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Distribution of Si II in the Galactic centerA map of the Galactic center region in the forbidden Si II 34.8-micron line is presented. The line emission arises from within the photodissociation region (PDR) associated with the neutral gas ring surrounding an ionized gas core confined within 2 pc of the Galactic center. Si II is a useful probe of the inner regions of the ring since it is always optically thin. The Si II data, when analyzed in conjunction with O I, C II, and molecular measurements, outlines the transition region between the PDR and the surrounding molecular cloud. The Si II emission is found to extend beyond that of the O II into the neutral gas ring. Although the interpretation is not unique, the data are consistent with a constant gas-phase abundance of silicon within the inner part of the PDR while the gaseous silicon is depleted by molecule formation in the transition region.
Document ID
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Graf, P.
(Cornell Univ. Ithaca, NY, United States)
Herter, T.
(Cornell Univ. Ithaca, NY, United States)
Gull, G. E.
(Cornell Univ. Ithaca, NY, United States)
Houck, J. R.
(Cornell University Ithaca, NY, United States)
Date Acquired
August 13, 2013
Publication Date
July 15, 1988
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 330
ISSN: 0004-637X
Subject Category
Accession Number
Funding Number(s)
Distribution Limits

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