All-sky monitoring of variable sources with Fermi GBM

Colleen A. Wilson-Hodge, NASA Marshall Space Flight Center
Michael L. Cherry, LSU
Gary L. Case, LSU
Ascension Camero-Arranz, USRA/NSSTC
Vandiver Chaplin, UAH
Valerie Connaughton, UAH
Mark H. Finger, USRA/NSSTC
Peter Jenke, NASA/MSFC
James C. Rodi, LSU
Wayne H. Baumgartner, National Aeronautics and Space Administration
Elif Beklen, METU/SDU
P. Narayana Bhat, NASA/MSFC
Michael S. Briggs, NASA/MSFC
Neil Gehrels, National Aeronautics and Space Administration
Jochen Greiner, MPE
Keith Jahoda, National Aeronautics and Space Administration
R. Marc Kippen, Los Alamos National Laboratory
Chryssa Kouveliotou, NASA/MSFC
Hans A. Krimm, National Aeronautics and Space Administration
Erik Kuulkers, ESA/ESAC
Niels Lund, Danmarks Tekniske Universitet
Charles A. Meegan, USRA/NSSTC
Lorenzo Natalucci, INAF-IASF
William S. Paciesas, UAH
Robert Preece, UAH
Nikolai Shaposhnikov, National Aeronautics and Space Administration
Gerald K. Skinner, National Aeronautics and Space Administration
Doug Swartz, USRA/NSSTC
Andreas von Kienlin, MPE
Roland Diehl, MPE
Xiao Ling Zhang, MPE


Using the Gamma ray Burst Monitor (GBM) on Fermi, we monitor the transient hard X-ray/soft gamma ray sky. The twelve GBM NaI detectors span 8 keV to 1 MeV, while the two BGO detectors span 150 keV to 40 MeV. We use the Earth occultation technique to monitor a number of sources, including X-ray binaries, AGN, and solar flaring activity. Our monitoring reveals predictable and unpredictable phenomena such as transient outbursts and state changes. With GBM we also track the pulsed flux and spin frequency of accretion powered pulsars using epoch-folding techniques. Highlights from the Earth Occultation and Pulsar projects will be presented including our recent surprising discovery of variations in the total flux from the Crab. Searches for quasi-periodic oscillations and X-ray bursts are also possible with GBM all-sky monitoring capabilities. With these results we show how crucial an all-sky monitor is for any future X-ray timing mission.