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When a standard candle flickers: crab nebula variations in hard x-rays
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Briggs, M. S. Kouveliotou, C. Paciesas, W. S. Connaughton, V. Krimm, H. A. Lund, N. Finger, M. H. Meegan, C. A. Rodi, J. C. Jahoda, K. Wilson-Hodge, Collen A. Cherry, M. L. Preece, R. Bhat, P. N. Case, G. L. Jenke, P. Camero-Arranz, A. Chaplin, V. Natalucci, L. Baumgartner, W. H. Kippen, R. M. Gehrels, N. Kuulkers, E. |
| Copyright Year | 2012 |
| Description | RXTE played a crucial role in our surprising discovery that the Crab Nebula is variable in hard X-rays. In the first two years of science operations of the Fermi Gamma-ray Burst Monitor (GBM), August 2008-2010, a approx.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 in the ~15-50 keV band 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 approx.3.5% per year in the 15-50 keV band. These variations were confirmed with INTEGRAL/SPI starting in 2003 and Swift/BAT starting in 2005. Before 2001 and since 2010, the Crab nebula 15-50 keV flux measured with RXTE/PCA appeared more stable, varying by less than 2% per year. In this talk I will present Crab light curves including RXTE data for the entire 16-year mission in multiple energy bands. |
| File Size | 7623 |
| Page Count | 1 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20120014194 |
| Archival Resource Key | ark:/13960/t38103738 |
| Language | English |
| Publisher Date | 2012-03-29 |
| Access Restriction | Open |
| Subject Keyword | Astrophysics X Rays Energy Bands Crab Nebula Pulsars X Ray Timing Explorer Occultation Gamma Ray Bursts Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
