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Hard X-ray Variations in the Crab NebulaIn the first two years of science operations of the Fermi Gamma-ray Burst Monitor (GBM), August 2008 to August 2010, approximately 7% (70 mcrab) decline was discovered in the overall Crab Nebula flux in the 15 - 50 keV band, measured with the Earth occultation technique. This decline was independently confirmed with four other instruments: the RXTE/PCA, Swift/BAT, INTEGRAL/IBIS, and INTEGRAL/SPI. The pulsed flux measured with RXTE/PCA from 1999-2010 was consistent with the pulsar spin-down, indicating that the observed changes were nebular. From 2001 to 2010, the Crab nebula flux measured with RXTE/ PCA was particularly variable, changing by up to approximately 3.5% per year in the 15-50 keV band. These variations were confirmed with INTEGRAL/SPI starting in 2003, Swift/BAT starting in 2005, and Fermi GBM starting in 2008. Before 2001 and since 2010, the Crab nebula flux has appeared more stable, varying by less than 2% per year. I will present updated light curves in multiple energy bands for the Crab Nebula, including recent data from Fermi GBM, Swift/BAT, INTEGRAL and MAXI, and a 16-year long light curve from RXTE/PCA.
Document ID
20130013900
Acquisition Source
Marshall Space Flight Center
Document Type
Presentation
Authors
Wilson-Hodge, Colleen A.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Cherry, M. L.
(La Sierra Univ. Riverside, CA, United States)
Case, G. L.
(La Sierra Univ. Riverside, CA, United States)
Baumgartner, W. H.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Beklen, E.
(Max-Planck-Inst. France)
Bhat, P. N.
(Alabama Univ. Huntsville, AL, United States)
Briggs, M. S.
(Alabama Univ. Huntsville, AL, United States)
Camero-Arranz, A.
(Consejo Superior de Investigaciones Cientificas Spain)
Connaughton, V.
(Alabama Univ. Huntsville, AL, United States)
Finger, M. H.
(Universities Space Research Association United States)
Gehrels, N.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Greiner, J.
(Max-Planck-Inst. France)
Jahoda, K.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Jenke, P.
(Alabama Univ. Huntsville, AL, United States)
Kippen, R. M.
(Los Alamos National Lab. NM, United States)
Kouveliotou, C.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Krimm, H. A.
(Universities Space Research Association United States)
Kuulkers, E.
(Danish National Space Center Denmark)
Meegan, C. A.
(Universities Space Research Association United States)
Natalucci, L.
(Istituto di Astrofisica Spaziale e Fisica Cosmica (INAF-IASF) Rome, Italy)
Paciesas, W. S.
(Universities Space Research Association United States)
Preece, R.
(Alabama Univ. Huntsville, AL, United States)
Rodi, J. C.
(La Sierra Univ. Riverside, CA, United States)
Skinner, G. K.
(Maryland Univ. Greenbelt, MD, United States)
Date Acquired
August 27, 2013
Publication Date
April 7, 2013
Subject Category
Astrophysics
Report/Patent Number
M13-2544
Meeting Information
Meeting: 13th Meeting of the High Energy Astrophysics Division/American Astrophysical Society (AAS)
Location: Monterey, CA
Country: United States
Start Date: April 7, 2013
End Date: April 11, 2013
Distribution Limits
Public
Copyright
Public Use Permitted.
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