[vsnet-grb-info 22041] LIGO-Virgo S190421ar: AGILE MCAL observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24140
SUBJECT: LIGO-Virgo S190421ar: AGILE MCAL observations
DATE:    19/04/22 17:10:21 GMT
FROM:    Alessandro Ursi at INAF/IAPS  <alessandro.ursi at gmail.com>

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

In response to the LIGO-Virgo GW event S190421ar at T0 = 2019-04-21
21:38:56 (UT), a preliminary analysis of the AGILE minicalorimeter (MCAL)
data found no event candidates within a time interval covering -/+ 1000 sec
from the LIGO-Virgo T0.

Two-sigma upper limits (ULs) are obtained for a 1 s integration time at
different celestial positions within the accessible S190421ar 90% c.l.
localization region, from a minimum of 1.30E-06 erg cm^-2 to a maximum of
3.02E-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.