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arXiv · 1406.5727

Variation of the X-ray non-thermal emission in the Arches cloud

Maïca Clavel·S. Soldi·R. Terrier·V. Tatischeff·G. Maurin·G. Ponti·A. Goldwurm·A. Decourchelle
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Abstract

The origin of the iron fluorescent line at 6.4 keV from an extended region surrounding the Arches cluster is debated and the non-variability of this emission up to 2009 has favored the low-energy cosmic-ray origin over a possible irradiation by hard X-rays. By probing the variability of the Arches cloud non-thermal emission in the most recent years, including a deep observation in 2012, we intend to discriminate between the two competing scenarios. We perform a spectral fit of XMM-Newton observations collected from 2000 to 2013 in order to build the Arches cloud lightcurve corresponding to both the neutral Fe Kalpha line and the X-ray continuum emissions. We reveal a 30% flux drop in 2012, detected with more than 4 sigma significance for both components. This implies that a large fraction of the studied non-thermal emission is due to the reflection of an X-ray transient source.

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Maïca Clavel, S. Soldi, R. Terrier, V. Tatischeff, G. Maurin, G. Ponti, A. Goldwurm, A. Decourchelle. 2014-06-22. Variation of the X-ray non-thermal emission in the Arches cloud. https://doi.org/10.1093/mnrasl/slu100

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