An XMM-Newton Survey of the Galactic Centre Region

R.S. Warwick1, A. Decourchelle2, M. Sakano 1, D. Porquet2

1 Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK
2 Service d'Astrophysique, Orme des Merisiers, CE-Saclay, 91191 Gif-sur-Yvette, Cedex, France

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An X-ray survey of the Galactic Plane within 1 degree of the Galactic Centre has been carried out by XMM-Newton. The full programme consists of a set of 10 overlapping pointings plus one or two additional observations targeted at specific Galactic Centre X-ray sources. The resulting 0.4-9 keV image mosaic charts the distribution of bright discrete sources and diffuse emission throughout the region. Here we focus on the spatial properties and spectral characteristics of the diffuse component. Away from the prominent Sgr A East complex, the large-scale diffuse X-ray emission has an asymmetric distribution, with the Radio Arc Region, 10' to the southeast of the Galactic Centre, exhibiting a particularly high X-ray surface brightness. On the other side of the Galactic Centre diffuse X-ray emission sweeps southward away from the Galactic Plane. The Sgr A and Radio Arc regions and various X-ray reflection nebulae, such as those associated with the Sgr B2 and Sgr C molecular clouds, are also prominent in narrow-band images centred on specific X-ray emissions lines. Here we compare the X-ray spectra properties of the different regions and discuss the origin of the emission in terms of diffuse thermal and non-thermal processes.