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IUE observations of interstellar hydrogen and deuterium toward Alpha Centauri BA high dispersion profile is presented of the Lyman-alpha emission toward Alpha Cen B as recorded in two images taken with the IUE spacecraft. The spectra were examined with a three-parameter Gaussian or five-parameter solar-type profile to derive the intrinsic background stellar emission. Voight absorption profiles were calculated for the intervening H I and D I gas. A uniform, thermally broadened medium was assumed, with the calculations being based on the free stellar parameters of density, velocity dispersion and the bulk velocity of H I, and the density of D I. The use of a small aperture is shown to have been effective in eliminating geocoronal and interplanetary diffuse Ly-alpha contamination. The H I absorption profile toward Alpha Cen B is found to be equivalent to that toward Alpha Cen A, indicating that the H I profiles derived are essentially independent of stellar emission. Less success, however, was attained in obtaining any definitive D I profile, although an asymmetry in the blue and red wings of the Lyman-alpha emissions did show the presence of absorption by interstellar deuterium and allow setting a lower limit of 0.00001 for the D I/H I ratio.
Document ID
19860051039
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Landsman, W. B.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Murthy, J.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Henry, R. C.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Moos, H. W.
(Johns Hopkins University Baltimore, MD, United States)
Linsky, J. L.
(Joint Institute for Laboratory Astrophysics Boulder, CO, United States)
Date Acquired
August 12, 2013
Publication Date
April 15, 1986
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 303
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
86A35777
Distribution Limits
Public
Copyright
Other

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