Low-energy Cosmic Rays in the Galactic Center Region
Abstract
The Fe Ka line emission at 6.4 keV is often attributed to photoionized matter in the vicinity of a bright X-ray source. In the Galactic center region, the bulk of the 6.4 keV line emission is likely a fluorescence radiation testifying to a past X-ray flaring activity of the supermassive black hole at the center of the Milky Way. However, the Fe Ka line can also be excited by impacts of low-energy cosmic rays. Using data from XMMNewton, we recently identified a large population of fast ions from the X-ray emission prominent in the 6.4 keV line emanating from the Arches cluster region. These low-energy cosmic rays are most likely accelerated in the bow shock created by the cluster's proper motion. However, such a cosmic-ray source is probably unique in the Galactic center environment.
- Publication:
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International Cosmic Ray Conference
- Pub Date:
- 2013
- Bibcode:
- 2013ICRC...33..722T
- Keywords:
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- X-rays: ISM — cosmic rays — Galaxy: center — ISM: abundances.