Oscillator strengths for Y I and Y II and the solar abundance of yttrium.
Abstract
Oscillator strengths for 154 Y I lines and 66 Y II lines with wavelengths between 2948 and 7055 A are determined by combining laboratory measurements of radiative lifetimes and branching ratios. Lifetimes are presented for 34 levels of Y I and 14 levels of Y II; branching ratios are given for all levels below 9000 A with parity change and delta J equals plus or minus 1, 0. Together with equivalent widths measured on a photometric atlas of the solar photospheric spectrum for eight Y I lines and 41 Y II lines with laboratory wavelenths between 2467 and 7882 A, the data are used to determine the solar abundance of yttrium. Mean logarithmic solar abundances of 2.18 plus or minus 0.12 for Y I and 2.25 plus or minus 0.03 for Y II are deduced, and an yttrium abundance of 2.24 plus or minus 0.03 is derived. It is noted that the data presented have important implications for the yttrium abundances in both cool and hot stars, particularly in chemically peculiar stars.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1982
- DOI:
- Bibcode:
- 1982ApJ...261..736H
- Keywords:
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- Abundance;
- Solar Spectra;
- Transition Probabilities;
- Yttrium;
- Absorptivity;
- Line Spectra;
- Tables (Data);
- Solar Physics