TITLE:   GCN CIRCULAR
NUMBER:  26547
SUBJECT: LIGO/Virgo S191222n: upper limits from AGILE/MCAL observations
DATE:    19/12/22 07:54:54 GMT
FROM:    Francesco Longo at U of Trieste,INFN Trieste  <franzlongo1969@gmail.com>

F. Longo (UniTS and INFN Trieste),  M. Pilia (INAF/OA-Cagliari),
M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata),
M. Cardillo, C. Casentini, G. Piano, A. Ursi (INAF/IAPS),
F.Lucarelli, C. Pittori, F. Verrecchia (SSDC, and INAF/OAR),
A.Bulgarelli, V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna),
report on behalf of the AGILE Team:

In response to the LIGO/Virgo GW event S191222n at T0 = 2019-12-22
03:35:37.119 (UT), a preliminary analysis of the AGILE minicalorimeter
(MCAL) triggered data found no event  candidates within a time
interval covering -/+ 15 sec from the LIGO/Virgo T0.

At the T0, about 60% of the S191222n 90% c.l. localization region was
accessible to the AGILE MCAL.Three-sigma upper limits (ULs) are
obtained for a 1 s integration time at different celestial positions
within the accessible S191222n localization region, from a minimum of
1.4E-06 erg cm^-2 to a maximum of 6.5E-06 erg cm^-2 (assuming as
spectral model a single power law with photon index 1.5).

The AGILE-MCAL detector is a CsI detector with a 4 pi FoV, sensitive
in the energy range 0.4-100 MeV. Additional analysis of AGILE data is
in progress.