Hard X-ray properties of a variable standard candle, Crab, with the Suzaku/HXD
Abstract
The Crab Nebula had been believed to be a stable standard candle for historical X-ray instruments for many years. Recently it was found that a hard X-ray flux (15-100 keV) of Crab Nebula fluctuated by 10% over 10 years . The origin of the long-term variation is still unclear, but the nature of the Crab Nebula is now hot topic both on science and hardware developments. The HXD onboard Suzaku has the highest sensitivity in the 10-600 keV band. Hence it is useful to search for flux variations and possible spectral changes. We performed systematic studies on Crab X-ray spectra in the 10-600 keV band with the HXD, by using 12 observations of Crab until 2010. In this paper, we summarized a hard X-ray study of Crab with the HXD.
- Publication:
-
Suzaku 2011: Exploring the X-ray Universe: Suzaku and Beyond
- Pub Date:
- March 2012
- DOI:
- 10.1063/1.3696196
- Bibcode:
- 2012AIPC.1427..265K