[vsnet-grb-info 23514] LIGO/Virgo S190901ap: No counterpart candidates in AGILE-MCAL observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  25613
SUBJECT: LIGO/Virgo S190901ap: No counterpart candidates in AGILE-MCAL observations
DATE:    19/09/02 08:16:12 GMT
FROM:    Martina Cardillo at INAF-IAPS  <martina.cardillo at inaf.it>

M. Cardillo (INAF/IAPS), F. Verrecchia (SSDC,and INAF/OAR), F. Longo (Univ. Trieste, and INFN Trieste), C. Pittori, F. Lucarelli (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), C. Casentini, G. Piano, A. Ursi (INAF/IAPS), 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 S190901ap at T0 = 2019-09-01 23:31:01 (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 S190901ap 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 S190901ap localization region, from a minimum of 1.31E-06 erg cm^-2 to a maximum of 7.28E-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.