Relative abundances of /sup 28/Si, /sup 29/Si, and /sup 30/Si in the interstellar medium

Journal Article · Mon Dec 15 04:00:00 EST 1980 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/158531· OSTI ID:6535692

Wolff, R S

Millimeter-wave observations of the J = 2..-->..1 (v = 0) rotational transition of /sup 28/SiO and the isotopically substituted species /sup 29/SiO and /sup 30/SiO have been made toward four dense molecular clouds. Additional observations of the J = 3..-->..2 (v = 0) transition of /sup 28/SiO toward the same clouds were also made. The results are utilized to derive relative isotope abundances in the interstellar medium. It is shown that (/sup 29/Si//sup 28/Si) and (/sup 30/Si//sup 28/Si) are significantly larger than the terrestrial values, whereas the terrestrial and interstellar (/sup 30/Si//sup 29/Si) abundance ratios are comparable provided all lines are optically thin. No evidence for variation of isotope abundance with galactic radius is found.

• Research Organization: Bell Telephone Laboratories, Holmdel, New Jersey
• OSTI ID: 6535692
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 242:3; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
CHALCOGENIDES
CHEMICAL COMPOSITION
ELECTROMAGNETIC RADIATION
ENERGY SPECTRA
ENERGY-LEVEL TRANSITIONS
INTERSTELLAR SPACE
ISOTOPE RATIO
ISOTOPES
MICROWAVE RADIATION
MOLECULES
OXIDES
OXYGEN COMPOUNDS
RADIATIONS
SILICON COMPOUNDS
SILICON ISOTOPES
SILICON OXIDES
SPACE
SPECTRA