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Discovery of variable iron fluorescence from reflection nebulae in the galactic center

Muno, M. P. and Baganoff, F. K. and Brandt, W. N. and Park, S. and Morris, M. R. (2007) Discovery of variable iron fluorescence from reflection nebulae in the galactic center. Astrophysical Journal, 656 (2). L69-L72. ISSN 0004-637X. doi:10.1086/512236.

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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.

Item Type:Article
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Brandt, W. N.0000-0002-0167-2453
Morris, M. R.0000-0002-6753-2066
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.
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Subject Keywords:galaxy: center; ISM: clouds; X-rays: ISM
Issue or Number:2
Record Number:CaltechAUTHORS:MUNapjl07
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:13435
Deposited By: Tony Diaz
Deposited On:19 Jun 2009 16:14
Last Modified:08 Nov 2021 22:37

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