Fermi Gamma-ray Space Telescope

LAT Flare Advocate Service at 10 Years

Stefano Ciprini


The Fermi Flare Advocate (also known as Gamma-ray Sky Watcher, FA-GSW) service provides for a quick look and review of the gamma-ray sky observed daily by the Fermi Large Area Telescope (LAT) through on-duty shifters of the LAT Collaboration and high level software pipelines like the LAT Automatic Science Processing (ASP), the Fermi All-sky Variability Analysis (FAVA), the specific software for automatic processing of daily data and wiki-report tables. The FA-GSW service provides alerts and communicates to the external scientific community potential pop-ups of new gamma-ray sources, interesting transients, relevant flares, particular spectral hardenings, through the Fermi multiwavelength mailing list, the TeV-Cherenkov collaborations mailing list, Astronomer's Telegrams (ATels) and particular GCN notices. For example in the ten years from August 4, 2008, 435 ATels, 155 Fermi-Notice type of GCNs, 517 weekly FAVA public tables have been published by the LAT Collaboration, in addition to 3566 daily summary internal reports compiled by FA-GSWs and 18972 ASP all-sky pipeline runs with related automatic source search and analysis on 6-hour, 1-day and 1-week intervals. Target of opportunity observing programs to other satellites like Swift and NuSTAR and ground based telescopes (VLBI, optical, Cherenkov telescope) have been triggered by FA-GSW reports based in the main part on gamma-ray flares of blazars or their newly candidate detections, but also for other kinds of sources. Statistics and highlights of this unprecedented, high-energy monitoring service are presented.