[vsnet-alert 10287] (ATEL) 3C454.3 gamma-ray flare

[Taichi Kato]

   Optical follow-up observations are requested.  We haven't received
any data since February:

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ATEL #1592							     ATEL #1592

Title:		AGILE detection of new flaring activity from blazar 3C 454.3
Author:	D. Gasparrini, C. Pittori, F. Verrecchia, B. Preger, P. Santolamazza,
		S. Colafrancesco, P. Giommi (ASDC), S. Vercellone, A. Chen, A. Giuliani
		(INAF/IASF Milan), I. Donnarumma, F. D'Ammando, L. Pacciani, G. Pucella,
		V. Vittorini (INAF/IASF Rome), F. Longo (INFN, Trieste), A. Bulgarelli
		(INAF/IASF Bologna), S. Mereghetti, A. Pellizzoni, F. Perotti, F.
		Fornari, M. Fiorini, P. Caraveo, A. Zambra (INAF/IASF Milan), F. Gianotti,
		M. Trifoglio, G. Di Cocco, C. Labanti, F. Fuschino, M. Marisaldi,
		M. Galli, (INAF/IASF Bologna), M. Tavani, E. Costa, M. Feroci, E.
		Del Monte, F. Lazzarotto, G. Piano, P. Soffitta, Y. Evangelista, I.
		Lapshov, M. Rapisarda, A. Argan, A. Trois, G. De Paris (INAF/IASF
		Rome), G. Barbiellini, E. Vallazza (INFN Trieste), P. Picozza, A.
		Morselli (INFN Roma-2), M. Prest, (Universita` dell'Insubria), P.
		Lipari, D. Zanello (INFN Roma-1), F. Boffelli, P. Cattaneo (INFN Pavia)
		and L. Salotti (ASI)
Queries:	carlotta.pittori at asdc.asi.it
Posted:	26 Jun 2008;  17:06  UT
Subjects:	Gamma Ray, >GeV, AGN, Quasars

During the current Observing Block started on 2008-06-15 12:00 UT,   the
AGILE Gamma Ray Imaging Detector (GRID) detected 3C 454.3 in   high state
in the period between 2008-06-25 03:00 UT and   2008-06-26 03:00 UT.  

A preliminary maximum likelihood analysis shows a detection   at
a significance level above 5 sigma, with a source flux in excess of   about
200e-8 ph/cm2/s for E>100 MeV.   

3C 454.3 was previously detected in high state several times by the
AGILE-GRID during 2007 and 2008 (see also ATels #1160, #1167, #1278,
#1300 and #1545). A very recent gamma-ray flare episode is reported in
ATel #1581.   

The AGILE monitoring of the source will continue till 2008-06-30
12:00 UT.   We strongly encourage multi-frequency observations of 3C 454.3
during this   gamma-ray high-state.           

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Password Certification:  Carlotta Pittori (carlotta.pittori at asdc.asi.it)
http://www.astronomerstelegram.org/?read=1592
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