Discovery of variable iron fluorescence from reflection nebulae in the galactic center
Abstract
On the basis of 3 years of deep observations of the Galactic center with the Chandra X-Ray Observatory, we report the discovery of changes in the intensities and morphologies of two hard X-ray nebulosities. The nebulosities are dominated by fluorescent iron emission and are coincident with molecular clouds. The morphological changes are manifest on parsec scales, which requires that these iron features are scattered X-rays from a 2 or 3 year long outburst of a point source (either Sgr A* or an X-ray binary) with a luminosity of at least 10^37 ergs s^-1. The variability precludes the hypotheses that these nebulae either are produced by keV electrons bombarding molecular clouds or are iron-rich ejecta from supernovae. Moreover, the morphologies of the reflection nebulae implies that the dense regions of the clouds are filamentary, with widths of ≈0.3 pc and lengths of ≈2 pc.
Additional Information
© 2007 The American Astronomical Society. Received 2006 November 2; accepted 2007 January 4; published 2007 January 31. This work was funded by NASA through the Chandra X Ray Observatory.Attached Files
Published - MUNapjl07.pdf
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Additional details
- Eprint ID
- 13435
- Resolver ID
- CaltechAUTHORS:MUNapjl07
- NASA
- Created
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2009-06-19Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field