AGILE detects enhanced gamma-ray emission from the blazar PKS 0537-441
ATel #2454; F. Lucarelli (ASDC), E. Striani (Univ. Roma Tor Vergata and INFN Roma), F. D'Ammando (INAF/IASF-Pa), F. Verrecchia, C. Pittori (ASDC), M. Tavani (INAF/IASF-Rm), S. Vercellone(INAF/IASF-Pa), E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci, F. Lazzarotto, L. Pacciani, P. Soffitta, E. Costa, I. Lapshov, M. Rapisarda, A. Argan, G. Piano, G. Pucella, S. Sabatini, A. Trois, V. Vittorini (INAF/IASF-Rm), A. Bulgarelli, F. Gianotti, M. Trifoglio, F. Fuschino, M. Galli, C. Labanti, M. Marisaldi, G. Di Cocco (INAF/IASF-Bo), A. Chen, A. Giuliani, S. Mereghetti, P. Caraveo, F. Perotti (INAF/IASF-Mi), A. Pellizzoni, M. Pilia (INAF/OA-Cagliari), G. Barbiellini, F. Longo, E. Moretti, E. Vallazza (INFN Trieste), A. Morselli, P. Picozza (INFN and Univ. Roma Tor Vergata), M. Prest (Universita` dell'Insubria), P. Lipari, D. Zanello (INFN and Univ. Roma Sapienza), P. W. Cattaneo, A. Rappoldi (INFN Pavia), P. Santolamazza, S. Colafrancesco, P. Giommi (ASDC), L. Salotti (ASI)
on 24 Feb 2010; 11:27 UT
Credential Certification: Carlotta Pittori (carlotta.pittori@asdc.asi.it)
Subjects: Gamma Ray, >GeV, Request for Observations, AGN, Quasar
AGILE is detecting during the last 5 days enhanced gamma-ray emission above 100 MeV from a source positionally consistent with the blazar PKS 0537-441. PKS 0537-441, RA=05 38 29.6, DEC=-44 24 17.8 (J2000), is a low-energy peaked BL Lac with redshift z=0.894 (Peterson et al. 1976, Apj 207). Its mean flux above 100 MeV, as measured in the First AGILE Catalog (Pittori et al. 2009, A&A 506) during the first year of observations, was (43+/-10)x10^-8 ph/cm2/s.
Integrating from 2010-02-18 00:00 UT to 2010-02-23 10:30 UT, a quicklook maximum likelihood analysis yields a detection of PKS 0537-441 at a significance level of about 5 sigma and flux F = (150+/-50)x10^-8 ph/cm2/s (E > 100 MeV), roughly 3 times the source gamma-ray average flux (43+/-10)x10^-8 ph/cm2/s, as measured by AGILE during the first year of observations (Pittori et al. 2009, A&A 506). Fermi LAT reported past flaring activity from this Blazar in the ATels 2124 and 1759.
The AGILE detection was obtained with the satellite observing in a spinning mode, surveying a large fraction of the sky every day.
Multifrequency observations of PKS 0537-441 are strongly encouraged.
