[vsnet-grb-info 23411] LIGO/Virgo S190828l: No counterpart candidates in AGILE-MCAL observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  25510
SUBJECT: LIGO/Virgo S190828l: No counterpart candidates in AGILE-MCAL observations
DATE:    19/08/28 10:03:25 GMT
FROM:    Francesco Longo at U of Trieste,INFN Trieste  <franzlongo1969 at gmail.com>

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

In response to the LIGO/Virgo GW event S190828l at T0 = 2019-08-28
06:55:09 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 50% of the S190828l 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 S190828l localization region, from a minimum of
1.83E-06 erg cm^-2 to a maximum of 6.33E-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.