XMM-Newton observation of the galactic centre - evidence against the X-ray reflection nebulae model?
Abstract
We present preliminary results of a 50 ksec \XMM observation of the Galactic Centre. Due to the excellent spectral resolution of \XMM combined with its high throughput at energies even beyond 7 keV, the iron line complex could be resolved into individual components (neutral, ionized, both in Kalpha and Kbeta ) in the spectra of a number of sources. In the spectrum of Sgr A East, we find an overabundance of iron, although less than reported in a recent analysis of \Chandra data. No flare from \Sgr was detected. The large scale diffuse emission seen already by \Einstein, \ROSAT, and \ASCA extending into the north-east direction is most probably of thermal origin. This region extends from Sgra A East also towards both directions perpendicular to the Galactic Plane (''outflow'') and contains some blobs of plasma with a higher temperature. Particularly interesting is the map of the 6.4 keV fluorescence line of neutral iron which shows a very peculiar filamentary structure. Spectral modelling of these filaments is obviously not in agreement with the X-ray reflection nebulae (XRN) model commonly discussed for the origin of the fluorescence line, primarily because we do not see a significant iron absorption edge at 7.1 keV.
- Publication:
-
Astronomische Nachrichten
- Pub Date:
- 2003
- DOI:
- 10.1002/asna.200310019
- Bibcode:
- 2003AN....324...73P
- Keywords:
-
- Galaxy: center;
- X-rays