[vsnet-grb-info 23657] LIGO/Virgo S190915ak: No counterpart candidate in AGILE-MCAL observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  25756
SUBJECT: LIGO/Virgo S190915ak: No counterpart candidate in AGILE-MCAL observations
DATE:    19/09/16 03:37:32 GMT
FROM:    Fabrizio Lucarelli at SSDC/INAF-OAR  <fabrizio.lucarelli at ssdc.asi.it>

F. Lucarelli, F. Verrecchia (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ.
Roma Tor Vergata), C. Casentini, M. Cardillo, G. Piano, A. Ursi (INAF/IAPS),
C. Pittori (SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti, 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 S190915ak at T0 = 2019-09-15 23:57:02 (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, the whole S190915ak 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 S190915ak
localization region, from a minimum of 1.6E-06 erg cm^-2 to a maximum of
7.0E-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.