a minimum of 5.3e-7 erg cm^-2 to a maximum of 10.3e-7 erg cm^-2, assuming as spectral model a single power law with photon index 1.4. The AGILE-MCAL instrument is a mini-calorimeter with a 4-PI FoV, working in the range 0.4 - 100 MeV. Additional analysis of AGILE GRID and Super-Agile data is in progress.