A search for localized sources of noncosmological deuterium near the Galactic center

Lubowich, D. A. ; Anantharamaiah, K. R. ; Pasachoff, Jay M. (1989) A search for localized sources of noncosmological deuterium near the Galactic center The Astrophysical Journal, 345 . pp. 770-775. ISSN 0004-637X

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Official URL: http://adsabs.harvard.edu/doi/10.1086/167948

Abstract

The VLA at the 92 cm D I hyperfine transition was used to search for a possible localized concentration of atomic deuterium near the Galactic center over a velocity range of + or - 180 km/s. The search yielded an upper limit for the D column density N(D) = 7.78 × 10 to the 16th T(s)/sq cm where T(s) is the spin temperature of the D I hyperfine lines. For the smaller velocity range of + or - 30 km/s, a more sensitive upper limit of N(D) = 3.12 × 10 to the 16th T(s)/sq cm is obtained. If D is associated with the H I clouds to the Galactic center, an upper limit for the D/H ratio of 0.0043 is obtained for the clouds at V = 20 km/s and 50 km/s. If a significant fraction of the D exists in atomic form in molecular clouds, the upper limits are 1.2 × 10 to the -7th for the V = 20 km/s molecular cloud near the Galactic center and 8.3 × 10 to the -7th for the V = 50 km/s molecular cloud near the Galactic center. These results are consistent with the D observed in the Galactic center and the ISM being primarily cosmological in origin.

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Source:Copyright of this article belongs to American Astronomical Society.
ID Code:28005
Deposited On:15 Dec 2010 12:36
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