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Volume 328 - Revisiting narrow-line Seyfert 1 galaxies and their place in the Universe (NLS1-2018) - Jetted NLS1s
GeV gamma-ray narrow-line Seyfert 1 galaxies and the Fermi LAT Flare Advocate service
S. Ciprini* on behalf of the Fermi-LAT Collaboration
*corresponding author
Full text: pdf
Pre-published on: 2018 November 13
Published on: 2018 December 21
Since August 2008 the Fermi LAT Flare Advocate service (also known as all-sky Gamma-ray Sky Watcher, FA-GSW) is providing for a quick look and review of the gamma-ray sky observed day by day by the Fermi Large Area Telescope (LAT). The FA-GSW duty is based on high level automatic software pipelines and on shifters compiling analysis and summaries about the gamma-ray sources of the day, their detection and flux/spectral/variability status, their multi-frequency/multi-messenger associations and properties. The first detection of a GeV gamma-ray emitting narrow-line Seyfert 1 (NLSy1) galaxy, with a beamed relativistic jet during the first three months of Fermi LAT observations in 2008, was a milestone for AGN science. More than a dozen of NLSy1 galaxies are claimed to be detected at energies E>100 MeV. Beyond time-integrated LAT catalogs, the detection of daily/weekly scale gamma-ray variability, flares and larger outbursts episodes from radio-loud NLSy1 galaxies, is an important discovery, where the FA-GSW service played a useful role since about 2010.
Some historical remarks on GeV gamma-ray NLSy1 galaxies are here reported, highlighting the Fermi LAT contribution.
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