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Fermi LAT detection of a new GeV flare from the radio-loud Narrow-Line Sy1 PMN J0948+0022

ATel #3429; F. D'Ammando (INAF-IASF Palermo and CIFS), S. Ciprini (ASI Science Data Center, & INAF Roma Observatory, Italy) on behalf of the Fermi Large Area Telescope Collaboration
on 12 Jun 2011; 21:53 UT
Credential Certification: Filippo D'Ammando (filippo.dammando@iasf-roma.inaf.it)

Subjects: Gamma Ray, >GeV, Request for Observations, AGN, Blazar

Referred to by ATel #: 3448, 4659, 4694, 7266

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed an increasing gamma-ray flux from a source positionally consistent with PMN J0948+0022 (1FGL J0949.0+0021, Abdo et al. 2010, ApJS, 188, 405; R.A.= 09h48m57.3201s, Dec.= +00d22'25.558", J2000, Beasley et al. 2002, ApJS, 141, 13), a radio-loud narrow-line Seyfert 1 at z=0.5846 (Sloan Digital Sky Survey, 2004, SDSS2.C, 0000).

Preliminary analysis indicates that the source on June 10, 2011 was in a high state with a gamma-ray flux (E > 100 MeV) of (1.5 +/- 0.3) x10^-6 photons cm^-2 s^-1 (errors are statistical only), representing more than an order of magnitude above its average flux during the first 11 months of Fermi observations (1FGL catalog, Abdo et al. 2010, ApJS, 188, 405). Flaring activity from PMN J0948+0022 has been previously observed by Fermi-LAT in July 2010 (ATel #2733, ATel #2752; Foschini et al. 2011, MNRAS, 413, 1671).

Since Fermi operates in an all-sky scanning mode, regular monitoring of this source will continue. In consideration of the ongoing activity of this source we strongly encourage multiwavelength observations. The Fermi LAT contact persons for this source are Davide Donato (donato@milkyway.gsfc.nasa.gov) and Filippo D'Ammando (dammando@ifc.inaf.it).

The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.