An empirical test of the MgII λ1240 doublet branching ratio and oscillator strength

被引：22

作者：

Sofia, UJ ^{[1
]}

Fabian, D

Howk, JC

机构：

[1] Whitman Coll, Dept Astron, Walla Walla, WA 99362 USA

[2] Univ Wisconsin, Dept Astron, Madison, WI 53706 USA

[3] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA

来源：

ASTROPHYSICAL JOURNAL | 2000年 / 531卷 / 01期

关键词：

atomic data; ISM : abundances; ultraviolet : ISM;

D O I：

10.1086/308455

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We empirically confirm the theoretical branching ratio and oscillator strength for the weak Mg II 3s-4p doublet at 1240 Angstrom as determined by Theodosiou & Federman. We use the independent methods of apparent optical depth analysis for the sight lines toward mu Col, gamma Ara, and rho Leo and profile component fitting for the sight line toward mu Col in order to determine the branching ratio. We find f(1239)/f(1240) = 1.74 +/- 0.06, in agreement with the theoretical value of 1.78 +/- 0.03. Profile fitting for the line of sight toward mu Col gives an f-value for the doubler of 9.71 +/- 0.32 x 10(-4), which agrees with both the theoretical value of Theodosiou & Federman and the empirical value of Fitzpatrick.

引用

页码：384 / 390

页数：7

共 20 条

[1] OSCILLATOR-STRENGTHS AND PHOTOIONISATION CROSS-SECTIONS FOR POSITIVE-IONS IN THE SODIUM ISOELECTRONIC SEQUENCE [J].